Original research article
Prevalence of antibodies against Treponema pallidum among HIV-positive patients in a tertiary care hospital in Mexico
International Journal of STD & AIDS 2015, Vol. 26(2) 81–85 ! The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0956462414530888 std.sagepub.com
Jose´ Antonio Mata-Marı´n1, Juan Joel Sandoval-Sa´nchez2, Gloria Huerta-Garcı´a3, Carla Ileana Arroyo-Anduiza4, Enrique Alcala´-Martı´nez2, Luis Alberto Mata-Marı´n5, Jorge Luis Sandoval-Ramirez1 and Jesu´s Gayta´n-Martı´nez1
Abstract Our objective was to determine the seroprevalence of syphilis among HIV-infected patients in a tertiary care hospital in Mexico City. A cross-sectional study was developed, and 318 HIV-positive patients were evaluated from January to February 2013 at Hospital de Infectologı´a, National Medical Center ‘La Raza’ (a tertiary care hospital specialising in infectious diseases in Mexico City). Laboratory data were screened for the detection of antibodies against Treponema pallidum. Patients completed a questionnaire relating to socio-demographic data and factors associated with syphilis. Of the 318 patients, 83% were men. The mean age SD was 36 11 years; 52% were men who have sex with men and 47% had undertaken higher education. The overall seroprevalence of syphilis among these patients was 25% (95% confidence interval 21%, 30%). Men who have sex with men had a significantly higher seroprevalence (30% vs. 15%, p ¼ 0.009). We conclude that, in Mexico, there is a high seroprevalence of syphilis antibodies in HIV-infected patients and that men who have sex with men are the group most affected.
Keywords HIV, AIDS, sexually transmitted infection, epidemiology, prevalence, Treponema pallidum, syphilis, clinical features, socio-demographic Date received: 27 November 2013; accepted: 10 March 2014
Introduction Syphilis is a global public health problem. About 12 million new infections occur annually worldwide,1 of which 3 million occur in Latin America.2 This sexually transmitted infection (STI) increases the transmissibility of human immunodeficiency virus (HIV), in part because of damage to the mucous membranes and natural epithelial barriers.3 Every patient who has an STI diagnosis should also be tested for HIV antibodies using an enzyme-linked immunosorbent assay, and similarly, every patient diagnosed with HIV infection should be screened for syphilis.4,5 Similar to the HIV epidemic, the current syphilis epidemic affects primarily three groups: men who have sex with men (MSM), injecting drug users and people who engage in sex for money or drugs. A lower proportion of other groups, such as pregnant women and
heterosexuals with low sexual risk behaviour, is also affected by the syphilis epidemic. In most countries, the association between HIV and other STIs including 1 Infectious Diseases Department, Hospital de Infectologı´a, ‘‘La Raza’’ National Medical Center, IMSS, Mexico City, Mexico 2 Epidemiology Department, Hospital de Infectologı´a, ‘‘La Raza’’ National Medical Center, IMSS, Mexico City, Mexico 3 Pediatric Infectious Diseases Department, ‘‘Siglo XXI’’ National Medical Center, IMSS, Mexico City, Mexico 4 Central Blood Bank, ‘‘La Raza’’ National Medical Center, IMSS, Mexico City, Mexico 5 Internal Medicine Department, St. Johannisstift Ev. Krankenhaus Paderborn, Germany
Corresponding author: Jose´ Antonio Mata Marı´n, Instituto Mexicano del Seguro Social. Hospital de Infectologı´a, Centro Me´dico Nacional ‘‘La Raza’’. Seris y Jacarandas s/n, colonia la raza. Del Azcapotzalco, Me´xico D.F. CP 02990, Mexico. Email: [email protected]
Downloaded from std.sagepub.com at CHINESE UNIV HONG KONG LIB on February 5, 2015
82
International Journal of STD & AIDS 26(2)
syphilis has been well described, and the frequency of acquisition of any of these STIs is directly related to the number of sexual partners, other sexual risk practices and sexual identity, among other factors.3 In 2011, the US Centers for Disease Control and Prevention reported that 70% of patients with primary or secondary syphilis in the United States are MSM and that, although the prevalence in women was much lower, it has increased in the past 10 years.6 In Latin America, the syphilis prevalence in MSM varies between 5% and 29%; Argentina and Peru are the countries with the highest prevalence (17% and 29%, respectively). Reinfection has also been shown to be frequent.7 In Mexico, the trend in the number of syphilis infections showed a slight increase from 2000 to 2007. In 2009, 2191 new cases of acquired syphilis were reported with a national rate of 2.0 per 100,000 inhabitants. Of these cases, 56.8% were in women, and the highest prevalence was in the 20–24-year-old age group.8 Of 111,030 blood donors, 471 (0.42%) had positive results when analysed by the Venereal Disease Research Laboratory or the unheated serum reagin tests. One hundred ninety-six were confirmed positive (0.17%) with the fluorescent treponemal antibody absorption test.8 Thus, the seroprevalence in blood donors is about 0.20%. The seroprevalence in the Mexican adult population is 3.1%, with a higher frequency of antibodies in men, people who had sex at an early age, and people who do not use a condom.9 In Tijuana, Mexico, a study showed that HIVpositive clients of female sex workers were more likely to test positive for syphilis (odds ratio 7.53; 95% confidence interval [CI] 1.43, 39.59).10 To our knowledge, there are no published studies that determined the syphilis seroprevalence in HIV-infected patients in Mexico. Given the importance of this disease in HIV-infected people, it is necessary to establish the seroprevalence of syphilis in our population of HIV-infected patients.
Patients and methods Design We conducted a cross-sectional study at the Hospital de Infectologı´ a, ‘La Raza’ Medical Center; this is an infectious diseases tertiary hospital in Mexico City. This hospital receives naı¨ ve and treatment-experienced HIV patients. We assess the clinical and immunological status of the naı¨ ve patients and determine their eligibility for antiretroviral therapy. During the first visit, all outpatients are screened for syphilis antibodies, CD4þ T-cell count, plasma HIV-1 RNA, hepatitis B and C, blood chemistry, liver function tests and blood cell count. The HIV clinic has around 1000 HIV-infected patients.
Patients The institutional review board and ethics committee at Hospital de Infectologı´ a ‘La Raza’ National Medical Center reviewed and approved this study (number 35021, with reference number for approval R-201335021-6). All included patients provided written informed consent to complete a socio-demographic questionnaire. Over a two-month period from 3 December 2012 to 31 January 2013, we randomly selected 334 HIV-positive treatment-naı¨ ve outpatients who were tested for syphilis antibodies (LiaisonÕ Treponema Screen [310840], DiaSorin S.p.A, Saluggia, Italy). Patients were asked to complete a questionnaire to provide epidemiological data; there was a 95.5% response rate (n ¼ 318). A level of anti-Treponema pallidum antibody 1.1 was considered positive; the test sensitivity was 99.4% (95% CI 96.73, 99.98) and specificity was 99.91% (95% CI 99.75, 98.98). Clinical data and laboratory information were obtained from the patients’ records. This information comprised the immunological and virological status at the time of HIV diagnosis and at the time of the data collection. Patients had neither been treated previously for syphilis nor had a previous diagnosis of this disease. Patients completed a questionnaire to identify socio-demographic variables including educational level, Mexico state origin, kind of activity, educational level and place of birth.
Statistical analysis Data entry and analysis were performed using SPSS. The results were summarised using descriptive statistics; medians with interquartile ranges of 25–75% (IQR 25.75) were used for the variables without a normal distribution. The Kolmogorov–Smirnov test was used to determine the integrity of the sampling distributions for the quantitative variables. The Mann–Whitney U and 2 tests were used to compare between patients who were positive and negative for syphilis antibodies. We estimated syphilis seroprevalence in patients with HIV (and 95% CI) with significant p-values
Prevalence of antibodies against Treponema pallidum among HIV-positive patients in a tertiary care hospital in Mexico
International Journal of STD & AIDS 2015, Vol. 26(2) 81–85 ! The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0956462414530888 std.sagepub.com
Jose´ Antonio Mata-Marı´n1, Juan Joel Sandoval-Sa´nchez2, Gloria Huerta-Garcı´a3, Carla Ileana Arroyo-Anduiza4, Enrique Alcala´-Martı´nez2, Luis Alberto Mata-Marı´n5, Jorge Luis Sandoval-Ramirez1 and Jesu´s Gayta´n-Martı´nez1
Abstract Our objective was to determine the seroprevalence of syphilis among HIV-infected patients in a tertiary care hospital in Mexico City. A cross-sectional study was developed, and 318 HIV-positive patients were evaluated from January to February 2013 at Hospital de Infectologı´a, National Medical Center ‘La Raza’ (a tertiary care hospital specialising in infectious diseases in Mexico City). Laboratory data were screened for the detection of antibodies against Treponema pallidum. Patients completed a questionnaire relating to socio-demographic data and factors associated with syphilis. Of the 318 patients, 83% were men. The mean age SD was 36 11 years; 52% were men who have sex with men and 47% had undertaken higher education. The overall seroprevalence of syphilis among these patients was 25% (95% confidence interval 21%, 30%). Men who have sex with men had a significantly higher seroprevalence (30% vs. 15%, p ¼ 0.009). We conclude that, in Mexico, there is a high seroprevalence of syphilis antibodies in HIV-infected patients and that men who have sex with men are the group most affected.
Keywords HIV, AIDS, sexually transmitted infection, epidemiology, prevalence, Treponema pallidum, syphilis, clinical features, socio-demographic Date received: 27 November 2013; accepted: 10 March 2014
Introduction Syphilis is a global public health problem. About 12 million new infections occur annually worldwide,1 of which 3 million occur in Latin America.2 This sexually transmitted infection (STI) increases the transmissibility of human immunodeficiency virus (HIV), in part because of damage to the mucous membranes and natural epithelial barriers.3 Every patient who has an STI diagnosis should also be tested for HIV antibodies using an enzyme-linked immunosorbent assay, and similarly, every patient diagnosed with HIV infection should be screened for syphilis.4,5 Similar to the HIV epidemic, the current syphilis epidemic affects primarily three groups: men who have sex with men (MSM), injecting drug users and people who engage in sex for money or drugs. A lower proportion of other groups, such as pregnant women and
heterosexuals with low sexual risk behaviour, is also affected by the syphilis epidemic. In most countries, the association between HIV and other STIs including 1 Infectious Diseases Department, Hospital de Infectologı´a, ‘‘La Raza’’ National Medical Center, IMSS, Mexico City, Mexico 2 Epidemiology Department, Hospital de Infectologı´a, ‘‘La Raza’’ National Medical Center, IMSS, Mexico City, Mexico 3 Pediatric Infectious Diseases Department, ‘‘Siglo XXI’’ National Medical Center, IMSS, Mexico City, Mexico 4 Central Blood Bank, ‘‘La Raza’’ National Medical Center, IMSS, Mexico City, Mexico 5 Internal Medicine Department, St. Johannisstift Ev. Krankenhaus Paderborn, Germany
Corresponding author: Jose´ Antonio Mata Marı´n, Instituto Mexicano del Seguro Social. Hospital de Infectologı´a, Centro Me´dico Nacional ‘‘La Raza’’. Seris y Jacarandas s/n, colonia la raza. Del Azcapotzalco, Me´xico D.F. CP 02990, Mexico. Email: [email protected]
Downloaded from std.sagepub.com at CHINESE UNIV HONG KONG LIB on February 5, 2015
82
International Journal of STD & AIDS 26(2)
syphilis has been well described, and the frequency of acquisition of any of these STIs is directly related to the number of sexual partners, other sexual risk practices and sexual identity, among other factors.3 In 2011, the US Centers for Disease Control and Prevention reported that 70% of patients with primary or secondary syphilis in the United States are MSM and that, although the prevalence in women was much lower, it has increased in the past 10 years.6 In Latin America, the syphilis prevalence in MSM varies between 5% and 29%; Argentina and Peru are the countries with the highest prevalence (17% and 29%, respectively). Reinfection has also been shown to be frequent.7 In Mexico, the trend in the number of syphilis infections showed a slight increase from 2000 to 2007. In 2009, 2191 new cases of acquired syphilis were reported with a national rate of 2.0 per 100,000 inhabitants. Of these cases, 56.8% were in women, and the highest prevalence was in the 20–24-year-old age group.8 Of 111,030 blood donors, 471 (0.42%) had positive results when analysed by the Venereal Disease Research Laboratory or the unheated serum reagin tests. One hundred ninety-six were confirmed positive (0.17%) with the fluorescent treponemal antibody absorption test.8 Thus, the seroprevalence in blood donors is about 0.20%. The seroprevalence in the Mexican adult population is 3.1%, with a higher frequency of antibodies in men, people who had sex at an early age, and people who do not use a condom.9 In Tijuana, Mexico, a study showed that HIVpositive clients of female sex workers were more likely to test positive for syphilis (odds ratio 7.53; 95% confidence interval [CI] 1.43, 39.59).10 To our knowledge, there are no published studies that determined the syphilis seroprevalence in HIV-infected patients in Mexico. Given the importance of this disease in HIV-infected people, it is necessary to establish the seroprevalence of syphilis in our population of HIV-infected patients.
Patients and methods Design We conducted a cross-sectional study at the Hospital de Infectologı´ a, ‘La Raza’ Medical Center; this is an infectious diseases tertiary hospital in Mexico City. This hospital receives naı¨ ve and treatment-experienced HIV patients. We assess the clinical and immunological status of the naı¨ ve patients and determine their eligibility for antiretroviral therapy. During the first visit, all outpatients are screened for syphilis antibodies, CD4þ T-cell count, plasma HIV-1 RNA, hepatitis B and C, blood chemistry, liver function tests and blood cell count. The HIV clinic has around 1000 HIV-infected patients.
Patients The institutional review board and ethics committee at Hospital de Infectologı´ a ‘La Raza’ National Medical Center reviewed and approved this study (number 35021, with reference number for approval R-201335021-6). All included patients provided written informed consent to complete a socio-demographic questionnaire. Over a two-month period from 3 December 2012 to 31 January 2013, we randomly selected 334 HIV-positive treatment-naı¨ ve outpatients who were tested for syphilis antibodies (LiaisonÕ Treponema Screen [310840], DiaSorin S.p.A, Saluggia, Italy). Patients were asked to complete a questionnaire to provide epidemiological data; there was a 95.5% response rate (n ¼ 318). A level of anti-Treponema pallidum antibody 1.1 was considered positive; the test sensitivity was 99.4% (95% CI 96.73, 99.98) and specificity was 99.91% (95% CI 99.75, 98.98). Clinical data and laboratory information were obtained from the patients’ records. This information comprised the immunological and virological status at the time of HIV diagnosis and at the time of the data collection. Patients had neither been treated previously for syphilis nor had a previous diagnosis of this disease. Patients completed a questionnaire to identify socio-demographic variables including educational level, Mexico state origin, kind of activity, educational level and place of birth.
Statistical analysis Data entry and analysis were performed using SPSS. The results were summarised using descriptive statistics; medians with interquartile ranges of 25–75% (IQR 25.75) were used for the variables without a normal distribution. The Kolmogorov–Smirnov test was used to determine the integrity of the sampling distributions for the quantitative variables. The Mann–Whitney U and 2 tests were used to compare between patients who were positive and negative for syphilis antibodies. We estimated syphilis seroprevalence in patients with HIV (and 95% CI) with significant p-values
