Yellow fever virus in Haemagogus leucocelaenus and Aedes serratus mosquitoes, southern Brazil, 2008.

Yellow fever virus (YFV) was isolated from Haemagogus leucocelaenus mosquitoes during an epizootic in 2001 in the Rio Grande do Sul State in southern Brazil. In October 2008, a yellow fever outbreak was reported there, with nonhuman primate deaths and human cases. This latter outbreak led to intensification of surveillance measures for early detection of YFV and support for vaccination programs. We report entomologic surveillance in 2 municipalities that recorded nonhuman primate deaths. Mosquitoes were collected at ground level, identified, and processed for virus isolation and molecular analyses. Eight YFV strains were isolated (7 from pools of Hg. leucocelaenus mosquitoes and another from Aedes serratus mosquitoes); 6 were sequenced, and they grouped in the YFV South American genotype I. The results confirmed the role of Hg. leucocelaenus mosquitoes as the main YFV vector in southern Brazil and suggest that Ae. serratus mosquitoes may have a potential role as a secondary vector.

Oropouche fever epidemic in Northern Brazil: epidemiology and molecular characterization of isolates.

BACKGROUND: Oropouche fever virus is an important arbovirus associated with febrile disease that re-emerged in 2006 in several municipalities of Pará State, Bragantina region, Amazon, Brazil, 26 years after the last epidemic. OBJECTIVE: To investigate an Oropouche fever outbreak in this region. STUDY DESIGN: A serologic survey and prospective study of acute febrile cases were performed in Magalhães Barata (urban and rural areas) and Maracanã (rural area) municipalities. Serology (IgM-ELISA and hemagglutination-inhibition [HI]), virus isolation, RT-PCR and real-time-PCR were used to confirm Oropouche virus (OROV) as responsible for the febrile outbreaks. RESULTS: Real-time-PCR showed high titers of OROV in acute-phase serum samples from febrile patients. From 113 of 119 acutely febrile patients with paired serum samples, OROV infections was confirmed by serologic conversion (n=76) or high titers (n=37) for both HI and IgM-ELISA. Patients had a febrile disease characterized by headache, chills, dizziness, photophobia, myalgia, nausea, and vomiting. Females and children under 15 years of age were most affected. Nucleotide sequencing of six OROV isolates identified that genotype II was associated with the human disease epidemic. CONCLUSIONS: Oropouche fever, which has re-emerged in the Bragantina region in eastern Amazon 26 years after the last epidemic, is caused by genotype II, a lineage previously found only in Peru and western Brazil.

Yellow Fever Virus in Haemagogus leucocelaenus and Aedes serratus Mosquitoes, Southern Brazil, 2008

Yellow fever virus (YFV) was isolated from Haemagogus leucocelaenus mosquitoes during an epizootic in 2001 in the Rio Grande do Sul State in southern Brazil. In October 2008, a yellow fever outbreak was reported there, with nonhuman primate deaths and human cases. This latter outbreak led to intensification of surveillance measures for early detection of YFV and support for vaccination programs. We report entomologic surveillance in 2 municipalities that recorded nonhuman primate deaths. Mosquitoes were collected at ground level, identified, and processed for virus isolation and molecular analyses. Eight YFV strains were isolated (7 from pools of Hg. leucocelaenus mosquitoes and another from Aedes serratus mosquitoes); 6 were sequenced, and they grouped in the YFV South American genotype I. The results confirmed the role of Hg. leucocelaenus mosquitoes as the main YFV vector in southern Brazil and suggest that Ae. serratus mosquitoes may have a potential role as a secondary vector. (AU)

Encontro de Aedes albopictus no Estado do Pará, Brazil / Occurence of Aedes albopictus in the state of Pará, Brazil

Pela primeira vez é registrada a presença do Aedes (Stg) albopictus no Estado do Pará, Brasil, em área urbana no município de Medicilândia distante cerca de 90 km de Altamira, onde foram capturados por meio de isca humana 42 exemplares de mosquitos adultos. Estes foram inoculados em C6/36 e em camundongos recém-nascidos na tentativa de isolamento viral, não tendo sido isolado nenhum vírus. A presença de Aedes albopictus em áreas da Amazônia onde circulam os vírus de dengue e de febre amarela é preocupante e representa um risco potencial desta espécie de mosquito se tornar infectada com tais vírus (AU)

Estudo do Anopheles (NYS) Darlingi Root, 1926 e Anopheles (NYS) Albitarsis Arribalzága, 1878 (Diptera: Culicidae) como vetores de malária numa mesma área de trasmissäo, e caracterizaçäo de espécies do complexo Albitarsis

Durante os anos de 1995 e 1996, 9.102 mosquitos anofelinos vetores da malária foram coletados com isca humana, em três localidades (Lagoa dos Índios-L.I, Granja Alves-G.A e Zeräo-ZE) do município de Macapá/AP, Brasil. Do total de mosquitos capturados 78,34 porcento (7.131) foram identificados como An. (Nys) albitarsis s.l.,Arribalzága, 1878; 8,93 porcento (813) como An. (Nys) darlingi Root, 1926; 6,66 porcento como An. (Nys) braziliensis Chagas, 1907; 3,60 porcento de An. (Nys) nuneztovari Galbadón, 1940; 1,28 porcento (117) An. (Nys) triannulatus Neiva & Pinto, 1922; 0,78 porcento (71) An. (Ano) peryassui Dyar & Knab, 1908; 0,25 porcento (2) An. (Ano) mattogrossensis Lutz & Neiva, 1911; 0,14 porcento (13) An. (Arr) intermedius Chaga, 1908 e 0,02 porcento (2) An. (Nys) aquasalis Curry, 1932. O índice de picada/homem/hora foi de 38,3 para o An. (Nys) marajoara e 4,3 para An. (Nys) darlingi. As análises das espécies do complexo albitarsis pelo método RAPD-PCR nas três áreas de estudo resultaram na identificaçäo de somente uma espécie do complexo, o An. (Nys) marajoara. Usando ensaio imunoenzimático (ELISA), a taxa de positividade foi de 1,58 porcento (144/9.100) distribuída em cinco espécies: 115 (1,61 porcento) An. (Nys) marajoara, 5 (0,61 porcento) An. (Nys) darlingi, 17 (2,80 porcento) An. (Nys) braziliensis, 4 (17,39 porcento) An. (Ano) mattogrossensis e 3 (0,05 porcento) An. peryassui. Cento e seis mosquitos (90 An. (Nys) marajoara, 2 An. (Nys) darlingi, 9 An. (Nys) Braziliensis, 3 An. (Ano) mattogrossensis e 2 An. (Ano) peryassui) foram positivos para o Plasmodium vivax - VK247; 25 (18 An. (Nys) marajoara, 3 An. darlingi, 4 An. braziliensis) para o Plasmodium malariae, 8 (4 An. (Nys) marajoara, 3 An. (Nys) braziliensis e 1 An. (Ano) mattogrossensis) para o Plasmodium vivax e 5 (3 An. (Nys) marajoara, 1 An. peryassui) para o Plasmodium falciparum. Dados epidemiológicos da Coordenaçäo Regional do Amapá/FNS/MS, mostram que a malária vivax foi mais prevalente nos humanos (96,33 porcento em 1996), no município de Macapá. Como neste estudo as capturas foram feitas com isca humana, e a espécie de mosquito mais prevalente, a com maior taxa de infectividade para todas as espécies de palsmódio humano, inclusive para P.vivax e a com maior índice de picada/homem/hora foi o An. (Nys) marajoara, podemos concluir que esta espécie tem grande importância na transmissäo de malária nas área estudadas (AU)