Yellow fever epizootics in non-human primates, São Paulo state, Brazil, 2008-2009.

Since 2000, the expansion of Sylvatic Yellow Fever (YF) has been observed in the southeast of Brazil, being detected in areas considered silent for decades. Epizootics in non-human primates (NHPs) are considered sentinel events for the detection of human cases. It is important to report epizootic events that could have impact on the conservation status of susceptible species. We describe the epizootics in NHPs, notified in state of São Paulo, Brazil, between September 2008 to August 2009. Ninety-one epizootic events, involving 147 animals, were reported in 36 counties. Samples were obtained from 65 animals (44.2%). Most of the epizootics (46.6%) were reported between March and April, the same period during which human cases of YF occurred in the state. Biological samples were collected from animals found dead and were sent to Instituto Adolfo Lutz, in São Paulo. Two samples, collected in two counties without an indication for YF vaccination, were positive for the virus. Another 48 animals were associated with YF by clinical-epidemiological linkage with laboratory confirmed cases. Because the disease in human and NHPs occurred in the same period, the detection of the virus in NHPs did not work as sentinel, but aided in the delineation of new areas of risk.

Reemergence of yellow fever: detection of transmission in the State of São Paulo, Brazil, 2008.

INTRODUCTION: Following yellow fever virus (YFV) isolation in monkeys from the São José do Rio Preto region and two fatal human autochthonous cases from the Ribeirão Preto region, State of São Paulo, Brazil, two expeditions for entomological research and eco-epidemiological evaluation were conducted. METHODS: A total of 577 samples from humans, 108 from monkeys and 3,049 mosquitoes were analyzed by one or more methods: virus isolation, ELISA-IgM, RT-PCR, histopathology and immunohistochemical. RESULTS: Of the 577 human samples, 531 were tested by ELISA-IgM, with 3 positives, and 235 were inoculated into mice and 199 in cell culture, resulting in one virus isolation. One sample was positive by histopathology and immunohistochemical. Using RT-PCR, 25 samples were processed with 4 positive reactions. A total of 108 specimens of monkeys were examined, 108 were inoculated into mice and 45 in cell culture. Four virus strains were isolated from Alouatta caraya. A total of 931 mosquitoes were captured in Sao Jose do Rio Preto and 2,118 in Ribeirão Preto and separated into batches. A single isolation of YFV was derived from a batch of 9 mosquitoes Psorophora ferox, collected in Urupês, Ribeirão Preto region. A serological survey was conducted with 128 samples from the municipalities of São Carlos, Rincão and Ribeirão Preto and 10 samples from contacts of patients from Ribeirão Preto. All samples were negative by ELISA-IgM for YFV. CONCLUSIONS: The results confirm the circulation of yellow fever, even though sporadic, in the Sao Paulo State and reinforce the importance of vaccination against yellow fever in areas considered at risk.

Isolation of yellow fever virus (YFV) from naturally infected Haemagogus (Conopostegus) leucocelaenus (diptera, cukicudae) in São Paulo State, Brazil, 2009.

After detecting the death of Howlers monkeys (genus Alouatta) and isolation of yellow fever virus (YFV) in Buri county, São Paulo, Brazil, an entomological research study in the field was started. A YFV strain was isolated from newborn Swiss mice and cultured cells of Aedes albopictus - C6/36, from a pool of six Haemagogus (Conopostegus) leucocelaenus (Hg. leucocelaenus) mosquitoes (Dyar & Shannon) collected at the study site. Virus RNA fragment was amplified by RT-PCR and sequenced. The MCC Tree generated showed that the isolated strain is related to the South American I genotype, in a monophyletic clade containing isolates from recent 2008-2010 epidemics and epizootics in Brazil. Statistical analysis commonly used were calculated to characterize the sample in relation to diversity and dominance and indicated a pattern of dominance of one or a few species. Hg. leucocelaenus was found infected in Rio Grande do Sul State as well. In São Paulo State, this is the first detection of YFV in Hg. leucocelaenus.

Yellow fever epizootics in non-human primates, São Paulo state, Brazil, 2008-2009 / Epizootias de febre amarela em primatas não humanos no estado de São Paulo, Brasil, 2008-2009

Since 2000, the expansion of Sylvatic Yellow Fever (YF) has been observed in the southeast of Brazil, being detected in areas considered silent for decades. Epizootics in non-human primates (NHPs) are considered sentinel events for the detection of human cases. It is important to report epizootic events that could have impact on the conservation status of susceptible species. We describe the epizootics in NHPs, notified in state of São Paulo, Brazil, between September 2008 to August 2009. Ninety-one epizootic events, involving 147 animals, were reported in 36 counties. Samples were obtained from 65 animals (44.2%). Most of the epizootics (46.6%) were reported between March and April, the same period during which human cases of YF occurred in the state. Biological samples were collected from animals found dead and were sent to Instituto Adolfo Lutz, in São Paulo. Two samples, collected in two counties without an indication for YF vaccination, were positive for the virus. Another 48 animals were associated with YF by clinical-epidemiological linkage with laboratory confirmed cases. Because the disease in human and NHPs occurred in the same period, the detection of the virus in NHPs did not work as sentinel, but aided in the delineation of new areas of risk.

Desde 2000, vem sendo observada a expansão da febre amarela (FA) no Sudeste do Brasil, sendo detectados casos em áreas consideradas silenciosas por décadas. Epizootias em primatas não humanos (NHPs) são considerados eventos sentinela para a detecção de casos humanos. É importante relatar eventos epizoóticos que podem ter impacto sobre o estado de conservação de espécies sensíveis. Descrevemos as epizootias, notificadas em NHPs no estado de São Paulo, Brasil, entre setembro de 2008 a agosto de 2009. Noventa e um eventos epizoóticos, envolvendo 147 animais, foram notificados em 36 municípios. As amostras foram obtidas a partir de 65 animais (44,2%). A maioria das epizootias (46,6%) foram registradas entre março e abril, no mesmo período no qual YF em que casos humanos ocorreram no estado. As amostras biológicas foram coletadas de animais encontrados mortos e enviadas ao Instituto Adolfo Lutz, em São Paulo. Duas amostras, coletadas em dois municípios, sem indicação para a vacinação de febre amarela, foram positivos para o vírus. Outros 48 animais foram associados com FA por vínculo clínico-epidemiológico com casos confirmados laboratorialmente. Devido a doença em humanos e NHPs terem ocorrido no mesmo período, a detecção do vírus em NHPs não funcionou como sentinela, mas ajudou no processo de delimitação de novas áreas de risco.

Reemergence of yellow fever: detection of transmission in the State of São Paulo, Brazil, 2008 / Reemergência de febre amarela: detecção de transmissão no Estado de São Paulo, Brasil, 2008

INTRODUCTION: Following yellow fever virus (YFV) isolation in monkeys from the São José do Rio Preto region and two fatal human autochthonous cases from the Ribeirão Preto region, State of São Paulo, Brazil, two expeditions for entomological research and eco-epidemiological evaluation were conducted. METHODS: A total of 577 samples from humans, 108 from monkeys and 3,049 mosquitoes were analyzed by one or more methods: virus isolation, ELISA-IgM, RT-PCR, histopathology and immunohistochemical. RESULTS: Of the 577 human samples, 531 were tested by ELISA-IgM, with 3 positives, and 235 were inoculated into mice and 199 in cell culture, resulting in one virus isolation. One sample was positive by histopathology and immunohistochemical. Using RT-PCR, 25 samples were processed with 4 positive reactions. A total of 108 specimens of monkeys were examined, 108 were inoculated into mice and 45 in cell culture. Four virus strains were isolated from Alouattacaraya. A total of 931 mosquitoes were captured in Sao Jose do Rio Preto and 2,118 in Ribeirão Preto and separated into batches. A single isolation of YFV was derived from a batch of 9 mosquitoes Psorophoraferox, collected in Urupês, Ribeirão Preto region. A serological survey was conducted with 128 samples from the municipalities of São Carlos, Rincão and Ribeirão Preto and 10 samples from contacts of patients from Ribeirão Preto. All samples were negative by ELISA-IgM for YFV. CONCLUSIONS: The results confirm the circulation of yellow fever, even though sporadic, in the Sao Paulo State and reinforce the importance of vaccination against yellow fever in areas considered at risk.

INTRODUÇÃO: A partir do isolamento do vírus febre amarela (VFA), de macacos, da região de São José do Rio Preto e de dois casos humanos autóctones fatais, da região de Ribeirão Preto, Estado de São Paulo, foram realizadas duas expedições para pesquisa entomológica e avaliação ecoepidemiológica. MÉTODOS: Um total de 577 amostras de humanos, 108 de macacos e 3.049 mosquitos foram analisados por um ou mais métodos: isolamento viral, ELISA-IgM, RT-PCR, histopatologia e imunohistoquímica. RESULTADOS: De 577 amostras humanas, 531 foram testadas por ELISA-IgM, sendo 3 positivas, 235 foram inoculadas em camundongos, 199 em cultura de células, obtendo-se 1 isolamento viral. Uma amostra foi positiva por histopatologia e imunohistoquímica. Por RT-PCR foram processadas 25 amostras com 4 reações positivas. Os 108 espécimes de macacos foram inoculados em camundongos, 45 em cultura de células, obtendo-se 4 isolamentos de VFA, de Alouatta caraya. Um total de 931 mosquitos foram capturados em São José do Rio Preto e 2.118 em Ribeirão Preto e separados em lotes. Um único isolamento de VFA foi derivado de um lote de 9 mosquitos Psorophora ferox, coletados em Urupês, região de Ribeirão Preto. Um inquérito sorológico foi realizado com 128 amostras dos municípios de São Carlos, Rincão e Ribeirão Preto e mais 10 amostras de contactantes de pacientes de Ribeirão Preto. Todas as amostras foram negativas por ELISA-IgM para VFA. CONCLUSÕES: Os resultados confirmam a circulação, mesmo que esporádica, do VFA no Estado de São Paulo e reforça a importância da vacinação antiamarílica nas áreas consideradas de risco.

Isolation of yellow fever virus (YFV) from naturally infectied Haemagogus (Conopostegus) leucocelaenus (diptera, cukicudae) in São Paulo State, Brazil, 2009 / Isolamento do vírus da Febre Amarela de mosquitos naturalmente infectados Haemagogus (Conopostegus) leucocelaenus (Diptera, Culicidae), São Paulo, Brasil, 2009

After detecting the death of Howlers monkeys (genus Alouatta) and isolation of yellow fever virus (YFV) in Buri county, São Paulo, Brazil, an entomological research study in the field was started. A YFV strain was isolated from newborn Swiss mice and cultured cells of Aedes albopictus - C6/36, from a pool of six Haemagogus (Conopostegus) leucocelaenus (Hg. leucocelaenus) mosquitoes (Dyar & Shannon) collected at the study site. Virus RNA fragment was amplified by RT-PCR and sequenced. The MCC Tree generated showed that the isolated strain is related to the South American I genotype, in a monophyletic clade containing isolates from recent 2008-2010 epidemics and epizootics in Brazil. Statistical analysis commonly used were calculated to characterize the sample in relation to diversity and dominance and indicated a pattern of dominance of one or a few species. Hg. leucocelaenus was found infected in Rio Grande do Sul State as well. In São Paulo State, this is the first detection of YFV in Hg. leucocelaenus.

Após a detecção de morte de macacos Bugios (gênero Alouatta) e isolamento do vírus da Febre Amarela (YFV) no município de Buri, Estado de São Paulo, Brasil, foi iniciada uma investigação entomológica em campo. Uma cepa de YFV foi isolada em camundongos recém-nascidos e cultura de células de Aedes albopictus - C6/36, a partir de um lote de seis mosquitos Haemagogus (Conopostegus) leucocelaenus (Hg leucocelaenus) Dyar & Shannon coletados no local de estudo. RNA do vírus foi amplificado por RT-PCR e seqüenciado. A topologia gerada indica que a cepa isolada está relacionada ao genótipo South American I, em clado monofilético englobando isolados recentes de epidemias e epizootias entre 2008 e 2009. Análises estatísticas geralmente usadas caracterizaram a amostra em relação à diversidade e dominância, indicando dominância relativa de uma ou poucas espécies. Hg. leucocelaenus foi detectado infectado também no Rio Grande do Sul. No Estado de São Paulo trata-se da primeira detecção do YFV em Hg leucocelaenus.