High Incidence, Reinfections, and Active Syphilis in Populations Attending a Specialized HIV Clinic in Mexico, a Dynamic Cohort Study.

Syphilis, a sexually transmitted infection, has reemerged in many vulnerable groups around the world. The objective of the current study was to determine the prevalence and incidence of syphilis among people who attended a specialized HIV clinic in Mexico from 2011 to 2015. Databases from the laboratory were analyzed, and the following four groups were formed: people seeking HIV-1 voluntary counseling and testing (VCT), people in prison (PPr), people living with HIV (PLWH), and patients from primary care clinics (others). The diagnosis of syphilis was made using the reverse algorithm; antibody titers were examined to determine the stage of infection. Baseline data were analyzed and, with follow-up information, a retrospective dynamic cohort was formed. Factors associated with the seroprevalence of syphilis and active syphilis were evaluated by the chi-square test. Moreover, risk factors for the incidence of syphilis were described. A total of 81,863 baseline individuals were analyzed. The seroprevalence of syphilis was 9.9% in the VCT group, 8.2% in the PPr group, 37.0% in the PLWH group, and 8.7% in the others group; the prevalence of active syphilis was 1.7-13.1%. A total of 11,124 people were followed up. The incidence (cases per 100 person-years) was 3.5 among the VCT group, 16.0 among the PLWH group, and < 0.1 among both the PPr and others groups, respectively; moreover, the frequency of reinfections was 11.1-24.4%. The high prevalence and incidence of syphilis, active syphilis, and reinfections among men, transgender people, individuals aged 20-39 years, and people with a history of HIV or hepatitis B suggest that it is critical to improve prevention, diagnosis, and treatment measures to stop the reemergence of syphilis. There are also new factors such as methamphetamine use, group sex, or contacting partners over the internet that are associated with syphilis. In addition, HIV preexposure prophylaxis could contribute to the increased incidence of syphilis by providing false security in the prevention of STIs, thereby increasing risky sexual behaviors.

[High seroprevalence of syphilis and genital herpes in migrants in transit in Chiapas, MexicoAlta soroprevalência de sífilis e herpes genital em migrantes em trânsito por Chiapas, México]. / Alta seroprevalencia de sífilis y herpes genital en migrantes en tránsito en Chiapas, México.

Objectives: To determine the prevalence of antibodies against Treponema pallidum and herpes simplex virus type 2 (HSV-2), and to identify the factors associated with these infections among migrants in transit in Chiapas, Mexico. Methods: Cross-sectional study conducted during 2021-2022, in three migrant shelters in Chiapas, Mexico. Participants answered a questionnaire and provided a blood sample to detect antibodies against Treponema pallidum and HSV-2. The study calculated seroprevalence and assessed associated factors using Chi-square (χ2) tests and odds ratios. Results: A total of 462 migrants participated, with an average age of 31.2 years; 56.9% were women, and 41.1% came from Honduras. The seroprevalence of HSV-2 was 29.9%; for syphilis it was 4.5%, and it was higher in men (8.0%) than in women (1.9%). Among pregnant women, 15.4% had antibodies against syphilis. Notable variables associated with syphilis include being male, having a history of genital lesions, having same-sex partners, and seropositivity to HSV-2. Regarding HSV-2, factors associated with infection included being female, age, schooling, sleeping in the street, a history of HIV testing, early sexual debut, number of sexual partners, and syphilis. Conclusions: A high prevalence of syphilis and HSV-2 was found among the migrant population evaluated. Syphilis is confirmed as a re-emerging infection, even in women. Migrants have vulnerabilities associated with sexual behavior, so prevention, diagnosis, and treatment measures should be focused on this population group.

Objetivos: Determinar a prevalência de anticorpos contra Treponema pallidum e vírus herpes simples tipo 2 (HSV-2) e identificar os fatores associados a essas infecções entre migrantes em trânsito por Chiapas, México. Métodos: Estudo transversal realizado nos anos de 2021 e 2022 em três abrigos de migrantes em Chiapas, México. Os participantes preencheram um questionário e forneceram uma amostra de sangue para a detecção de anticorpos contra Treponema pallidum e HSV-2. Calculou-se a soroprevalência e avaliaram-se os fatores associados usando testes de χ2 e razões de chances. Resultados: O estudou incluiu 462 migrantes com idade média de 31,2 anos, dos quais 56,9% eram mulheres e 41,1% vinham de Honduras. A soroprevalência do HSV-2 foi de 29,9%. A soroprevalência de sífilis, por sua vez, foi de 4,5%, sendo mais alta nos homens (8,0%) do que nas mulheres (1,9%). Os anticorpos contra a sífilis estavam presentes em 15,4% das mulheres grávidas. As principais variáveis associadas à sífilis foram sexo masculino e história de lesões genitais, além de parceiros do mesmo sexo e soropositividade para HSV-2. Com relação ao HSV-2, fatores como sexo feminino, idade, escolaridade, dormir na rua, história de teste de HIV, iniciação sexual precoce, número de parceiros sexuais e sífilis estavam associados a infecção. Conclusões: A população migrante avaliada apresenta alta prevalência de sífilis e HSV-2. Confirmou-se que a sífilis é uma infecção reemergente, inclusive em mulheres. Os migrantes apresentam vulnerabilidades associadas ao comportamento sexual; portanto, é preciso concentrar medidas de prevenção, diagnóstico e tratamento nesse grupo populacional.

Prevalence of anti-SARS-CoV-2 antibodies and associated factors in healthcare workers of a Mexican Covid-19 hospital

OBJECTIVE: To determine the prevalence of SARS-CoV-2 antibodies among healthcare workers (HCW) and to identify factors associated with infection. Materials and meth-ods. A cross-sectional study was conducted in a Covid-19 hospital in Morelos, Mexico. Antibodies against SARS-CoV-2 spike and nucleocapsid proteins were detected by ELISA. A bivariate and multivariable Poisson regression model were performed to identify factors associated with infection. RESULTS: Among all participants, 31% had anti-SARS-CoV-2 antibodies, while only 13.1% had reported a history of positive RT-PCR. Individuals who reported cohabiting with someone with Covid-19, and those who had a previous RT-PCR test, were more likely to be seropositive. Laboratory personnel had the lowest seroprevalence (12.0%), while social workers had the highest (35.7%). CONCLUSIONS: The results of this study show the seroprevalence of SARS-CoV-2 antibodies among HCW in a hospital in Mexico, and underline the importance of serological tests for a better estimate of prevalence in health systems where only symptomatic cases are recorded.

Re-emergence of syphilis in women of reproductive age and its association with the increase in congenital syphilis in Mexico during 2010-2019: an ecological study.

BACKGROUND: Syphilis is a sexually transmitted infection that is re-emerging in different parts of the world. This infection can be transmitted during pregnancy, causing neonatal syphilis. The objective of this study was to examine trend in syphilis, congenital syphilis, and neonatal deaths among the Mexican population during 2010-2019. METHODS: An ecological study was carried out to collect information about the incidence of syphilis, the incidence of congenital syphilis, and the incidence of neonatal death from congenital syphilis. The variables were described considering age, sex, Mexican state, and year. Trends across time (calendar year) were analyzed using linear regression, increases were estimated with 95% confidence intervals, and p < 0.05 was considered statistically significant. RESULTS: The incidence of syphilis increased by an average of 0.336 cases/100,000 per year and was higher among women aged 15-19 years (0.693 cases). Cases of congenital syphilis increased from 62 cases in 2010 to 372 cases in 2019; furthermore, the increase in syphilis cases among women aged 20 to 24 years was associated with an increase in cases of congenital syphilis. In 2010, 50% of Mexican states did not report cases of congenital syphilis, but in 2018, only 10% did not report cases of congenital syphilis. Between 2010 and 2018, 83 neonatal deaths were reported, with the highest incidence in 2018 (0.88 deaths/100,000 newborns). CONCLUSION: The incidence of congenital syphilis is increasing in Mexico. As a consequence of the reemergence of syphilis among the population of reproductive age, it is necessary to address and treat syphilis in various population groups.

Sífilis congénita en México. Análisis de las normas nacionales e internacionales desde la perspectiva del diagnóstico de laboratorio.

INTRODUCTION: Congenital syphilis continues to be a public health problem in Mexico. OBJECTIVE: To assess the similarities and differences between national standards, guidelines and international documents related to the detection of syphilis in pregnant women and congenital syphilis. METHOD: Two algorithms were developed based on the standard of female care during pregnancy and on the standard for prevention and control of sexually transmitted infections. Based on the Centers for Disease Control (CDC) guidelines, algorithms were developed for syphilis during pregnancy, syphilis in the newborn and sexual contacts. RESULTS: The standard for pregnancy mentions that syphilis testing should be carried out in every pregnant woman on her first contact or at delivery, without diagnostic tests being specified. The Official Mexican Standard (NOM) on sexually transmitted infections mentions the traditional algorithm for syphilis detection, treatment follow-up, coinfection with human immunodeficiency virus and congenital syphilis criteria. The CDC recommend reverse algorithm, antibody titer, treatment and follow-up as part of diagnosis. CONCLUSIONS: The elimination of mother-to-child transmission of syphilis requires NOMs updating and homogenizing, as well as the study of stillbirths and neonates born to mothers with syphilis.

INTRODUCCIÓN: La sífilis congénita continúa siendo un problema de salud pública en México. OBJETIVO: Evaluar las similitudes y diferencias entre normas nacionales, guías y documentos internacionales relacionados con la detección de sífilis en embarazadas y sífilis congénita. MÉTODO: Se elaboraron dos algoritmos basados en las normas sobre atención de la mujer durante el embarazo y sobre prevención y control de infecciones de transmisión sexual. A partir de la guía de Centers for Disease Control and Prevention (CDC) se realizaron algoritmos sobre sífilis durante el embarazo, sífilis en recién nacido y contactos sexuales. RESULTADOS: La norma sobre embarazo menciona que la prueba de sífilis debe efectuarse a toda mujer embarazada en su primer contacto o durante el parto, sin especificar pruebas diagnósticas. La norma oficial mexicana (NOM) sobre infecciones de transmisión sexual menciona el algoritmo tradicional para detección de sífilis, seguimiento al tratamiento, coinfección con virus de inmunodeficiencia humana y criterios de sífilis congénita. CDC recomienda algoritmo reverso, título de anticuerpos, tratamiento y seguimiento como parte del diagnóstico. CONCLUSIONES: La eliminación de la transmisión maternoinfantil de sífilis requiere actualizar y homogeneizar las NOM, así como el estudio de mortinatos y de recién nacidos de madres con sífilis.

Congenital syphilis in Mexico. Analysis of national and international standards from the perspective of laboratory diagnosis.

INTRODUCTION: Congenital syphilis continues to be a public health problem in Mexico. OBJECTIVE: To assess the similarities and differences between national standards, guidelines and international documents related to the detection of syphilis in pregnant women and congenital syphilis. METHOD: Two algorithms were developed based on the standard of female care during pregnancy and on the standard for prevention and control of sexually transmitted infections. Based on the Centers for Disease Control (CDC) guidelines, algorithms were developed for syphilis during pregnancy, syphilis in the newborn and sexual contacts. RESULTS: The standard for pregnancy mentions that syphilis testing should be carried out in every pregnant woman on her first contact or at delivery, without diagnostic tests being specified. The Official Mexican Standard (NOM) on sexually transmitted infections mentions the traditional algorithm for syphilis detection, treatment follow-up, coinfection with human immunodeficiency virus and congenital syphilis criteria. The CDC recommend reverse algorithm, antibody titer, treatment and follow-up as part of diagnosis. CONCLUSIONS: The elimination of mother-to-child transmission of syphilis requires NOMs updating and homogenizing, as well as the study of stillbirths and neonates born to mothers with syphilis.

Punto Seguro: A Randomized Controlled Pilot Using Conditional Economic Incentives to Reduce Sexually Transmitted Infection Risks in Mexico.

Randomized controlled pilot evaluated effect of conditional economic incentives (CEIs) on number of sex partners, condom use, and incident sexually transmitted infections (STIs) among male sex workers in Mexico City. Incentives were contingent on testing free of new curable STIs and/or clinic attendance. We assessed outcomes for n = 227 participants at 6 and 12 months (during active phase with incentives), and then at 18 months (with incentives removed). We used intention-to-treat and inverse probability weighting for the analysis. During active phase, CEIs increased clinic visits (10-13 percentage points) and increased condom use (10-15 percentage points) for CEI groups relative to controls. The effect on condom use was not sustained once CEIs were removed. CEIs did not have an effect on number of partners or incident STIs. Conditional incentives for male sex workers can increase linkage to care and retention and reduce some HIV/STI risks such as condomless sex, while incentives are in place.

High Prevalence of Syphilis and Syphilis/HIV Coinfection among Men Who Have Sex with Men Who Attend Meeting Places in Mexico.

Men who have sex with men (MSM) are disproportionately affected by syphilis, HIV, and syphilis/HIV coinfection. Antiretroviral therapy (ART) prevents HIV transmission but does not impede the spread or acquisition of syphilis. Information about syphilis/HIV coinfection among MSM is scarce. We aimed to determine the prevalence of syphilis/HIV coinfection in a national sample of MSM who attend meeting places (such as movies, clubs, gay bars, saunas, shopping malls, and others referred to by the same MSM participants of the study) in Mexico to evaluate factors associated with syphilis, and to compare the prevalence rates of syphilis between the current survey and DGE data. We performed a laboratory diagnosis to determine the rates of syphilis and HIV among the included MSM. The national and regional prevalence of syphilis was calculated. HIV and coinfection prevalence were determined only for the survey. All prevalence rates included 95%CIs. Descriptive, bivariate, and multivariate analyses were performed. The national prevalence rates of syphilis, HIV, and coinfection were 15.2%, 10.2%, and 5.7%, respectively. The region with the highest prevalence rate was Mexico City (39.4%). The center region, minimal "goods" (i.e., a minimal number of material possessions such as a car or dryer, etc., which served as a proxy for low economic income level), use of "inhalant drugs", "HIV infection", "sexual intercourse" only with men, "rewarded sex", and "youngest age at first sexual encounter or debut" were risk factors for syphilis. In general, regional prevalence of syphilis was higher in the survey (2013) and DGE data from 2019 than in the DGE data from 2013. Similar to other countries, Mexico needs to assess elements around not only syphilis and HIV infections but also syphilis/HIV coinfection, and preventive measures focusing on MSM are needed.

Seroprevalence and Vaginal Shedding of Herpes Simplex Virus Type 2 in Pregnant Adolescents and Young Women from Morelos, Mexico.

Adolescents and young people are particularly vulnerable to contracting STIs, including HSV-2; furthermore, vaginal shedding of HSV-2 during pregnancy can cause vertical transmission and neonatal herpes. To evaluate the seroprevalence of HSV-2 and vaginal HSV-2 shedding in adolescent and young pregnant women, a cross-sectional study was carried out in 496 pregnant women-adolescents and young women. Venous blood and vaginal exudate samples were taken. The seroprevalence of HSV-2 was determined by ELISA and Western blot. Vaginal HSV-2 shedding was assessed by qPCR of the HSV-2 UL30 gene. The seroprevalence of HSV-2 in the study population was 8.5% (95% CI 6-11), of which 38.1% had vaginal HSV-2 shedding (95% CI 22-53). Young women presented a higher seroprevalence of HSV-2 (12.1%) than adolescents (4.3%), OR = 3.4, 95% CI 1.59-7.23. Frequent alcohol consumption was significantly associated with HSV-2 seroprevalence, OR = 2.9, 95% CI 1.27-6.99. Vaginal HSV-2 shedding is highest in the third trimester of pregnancy, but this difference is not significant. The seroprevalence of HSV-2 in adolescents and young women is similar to that previously reported in other studies. However, the proportion of women with vaginal shedding of HSV-2 is higher during the third trimester of pregnancy, increasing the risk of vertical transmission.

[Native and non-native antigen to determine the seroprevalence of Trypanosoma cruzi in pregnant women from the state of Morelos, Mexico]. / Antígeno nativo y no nativo para determinar la seroprevalencia de Trypanosoma cruzi en mujeres embarazadas en el estado de Morelos, México.

BACKGROUND: Chagas disease is a globally important chronic systemic parasitic infection caused by Trypanosoma cruzi. AIM: To determine the prevalence of antibodies against T cruzi in pregnant women from the state of Morelos, México. METHODS: 1,620 sera from pregnant women were analyzed using two serological tests: ELISAc (native crude antigen) and ELISAr (recombinant, non-native antigen). Reactive samples were subsequently analyzed by indirect hemagglutination (IHA). Two detection approaches were used, in parallel (reactive samples by any method are positive) and serial (samples confirmed by IHA are positive). Sociodemographic and health factors associated with the presence of antibodies against T cruzi were evaluated using 95% odds ratios. RESULTS: A seroprevalence of 4.87% was obtained with parallel diagnosis and 0.43% in series. From the parallel results, the women who were attended at the general hospitals of Tetecala and Jojutla had respectively 2.2 and 2.0 times greater chance of presenting antibodies against T cruzi compared to the women who were attended at the General Hospital of Cuautla. CONCLUSION: The prevalence of antibodies against T cruzi in pregnant women from the state of Morelos fluctuated between 0.43 and 4.87%, depending on the antigen and the approach used. It is necessary to continue with the surveillance of the seroprevalence of antibodies against T cruzi in pregnant women from the state of Morelos, Mexico, using the techniques with the highest sensitivity and specificity available.

Low Seroprevalence of Measles-Specific IgG in Children of Three Ethnic Groups from Mexico: Influence of Age, Sex, Malnutrition and Family Size.

BACKGROUND: The reemergence of measles represents a public health problem. The aim of the study was to determine the seroprevalence of IgG antibodies against measles in children of three ethnic groups in southern Mexico and the nutritional status and demographic risk factors associated. METHODS: A cross-sectional study in 416 school-age children, 207 belonging to the Tlapaneco ethnic group, 101 to the Mixteco group and 108 were considered Mestizo. Sociodemographic data were collected, an anthropometric evaluation of the children was performed and a fasting blood sample was obtained from each child for the measurement of measles IgG antibodies by Enzyme-Linked Immunosorbent Assay (ELISA). RESULTS: From the total sample, 59% of the children were seropositive for IgG antibodies against measles; in contrast, 41% lacked IgG antibodies. Measles antibody seropositivity was higher in girls (64%). 90.5% of 6-year-old children had higher antibodies seroprevalence, compared to the children between 10 and 13 years old (45.5%). In the three ethnic groups, age was negatively correlated with the index standard ratio (ISR) of measles antibody levels and the families with ≥8 members showed less seropositivity. According to the antibodies levels, most of the positive cases remained around 1 Standard Deviation (SD) of the ISR values and no underweight children had antibody levels above 2 SD. CONCLUSIONS: The Anti-Measles serological coverage is low in children of three ethnic groups from Southern Mexico and the age, sex, malnutrition and family size are associated factors. Therefore, it is important to strengthen immunization campaigns, principally in vulnerable groups.

Evaluation of an HIV recent infection testing algorithm with serological assays among men who have sex with men in Mexico.

BACKGROUND: Human immunodeficiency virus (HIV) incidence should be calculated in cross-sectional studies using recent infection testing algorithms (RITA) that consider clinical variables and serological test results such as enzyme-linked immunosorbent assay (ELISA) and dried blood spot (DBS) analysis. METHODS: The correlation between serum samples and DBS was evaluated using two commercial ELISA kits: SediaTM BED HIV-1 Incidence EIA (BED-Sedia) and Maxim HIV-1 Limiting Antigen Avidity (LAg-Avidity). Eight different RITAs were developed; all of them included serological assays. A combination of the variables viral load, antiretroviral therapy (ART) and CD4 count was used to build the RITAs. The sensitivity, specificity, Youden index, predictive positive value, predictive negative value, false recent rate (FRR) and false long-term rate were evaluated. RESULTS: The correlations between serum samples and DBS were 0.990 and 0.867 for BED-Sedia and LAg-avidity, respectively. Using only serological assays, the Youden index was higher for LAg-avidity than BED-Sedia (82.1-83.0% versus 69.2-69.6%). The best RITA was ART-serology, which showed a Youden index of 91.2-93.9% and FRR of 1.8-2.2%. CONCLUSIONS: Using DBS samples to determine HIV incidence is a good tool for epidemiological surveillance. The RITA that included ART and serological tests (BED-Sedia or LAg-avidity) showed the highest sensitivity and specificity and a low FRR.

Performance of ELISA and Western blot to detect antibodies against HSV-2 using dried blood spots.

BACKGROUND AND AIMS: Herpes simplex virus type 2 (HSV-2) is a sexually transmitted agent and is detected worldwide. HSV-2 is the main cause of genital ulcers and is diagnosed mainly with serological tests. The objective of current study was to evaluate the use of DBS samples to detect HSV-2 antibodies using commercial ELISA and Western blot tests. MATERIALS AND METHODS: IgG-G2 ELISA (Human® Diagnostics, Germany) and Western blot IgG/IgM (EUROLINE-WB, Euroimmun® Germany) tests were modified to use DBS samples. Samples were processed by both methods to determine ELISA cutoff points using ROC curves. ELISA was performed with 100µl and the Western blot with 200µl of eluted DBS. A 1:5 dilution was used and the incubation times were increased for the Western blot. RESULTS: 908 DBS samples were processed and the following cutoff points were determined: negative (0-3.79), undetermined (3.8-4.6) and positive (≥4.61), with sensitivity and specificity close to 95%. CONCLUSION: Modifications of the cutoff points of the ELISA test were obtained with technical adjustments done to detect HSV-2 antibodies by ELISA and Western blot using DBS samples.

Hepatitis B seroprevalence in 10-25-year-olds in Mexico - the 2012 national health and nutrition survey (ENSANUT) results.

OBJECTIVES: To estimate hepatitis B virus (HBV) seroprevalence from natural infection or vaccination in 10-25-year-olds in Mexico, using the 2012 National Health and Nutrition Survey (ENSANUT). METHODS: Randomly selected serum samples (1,581) from adolescents and young adults, representative of 38,924,584 Mexicans, were analyzed to detect hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs) and hepatitis B core antibody (anti-HBc). Weighted HBV seroprevalence in the Mexican population and association with sociodemographic variables were calculated. RESULTS: Overall weighted seroprevalence from natural infection (positive for anti-HBs and anti-HBc) was 0.23% (95% confidence interval [95% CI] 0.10-0.52). No HBsAg was detected, indicating no acute or chronic infection. Vaccine-derived immunity (positive ≥ 10.0 mIU/ml for anti-HBs and negative to anti-HBc) was 44.7% (95% CI: 40.2-49.4) overall; lower in persons aged 20-25 years (40.83%) than in persons aged 10-19 years (47.7%). Among the population analyzed, 54.2% (95% CI: 49.6-58.8) were seronegative to HBV (negative for all three markers) and no sociodemographic risk factors were identified. CONCLUSIONS: HBV seroprevalence from natural infection was low. Vaccination-induced immunity was higher among Mexican adolescents than young adults, possibly due to vaccination policies since 1999.

Alta seroprevalencia de sífilis y herpes genital en migrantes en tránsito en Chiapas, México / High seroprevalence of syphilis and genital herpes in migrants in transit in Chiapas, Mexico / Alta soroprevalência de sífilis e herpes genital em migrantes em trânsito por Chiapas, México

RESUMEN Objetivos. Determinar la prevalencia de anticuerpos contra Treponema pallidum y virus herpes simple tipo 2 (VHS-2), así como identificar los factores asociados a dichas infecciones entre migrantes en tránsito en Chiapas, México. Métodos. Estudio transversal realizado durante 2021-2022, en tres albergues para migrantes en Chiapas, México. Las personas contestaron un cuestionario y proporcionaron una muestra de sangre para la detección de anticuerpos contra Treponema pallidum y VHS-2. Se calculó la seroprevalencia y se evaluaron los factores asociados mediante pruebas de χ2 y razones de momios. Resultados. Participaron 462 migrantes, con edad promedio de 31,2 años, 56,9 % eran mujeres, 41,1 % provenían de Honduras. La seroprevalencia de VHS-2 fue 29,9 % mientras que la de sífilis fue 4,5 %, siendo mayor en hombres (8,0 %) que en mujeres (1,9 %). El 15,4 % de las embarazadas presentaban anticuerpos contra sífilis. Entre las variables asociadas a sífilis destacan el ser hombre, antecedente de lesiones genitales, así como tener parejas del mismo sexo y la seropositividad a VHS-2. Con relación al VHS-2, factores como ser mujer, edad, escolaridad, dormir en la calle, antecedente de prueba de VIH, debut sexual temprano, número de parejas sexuales y sífilis estuvieron asociados a la infección. Conclusiones. Se encontró una prevalencia elevada de sífilis y VHS-2 entre la población migrante evaluada. La sífilis se confirma como una infección reemergente, incluso en las mujeres. Los migrantes presenta vulnerabilidades asociadas al comportamiento sexual, por lo que se deben enfocar medidas de prevención, diagnóstico y tratamiento para este grupo poblacional.

ABSTRACT Objectives. To determine the prevalence of antibodies against Treponema pallidum and herpes simplex virus type 2 (HSV-2), and to identify the factors associated with these infections among migrants in transit in Chiapas, Mexico. Methods. Cross-sectional study conducted during 2021-2022, in three migrant shelters in Chiapas, Mexico. Participants answered a questionnaire and provided a blood sample to detect antibodies against Treponema pallidum and HSV-2. The study calculated seroprevalence and assessed associated factors using Chi-square (χ2) tests and odds ratios. Results. A total of 462 migrants participated, with an average age of 31.2 years; 56.9% were women, and 41.1% came from Honduras. The seroprevalence of HSV-2 was 29.9%; for syphilis it was 4.5%, and it was higher in men (8.0%) than in women (1.9%). Among pregnant women, 15.4% had antibodies against syphilis. Notable variables associated with syphilis include being male, having a history of genital lesions, having same-sex partners, and seropositivity to HSV-2. Regarding HSV-2, factors associated with infection included being female, age, schooling, sleeping in the street, a history of HIV testing, early sexual debut, number of sexual partners, and syphilis. Conclusions. A high prevalence of syphilis and HSV-2 was found among the migrant population evaluated. Syphilis is confirmed as a re-emerging infection, even in women. Migrants have vulnerabilities associated with sexual behavior, so prevention, diagnosis, and treatment measures should be focused on this population group.

RESUMO Objetivos. Determinar a prevalência de anticorpos contra Treponema pallidum e vírus herpes simples tipo 2 (HSV-2) e identificar os fatores associados a essas infecções entre migrantes em trânsito por Chiapas, México. Métodos. Estudo transversal realizado nos anos de 2021 e 2022 em três abrigos de migrantes em Chiapas, México. Os participantes preencheram um questionário e forneceram uma amostra de sangue para a detecção de anticorpos contra Treponema pallidum e HSV-2. Calculou-se a soroprevalência e avaliaram-se os fatores associados usando testes de χ2 e razões de chances. Resultados. O estudou incluiu 462 migrantes com idade média de 31,2 anos, dos quais 56,9% eram mulheres e 41,1% vinham de Honduras. A soroprevalência do HSV-2 foi de 29,9%. A soroprevalência de sífilis, por sua vez, foi de 4,5%, sendo mais alta nos homens (8,0%) do que nas mulheres (1,9%). Os anticorpos contra a sífilis estavam presentes em 15,4% das mulheres grávidas. As principais variáveis associadas à sífilis foram sexo masculino e história de lesões genitais, além de parceiros do mesmo sexo e soropositividade para HSV-2. Com relação ao HSV-2, fatores como sexo feminino, idade, escolaridade, dormir na rua, história de teste de HIV, iniciação sexual precoce, número de parceiros sexuais e sífilis estavam associados a infecção. Conclusões. A população migrante avaliada apresenta alta prevalência de sífilis e HSV-2. Confirmou-se que a sífilis é uma infecção reemergente, inclusive em mulheres. Os migrantes apresentam vulnerabilidades associadas ao comportamento sexual; portanto, é preciso concentrar medidas de prevenção, diagnóstico e tratamento nesse grupo populacional.

Hepatitis A seroprevalence in adolescents and young adults in Mexico: A 2012 National Health and Nutrition Survey analysis.

To describe hepatitis A virus (HAV) seroprevalence and associated factors in adolescents (10-19 years) and young adults (20-25 years) in different Mexican regions, using 2012 National Health and Nutrition Survey data. A random selection of 1581 serum samples was analyzed. Weighted HAV seroprevalence with 95% confidence intervals (95%CI) and its association with sociodemographic factors were estimated. Mean weighted HAV seroprevalence was 69.3% (95%CI: 64.8-73.4) overall, with 58.8% (95%CI: 53.4-64.1) in adolescents and 83.0% (95%CI: 75.3-88.7) in young adults. By age of 10, 46.7% (95%CI: 33.9-60.0) were seropositive and by age of 15, 52.8% (95%CI: 36.5-68.5), corresponding to intermediate endemicity nationally. Factors associated with HAV seropositivity (adjusted odds ratio, aOR) included: lower socioeconomic status (SES) (aOR = 4.09 for low and aOR = 2.31 for medium versus high SES), older age (aOR = 0.29 for adolescents versus young adults), living in the South (aOR = 2.12 versus Central Mexico) or in rural areas (aOR = 2.25 versus urban areas). Regional differences and increased seroprevalence of HAV in marginalized populations present an important public health issue, as a relatively large proportion of young adults are susceptible to infection. The burden of symptomatic disease must be addressed further to support specific programs of continued sanitation and education improvement, and the possibility of vaccination in more susceptible regions.

Evaluation of a rapid strip and a particle agglutination tests for syphilis diagnosis.

The availability of new diagnostic approaches, which are easier and faster to perform than conventional tests, offers the opportunity to improve the attention given to public health problems as syphilis. This study aimed to evaluate a rapid immunochromatographic strip test (Determine TP; Abbott Laboratories, Chicago, IL) and a nonequipment demanding particle microagglutination test (Serodia TP-PA; Fujirebio, Japan) for qualitative detection of treponemic antibodies. Sera from 548 women belonging to 3 population groups were tested; one of them showing low syphilis seroprevalence (1.5%) and the other 2 showing higher seroprevalences (>15%). By comparison with the gold standard (Venereal Disease Research Laboratories plus fluorescent treponemal antibody absorption), sensitivity and specificity values for both diagnostic tests were calculated. Sensitivity values of both tests evaluated were higher than 95% for 2 groups of 3 addressed; in one of the high syphilis prevalence groups, Serodia TP-PA showed 88.6% sensitivity. Specificity values were above 95% for all 3 groups. The use of simple/rapid treponemic tests as those included here may prove to be a suitable replacement for the traditional syphilis serology diagnosis approach, particularly at primary care settings.

Antígeno nativo y no nativo para determinar la seroprevalencia de Trypanosoma cruzi en mujeres embarazadas en el estado de Morelos, México / Native and non-native antigen to determine the seroprevalence of Trypanosoma cruzi in pregnant women from the state of Morelos, Mexico

INTRODUCCIÓN: La enfermedad de Chagas es una infección parasitaria crónica sistémica, de importancia global, causada por Trypanosoma cruzi. OBJETIVO: Determinar la prevalencia de anticuerpos contra T cruzi en mujeres embarazadas en el estado de Morelos, México. MATERIALES Y MÉTODOS: Se analizaron 1.620 sueros de mujeres embarazadas mediante dos pruebas serológicas: ELISAc (antígeno crudo nativo) y ELISAr (antígeno recombinante, no nativo). Las muestras reactivas se analizaron posteriormente mediante hemaglutinación indirecta (HAI). Se utilizaron dos enfoques de detección, en paralelo (son positivas las muestras reactivas por cualquier método) y en serie (son positivas las muestras confirmadas por HAI). Se evaluaron factores sociodemográficos y de salud asociados a la presencia de anticuerpos contra T. cruzi mediante razones de momios al 95%. RESULTADOS: Se obtuvo una seroprevalencia de 4,87% con el diagnóstico en paralelo y de 0,43% en serie. A partir de los resultados en paralelo las mujeres que fueron atendidas en los hospitales generales de Tetecala y Jojutla tuvieron, respectivamente, 2,2 y 2,0 veces mayor posibilidad de presentar anticuerpos contra T cruzi con respecto a las mujeres que fueron atendidas en el Hospital General de Cuautla. CONCLUSIÓN: La prevalencia de anticuerpos contra T cruzi en mujeres embarazadas en el estado de Morelos fluctuó entre 0,43 y 4,87%, según el antígeno y el abordaje utilizado. Es necesario continuar con la vigilancia de la seroprevalencia de anticuerpos contra T cruzi en mujeres embarazadas en el estado de Morelos, México, con las técnicas de mayor sensibilidad y especificidad disponibles.

BACKGROUND: Chagas disease is a globally important chronic systemic parasitic infection caused by Trypanosoma cruzi. AIM: To determine the prevalence of antibodies against T cruzi in pregnant women from the state of Morelos, México. METHODS: 1,620 sera from pregnant women were analyzed using two serological tests: ELISAc (native crude antigen) and ELISAr (recombinant, non-native antigen). Reactive samples were subsequently analyzed by indirect hemagglutination (IHA). Two detection approaches were used, in parallel (reactive samples by any method are positive) and serial (samples confirmed by IHA are positive). Sociodemographic and health factors associated with the presence of antibodies against T cruzi were evaluated using 95% odds ratios. RESULTS: A seroprevalence of 4.87% was obtained with parallel diagnosis and 0.43% in series. From the parallel results, the women who were attended at the general hospitals of Tetecala and Jojutla had respectively 2.2 and 2.0 times greater chance of presenting antibodies against T cruzi compared to the women who were attended at the General Hospital of Cuautla. CONCLUSION: The prevalence of antibodies against T cruzi in pregnant women from the state of Morelos fluctuated between 0.43 and 4.87%, depending on the antigen and the approach used. It is necessary to continue with the surveillance of the seroprevalence of antibodies against T cruzi in pregnant women from the state of Morelos, Mexico, using the techniques with the highest sensitivity and specificity available.

Congenital syphilis in Mexico. Analysis of national and international standards from the perspective of laboratory diagnosis

Introduction: Congenital syphilis continues to be a public health problem in Mexico. Objective: To assess the similarities and differences between national standards, guidelines and international documents related to the detection of syphilis in pregnant women and congenital syphilis. Method Two algorithms were developed based on the standard of female care during pregnancy and on the standard for prevention and control of sexually transmitted infections. Based on the Centers for Disease Control (CDC) guidelines, algorithms were developed for syphilis during pregnancy, syphilis in the newborn and sexual contacts. Results: The standard for pregnancy mentions that syphilis testing should be carried out in every pregnant woman on her first contact or at delivery, without diagnostic tests being specified. The Official Mexican Standard (NOM) on sexually transmitted infections mentions the traditional algorithm for syphilis detection, treatment follow-up, coinfection with human immunodeficiency virus and congenital syphilis criteria. The CDC recommend reverse algorithm, antibody titer, treatment and follow-up as part of diagnosis. Conclusions: The elimination of mother-to-child transmission of syphilis requires NOMs updating and homogenizing, as well as the study of stillbirths and neonates born to mothers with syphilis.

Serosurvey of antibodies against Toxoplasma gondii and Neospora caninum in white-tailed deer from Northern Mexico.

The objective of this study was to determine the seroprevalence of Toxoplasma gondii and Neospora caninum in white-tailed deer from Northern Mexico. Sera from 532 white-tailed deer (Odocoileus virginianus) from three Northern states of Mexico were assayed for antibodies to T. gondii by ELISA and western blot. From these samples, 368 were available to test for N. caninum antibodies by ELISA. The overall prevalence for T. gondii antibodies was 13.9% (74/532; CI(95) 11-17) and for N. caninum 8.4% (31/368; CI(95) 6-12). There was a significant association between positive ELISA results for T. gondii, with management factors within ranches, such number of deer per hectare and geographic location of deer, but none for N. caninum. T. gondii infection in the deer from Guerrero, Coahuila had an increased risk than those from Nuevo Laredo, Tamaulipas (OR, 8.3; CI(95) 1.9-35.4; P<0.05) and ranches with one deer in 15 ha had increased risk of positive association (OR, 2.61; CI(95) 1.5-4.4; P<0.05). These findings may have environmental or public health implications because venison can be an important meat source of T. gondii infections for humans and feral cats.