Seroprevalencia de anticuerpos contra el virus de hepatitis C (VHC) en trabajadoras sexuales que acuden a un Centro de Referencia de Infecciones de Transmisión Sexual (CERITSS) de la ciudad de Iquitos, Perú

Introducction: the principal described risk factors to contract the hepatitis C virus (HCV) are blood transfusion antecedents and intravenous drug use; sexual transmission risk is controversial. In Peru there exist few studies whose female sex worker (FSW) HCV prevalence oscillates between 0-1%. The present study is based in Iquitos, a Peruvian jungle city with high sexual commerce and HIV/AIDS prevalence. Objetive: determine the HCV serological prevalence in Iquitos FSWs attending the STI/ HIV specialist center (CERITSS) and identify associated risk factors. Material and methods: cross-sectional study in FSWs who attended periodic San Juan CERITSS examinations from May 2003 to January 2004. Epidemical questionnaires where used to evaluate the risk factors. To determine HCV antibodies presence, the immunoassay enzyme (EIA) positive results were confirmed by the recombinant immunoblot assay (RIBA) test. Results: 4/200 FSWs enrolled in the study were EIA test positive; all had confirmed positive RIBA results, representing 2%(95%IC 0,06%-3,94%) prevalence. the 4 FSWs referred to be were born in Iquitos, to having been a sex worker for five years and stated condom use was <50%. Three to having had 9 sexual clients daily; to heavy alcohol consumption and to frequent anal sex . None declared intravenous drug use; having had tattoos and blood transfusions. Only one of 4 HCV positives had syphilis serology and none had HIV infections. 1/200 was diagnosed with HIV. Conclusion: the antibody against HCV seroprevalence in Iquitos FSWs is greater than reported in similar populations or the general population of other Peruvian cities. This population was characterized by having high risk sexual behavior and no blood transfusion antecedent nor intravenous drug userIntroducción: los principales factores de riesgo descritos para contraer la infección por el virus de la hepatitis C (VHC) son antecedentes de transfusión sanguínea y uso de droga endovenosa; el riesgo por transmisión sexual es controversial. Existen pocos estudios de VHC en trabajadoras sexuales (TS) en el Perú, encontrando bajas prevalencias de VHC (0-1%). El presente estudio se ha realizado en Iquitos, una ciudad en la selva peruana, en donde existe gran comercio sexual y la prevalencia de HIV/SIDA y otras Infecciones de Transmisión Sexual (ITS) es alta. Objetivo: determinar la seroprevalencia de anticuerpos contra el VHC en TS de la ciudad de Iquitos atendidas en un Centro Especializado de Referencia de Infecciones de transmisión sexual (CERITSS) e identificar los factores de riesgo asociados a esta. Material y métodos: es un estudio de corte transversal en TS quienes acudieron a su control periódico al CERITSS San Juan entre mayo 2003 a enero 2004. Una encuesta clínica-epidemiológica fue utilizada para determinar la frecuencia de factores de riesgo para adquirir la infección por VHC. Para determinar la presencia de anticuerpos contra el VHC, se utilizó la prueba de enzima inmunoensayo (EIA); todos los resultados positivos fueron confirmados con la prueba inmunoblot recombinante (RIBA). Resultados: cuatro de las 200 TS enroladas en el estudio fueron positivos para la prueba EIA, todas ellas tuvieron resultados positivos de RIBA (prevalencia de 2%, IC95% 0,06-3,94%). Estas 4 TS reportaron ser naturales de Iquitos, tener mas de 5 años de trabajo sexual, reportaron un bajo uso de condón (<50%). Tres de ellas reportaron haber tenido mas de 9 parejas/ día, realizar trabajo sexual bajo efecto del alcohol y tener sexo anal frecuentemente. Ninguna refirió transfusiones sanguíneas, antecedente de tatuajes o uso de drogas endovenosas. Solo una de las 4 VHC positivas tuvo serología positiva para sífilis co-existentemente y ninguna para VIH. Una de las 200 TS enroladas tuvo infección por VIH. Conclusiones: la seroprevalencia de anticuerpos contra el VHC en TS es mayor que la reportada en poblaciones similares en otras ciudades del Perú. Esta población se caracterizó por tener una conducta sexual de alto riesgo y no tener antecedentes de transfusión sanguínea ni consumo de droga endovenosa

Preexposure Chemoprophylaxis for HIV Prevention in Men Who Have Sex with Men.

Background: Antiretroviral chemoprophylaxis before exposure is a promising approach for the prevention of human immunodeficiency virus (HIV) acquisition. Methods: We randomly assigned 2499 HIV-seronegative men or transgender women who have sex with men to receive a combination of two oral antiretroviral drugs, emtricitabine and tenofovir disoproxil fumarate (FTC-TDF), or placebo once daily. All subjects received HIV testing, risk-reduction counseling, condoms, and management of sexually transmitted infections. Results: The study subjects were followed for 3324 person-years (median, 1.2 years; maximum, 2.8 years). Of these subjects, 10 were found to have been infected with HIV at enrollment, and 100 became infected during follow-up (36 in the FTC-TDF group and 64 in the placebo group), indicating a 44% reduction in the incidence of HIV (95% confidence interval, 15 to 63; P=0.005). In the FTC-TDF group, the study drug was detected in 22 of 43 of seronegative subjects (51%) and in 3 of 34 HIV-infected subjects (9%) (P<0.001). Nausea was reported more frequently during the first 4 weeks in the FTC-TDF group than in the placebo group (P<0.001). The two groups had similar rates of serious adverse events (P=0.57). Conclusions: Oral FTC-TDF provided protection against the acquisition of HIV infection among the subjects. Detectable blood levels strongly correlated with the prophylactic effect. (Funded by the National Institutes of Health and the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT00458393.) N Engl J Med 2010;363:2587-99.Division of Acquired Immunodeficiency Syndrome (DAIDS), National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH)[UO1 AI64002]Bill and Melinda Gates FoundationDAIDS[UO1 AI84735]DAIDS[AI062333]National Institutes of Health (NIH)[UL1 RR024131]GileadMerckBristol-Myers Squib

Risk of COVID-19 after natural infection or vaccinationResearch in context

Summary: Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health

Risk of COVID-19 after natural infection or vaccinationResearch in context

Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health