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.

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.

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 Chia-pas, 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 (chi 2) 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 syphi-lis. 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.

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.

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.

Background. Syphilis 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 2011-2015. Methods. Databases from the laboratory were analyzed and 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). Syphilis diagnosis was made using the reverse algorithm; antibody titers were examined to determine the stage of infection. Baseline data was analyzed, and with follow-up information, a retrospective dynamic cohort was formed. Factors associated with seroprevalence of syphilis and active syphilis were evaluated by the chi-square test. Moreover, risk factors for the incidence of syphilis were described. Results. A total of 81,863 baseline individuals were analyzed. Syphilis seroprevalence was 9.9% in VCT, 8.2% in PPr, 37.0% in PLWH, and 8.7% in others; the prevalence of active syphilis was 1.7-13.1%. A total of 11,124 people were followed-up; the incidence (cases per 100 years people) was 3.5 among VCT and 16.0 among PLWH; moreover, the frequency of re-infections was 11.1-24.4%. Men, transgender, persons between 20-39 years old, and individuals with a history of HIV or hepatitis B had a higher risk of syphilis. Conclusions. Several vulnerable groups have exhibited a reemergence of syphilis, with high prevalence of active syphilis, high incidence, and re-infections. Persons living with HIV had the highest risk.

Objective. To determine the prevalence of SARS-CoV-2 antibodies among healthcare workers (HCW) and to identify factors associated with infection. Materials and methods. 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.

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.

Chagas disease is a globally important chronic systemic parasitic infection caused by Trypanosoma cruzi.To determine the prevalence of antibodies against T cruzi in pregnant women from the state of Morelos, México.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.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.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.

Much is known about the natural history of syphilis; however, less is known about the immune response against it, and even less is known about people living with HIV (PLWH). Due to the lack of an animal model to study host-pathogen interactions, it remains unclear how the host eliminates the bacteria. Here, we attempt to elucidate the immune response against infection by summarizing all the reported data in a systematic review. We found that only seven papers included PLWH, and they did not accurately describe the immune response against Treponema pallidum since only lymphopenia was reported upon coinfection. On the other hand, at least sixteen papers described the host-pathogen interaction in individual cell populations. Using this information, we established the kinetics of the immune response against syphilis and hypothesized how CD4+ T cells, such as Th17 and T rex cells, worsen the progression of the disease in PLWH through their hallmark cytokines, IL-10 and IL-17, and how these two cytokines may play important roles as biomarkers.

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.

Background HIV incidence can be estimated with cross-sectional studies using clinical, serological, and molecular data. Worldwide, HIV incidence data in only men who have sex with men (MSM) are scarce and principally focus on those with healthcare or under treatment. However, better estimates can be obtained through studies with national representativeness. The objective was to estimate the prevalence, incidence, and factors associated with acquiring HIV in a national sample of MSM who attend meeting places, considering geographical regions. Methods A nationally representative survey of MSM attending meeting places was performed in Mexico. Participants answered a questionnaire, and a dried blood spot (DBS) was collected. Samples were classified as recent infections using an algorithm with HIV status, antiretroviral therapy, and the result of BED-EIA assay. Parameters were analysed considering regions and demographic and sexual behaviour characteristics. Results The national HIV prevalence was 17.4% with regional differences; the highest prevalence (20.7%) was found in Mexico City, and the lowest prevalence was found in the West region (11.5%). The incidence was 9.4 per 100 p/y, with regional values from 6.2 to 13.2 for the Northeast and the Centre regions, respectively. Age, age at sexual debut, low wealth index, and rewarded sex were associated with HIV prevalence. Centre region, use of private clinics as health services, and having sex exclusively with men were associated with recent HIV infections. Conclusions The incidence and prevalence showed regional differences, suggesting a difference in the dynamics of HIV transmission; some regions have a greater case accumulation, and others have a greater rate of new infections. Understanding this dynamic will allow developing health programs focused on HIV prevention or treating people already living with HIV.

Kaposi's sarcoma‐associated herpesvirus (KSHV) is an oncogenic virus associated with several human malignancies. KSHV lytic replication promotes the spread of infection and progression of KSHV‐associated malignancies; however, the mechanism regulating KSHV lytic replication remains unclear. In this study, we investigated the role of nitric oxide (NO) in KSHV lytic replication. In the TREx BCBL1‐RTA KSHV lytic replication cell system, induction of KSHV lytic replication increased intracellular and extracellular NO. Chemical inhibition of NO production resulted in a lower level of KSHV lytic replication as shown by a reduced level of infectious virions, and decreased levels of viral lytic transcripts and proteins. In a second KSHV lytic replication system of iSLK‐RGB‐BAC16 cells, we confirmed that KSHV lytic replication increased NO production. Chemical inhibition of NO production resulted in reduced numbers of cells expressing enhanced green fluorescent protein and blue fluorescent protein, two reporters that closely track the expression of KSHV early and late genes, respectively. Consistent with these results, inhibition of NO production resulted in reduced levels of infectious virions, and viral lytic transcripts and proteins. Importantly, exogenous addition of a NO donor was sufficient to enhance the full KSHV lytic replication program. These results demonstrate that NO is required for efficient KSHV lytic replication, and NO plays a crucial role in the KSHV life cycle and KSHV‐induced malignancies.

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.

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.

Background Herpes simplex virus type 2 (HSV-2) seroprevalence and associated infection risk factors show differences by regions and countries. The aims of the study were to determine the HSV-2 seroprevalence and to evaluate the risk factors for HSV-2 in a national representative survey among adolescents and adults in Mexico. Methods A cross-sectional study was carried out in Mexico on the basis of the National Health and Nutrition Survey 2012, a national representative survey. Demographic, sexual behavior, reproductive health, and lifestyles indicators were considered in the current study. Participants provided biological samples—dried blood spots—to test for HSV-2 antibodies using enzyme-linked immunosorbent assay and Western blot. Bivariate and multivariate analyses were performed to identify variables associated with HSV-2 infections analyzed by sex. Results National HSV-2 seroprevalence was 9.9%, 2.4% among adolescents and 11.7% among adults with HSV-2 seroprevalence heterogeneous across the country. Women had 12.2% of antibodies against HSV-2 and men had 7.5%. The factors associated with HSV-2 infection among women were age (45–49 years; odds ratio [OR], 19.8), region (southwest; OR, 3.0), urbanization (urban; OR, 1.9), age at sexual debut (≤14 years; OR, 3.4), education level (any; OR, 3.0), and previous abortion (≥2 abortion; OR, 2.1). Among men, age (45–49 years; OR, 11.7), region (southwest; OR, 3.0), urbanization (urban, odds ratio [OR], 1.7), and HIV care (OR, 7.1) were associated with the infection. Conclusions Approximately 10% of Mexicans aged 15 to 49 years had HSV-2 antibodies, with differences by sex, region, education level, urbanization, HIV care, and childbirth, highlighting the relevance of health inequalities in the country: social inequalities seem to matter in terms of the probability of HSV-2 infections.

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 (R) Diagnostics, Germany) and Western blot IgG/IgM (EUROLINE-WB, Euroimmun (R) 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 100 mu l and the Western blot with 200 mu l 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. (C) 2018 The Authors. Published by Elsevier Limited on behalf of King Saud Bin Abdulaziz University for Health Sciences. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

This study shows the relative quantification of HSV‐2 by qPCR, using the MIQE Guidelines. The reaction efficiency was evaluated, and the relative quantification used the R = 2−ΔCq method. The relative quantification of HSV‐2 was conducted with anal and genital samples from men who have sex with men (MSM), living with HIV. The presence of a single amplification product was validated with a dissociation curves profile and the determination of the melting temperature. The limit of detection for β‐globin was determined as 3.3 × 10−5 ng/μL, and for HSV‐2 at 6.0 × 10−6 ng/μL. The efficiency for β‐globin was 100.2% and for HSV‐2 was 106.8%. From 336 MSM, 2.1% and 3.9% individuals presented anal or genital HSV‐2 shedding, respectively. The HSV‐2 viral load was 9.2 RU, individuals with fewer CD4+ presented higher HSV‐2 viral load. The qPCR method is reproducible and has optimal reaction efficiency.

Allatotropins (AT) are neuropeptides with pleotropic functions on a variety of insect tissues. They affect processes such as juvenile hormone biosynthesis, cardiac rhythm, oviduct and hindgut contractions, nutrient absorption and circadian cycle. The present work provides experimental evidence that AT elicits immune responses in two important mosquito disease vectors, Anopheles albimanus and Aedes aegypti. Hemocytes and an immune-competent mosquito cell line responded to AT by showing strong morphological changes and increasing bacterial phagocytic activity. Phenoloxidase activity in hemolymph was also increased in Ae. aegypti mosquitoes treated with AT but not in An. albimanus, suggesting differences in the AT-dependent immune activation in the two species. In addition, two important insect immune markers, nitric oxide levels and expression of antimicrobial peptide genes, were increased in An. albimanus guts after AT treatment. AT conjugated to quantum dot nano-crystals (QDots) specifically labeled hemocytes in vivo in both mosquito species, implying molecular interactions between AT and hemocytes. The results of our studies suggest a new role for AT in the modulation of the immune response in mosquitoes.