VECTOR-BORNE AND ZOONOTIC DISEASES Volume 15, Number 3, 2015 ª Mary Ann Liebert, Inc. DOI: 10.1089/vbz.2014.1726
Epidemiological, Diagnostic, Clinical, and Therapeutic Aspects of Brucella Bacteremia in Children in Southern Israel: A 7-Year Retrospective Study (2005–2011) Yariv Fruchtman,1 Renana Wilkof Segev,2 Avivit Asher Golan,1,4 Yael Dalem,1 Muhammad Abu Tailakh,2 Victor Novak,2 Nehama Peled,3 Mihai Craiu,4 and Eugene Leibovitz1
Abstract
Background: Data on the various aspects of brucellosis in children living in southern Israel are missing. Objectives: Our aim was to study the epidemiological, microbiological, diagnostic, clinical, therapeutic and outcome features of brucellosis in children < 19 years of age in southern Israel during 2005–2011. Patients and Methods: The study population included all patients hospitalized with a diagnosis of brucellosis, established according to a clinical presentation compatible with brucellosis + presence of Brucella bacteremia (BB). Results: A total of 128 (50.8%) of 252 patients admitted with a diagnosis of brucellosis had BB (all with Brucella melitensis). All patients were of Muslim Bedouin ethnicity. The mean incidence of BB in southern Israel was 16 cases/100,000 Bedouin, with no significant changes during the study period. Overall duration of symptoms before diagnosis was 10.1 – 10.9 days. Fever at diagnosis was recorded in < 20% of the patients. The most frequent symptoms were arthralgia (61.7%), weakness (32.8%), gastrointestinal disturbances (27.3%), myalgia (25%), and headache (18.8%). The main clinical findings included monoarthritis (36.7%), hepatosplenomegaly (25%), lymphadenopathy (17.2%), heart murmur (11.7%), and skin rash (9.4%), respectively. Anemia, leukopenia, thrombocytopenia, and pancytopenia were reported in 17.6%, 29.6%, 12.8%, and 2.3% of the patients, respectively. Twenty-nine (30.5%) patients with BB had serum agglutinin titers £ 1/160 (13, 13.7%%, had titers < 1/160). Twenty-seven (93%) of the 29 patients aged 0–4 years were treated with gentamicin and trimethoprim–sulfamethoxazole; a total of 77 (60.2%) patients received gentamicin and doxycycline. Conclusions: Childhood brucellosis remains an important public health problem in southern Israel. BB was diagnosed in > 50% of the children with brucellosis, and B. melitensis was identified in all cases. Arthralgia, weakness, and gastrointestinal complaints were the most common symptoms, and monoarthritis, hepatosplenomegaly, and lymphadenopathy were the most common clinical findings. A considerable number of patients with BB had undetectable/low serum agglutinin titers, suggesting insufficient reliability on serology alone in diagnosis of brucellosis. Key Words:
Brucella—Bacteremia—Children—Serum agglutination—Antibiotics.
Introduction
B
rucellosis remains a highly endemic zoonosis among domesticated animals in many regions, including Middle Eastern countries (Corbel 1997, Doganay and Aygen 2003, Pappas et al. 2005, Franco et al. 2007, Buzgan et al. 2010). Much of the brucellosis in children is food-borne and is associated with consumption of unpasteurized milk prod-
ucts (Corbel 1997, Doganay and Aygen 2003, Pappas et al. 2005, Franco et al. 2007, Buzgan et al. 2010, Sathyanarayanan et al. 2011). In Turkey, Buzgan et al. (2010) found that 69.6% of 1028 brucellosis cases were aged 13–34 years. Arthralgia and fever (73.7% and 72.2%, respectively) were the most frequently seen symptoms, whereas hepatomegaly and osteoarticular involvement (26% and 25.3%, respectively) were the most
1 Pediatric Emergency Medicine Department, 2Clinical Research Center and 3Microbiology Laboratories, Soroka University Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. 4 Pediatric Emergency Medicine Department, Alfred Rusescu Children’s Hospital, Carol Davila Medical School, Bucharest, Romania.
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common clinical findings. The treatment regimen with doxycycline + streptomycin with and without rifampicin was more effective than other regimens in the cases with osteoarticular involvement (Buzgan et al. 2010). In southern India (Sathyanarayanan et al. 2011), 68% of the 68 enrolled adult patients were male and all presented with fever. A serum Brucella agglutination titer of 1:320 was positive in 61 (90%) of patients (Sathyanarayanan et al. 2011). In a review of recent trends in human brucellosis in Israel, a decline of almost 17% of brucellosis cases was reported during 1998–2002 (Anis et al. 2011). The disease is mostly limited to certain sectors of the rural Arab population. In 2008, the incidence rate of brucellosis was 7.0/100,000 among Bedouin Muslims compared with 0.2/100,000 among the Jewish population. In the Negev region in southern Israel, two populations live side by side: Jewish children, largely urban, and Bedouin children, from formerly desert nomadic families and now in transition to a Western lifestyle, both enjoying similar medical community and hospitalization services. Hospitalization rates due to respiratory and gastrointestinal infections in general and due to invasive pneumococcal diseases particularly are more prevalent among Bedouin children (Rosenthal et al. 1988, Fraser et al. 2001, Novack et al. 2007). Among bacterial zoonoses causing fever among hospitalized Bedouins in southern Israel, zoonoses were diagnosed in 30 (27%) of 110 patients admitted with fever. Brucellosis was diagnosed in 9 (8%) and rickettsial infections in 20 (18%) (Perez-Avraham et al. 2001). Data on the various aspects of brucellosis in children living in southern Israel are missing. The purpose of the present work was to study the epidemiological, microbiological, diagnostic, clinical, and therapeutic features of brucellosis in children 0–19 years in the Negev area of southern Israel during 2005–2011. Patients and Methods Setting
The Soroka University Medical Center is the only general hospital in the region and provides primary and tertiary health services to the entire population of the southern region of Israel. It served a population of > 800,000 inhabitants in 2012; of them > 250,000 children were < 19 years of age. Medical insurance in Israel is universal and is provided free of charge. Criteria for referral to hospital are also similar.
FRUCHTMAN ET AL.
Blood cultures were obtained using the Bactec 9240 system (Becton Dickinson). Inoculated blood culture vials were incubated following the manufacturer’s recommendations; negative vials were discarded after 7 days without further processing (Yagupsky 1999). Brucella was identified on the basis of a typical biochemical profile and positive agglutination reaction with specific antiserum (Welcome Diagnostics). Speciation was performed at the Kimron Veterinary Institute at Bet Dagan, Israel, with phages Tb and Iz (Banai et al. 1990). The laboratory practices did not change, and the blood culture yields stayed constant during the study years (Banai et al. 1990, Yagupsky 1999, Perez-Avraham et al. 2001, Shemesh and Yagupsky 2011). Sera were screened for Brucella antibodies by the Rose–Bengal test (Shemesh and Yagupsky 2011). Positive specimens were serially diluted from 1/20 up to 1/1280 to eliminate the ‘‘prozone effect’’ (inhibition of the agglutination phenomenon at low dilutions due to antibody excess) and tested by the SAT (Christopher et al. 2010, Al Dahouk et al. 2011). Clinical and laboratory data collection
The handwritten and electronic medical records of all patients admitted with the diagnosis of Brucella bacteremia (BB) were searched, and all of the relevant demographic, microbiologic, clinical, and therapeutic parameters were summarized. No follow-up data were available for the discharged patients (followed in the community clinics only). Treatment
All patients diagnosed with brucellosis were treated according to the following protocols: 1. Children > 8 years of age: Doxycycline per os (p.o.) 2 mg/kg per dose (maximum 100 mg) twice daily for a six weeks + intravenous/intramuscular gentamicin 5 mg/ kg one daily dose for 2 weeks. 2. Children < 8 years of age: Sulfamethoxazole p.o. 20 mg/kg per dose + trimethoprim 4 mg/kg per dose (maximum 800 mg sulfamethoxazole + 160 mg trimethoprim) twice daily for 6 weeks + intravenous/intramuscular gentamicin 5 mg/kg one daily dose (no maximal dose) for 2 weeks (World Health Organization 2006, Skalsky et al. 2008).
Study Population
Statistical analysis
The study population included all patients < 19 years of age admitted with a diagnosis of brucellosis at the pediatric departments of Soroka University Medical Center during January, 2005–December, 2011. The study protocol was approved by the institutional ethical committee.
A t-test and analysis of variance (ANOVA) were used for comparing continuous variables, and the chi-squared test was used for categorical data, augmented by the Fisher exact test if needed. We used the Kruskal–Wallis test for the comparison of variables not distributed normally. All reported p values were two-sided and the level of p < 0.05 was considered statistically significant. Data analysis was performed using SPSS version 18 (SPSS Inc. Chicago, IL).
Diagnosis
Diagnosis was established according to a clinical presentation compatible with brucellosis + a positive blood culture. Standard agglutination test (SAT) titers > 1/160 were obtained at admission for all patients and, together with an appropriate clinical presentation, were considered compatible for brucellosis; however, confirmation by a positive blood culture was needed for a definitive diagnosis.
Results
A total of 252 patients were admitted with the diagnosis of brucellosis. Of them, 128 (50.8%, the study population) were included in the present study due to positive cultures for Brucella spp. Nine (7%) patients were admitted with diagnosis of
Brucella BACTEREMIA IN CHILDREN IN ISRAEL
recurrent brucellosis. All positive blood cultures revealed B. melitensis. All patients were of Muslim Bedouin ethnicity. The highest number of cases was recorded in 2008 and 2007 (28 and 26, respectively) and the lowest in 2005 and 2010 (4 and 12, respectively). The mean incidence of BB in southern Israel was 16 cases/100,000 Bedouin children aged 0–19 years, with no significant changes during the study period ( p = 0.46). There were 29 (22, 6%), 85 (66.4%), and 14 (11%) patients, respectively, in the 0–4, 5–14, and 15–19 year age groups. Mean ( – standard deviation [SD]) age was 8.5 – 10.9 years. There were 5 patients < 1 year of age. There were 93 (72.7%) males (72.4%, 70.6%, and 85.7%, respectively, in the three age groups, p = 0.50). Consumption of unpasteurized milk, contact with livestock, and presence of brucellosis in family relatives were recorded in 40.8%, 72.9%, and 56.8%, respectively, with no significant differences between the three age groups. A total of 95/128 (73.4%) of the cases were recorded during the spring and summer seasons (March– September); the highest number of patients was recorded in April (21, 16.4%) and the lowest (4, 3.1%) in October. Nineteen (14.8%) patients suffered from 21 pre-existing pathologies (heart murmurs, 6; septicemia, and chronic liver disease, 3 each; failure to thrive, short stature, and mental retardation, 2 each; asthma, Bells’ palsy, and septic arthritis, 1 each). There was no significant difference in background diseases/conditions between the three age groups. Overall, 23 (18.7%) patients had a temperature > 38C and 6 (4.9%) a temperature > 39C at admission (Fig. 1); 15.4% of the children aged 15–19 years had a temperature > 39C. More patients aged 0–4 years and 15–19 years had a temperature > 39C compared with patients aged 5–14 years (10.3% vs. 1.2%, p = 0.025, and 15.4% vs. 1.2%, p = 0.007), respectively. Overall duration of symptoms before diagnosis was 10.1 – 10.9 days, with no differences between the three age groups. The most frequent symptoms of brucellosis were arthralgia, weakness, gastrointestinal disturbances, myalgia, and headache (present in 61.7%, 32, 8%, 27.3%, 25%, and
FIG. 1.
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18.8%, respectively). Patients aged 15–19 years presented with more weakness, headache, back pain, and weight loss compared with patients 0–4 years of age (57.1%, 50%, 35.7%, and 42.9% vs. 17.2%, 3.4%, 0%, and 0%, respectively, p < 0.05 for all comparisons). The presence of back pain was increasingly recorded with increasing patient age ( p = 0.007). On physical examination, the main clinical findings recorded included monoarthritis (36.7%), hepatosplenomegaly (25%), lymphadenopathy (17.2%), heart murmur (11.7%), and skin rash (9.4%), with no differences between the three age groups (Table 1). None of the patients aged 15–19 years had hepatosplenomegaly. All of the patients had a complete blood count and liver function tests performed at admission. Anemia (hemoglobin [Hb] < 10 g/dL) was present in 17.6% of the patients. White blood cell (WBC) counts were significantly lower among patients 15–19 years old compared with patients 5–14 years old (4.5 – 1.2 cells/mL vs. 6.9 – 3.2 cells/mL, respectively, p = 0.002) and also between those 5–14 years old compared with 0–4 years old (11.1 – 4.6 cells/mL, p < 0.001). Leukopenia of < 5000 WBC/mL was reported in 29.6% of the patients. Leukopenia was recorded in 71.4% of patients aged 15–19 years. Neutropenia of < 1500, < 1000, and < 500 cells/mL was recorded in 15 (13.4%), 6 (6.3%), and 1 (0.9) patients. Thrombocytopenia ( < 150,000 cells/mL) was found in 12.8% of the patients; it was reported more frequently among patients 15–19 years old (5, 35.7%) compared with 1 (3.6%) and 10 (12%) among patients aged 0–4 and 5–14 years, respectively ( p = 0.001 and p = 0.039, respectively). Pancytopenia was observed in three patients. Increased aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values were found in 68.9% and 30.3% patients, respectively, with no differences between the three age groups. C-reactive protein was examined in 31 patients and values > 3 mg/liter were found in 11 (35.5%) of them, with no differences between the three age groups.
Clinical features: 128 patients with Brucella bacteremia.
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FRUCHTMAN ET AL.
Table 1. Clinical Findings at Admission All patients n = 128
Variables Monoarthritis (n, %) Lymphadenopthy (n, %) Hepatomegaly (n, %) Heart murmur (n, %) Rash (n, %) Hepatomegaly + splenomeagly (n, %) Splenomegaly (n, %) Polyarthritis (n, %) Vertebral findings (n, %)
47 22 16 15 12 11 5 5 2
(36.7) (17.2) (12.5) (11.7) (9.4) (8.6) (3.9) (3.9) (1.6)
Patients 0–4 years old n = 29 12 4 5 3 2 4 1 1 0
Serologic examinations (Brucella antibody titers, SAT) were available for 95/128 (74.2%) patients; 13 (13.7%) had titers of < 1/160 (Fig. 2). Sixty-seven (70.5%) patients had SAT titers between 1/160 and 1/640. Titers higher than 1/ 1280 were reported in 15 (15.8%) with no differences between the three age groups ( p = 0.47). Of the three children with pancytopenia, one had a titer of 1/640 and two a titer of 1/1280. Twenty-seven (93%) of the 29 patients aged 0–4 years were treated with a combination of gentamicin and trimethoprim–sulfamethoxazole. All patients (14) aged 15–19 years and 62/86 (72.9%) of the patients aged 5–14 years were treated with the combination of gentamicin and doxycycline. Overall length of hospitalization was 5.03 – 3.21 days, with no differences between the three age groups. Adverse effects (mild abdominal pain and vomiting) were recorded during hospitalization in two (1.6%) patients, without need for interruption of the treatment. The mean age (8.49 – 4.76 years), duration of symptoms before admission (10.36 – 11.18 days), and length of hospitalization (5.1 – 3.2 days) were similar between the 10 patients hospitalized with recurrent brucellosis and the other patients. SAT results were available in five of them (1/640 in 3 and 1/1280 in two of them).
FIG. 2.
(41.4) (13.8) (17.2) (10.3) (6.9) (13.8) (3.4) (3.4) (0)
Patients 5–14 years old n = 85 32 15 10 11 9 7 2 2 1
(37.6) (17.6) (11.8) (12.9) (10.6) (8.2) (2.4) (2.4) (1.2)
Patients 15–19 years old n = 14 3 3 1 1 1 0 2 2 1
(31.4) (21.4) (7.1) (7.1) (7.1) (0) (14.3) (14.3) (7.1)
p value 0.425 0.809 0.605 0.795 0.803 0.312 0.101 0.101 0.185
Discussion
Information on epidemiology, clinical features of the disease, and its diagnosis and treatment in children is limited. In Greece, Tsolia et al. (2002) reported positive blood cultures in 78.9% of enrolled children. Most of the patients presented with fever (61%) and musculoskeletal symptoms (69%). None of the 22 patients who received a combination of two or three antibiotics for ‡ 6 weeks and had adequate F/U had a relapse. In Iran (an country endemic for brucellosis), Fanni et al. (2013) diagnosed that the major complications and symptoms in 34 children with brucellosis were fever (74%), anorexia (71%), fatigue (68%), and arthralgia (65%). Clinical findings were arthritis (77%), splenomegaly (32%), hepatomegaly (18%), and skin rashes (3%), whereas the most common hematologic findings were anemia (53%) and leukopenia (33%) (Fanni et al. 2013). In a study reporting on childhood brucellosis in a nonendemic country, Shen (2008) analyzed 20 cases of disease in children aged 2–18 years diagnosed in Dallas, Texas, during 1993–2006. Diagnosis was confirmed via blood culture for 18 patients, and 100% of them grew B. melitensis. Nineteen patients had a recent history of either travel to Mexico or ingestion of unpasteurized milk products from Mexico.
Brucella agglutination titers: 95 patients with Brucella bacteremia.
Brucella BACTEREMIA IN CHILDREN IN ISRAEL
In 86 children with brucellosis diagnosed in Central Israel during 1987–1992, Gottesman et al. (1996) found that the classical triad of fever (91%), arthralgia or arthritis (83%), and hepatomegaly/hepatosplenomegaly (63%) characterized the majority of patients. The diagnosis was based on positive blood cultures (61.0% of cases) and a SAT titer > 1/160. The relapse rate in patients treated with doxycycline only was 43% compared with 14% with the regimens of combined therapy. The total relapse rate of infection was 20% (Gottesman et al. 1996). B. melitensis infections were previously reported to cause substantial human morbidity in the seminomadic Bedouin population of southern Israel that consumes unpasteurized dairy products (Slater et al. 1990–1991, Banai 2010). We showed in the present study that: 1. All cases of BB were recorded in children of Muslim Bedouin ethnicity. 2. Bacteremia was diagnosed in > 50% of the children with brucellosis and B. melitensis was identified in all cases. 3. The most frequent symptoms were arthralgia, weakness, and gastrointestinal complaints; overall duration of symptoms before diagnosis was unexpectedly short (around 10 days), and fever at diagnosis was recorded in only 20% of the patients. 4. The main clinical findings at admission included monoarthritis, hepatosplenomegaly, and lymphadenopathy. 5. A considerable amount of patients with BB had undetectable SAT titers, suggesting insufficient reliability on serology alone in the diagnosis of brucellosis. In endemic areas, blood cultures are required for a definitive diagnosis because the symptoms and signs of brucellosis are nonspecific and the interpretation of SAT results can be confounded by persistently elevated titers in persons without active disease who have been repeatedly exposed to infected animals (Young 1991). The rate of positive blood cultures in brucellosis ranges from 15% to 80% (Ganado and Bannister 1960, Corbel 1997, Yagupsky 1999, Memish et al. 2000, Doganay and Aygen 2003, Pappas et al. 2005, Franco et al. 2007, Mantur et al. 2008, Araj 2010). In the present study, Brucella spp. were isolated from the blood cultures in 50.8% of the patients. These results supported previous studies including children, with the isolation rate ranging from 17.6% to 61% (Shaalan et al. 2002, Tanir et al. 2009, Banai 2010). Documentation of fever during the period of time preceding the diagnosis, severity of fever, presence of hepatomegaly and splenomegaly, high C-reactive protein and liver function enzymes levels, and a positive Rose–Bengal test were found as the major factors affecting the isolation of Brucella spp. from blood cultures (Apa et al. 2013). In addition to its crucial diagnostic importance when the serology is negative, the presence of bacteremia may represent an increased risk for relapse and may be also associated with secondary seeding and focal complications of the disease (Ariza et al. 1995, Pappas and Papadimitriou 2007, Solera 2010). In a study comparing 60 bacteremic and 63 nonbacteremic Turkish patients, mean age was younger and duration to onset of symptoms shorter in bacteremic patients (Kadanali et al. 2009). More bacteremic patients presented with fever and chills, whereas arthralgia was the most common symptom in
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nonbacteremic patients. Arthritis (63.4% of the patients) was more common in bacteremic cases. More elevations in liver function test and more diagnoses of leukopenia were detected in bacteremic patients (Kadanali et al. 2009). A high or rising antibody titer in Brucella agglutination tests establishes the presumptive diagnosis of brucellosis. However, false-positive and false-negative SAT results have been observed (Corbel 1979, Corbel 1985, Mantecon et al. 2006, Shemesh and Yagupsky 2011). In environments where brucellosis is endemic, a titer of 1/320 or higher has been found to be indicative of active brucellosis with or without positive blood cultures (Corbel 1993, Memish et al. 2000, Pappas and Memish 2007). In our study, 29 (30.5%) patients with BB had titers of £ 1/160, whereas 67 (70.5%) had titers between 1/160 and 1/640, confirming a previous study from southern Israel where SAT titers ‡ 1/160 had a diagnostic sensitivity of 91.7%, whereas raising the cutoff to 1/320 reduced the sensitivity to 82.6% (Shemesh and Yagupsky 2011). The lack of seropositivity in patients with positive blood cultures for Brucella and a strongly suspected clinical picture may be attributed to the performance of tests early in the course of infection, presence of blocking antibodies (nonagglutinating, incomplete), or the so-called ‘‘prezone’’ phenomenon (Al Dahouk et al. 2003, Aliskan 2008). Brucella enzyme immunosorbent assays (ELISA), which measure specific immunoglobulin M (IgM), IgG, and IgA antibodies, are more sensitive and specific than other serological tests, may allow for a better interpretation of the clinical situation, and may therefore overcome the false negatives/positives that may arise in SAT (Al Dahouk et al. 2003, Aliskan 2008). Fever was reported to be the main symptom in Brucella patients, with rates of 64.4–100% (Tanir et al. 2009, Mantur et al. 2006, Andriopoulos et al. 2007, Akhvlediani et al. 2010) and higher rates of fever in children than in adults (Tsolia et al. 2002). We could not retrieve reliable information on our patients’ temperature during the period of time preceding the diagnosis of brucellosis, but at the time of diagnosis, fever > 38C was documented in only 20% of the patients. This finding is intriguing, particularly in our population, who were referred relatively early to PER during the acute phase of the disease and presented with bacteremia at diagnosis. Childhood brucellosis deserves special mention, because the condition is easily overlooked in infants (Tsolia et al. 2002, Franco et al 2007). The most common osteoarticular finding in children is monoarticular arthritis (usually of the knees and hips), whereas in adults, sacroiliitis is most frequent. We found in the present study that the most frequent osteoarticular symptoms of brucellosis in our patients were arthralgia and back pain (the last one increasingly recorded with increasing patient age), whereas monoarthritis was the most common clinical finding. Leukocytosis may be observed in about 9% of brucellosis patients, and if found, focal complications should be ruled out (Franco et al. 2007). Leukopenia and thrombocytopenia may be encountered in similar frequencies (11% and 10% of the patients, respectively), wereasanemia is more common (around 26%) (Franco et al. 2007). Anemia, leukocytosis, leukopenia, thrombocytopenia, and pancytopenia were reported in 17.6%, 5.6%, 29.6%, 12.8%, and 2.3% of our patients, respectively. In 30 patients with brucellosis with pancytopenia, the most common findings in the bone marrow
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evaluation were histiocytic hemophagocytosis and granulomas (Sari et al. 2008). Among all cases, five hematological malignancies were diagnosed concurrently with brucellosis (Andriopoulos et al. 2007). In Israel, Shalev et al. (1994) reported on the hematologic manifestations of 6/21 (29%) children with brucellosis. All patients had pancytopenia and splenomegaly; two presented with purpura. Five patients recovered completely; one patient developed bone marrow aplasia requiring repeated blood and platelet transfusions and later three bone marrow transplantations (Shalev et al. 1994). For children < 8 years, a regimen of oral trimethoprim– sulfamethoxazole for 6 weeks in combination with either intramuscular streptomycin for 3 weeks or parenteral gentamicin once daily) for 7–10 days, is recommended (Doganay and Aygen 2003, World Health Organization 2006, Franco et al. 2007, Skalsky et al. 2008). Alternatively, an oral combination of trimethoprim–sulfamethoxazole and rifampin each for 6 weeks, or rifampin plus an aminoglycoside may be used (World Health Organization 2006). Children > 8 years should be treated with a combination of oral doxycycline twice a day for 6 weeks and an aminoglycoside the first 2–3 weeks (Doganay and Aygen 2003, World Health Organization 2006, Franco et al. 2007, Skalsky et al. 2008). At our medical center, the therapeutic protocol for brucellosis included oral trimethoprim–sulfamethoxazole (in children < 8 years) or doxycycline (in children > 8 years) for 6 weeks combined with gentamicin for 14 days. These two drug combinations were used in 97.7% of our patients. So far, there is no evidence to suggest that drug resistance has an important part in treatment failure and relapse (Ariza et al. 1986, Akova et al. 1999, Turkmani et al. 2006). The findings of our study, based on a considerable number of patients with BB diagnosed in an endemic area, are, in general, similar to the published data on the epidemiology and clinical and laboratory presentation of brucellosis in children. The critical importance of a correct diagnosis based on skillful analysis of the serology tests and recovery of the organisms from the blood cultures is emphasized. The main limitations of this study are related to its retrospective data collection, enrollment of only hospitalized patients, and lack of data on patients’ compliance with treatment and of their follow-up. Ariza et al. (1995) determined the following independent risk factors for relapse from a prospective cohort of 530 adults—‘‘less effective’’ antibiotic therapy, positive blood cultures during initial disease, disease duration of 10 days or less before start of treatment, male sex, and a platelet count of £ 150,000/lL. Solera et al. (1998) have proposed a multivariate model to stratify a patient’s risk of relapsing into groups of low (4.5%), medium (32%), and high (67%) probability of relapse within 12 months. The independent predictors of relapse were temperatures of ‡ 38.3C, positive blood cultures at baseline, and duration of symptoms before treatment < 10 days. In conclusion, childhood brucellosis remains an important public health problem in southern Israel. Bacteremia was diagnosed in > 50% of the children with brucellosis; B. melitensis was identified in all diagnosed cases and all patients were of Muslim Bedouin ethnicity. A considerable number of patients with BB had undetectable/low serum agglutinin titers, suggesting insufficient reliability on serology alone in the diagnosis of brucellosis.
FRUCHTMAN ET AL. Acknowledgments
This paper was submitted in partial fulfillment of the requirements for degree of Doctor of Medicine Avivit Asher Golan, 6th year student at the ‘‘Carol Davila’’ Faculty of Medicine, Bucharest, Romania. Author Disclosure Statement
No competing financial interests exist. References
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Corbel MJ. Recent advances in the study of Brucella antigens and their serological cross-reactions. Vet Bull 1985; 55: 927–942. Corbel MJ. Microbiological aspects of Brucellosis. Saudi Med J 1993; 14:489–502. Corbel MJ. Brucellosis: An overview. Emerg Infect Dis 1997; 3:213–221. Doganay M, Aygen B. Human brucellosis: An overview. Int J Infect Dis 2003; 7:173–182. Fanni F, Shahbaznejad L, Pourakbari B, Mahmoudi S, et al. Clinical manifestations, laboratory findings, and therapeutic regimen in hospitalized children with brucellosis in an Iranian referral children medical center. J Health Popul Nutr 2013; 2:218–222. Franco MP, Mulder M, Gilman RH, Smits HL. Human brucellosis. Lancet Infect Dis 2007; 7:775–786. Fraser D, Givon-Lavi N, Bilenko N, Dagan R. A decade (1989– 1998) of pediatric invasive pneumococcal disease in 2 populations residing in 1 geographic location: Implications for vaccine choice. Clin Infect Dis 2001; 33:421–427. Ganado W, Bannister W. Bacteraemia in human brucellosis. Br Med J 1960; 1:601–603. Gottesman G, Vanunu D, Maayan MC, Lang R, et al. Childhood brucellosis in Israel. Pediatr Infect Dis J 1996; 15: 610–615. Kadanali A, Ozden K, Altoparlak U, Erturk A, et al. Bacteremic and nonbacteremic brucellosis: Clinical and laboratory observations. Infection 2009; 37:67–69. Mantecon, MA, Gutierrez, P, Zarzosa, MP, Duenas, AI, et al. Utility of an immunocapture-agglutination test and an enzyme-linked immunosorbent assay test against cytosolic proteins from Brucella melitensis B115 in the diagnosis and follow-up of human acute brucellosis. Diagn Microbiol Infect Dis 2006; 55:27–35. Mantur BG, Biradar MS, Bidri RC, Mulimani M, et al. Protean clinical manifestations and diagnostic challenges of human brucellosis in adults: 16 years’ experience in an endemic area. J Med Microbiol 2006; 55:897–903. Mantur BG, Mulimani MS, Bidari LH, Akki AS, et al. Bacteremia is as unpredictable as clinical manifestations in human brucellosis. Int J Infect Dis 2008; 12:303–307. Memish Z, Mah MW, Al Mahmoud S, Al Shaalan M, et al. Brucella bacteraemia: Clinical and laboratory observations in 160 patients. J Infect 2000; 40:59–63. Novack V, Avnon LS, Etzion O, Riesenberg K, et al. Differences between Bedouin and Jewish populations in incidence and characteristics of patients hospitalized with communityacquired pneumonia. Ethn Dis 2007; 17:441–446. Pappas, G, Memish, ZA. Brucellosis in the Middle East: A persistent medical, socioeconomic and political issue. J Chemother 2007; 19:243–246. Pappas G, Akritidis N, Bosilkovski M, Tsianos E. Brucellosis. N Engl J Med 2005; 352:2325–2336. Pappas G, Papadimitriou P. Challenges in Brucella bacteremia. Int J Antimicrob Agents 2007; 30:29–31. Perez-Avraham G, Yagupsky P, Schlaeffer F, Borer A, et al. Zoonotic infections as causes of hospitalization among febrile Bedouin patients in southern Israel. Trans R Soc Trop Med Hyg 2001; 95:301–303. Rosenthal J, Dagan R, Press J, Sofer S. Differences in the epidemiology of childhood community-acquired bacterial
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meningitis between two ethnic populations cohabiting in one geographic area. Pediatr Infect Dis J 1988; 7:630–633. Sari I, Altuntas F, Hacioglu S, Ismail K, et al. A multicenter retrospective study defining the clinical and hematological manifestations of brucellosis and pancytopenia in a large series: Hematological malignancies, the unusual cause of pancytopenia in patients with brucellosis. Am J Hematol 2008; 83:334–339. Sathyanarayanan V, Razak A, Saravu K, Ananthakrishna SB, et al. Clinical profile of brucellosis from a tertiary care center in southern India. Asian Pac J Trop Med 2011; 4:397–400. Shaalan MA, Memish ZA, Mahmoud SA, Alomari A, et al. Brucellosis in children: Clinical observations in 115 cases. Int J Infect Dis 2002; 6:182–186. Shalev H, Abramson O, Levy J. Hematologic manifestations of brucellosis in children. Pediatr Inf Dis J 1994; 6:543–545. Shemesh AA, Yagupsky P. Limitations of the standard agglutination test for detecting patients with Brucella melitensis bacteremia. Vector Borne Zoonotic Dis 2011; 11:1599–1601. Shen MW. Diagnostic and therapeutic challenged in childhood brucellosis in a nonendemic country. Pediatrics 2008; 121; e1178–e1183. Skalsky K, Yahav D, Bishara J, Pitlik S, et al. Treatment of human brucellosis: Systematic review and meta-analysis of randomized controlled trials. Br Med J 2008; 336:701–704. Slater, PE, Costin, C, Seidenbaum, M, Ever-Hadani, S. Epidemiology of human brucellosis in Israel. Public Health Rev 1990–1991; 18:159–169. Solera J, Martinez-Alfaro E, Espinosa A, Castillejos ML, et al. Multivariate model for predicting relapse in human brucellosis. J Infect 1998; 36:85–92. Solera J. Update on brucellosis: Therapeutic challenges. Int J Antimicrob Agents. 2010; 36(Suppl 1):S18–S20. Tanir G, Tufekci SB, Tuygun N. Presentation, complications, and treatment outcome of brucellosis in Turkish children. Pediatr Int 2009; 51:114–119. Tsolia M, Drakonaki S, Messaritaki A, et al. Clinical features, complications an treatment outcome of childhood brucellosis in central Greece. J Infect 2002; 44:257–262. Turkmani A, Ioannidis A, Christidou A, Psaroulaki A, et al. In vitro susceptibilities of Brucella melitensis isolates to eleven antibiotics. Ann Clin Microbiol Antimicrob 2006; 5:24. World Health Organization. Treatment of brucellosis in human. In: Brucellosis in Humans and Animals. Food and Agriculture Organization of the United Nations, World Organization for Animal Health, 2006:36–41. Yagupsky P. Detection of brucellae in blood cultures. J Clin Microbiol 1999; 37:3437–3442. Young EJ. Serologic diagnosis of human brucellosis: Analysis of 214 cases by agglutination tests and review of the literature. Rev Infect Dis 1991; 13:359–372.
Address correspondence to: Eugene Leibovitz Pediatric Emergency Medicine Department Soroka University Medical Center P.O. Box 151 Beer-Sheva 84101 Israel E-mail: [email protected]
Epidemiological, Diagnostic, Clinical, and Therapeutic Aspects of Brucella Bacteremia in Children in Southern Israel: A 7-Year Retrospective Study (2005–2011) Yariv Fruchtman,1 Renana Wilkof Segev,2 Avivit Asher Golan,1,4 Yael Dalem,1 Muhammad Abu Tailakh,2 Victor Novak,2 Nehama Peled,3 Mihai Craiu,4 and Eugene Leibovitz1
Abstract
Background: Data on the various aspects of brucellosis in children living in southern Israel are missing. Objectives: Our aim was to study the epidemiological, microbiological, diagnostic, clinical, therapeutic and outcome features of brucellosis in children < 19 years of age in southern Israel during 2005–2011. Patients and Methods: The study population included all patients hospitalized with a diagnosis of brucellosis, established according to a clinical presentation compatible with brucellosis + presence of Brucella bacteremia (BB). Results: A total of 128 (50.8%) of 252 patients admitted with a diagnosis of brucellosis had BB (all with Brucella melitensis). All patients were of Muslim Bedouin ethnicity. The mean incidence of BB in southern Israel was 16 cases/100,000 Bedouin, with no significant changes during the study period. Overall duration of symptoms before diagnosis was 10.1 – 10.9 days. Fever at diagnosis was recorded in < 20% of the patients. The most frequent symptoms were arthralgia (61.7%), weakness (32.8%), gastrointestinal disturbances (27.3%), myalgia (25%), and headache (18.8%). The main clinical findings included monoarthritis (36.7%), hepatosplenomegaly (25%), lymphadenopathy (17.2%), heart murmur (11.7%), and skin rash (9.4%), respectively. Anemia, leukopenia, thrombocytopenia, and pancytopenia were reported in 17.6%, 29.6%, 12.8%, and 2.3% of the patients, respectively. Twenty-nine (30.5%) patients with BB had serum agglutinin titers £ 1/160 (13, 13.7%%, had titers < 1/160). Twenty-seven (93%) of the 29 patients aged 0–4 years were treated with gentamicin and trimethoprim–sulfamethoxazole; a total of 77 (60.2%) patients received gentamicin and doxycycline. Conclusions: Childhood brucellosis remains an important public health problem in southern Israel. BB was diagnosed in > 50% of the children with brucellosis, and B. melitensis was identified in all cases. Arthralgia, weakness, and gastrointestinal complaints were the most common symptoms, and monoarthritis, hepatosplenomegaly, and lymphadenopathy were the most common clinical findings. A considerable number of patients with BB had undetectable/low serum agglutinin titers, suggesting insufficient reliability on serology alone in diagnosis of brucellosis. Key Words:
Brucella—Bacteremia—Children—Serum agglutination—Antibiotics.
Introduction
B
rucellosis remains a highly endemic zoonosis among domesticated animals in many regions, including Middle Eastern countries (Corbel 1997, Doganay and Aygen 2003, Pappas et al. 2005, Franco et al. 2007, Buzgan et al. 2010). Much of the brucellosis in children is food-borne and is associated with consumption of unpasteurized milk prod-
ucts (Corbel 1997, Doganay and Aygen 2003, Pappas et al. 2005, Franco et al. 2007, Buzgan et al. 2010, Sathyanarayanan et al. 2011). In Turkey, Buzgan et al. (2010) found that 69.6% of 1028 brucellosis cases were aged 13–34 years. Arthralgia and fever (73.7% and 72.2%, respectively) were the most frequently seen symptoms, whereas hepatomegaly and osteoarticular involvement (26% and 25.3%, respectively) were the most
1 Pediatric Emergency Medicine Department, 2Clinical Research Center and 3Microbiology Laboratories, Soroka University Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. 4 Pediatric Emergency Medicine Department, Alfred Rusescu Children’s Hospital, Carol Davila Medical School, Bucharest, Romania.
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common clinical findings. The treatment regimen with doxycycline + streptomycin with and without rifampicin was more effective than other regimens in the cases with osteoarticular involvement (Buzgan et al. 2010). In southern India (Sathyanarayanan et al. 2011), 68% of the 68 enrolled adult patients were male and all presented with fever. A serum Brucella agglutination titer of 1:320 was positive in 61 (90%) of patients (Sathyanarayanan et al. 2011). In a review of recent trends in human brucellosis in Israel, a decline of almost 17% of brucellosis cases was reported during 1998–2002 (Anis et al. 2011). The disease is mostly limited to certain sectors of the rural Arab population. In 2008, the incidence rate of brucellosis was 7.0/100,000 among Bedouin Muslims compared with 0.2/100,000 among the Jewish population. In the Negev region in southern Israel, two populations live side by side: Jewish children, largely urban, and Bedouin children, from formerly desert nomadic families and now in transition to a Western lifestyle, both enjoying similar medical community and hospitalization services. Hospitalization rates due to respiratory and gastrointestinal infections in general and due to invasive pneumococcal diseases particularly are more prevalent among Bedouin children (Rosenthal et al. 1988, Fraser et al. 2001, Novack et al. 2007). Among bacterial zoonoses causing fever among hospitalized Bedouins in southern Israel, zoonoses were diagnosed in 30 (27%) of 110 patients admitted with fever. Brucellosis was diagnosed in 9 (8%) and rickettsial infections in 20 (18%) (Perez-Avraham et al. 2001). Data on the various aspects of brucellosis in children living in southern Israel are missing. The purpose of the present work was to study the epidemiological, microbiological, diagnostic, clinical, and therapeutic features of brucellosis in children 0–19 years in the Negev area of southern Israel during 2005–2011. Patients and Methods Setting
The Soroka University Medical Center is the only general hospital in the region and provides primary and tertiary health services to the entire population of the southern region of Israel. It served a population of > 800,000 inhabitants in 2012; of them > 250,000 children were < 19 years of age. Medical insurance in Israel is universal and is provided free of charge. Criteria for referral to hospital are also similar.
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Blood cultures were obtained using the Bactec 9240 system (Becton Dickinson). Inoculated blood culture vials were incubated following the manufacturer’s recommendations; negative vials were discarded after 7 days without further processing (Yagupsky 1999). Brucella was identified on the basis of a typical biochemical profile and positive agglutination reaction with specific antiserum (Welcome Diagnostics). Speciation was performed at the Kimron Veterinary Institute at Bet Dagan, Israel, with phages Tb and Iz (Banai et al. 1990). The laboratory practices did not change, and the blood culture yields stayed constant during the study years (Banai et al. 1990, Yagupsky 1999, Perez-Avraham et al. 2001, Shemesh and Yagupsky 2011). Sera were screened for Brucella antibodies by the Rose–Bengal test (Shemesh and Yagupsky 2011). Positive specimens were serially diluted from 1/20 up to 1/1280 to eliminate the ‘‘prozone effect’’ (inhibition of the agglutination phenomenon at low dilutions due to antibody excess) and tested by the SAT (Christopher et al. 2010, Al Dahouk et al. 2011). Clinical and laboratory data collection
The handwritten and electronic medical records of all patients admitted with the diagnosis of Brucella bacteremia (BB) were searched, and all of the relevant demographic, microbiologic, clinical, and therapeutic parameters were summarized. No follow-up data were available for the discharged patients (followed in the community clinics only). Treatment
All patients diagnosed with brucellosis were treated according to the following protocols: 1. Children > 8 years of age: Doxycycline per os (p.o.) 2 mg/kg per dose (maximum 100 mg) twice daily for a six weeks + intravenous/intramuscular gentamicin 5 mg/ kg one daily dose for 2 weeks. 2. Children < 8 years of age: Sulfamethoxazole p.o. 20 mg/kg per dose + trimethoprim 4 mg/kg per dose (maximum 800 mg sulfamethoxazole + 160 mg trimethoprim) twice daily for 6 weeks + intravenous/intramuscular gentamicin 5 mg/kg one daily dose (no maximal dose) for 2 weeks (World Health Organization 2006, Skalsky et al. 2008).
Study Population
Statistical analysis
The study population included all patients < 19 years of age admitted with a diagnosis of brucellosis at the pediatric departments of Soroka University Medical Center during January, 2005–December, 2011. The study protocol was approved by the institutional ethical committee.
A t-test and analysis of variance (ANOVA) were used for comparing continuous variables, and the chi-squared test was used for categorical data, augmented by the Fisher exact test if needed. We used the Kruskal–Wallis test for the comparison of variables not distributed normally. All reported p values were two-sided and the level of p < 0.05 was considered statistically significant. Data analysis was performed using SPSS version 18 (SPSS Inc. Chicago, IL).
Diagnosis
Diagnosis was established according to a clinical presentation compatible with brucellosis + a positive blood culture. Standard agglutination test (SAT) titers > 1/160 were obtained at admission for all patients and, together with an appropriate clinical presentation, were considered compatible for brucellosis; however, confirmation by a positive blood culture was needed for a definitive diagnosis.
Results
A total of 252 patients were admitted with the diagnosis of brucellosis. Of them, 128 (50.8%, the study population) were included in the present study due to positive cultures for Brucella spp. Nine (7%) patients were admitted with diagnosis of
Brucella BACTEREMIA IN CHILDREN IN ISRAEL
recurrent brucellosis. All positive blood cultures revealed B. melitensis. All patients were of Muslim Bedouin ethnicity. The highest number of cases was recorded in 2008 and 2007 (28 and 26, respectively) and the lowest in 2005 and 2010 (4 and 12, respectively). The mean incidence of BB in southern Israel was 16 cases/100,000 Bedouin children aged 0–19 years, with no significant changes during the study period ( p = 0.46). There were 29 (22, 6%), 85 (66.4%), and 14 (11%) patients, respectively, in the 0–4, 5–14, and 15–19 year age groups. Mean ( – standard deviation [SD]) age was 8.5 – 10.9 years. There were 5 patients < 1 year of age. There were 93 (72.7%) males (72.4%, 70.6%, and 85.7%, respectively, in the three age groups, p = 0.50). Consumption of unpasteurized milk, contact with livestock, and presence of brucellosis in family relatives were recorded in 40.8%, 72.9%, and 56.8%, respectively, with no significant differences between the three age groups. A total of 95/128 (73.4%) of the cases were recorded during the spring and summer seasons (March– September); the highest number of patients was recorded in April (21, 16.4%) and the lowest (4, 3.1%) in October. Nineteen (14.8%) patients suffered from 21 pre-existing pathologies (heart murmurs, 6; septicemia, and chronic liver disease, 3 each; failure to thrive, short stature, and mental retardation, 2 each; asthma, Bells’ palsy, and septic arthritis, 1 each). There was no significant difference in background diseases/conditions between the three age groups. Overall, 23 (18.7%) patients had a temperature > 38C and 6 (4.9%) a temperature > 39C at admission (Fig. 1); 15.4% of the children aged 15–19 years had a temperature > 39C. More patients aged 0–4 years and 15–19 years had a temperature > 39C compared with patients aged 5–14 years (10.3% vs. 1.2%, p = 0.025, and 15.4% vs. 1.2%, p = 0.007), respectively. Overall duration of symptoms before diagnosis was 10.1 – 10.9 days, with no differences between the three age groups. The most frequent symptoms of brucellosis were arthralgia, weakness, gastrointestinal disturbances, myalgia, and headache (present in 61.7%, 32, 8%, 27.3%, 25%, and
FIG. 1.
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18.8%, respectively). Patients aged 15–19 years presented with more weakness, headache, back pain, and weight loss compared with patients 0–4 years of age (57.1%, 50%, 35.7%, and 42.9% vs. 17.2%, 3.4%, 0%, and 0%, respectively, p < 0.05 for all comparisons). The presence of back pain was increasingly recorded with increasing patient age ( p = 0.007). On physical examination, the main clinical findings recorded included monoarthritis (36.7%), hepatosplenomegaly (25%), lymphadenopathy (17.2%), heart murmur (11.7%), and skin rash (9.4%), with no differences between the three age groups (Table 1). None of the patients aged 15–19 years had hepatosplenomegaly. All of the patients had a complete blood count and liver function tests performed at admission. Anemia (hemoglobin [Hb] < 10 g/dL) was present in 17.6% of the patients. White blood cell (WBC) counts were significantly lower among patients 15–19 years old compared with patients 5–14 years old (4.5 – 1.2 cells/mL vs. 6.9 – 3.2 cells/mL, respectively, p = 0.002) and also between those 5–14 years old compared with 0–4 years old (11.1 – 4.6 cells/mL, p < 0.001). Leukopenia of < 5000 WBC/mL was reported in 29.6% of the patients. Leukopenia was recorded in 71.4% of patients aged 15–19 years. Neutropenia of < 1500, < 1000, and < 500 cells/mL was recorded in 15 (13.4%), 6 (6.3%), and 1 (0.9) patients. Thrombocytopenia ( < 150,000 cells/mL) was found in 12.8% of the patients; it was reported more frequently among patients 15–19 years old (5, 35.7%) compared with 1 (3.6%) and 10 (12%) among patients aged 0–4 and 5–14 years, respectively ( p = 0.001 and p = 0.039, respectively). Pancytopenia was observed in three patients. Increased aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values were found in 68.9% and 30.3% patients, respectively, with no differences between the three age groups. C-reactive protein was examined in 31 patients and values > 3 mg/liter were found in 11 (35.5%) of them, with no differences between the three age groups.
Clinical features: 128 patients with Brucella bacteremia.
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Table 1. Clinical Findings at Admission All patients n = 128
Variables Monoarthritis (n, %) Lymphadenopthy (n, %) Hepatomegaly (n, %) Heart murmur (n, %) Rash (n, %) Hepatomegaly + splenomeagly (n, %) Splenomegaly (n, %) Polyarthritis (n, %) Vertebral findings (n, %)
47 22 16 15 12 11 5 5 2
(36.7) (17.2) (12.5) (11.7) (9.4) (8.6) (3.9) (3.9) (1.6)
Patients 0–4 years old n = 29 12 4 5 3 2 4 1 1 0
Serologic examinations (Brucella antibody titers, SAT) were available for 95/128 (74.2%) patients; 13 (13.7%) had titers of < 1/160 (Fig. 2). Sixty-seven (70.5%) patients had SAT titers between 1/160 and 1/640. Titers higher than 1/ 1280 were reported in 15 (15.8%) with no differences between the three age groups ( p = 0.47). Of the three children with pancytopenia, one had a titer of 1/640 and two a titer of 1/1280. Twenty-seven (93%) of the 29 patients aged 0–4 years were treated with a combination of gentamicin and trimethoprim–sulfamethoxazole. All patients (14) aged 15–19 years and 62/86 (72.9%) of the patients aged 5–14 years were treated with the combination of gentamicin and doxycycline. Overall length of hospitalization was 5.03 – 3.21 days, with no differences between the three age groups. Adverse effects (mild abdominal pain and vomiting) were recorded during hospitalization in two (1.6%) patients, without need for interruption of the treatment. The mean age (8.49 – 4.76 years), duration of symptoms before admission (10.36 – 11.18 days), and length of hospitalization (5.1 – 3.2 days) were similar between the 10 patients hospitalized with recurrent brucellosis and the other patients. SAT results were available in five of them (1/640 in 3 and 1/1280 in two of them).
FIG. 2.
(41.4) (13.8) (17.2) (10.3) (6.9) (13.8) (3.4) (3.4) (0)
Patients 5–14 years old n = 85 32 15 10 11 9 7 2 2 1
(37.6) (17.6) (11.8) (12.9) (10.6) (8.2) (2.4) (2.4) (1.2)
Patients 15–19 years old n = 14 3 3 1 1 1 0 2 2 1
(31.4) (21.4) (7.1) (7.1) (7.1) (0) (14.3) (14.3) (7.1)
p value 0.425 0.809 0.605 0.795 0.803 0.312 0.101 0.101 0.185
Discussion
Information on epidemiology, clinical features of the disease, and its diagnosis and treatment in children is limited. In Greece, Tsolia et al. (2002) reported positive blood cultures in 78.9% of enrolled children. Most of the patients presented with fever (61%) and musculoskeletal symptoms (69%). None of the 22 patients who received a combination of two or three antibiotics for ‡ 6 weeks and had adequate F/U had a relapse. In Iran (an country endemic for brucellosis), Fanni et al. (2013) diagnosed that the major complications and symptoms in 34 children with brucellosis were fever (74%), anorexia (71%), fatigue (68%), and arthralgia (65%). Clinical findings were arthritis (77%), splenomegaly (32%), hepatomegaly (18%), and skin rashes (3%), whereas the most common hematologic findings were anemia (53%) and leukopenia (33%) (Fanni et al. 2013). In a study reporting on childhood brucellosis in a nonendemic country, Shen (2008) analyzed 20 cases of disease in children aged 2–18 years diagnosed in Dallas, Texas, during 1993–2006. Diagnosis was confirmed via blood culture for 18 patients, and 100% of them grew B. melitensis. Nineteen patients had a recent history of either travel to Mexico or ingestion of unpasteurized milk products from Mexico.
Brucella agglutination titers: 95 patients with Brucella bacteremia.
Brucella BACTEREMIA IN CHILDREN IN ISRAEL
In 86 children with brucellosis diagnosed in Central Israel during 1987–1992, Gottesman et al. (1996) found that the classical triad of fever (91%), arthralgia or arthritis (83%), and hepatomegaly/hepatosplenomegaly (63%) characterized the majority of patients. The diagnosis was based on positive blood cultures (61.0% of cases) and a SAT titer > 1/160. The relapse rate in patients treated with doxycycline only was 43% compared with 14% with the regimens of combined therapy. The total relapse rate of infection was 20% (Gottesman et al. 1996). B. melitensis infections were previously reported to cause substantial human morbidity in the seminomadic Bedouin population of southern Israel that consumes unpasteurized dairy products (Slater et al. 1990–1991, Banai 2010). We showed in the present study that: 1. All cases of BB were recorded in children of Muslim Bedouin ethnicity. 2. Bacteremia was diagnosed in > 50% of the children with brucellosis and B. melitensis was identified in all cases. 3. The most frequent symptoms were arthralgia, weakness, and gastrointestinal complaints; overall duration of symptoms before diagnosis was unexpectedly short (around 10 days), and fever at diagnosis was recorded in only 20% of the patients. 4. The main clinical findings at admission included monoarthritis, hepatosplenomegaly, and lymphadenopathy. 5. A considerable amount of patients with BB had undetectable SAT titers, suggesting insufficient reliability on serology alone in the diagnosis of brucellosis. In endemic areas, blood cultures are required for a definitive diagnosis because the symptoms and signs of brucellosis are nonspecific and the interpretation of SAT results can be confounded by persistently elevated titers in persons without active disease who have been repeatedly exposed to infected animals (Young 1991). The rate of positive blood cultures in brucellosis ranges from 15% to 80% (Ganado and Bannister 1960, Corbel 1997, Yagupsky 1999, Memish et al. 2000, Doganay and Aygen 2003, Pappas et al. 2005, Franco et al. 2007, Mantur et al. 2008, Araj 2010). In the present study, Brucella spp. were isolated from the blood cultures in 50.8% of the patients. These results supported previous studies including children, with the isolation rate ranging from 17.6% to 61% (Shaalan et al. 2002, Tanir et al. 2009, Banai 2010). Documentation of fever during the period of time preceding the diagnosis, severity of fever, presence of hepatomegaly and splenomegaly, high C-reactive protein and liver function enzymes levels, and a positive Rose–Bengal test were found as the major factors affecting the isolation of Brucella spp. from blood cultures (Apa et al. 2013). In addition to its crucial diagnostic importance when the serology is negative, the presence of bacteremia may represent an increased risk for relapse and may be also associated with secondary seeding and focal complications of the disease (Ariza et al. 1995, Pappas and Papadimitriou 2007, Solera 2010). In a study comparing 60 bacteremic and 63 nonbacteremic Turkish patients, mean age was younger and duration to onset of symptoms shorter in bacteremic patients (Kadanali et al. 2009). More bacteremic patients presented with fever and chills, whereas arthralgia was the most common symptom in
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nonbacteremic patients. Arthritis (63.4% of the patients) was more common in bacteremic cases. More elevations in liver function test and more diagnoses of leukopenia were detected in bacteremic patients (Kadanali et al. 2009). A high or rising antibody titer in Brucella agglutination tests establishes the presumptive diagnosis of brucellosis. However, false-positive and false-negative SAT results have been observed (Corbel 1979, Corbel 1985, Mantecon et al. 2006, Shemesh and Yagupsky 2011). In environments where brucellosis is endemic, a titer of 1/320 or higher has been found to be indicative of active brucellosis with or without positive blood cultures (Corbel 1993, Memish et al. 2000, Pappas and Memish 2007). In our study, 29 (30.5%) patients with BB had titers of £ 1/160, whereas 67 (70.5%) had titers between 1/160 and 1/640, confirming a previous study from southern Israel where SAT titers ‡ 1/160 had a diagnostic sensitivity of 91.7%, whereas raising the cutoff to 1/320 reduced the sensitivity to 82.6% (Shemesh and Yagupsky 2011). The lack of seropositivity in patients with positive blood cultures for Brucella and a strongly suspected clinical picture may be attributed to the performance of tests early in the course of infection, presence of blocking antibodies (nonagglutinating, incomplete), or the so-called ‘‘prezone’’ phenomenon (Al Dahouk et al. 2003, Aliskan 2008). Brucella enzyme immunosorbent assays (ELISA), which measure specific immunoglobulin M (IgM), IgG, and IgA antibodies, are more sensitive and specific than other serological tests, may allow for a better interpretation of the clinical situation, and may therefore overcome the false negatives/positives that may arise in SAT (Al Dahouk et al. 2003, Aliskan 2008). Fever was reported to be the main symptom in Brucella patients, with rates of 64.4–100% (Tanir et al. 2009, Mantur et al. 2006, Andriopoulos et al. 2007, Akhvlediani et al. 2010) and higher rates of fever in children than in adults (Tsolia et al. 2002). We could not retrieve reliable information on our patients’ temperature during the period of time preceding the diagnosis of brucellosis, but at the time of diagnosis, fever > 38C was documented in only 20% of the patients. This finding is intriguing, particularly in our population, who were referred relatively early to PER during the acute phase of the disease and presented with bacteremia at diagnosis. Childhood brucellosis deserves special mention, because the condition is easily overlooked in infants (Tsolia et al. 2002, Franco et al 2007). The most common osteoarticular finding in children is monoarticular arthritis (usually of the knees and hips), whereas in adults, sacroiliitis is most frequent. We found in the present study that the most frequent osteoarticular symptoms of brucellosis in our patients were arthralgia and back pain (the last one increasingly recorded with increasing patient age), whereas monoarthritis was the most common clinical finding. Leukocytosis may be observed in about 9% of brucellosis patients, and if found, focal complications should be ruled out (Franco et al. 2007). Leukopenia and thrombocytopenia may be encountered in similar frequencies (11% and 10% of the patients, respectively), wereasanemia is more common (around 26%) (Franco et al. 2007). Anemia, leukocytosis, leukopenia, thrombocytopenia, and pancytopenia were reported in 17.6%, 5.6%, 29.6%, 12.8%, and 2.3% of our patients, respectively. In 30 patients with brucellosis with pancytopenia, the most common findings in the bone marrow
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evaluation were histiocytic hemophagocytosis and granulomas (Sari et al. 2008). Among all cases, five hematological malignancies were diagnosed concurrently with brucellosis (Andriopoulos et al. 2007). In Israel, Shalev et al. (1994) reported on the hematologic manifestations of 6/21 (29%) children with brucellosis. All patients had pancytopenia and splenomegaly; two presented with purpura. Five patients recovered completely; one patient developed bone marrow aplasia requiring repeated blood and platelet transfusions and later three bone marrow transplantations (Shalev et al. 1994). For children < 8 years, a regimen of oral trimethoprim– sulfamethoxazole for 6 weeks in combination with either intramuscular streptomycin for 3 weeks or parenteral gentamicin once daily) for 7–10 days, is recommended (Doganay and Aygen 2003, World Health Organization 2006, Franco et al. 2007, Skalsky et al. 2008). Alternatively, an oral combination of trimethoprim–sulfamethoxazole and rifampin each for 6 weeks, or rifampin plus an aminoglycoside may be used (World Health Organization 2006). Children > 8 years should be treated with a combination of oral doxycycline twice a day for 6 weeks and an aminoglycoside the first 2–3 weeks (Doganay and Aygen 2003, World Health Organization 2006, Franco et al. 2007, Skalsky et al. 2008). At our medical center, the therapeutic protocol for brucellosis included oral trimethoprim–sulfamethoxazole (in children < 8 years) or doxycycline (in children > 8 years) for 6 weeks combined with gentamicin for 14 days. These two drug combinations were used in 97.7% of our patients. So far, there is no evidence to suggest that drug resistance has an important part in treatment failure and relapse (Ariza et al. 1986, Akova et al. 1999, Turkmani et al. 2006). The findings of our study, based on a considerable number of patients with BB diagnosed in an endemic area, are, in general, similar to the published data on the epidemiology and clinical and laboratory presentation of brucellosis in children. The critical importance of a correct diagnosis based on skillful analysis of the serology tests and recovery of the organisms from the blood cultures is emphasized. The main limitations of this study are related to its retrospective data collection, enrollment of only hospitalized patients, and lack of data on patients’ compliance with treatment and of their follow-up. Ariza et al. (1995) determined the following independent risk factors for relapse from a prospective cohort of 530 adults—‘‘less effective’’ antibiotic therapy, positive blood cultures during initial disease, disease duration of 10 days or less before start of treatment, male sex, and a platelet count of £ 150,000/lL. Solera et al. (1998) have proposed a multivariate model to stratify a patient’s risk of relapsing into groups of low (4.5%), medium (32%), and high (67%) probability of relapse within 12 months. The independent predictors of relapse were temperatures of ‡ 38.3C, positive blood cultures at baseline, and duration of symptoms before treatment < 10 days. In conclusion, childhood brucellosis remains an important public health problem in southern Israel. Bacteremia was diagnosed in > 50% of the children with brucellosis; B. melitensis was identified in all diagnosed cases and all patients were of Muslim Bedouin ethnicity. A considerable number of patients with BB had undetectable/low serum agglutinin titers, suggesting insufficient reliability on serology alone in the diagnosis of brucellosis.
FRUCHTMAN ET AL. Acknowledgments
This paper was submitted in partial fulfillment of the requirements for degree of Doctor of Medicine Avivit Asher Golan, 6th year student at the ‘‘Carol Davila’’ Faculty of Medicine, Bucharest, Romania. Author Disclosure Statement
No competing financial interests exist. References
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Address correspondence to: Eugene Leibovitz Pediatric Emergency Medicine Department Soroka University Medical Center P.O. Box 151 Beer-Sheva 84101 Israel E-mail: [email protected]
