Prevalence and causes of congenital microcephaly in the absence of a Zika virus outbreak in southern Brazil / Prevalência e causas da microcefalia congênita sem a presença do surto do vírus Zika no Sul do Brasil

Abstract Objective: The aim of this study was to identify the causes of congenital microcephaly in Rio Grande do Sul, a state in southern Brazil, where no ZIKV outbreak was detected, from December 2015 to December 2016, which was the period when ZIKV infection was at its peak in northeast Brazil. Methods: This was a cross-sectional study where all notifications of congenital microcephaly in the state of Rio Grande do Sul were included for analysis. Evaluation of cases followed the guidelines of the Brazilian Ministry of Health. Dysmorphological and neurological evaluations were performed by a specialized team, and genetic tests and neuroimaging were performed when clinically indicated. STORCH infections were diagnosed using standard tests. ZIKV infection was diagnosed through maternal serum RT-PCR and/or neuroimaging associated with clinical/epidemiological criteria. Results: From 153 744 registered live births in the study period, 148 cases were notified, but 90 (60.8%) of those were later excluded as "non-confirmed" microcephaly. In the 58 confirmed cases of microcephaly (prevalence = 3.8/10 000 live births), congenital infections (syphilis, toxoplasmosis, cytomegalovirus, and ZIKV) constituted the predominant etiology (50.0%), followed by isolated CNS (15.5%), and genetic syndromes (10.3%). Congenital ZIKV syndrome (CZS) with typical phenotype was diagnosed in three cases (5.2% of all confirmed microcephaly cases or 10.4% of all congenital infections). Conclusion: In Rio Grande do Sul, where no outbreak of ZIKV infection was recorded, congenital infections were the leading cause of congenital microcephaly, and the attributable risk for CZS in the etiology of microcephaly was 5.2%.

Resumo: Objetivo: Identificar as causas da microcefalia congênita no Rio Grande do Sul, Região Sul do Brasil, onde não foi detectado surto de ZIKV, de dezembro de 2015 a dezembro de 2016. Esse foi o período em que a infecção por ZIKV estava em seu auge no Nordeste do Brasil. Métodos: Este é um estudo transversal no qual todas as notificações de microcefalia congênita no estado do Rio Grande do Sul foram incluídas para análise. A avaliação dos casos seguiu as orientações do Ministério da Saúde. A avaliação dismorfológica e neurológica foi feita por uma equipe especializada e os testes genéticos e as neuroimagens foram feitos quando indicado clinicamente. As infecções STORCH (Sífilis, Toxoplasmose, Rubéola, Citomegalovírus e Herpes simples) foram diagnosticadas utilizando testes padrão. A infecção por ZIKV foi diagnosticada por meio da transcriptase reversa seguida de reação em cadeia da polimerase (RT-PCR) no soro materno e/ou neuroimagem associada a critérios clínicos/epidemiológicos. Resultados: De 153.744 nascidos vivos registrados no período do estudo, 148 bebês foram casos notificados, porém 90 (60,8%) casos foram excluídos posteriormente como microcefalia "não confirmada". Nos 58 casos confirmados de microcefalia (prevalência = 3,8/10.000 nascidos vivos), as infecções congênitas (sífilis, toxoplasmose, citomegalovírus e ZIKV) constituíram a etiologia predominante (50,0%), seguidas de doenças ligadas ao SNC isolado (15,5%) e síndromes genéticas (10,3%). A síndrome congênita do ZIKV (SCZ) com fenótipo típico foi diagnosticada em três casos (5,2% de todos os casos confirmados de microcefalia ou 10,4% de todas as infecções congênitas). Conclusão: No Rio Grande do Sul, Brasil, onde não foi registrado surto de infecção por ZIKV, a principal causa de microcefalia congênita foram infecções congênitas e o risco atribuível para SCZ na etiologia de microcefalia foi de 5,2%.

Prevalence and causes of congenital microcephaly in the absence of a Zika virus outbreak in southern Brazil.

OBJECTIVE: The aim of this study was to identify the causes of congenital microcephaly in Rio Grande do Sul, a state in southern Brazil, where no ZIKV outbreak was detected, from December 2015 to December 2016, which was the period when ZIKV infection was at its peak in northeast Brazil. METHODS: This was a cross-sectional study where all notifications of congenital microcephaly in the state of Rio Grande do Sul were included for analysis. Evaluation of cases followed the guidelines of the Brazilian Ministry of Health. Dysmorphological and neurological evaluations were performed by a specialized team, and genetic tests and neuroimaging were performed when clinically indicated. STORCH infections were diagnosed using standard tests. ZIKV infection was diagnosed through maternal serum RT-PCR and/or neuroimaging associated with clinical/epidemiological criteria. RESULTS: From 153744 registered live births in the study period, 148 cases were notified, but 90 (60.8%) of those were later excluded as "non-confirmed" microcephaly. In the 58 confirmed cases of microcephaly (prevalence = 3.8/10000 live births), congenital infections (syphilis, toxoplasmosis, cytomegalovirus, and ZIKV) constituted the predominant etiology (50.0%), followed by isolated CNS (15.5%), and genetic syndromes (10.3%). Congenital ZIKV syndrome (CZS) with typical phenotype was diagnosed in three cases (5.2% of all confirmed microcephaly cases or 10.4% of all congenital infections). CONCLUSION: In Rio Grande do Sul, where no outbreak of ZIKV infection was recorded, congenital infections were the leading cause of congenital microcephaly, and the attributable risk for CZS in the etiology of microcephaly was 5.2%.

Surveillance for yellow Fever virus in non-human primates in southern Brazil, 2001-2011: a tool for prioritizing human populations for vaccination.

In Brazil, epizootics among New World monkey species may indicate circulation of yellow fever (YF) virus and provide early warning of risk to humans. Between 1999 and 2001, the southern Brazilian state of Rio Grande do Sul initiated surveillance for epizootics of YF in non-human primates to inform vaccination of human populations. Following a YF outbreak, we analyzed epizootic surveillance data and assessed YF vaccine coverage, timeliness of implementation of vaccination in unvaccinated human populations. From October 2008 through June 2009, circulation of YF virus was confirmed in 67 municipalities in Rio Grande do Sul State; vaccination was recommended in 23 (34%) prior to the outbreak and in 16 (24%) within two weeks of first epizootic report. In 28 (42%) municipalities, vaccination began more than two weeks after first epizootic report. Eleven (52%) of 21 laboratory-confirmed human YF cases occurred in two municipalities with delayed vaccination. By 2010, municipalities with confirmed YF epizootics reported higher vaccine coverage than other municipalities that began vaccination. In unvaccinated human populations timely response to epizootic events is critical to prevent human yellow fever cases.

Risk factors for death from pandemic (H1N1) 2009, southern Brazil.

To identify risk factors for death from pandemic (H1N1) 2009, we obtained data for 157 hospitalized patients with confirmed cases of this disease. Multivariate analysis showed that diabetes and class III obesity were associated with death. These findings helped define priority vaccination groups in Brazil.

Mudança na suscetibilidade à hepatite A em crianças e adolescentes na última década / Shifting susceptibility to hepatitis A among children and adolescents over the past decade

OBJETIVOS: Estimar a prevalência de anticorpos contra hepatite A (anti-VHA) em grupo de crianças e adolescentes de laboratório público e privado em Porto Alegre e comparar com estudo realizado na década anterior. MÉTODOS: Entre 2007 e 2008 foi realizado estudo transversal onde foram incluídas, consecutivamente, 465 amostras de soros de crianças e adolescentes entre 1 e 19 anos de idade para determinar a prevalência de anticorpos anti-VHA total. As amostras foram fornecidas por laboratório público (grupo 1), que atende somente Sistema Único de Saúde, e por laboratório privado (grupo 2), representando os estratos socioeconômicos mais baixo e mais alto, respectivamente. O teste foi realizado em único laboratório (eletroquimioluminescência, Roche Diagnostics). Resultados > 20 UI/L foram considerados positivos. RESULTADOS: A soroprevalência de anti-VHA no grupo 1 foi de 37,6 por cento e o percentual de positividade aumentou conforme a idade, variando de 19,4 por cento entre 1-4 anos a 54,1 por cento entre 15-19 anos. No grupo 2, a frequência de anti-VHA foi de 46,1 por cento e foi inversamente relacionada à idade, caindo de cerca de 50,0 por cento nas faixas etárias menores para 29,1 por cento aos 15-19 anos. Houve diminuição significativa na prevalência do anti-VHA nas crianças de 5-9 anos do grupo 1 (p = 0,03), quando comparadas com estudo realizado na década de 1990. CONCLUSÕES: Os resultados sugerem queda na endemicidade da hepatite A em Porto Alegre na última década e indicam maior suscetibilidade à doença em crianças e adolescentes, principalmente no estrato socioeconômico mais baixo.

OBJECTIVES: To estimate the prevalence of anti-hepatitis A virus (anti-HAV) antibodies in serum samples from children and adolescents obtained at two clinical pathology laboratories in the city of Porto Alegre, south of Brazil, and to compare findings to those of a study carried out in the 1990s. METHODS: In this cross-sectional study conducted between 2007 and 2008, 465 serum samples obtained from subjects aged 1-19 years were consecutively tested to determine the prevalence of total anti-HAV antibodies. Samples were provided by a public laboratory (group 1) that serves the Unified Health System exclusively, meant to represent the lowest socioeconomic strata, and by a private laboratory (group 2), meant to represent the higher socioeconomic classes. Tests were performed at a single laboratory using commercially available electrochemiluminescence kits. Antibody levels > 20 UI/L were considered positive. RESULTS: The seroprevalence of anti-HAV in Group 1 was 37.6 percent. The percentage of anti-HAV reactivity increased from 19.4 percent in the 1-to-4 group to 54.1 percent in the 15-to-19 group. In Group 2, overall anti-HAV positivity was 46.1 percent and was inversely correlated with age, declining from roughly 50 percent in the youngest groups to 29.1 percent in the 15-to-19 group. Comparison of sample findings to those reported in a 1990s study showed a significant reduction in anti-HAV prevalence among 5-to-9-year-olds in group 1 (p = 0.03). CONCLUSIONS: The results suggest that the endemicity of hepatitis A in Porto Alegre has been declining over the past decade, and that children and adolescents, particularly those in the lowest socioeconomic strata, are more susceptible to the disease.

Shifting susceptibility to hepatitis A among children and adolescents over the past decade.

OBJECTIVES: To estimate the prevalence of anti-hepatitis A virus (anti-HAV) antibodies in serum samples from children and adolescents obtained at two clinical pathology laboratories in the city of Porto Alegre, south of Brazil, and to compare findings to those of a study carried out in the 1990s. METHODS: In this cross-sectional study conducted between 2007 and 2008, 465 serum samples obtained from subjects aged 1-19 years were consecutively tested to determine the prevalence of total anti-HAV antibodies. Samples were provided by a public laboratory (group 1) that serves the Unified Health System exclusively, meant to represent the lowest socioeconomic strata, and by a private laboratory (group 2), meant to represent the higher socioeconomic classes. Tests were performed at a single laboratory using commercially available electrochemiluminescence kits. Antibody levels ≥ 20 UI/L were considered positive. RESULTS: The seroprevalence of anti-HAV in Group 1 was 37.6%. The percentage of anti-HAV reactivity increased from 19.4% in the 1-to-4 group to 54.1% in the 15-to-19 group. In Group 2, overall anti-HAV positivity was 46.1% and was inversely correlated with age, declining from roughly 50% in the youngest groups to 29.1% in the 15-to-19 group. Comparison of sample findings to those reported in a 1990s study showed a significant reduction in anti-HAV prevalence among 5-to-9-year-olds in group 1 (p = 0.03). CONCLUSIONS: The results suggest that the endemicity of hepatitis A in Porto Alegre has been declining over the past decade, and that children and adolescents, particularly those in the lowest socioeconomic strata, are more susceptible to the disease.