During 2015 to 2016, Brazil reported more Zika virus (ZIKV) cases than any other country, yet population exposure remains unknown. Serological studies of ZIKV are hampered by cross-reactive immune responses against heterologous viruses. We conducted serosurveys for ZIKV, dengue virus (DENV), and Chikungunya virus (CHIKV) in 633 individuals prospectively sampled during 2015 to 2016, including microcephaly and non-microcephaly pregnancies, HIV-infected patients, tuberculosis patients, and university staff in Salvador in northeastern Brazil using enzyme-linked immunosorbent assays (ELISAs) and plaque reduction neutralization tests. Sera sampled retrospectively during 2013 to 2015 from 277 HIV-infected patients were used to assess the spread of ZIKV over time. Individuals were georeferenced, and sociodemographic indicators were compared between ZIKV-positive and -negative areas and areas with and without microcephaly cases. Epidemiological key parameters were modeled in a Bayesian framework. ZIKV seroprevalence increased rapidly during 2015 to 2016, reaching 63.3% by 2016 (95% confidence interval [CI], 59.4 to 66.8%), comparable to the seroprevalence of DENV (75.7%; CI, 69.4 to 81.1%) and higher than that of CHIKV (7.4%; CI, 5.6 to 9.8%). Of 19 microcephaly pregnancies, 94.7% showed ZIKV IgG antibodies, compared to 69.3% of 257 non-microcephaly pregnancies (P = 0.017). Analyses of sociodemographic data revealed a higher ZIKV burden in low socioeconomic status (SES) areas. High seroprevalence, combined with case data dynamics allowed estimates of the basic reproduction number R0 of 2.1 (CI, 1.8 to 2.5) at the onset of the outbreak and an effective reproductive number Reff of <1 in subsequent years. Our data corroborate ZIKV-associated congenital disease and an association of low SES and ZIKV infection and suggest that population immunity caused cessation of the outbreak. Similar studies from other areas will be required to determine the fate of the American ZIKV outbreak.

The Zika virus outbreak in Latin America resulted in congenital malformations, called congenital Zika syndrome (CZS). For unknown reasons, CZS incidence was highest in northeastern Brazil; one potential explanation is that dengue virus (DENV)–mediated immune enhancement may promote CZS development. In contrast, our analyses of historical DENV genomic data refuted the hypothesis that unique genome signatures for northeastern Brazil explain the uneven dispersion of CZS cases. To confirm our findings, we performed serotype-specific DENV neutralization tests in a case–control framework in northeastern Brazil among 29 Zika virus–seropositive mothers of neonates with CZS and 108 Zika virus–seropositive control mothers. Neutralization titers did not differ significantly between groups. In contrast, DENV seroprevalence and median number of neutralized serotypes were significantly lower among the mothers of neonates with CZS. Supported by model analyses, our results suggest that multitypic DENV infection may protect from, rather than enhance, development of CZS.

The majority of cases of congenital ZIKV syndrome have other ultrasonographic findings in addition to microcephaly. ZIKV-related CNS anomalies present mainly as progressive CNS lesions and slowing rate of growth of the fetal head, and this seems to be evident only in the late second trimester, even when maternal infection occurs in the first trimester. Other ultrasound findings, such as ventriculomegaly, brain calcifications and posterior fossa destruction lesions, are also common in this congenital syndrome. Posterior fossa destruction lesions and arthrogryposis are an uncommon finding in other congenital infections, perhaps suggesting a novel severe congenital syndrome associated with fetal ZIKV. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

The Latin American Zika virus (ZIKV) outbreak had a major impact on reproductive health worldwide. The reasons for the massively increased reports of neonatal microcephaly in northeastern Brazil are still unclear. Beyond the technical limitations of laboratory diagnostics, unambiguous diagnosis of ZIKV as the cause of congenital malformations is hampered by similar clinical pictures elicited by other pathogens known as TORCH pathogens. We performed a case-control study comparing mothers of children with congenital malformations to age-matched controls from Salvador, Brazil, one of the areas most extensively affected by the ZIKV outbreak. The ZIKV and Chikungunya virus seroprevalence rates differed significantly, whereas the levels of maternal exposure to TORCH pathogens were similar between cases and controls. Our data support a link between maternal ZIKV infection and congenital malformations and suggest the occurrence of predominantly vector-borne ZIKV transmission in these cases. In addition, some highly prevalent TORCH pathogens may be misinterpreted as representative of ongoing ZIKV activity in the absence of exhaustive diagnostics in northeastern Brazil.

Objective: to describe the clinical and epidemiological profile of patients with HIV/AIDS hospitalized at the Hospital for Reference in the state of Bahia, Brazil. Method: a descriptive retrospective cross-sectional study. The sample comprised of patients admitted to the hospital for the treatment of HIV/AIDS in Salvador, Bahia, Brazil, from January to December 2008; the data was obtained from medical records upon approval by the Committee for Ethics in Research of Hospital Couto Maia (protocol 15/2009). Results: for the 194 patients studied, the average age was 37.8 years, ± 10.7 years. The predominant age group was 21 to 50 years old, which represented 87.5% of the all patients. Prior to hospitalization, about 150 patients were already diagnosed with HIV/AIDS and 54 were in regular use of antiretroviral therapy. Diarrhea, toxoplasmosis and esophageal candidiasis were the most common opportunistic diseases encountered. The average CD4 was 82 cells/mm3, ranging from 7 to 1,099. Of the 194 patients studied, 65 (33.5%) died and the highest mortality rates were attributed to Kaposi's sarcoma (75.0%) and toxoplasmosis (42.2%). Conclusions: the clinical and epidemiological profile of the patients with HIV/AIDS analyzed consists of young heterosexuals adult males, who were diagnosed previously to their hospitalization and whose main reason for hospitalization was related to opportunistic diseases. Descriptors: acquired immunodeficiency syndrome; health profile; aids-related opportunistic infections.RESUMOObjetivo: descrever o perfil clínico-epidemiológico dos pacientes internados com HIV/AIDS no Hospital de Referência do Estado da Bahia. Método: estudo descritivo retrospectivo, de corte transversal. A amostra foi composta pelos pacientes internados no hospital de referência no tratamento de HIV/AIDS da cidade de Salvador-Ba, entre janeiro a dezembro de 2008; os dados foram obtidos de prontuários médicos após aprovação do Comitê de Ética em Pesquisa do Hospital Couto Maia com protocolo 15/2009. Resultados: dos 194 pacientes, observou-se média de idade de 37,8 anos ± 10,7 anos. Predominou faixa etária entre 21 e 50 anos somando 87,5% dos pacientes. Cerca de 150 pacientes tinham diagnóstico prévio à internação e 54 estavam em uso regular de TARV na admissão. Diarréia, neurotoxoplasmose e candidíase esofágica foram as doenças oportunistas mais freqüentes. A mediana de CD4 foi de 82 variando de 7-1.099 células/mm3. Observou-se que, 65 (33,5%) foram a óbito e as maiores taxas de letalidade foram atribuídas ao Sarcoma de Kaposi (75,0%) e neurotoxoplasmose (42,2%). Conclusão: o perfil clínico-epidemiológico dos pacientes com HIV/AIDS internados em estudo é composto por adultos jovens, do gênero masculino, heterossexuais que possuíam diagnóstico prévio a internação, cujo principal motivo de internação esteve relacionado à doença oportunista. Descritores: síndrome de imunodeficiência adquirida; perfil de saúde; infecções oportunistas relacionadas com a aids.RESUMENObjetivo: describir las características clínicas y epidemiológicas de los pacientes con VIH/SIDA en el hospital de referencia del estado de Bahía, Brasil. Método: estudio retrospectivo observacional descriptivo de corte transversal. La muestra se compone de los pacientes ingresados en el hospital para el tratamiento del VIH/SIDA, en Salvador, Bahía, Brasil, entre enero y diciembre de 2008; los datos se obtuvieron a partir de los registros médicos seguidamente a la aprobación por el Comité de Ética en Investigación del Hospital Couto Maia (protocolo 15/2009). Resultados: de los 194 pacientes estudiados la edad promedio fue de 37,8 años ± 10,7 años. El grupo de edad predominante fue de 21 a 50 años, lo que representa 87,5% del total de pacientes. Alrededor de 150 pacientes fueron diagnosticados antes de la admisión y 54 hacían uso regular de la terapia antirretroviral cuando del ingreso. Se observó que la diarrea, toxoplasmosis y candidiasis esofágica fueron las enfermedades oportunistas más frecuentes. El promedio de CD4 fue de 82 células/mm3, entre 7 y 1.099. De los 194 pacientes estudiados, 65 (33,5%) fallecieron y las tasas de mortalidad más altas se atribuyen al sarcoma de Kaposi (75,0%) y toxoplasmosis (42,2%). Conclusiones: el perfil clínico y epidemiológico de los pacientes con VIH/SIDA analizados se compone de jóvenes adultos, hombres, heterosexuales, que habían sido diagnosticados previamente a la hospitalización y cuyo principal motivo para el ingreso en el hospital estaba relacionado con enfermedades oportunistas. Descriptores: síndrome de inmunodeficiencia adquirida; perfil de salud; infecciones oportunistas relacionadas con la sida.