Pediatric Neurology 50 (2014) 265—268
Contents lists available at ScienceDirect
Pediatric Neurology journal homepage: www.elsevier.com/locate/pnu
Clinical Observations
Murine Typhus as a Cause of Cognitive Impairment: Case Report and a Review of the Literature Silvana B. Carr MD a, *, Dale F. Bergamo MD a, Patricia J. Emmanuel MD a, Jose A. Ferreira MD b a b
Pediatric Infectious Diseases Division, University of South Florida College of Medicine, St. Joseph Children’s Hospital, Tampa, Florida Pediatric Epilepsy and Neurology Service, St. Joseph Children’s Hospital, Tampa, Florida
abstract BACKGROUND: Murine typhus is a systemic febrile illness caused by Rickettsia typhi, a gram-negative, obligate intracellular bacterium. It is found worldwide, including in the United States, where cases are concentrated in suburban areas of Texas and California. The disease manifests with fever, headache, and rash. Central nervous system involvement is rare in both adults and children. Aseptic meningitis and meningoencephalitis are the most common neurological presentations, occurring in 2% to 5% of cases. Neurological dysfunction, including memory impairment and behavioral alterations, can occur and usually are reversible. Long-term deficits are considered rare even in untreated cases and have not been described in the pediatric population. METHODS: Single case report. RESULTS: We describe a previously healthy 17-year-old girl infected with R. typhi who developed meningoencephalitis that resulted in chronic cognitive impairment despite treatment. CONCLUSION: Murine typhus should be considered in the differential diagnosis of aseptic meningitis and meningoencephalitis. Early diagnosis and treatment can prevent death and long-term morbidity. Keywords: pediatric, murine typhus, meningoencephalitis, central nervous system
Pediatr Neurol 2014; 50: 265-268 Published by Elsevier Inc.
Introduction
Murine (endemic) typhus is a zoonotic infection caused by Rickettsia typhi, which is an obligate intracellular gramnegative bacterium that depends on hematophagous arthropods (e.g., fleas, ticks) and mammals to maintain its lifecycle. Typically, the lifecycle of R. typhi involves roof rats, Norway rats, and the rat flea.1 Murine typhus has been reported on every continent except Antarctica. In the United States, the disease is endemic in southern Texas, California, and Hawaii, particularly in settings where opossums, cats, and their fleas coexist. In southern Texas, most cases occur between April Article History: Received May 30, 2013; Accepted in final form September 14, 2013 * Communications should be addressed to: Dr. Carr; Assistant Professor; University of South Florida; 17 Davis Blvd, Suite 200; MDC 015; Tampa, FL 33606. E-mail address: [email protected] 0887-8994/$ - see front matter Published by Elsevier Inc. http://dx.doi.org/10.1016/j.pediatrneurol.2013.09.017
and June.1 Although adults are most often affected, up to 75% of infections have occurred in children in some outbreaks.2 Pathologically, typhus and spotted fever groups of diseases induce a systemic endothelial vasculitis affecting multiple organs.3 The usual incubation period for murine typhus is 7 to 10 days. The most common clinical manifestations include fever (98% to 100%), headache (41% to 90%), rash (20% to 80%), and arthralgia (40% to 77%).4 The most frequently described laboratory abnormalities include a mild increase (three to five times the normal) of the liver transaminases.4,5 Complications from murine typhus occur infrequently in children, and central nervous system involvement is unusual.4-7 The diagnosis of acute infection is confirmed by both immunoglobulin M and G antibody titers >1:150 and 1:400, respectively and/or a fourfold increase in titers in a second blood sample.8 Doxycycline, the antibiotic of choice, shortens the course of illness and is life-saving.4
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S.B. Carr et al. / Pediatric Neurology 50 (2014) 265—268
FIGURE 1. Left temporal intermittent rhythmic delta activity associated with mild shaking of the right leg primarily and transient impaired used of the right hand. This occurred intermittently until treatment was initiated.
Case report A 17-year-old Caucasian girl was admitted with a 12-day history of fever (up to 39.4 C), headaches, and a rash. She also complained of vomiting, myalgia, and weakness. There was no history of neurological or other symptoms. She lived in Tampa, Florida, and had returned 12 days earlier from a 2-week holiday in Corpus Christi, Texas. While there, she had adopted a stray kitten that was allegedly free of fleas, though they reported using a flea comb and flea medication on the kitten. Her medical history was not relevant, including her psychiatric history. At admission, her temperature was 38.3 C, heart rate 80 beats/minute, respiratory rate 18 breaths/minute, and blood pressure 84/57 mm Hg. Physical examination revealed an alert and dehydrated female. Her physical examination was normal. Her white blood cell count was 5.6/mm3 (segmented neutrophils 54.1%, lymphocytes 36%, monocytes 9.6%, eosinophils 0.1%, basophils 0.2%), her hemoglobin was 12.8 gm/dL with a relatively low hematocrit of 36.3% (normal: 35—45), and platelet count of 176,000/mm3 (normal: 140-450). The erythrocyte sedimentation rate and C-reactive protein levels were 54 mm/hour (normal
Contents lists available at ScienceDirect
Pediatric Neurology journal homepage: www.elsevier.com/locate/pnu
Clinical Observations
Murine Typhus as a Cause of Cognitive Impairment: Case Report and a Review of the Literature Silvana B. Carr MD a, *, Dale F. Bergamo MD a, Patricia J. Emmanuel MD a, Jose A. Ferreira MD b a b
Pediatric Infectious Diseases Division, University of South Florida College of Medicine, St. Joseph Children’s Hospital, Tampa, Florida Pediatric Epilepsy and Neurology Service, St. Joseph Children’s Hospital, Tampa, Florida
abstract BACKGROUND: Murine typhus is a systemic febrile illness caused by Rickettsia typhi, a gram-negative, obligate intracellular bacterium. It is found worldwide, including in the United States, where cases are concentrated in suburban areas of Texas and California. The disease manifests with fever, headache, and rash. Central nervous system involvement is rare in both adults and children. Aseptic meningitis and meningoencephalitis are the most common neurological presentations, occurring in 2% to 5% of cases. Neurological dysfunction, including memory impairment and behavioral alterations, can occur and usually are reversible. Long-term deficits are considered rare even in untreated cases and have not been described in the pediatric population. METHODS: Single case report. RESULTS: We describe a previously healthy 17-year-old girl infected with R. typhi who developed meningoencephalitis that resulted in chronic cognitive impairment despite treatment. CONCLUSION: Murine typhus should be considered in the differential diagnosis of aseptic meningitis and meningoencephalitis. Early diagnosis and treatment can prevent death and long-term morbidity. Keywords: pediatric, murine typhus, meningoencephalitis, central nervous system
Pediatr Neurol 2014; 50: 265-268 Published by Elsevier Inc.
Introduction
Murine (endemic) typhus is a zoonotic infection caused by Rickettsia typhi, which is an obligate intracellular gramnegative bacterium that depends on hematophagous arthropods (e.g., fleas, ticks) and mammals to maintain its lifecycle. Typically, the lifecycle of R. typhi involves roof rats, Norway rats, and the rat flea.1 Murine typhus has been reported on every continent except Antarctica. In the United States, the disease is endemic in southern Texas, California, and Hawaii, particularly in settings where opossums, cats, and their fleas coexist. In southern Texas, most cases occur between April Article History: Received May 30, 2013; Accepted in final form September 14, 2013 * Communications should be addressed to: Dr. Carr; Assistant Professor; University of South Florida; 17 Davis Blvd, Suite 200; MDC 015; Tampa, FL 33606. E-mail address: [email protected] 0887-8994/$ - see front matter Published by Elsevier Inc. http://dx.doi.org/10.1016/j.pediatrneurol.2013.09.017
and June.1 Although adults are most often affected, up to 75% of infections have occurred in children in some outbreaks.2 Pathologically, typhus and spotted fever groups of diseases induce a systemic endothelial vasculitis affecting multiple organs.3 The usual incubation period for murine typhus is 7 to 10 days. The most common clinical manifestations include fever (98% to 100%), headache (41% to 90%), rash (20% to 80%), and arthralgia (40% to 77%).4 The most frequently described laboratory abnormalities include a mild increase (three to five times the normal) of the liver transaminases.4,5 Complications from murine typhus occur infrequently in children, and central nervous system involvement is unusual.4-7 The diagnosis of acute infection is confirmed by both immunoglobulin M and G antibody titers >1:150 and 1:400, respectively and/or a fourfold increase in titers in a second blood sample.8 Doxycycline, the antibiotic of choice, shortens the course of illness and is life-saving.4
266
S.B. Carr et al. / Pediatric Neurology 50 (2014) 265—268
FIGURE 1. Left temporal intermittent rhythmic delta activity associated with mild shaking of the right leg primarily and transient impaired used of the right hand. This occurred intermittently until treatment was initiated.
Case report A 17-year-old Caucasian girl was admitted with a 12-day history of fever (up to 39.4 C), headaches, and a rash. She also complained of vomiting, myalgia, and weakness. There was no history of neurological or other symptoms. She lived in Tampa, Florida, and had returned 12 days earlier from a 2-week holiday in Corpus Christi, Texas. While there, she had adopted a stray kitten that was allegedly free of fleas, though they reported using a flea comb and flea medication on the kitten. Her medical history was not relevant, including her psychiatric history. At admission, her temperature was 38.3 C, heart rate 80 beats/minute, respiratory rate 18 breaths/minute, and blood pressure 84/57 mm Hg. Physical examination revealed an alert and dehydrated female. Her physical examination was normal. Her white blood cell count was 5.6/mm3 (segmented neutrophils 54.1%, lymphocytes 36%, monocytes 9.6%, eosinophils 0.1%, basophils 0.2%), her hemoglobin was 12.8 gm/dL with a relatively low hematocrit of 36.3% (normal: 35—45), and platelet count of 176,000/mm3 (normal: 140-450). The erythrocyte sedimentation rate and C-reactive protein levels were 54 mm/hour (normal
