Presence of antibodies against H5, H7 and H9 influenza A virus in wild birds in the State of São Paulo, Brazil

Although the natural reservoirs of the avian influenza (AI) virus have been extensively studied in many countries, there is a clear lack of information on this subject in South America, particularly in Brazil. The objective of this study was to conduct a serological survey for H5, H7 and H9 antibodies to AI-subtype viruses in wild birds in the state of São Paulo , Brazil. Serum samples were tested using the hemagglutination-inhibition assay. Out of the 31 wild birds sampled between January and December of 2006, seven (22.58%), were seropositive for H5, H7 and H9; four (12.90%) were seropositive for H5 and H7; 13 (41.94%), were seropositive only for H7; three (9.7%), were seropositive only for H9; and four (12.90%) were negative for all three hemagglutinin subtypes. These results indicate that AI viruses belonging to H5, H7 and H9 subtypes circulate among wild birds in the state of São Paulo in the form of either concurrent or consecutive infections. This study contributes to the knowledge of AI epidemiology in Brazil, and stresses the need of further detailed and long-term epidemiological and ecological investigation to determine the current status of this virus.

Presence of antibodies against H5, H7 and H9 influenza A virus in wild birds in the State of São Paulo, Brazil

Although the natural reservoirs of the avian influenza (AI) virus have been extensively studied in many countries, there is a clear lack of information on this subject in South America, particularly in Brazil. The objective of this study was to conduct a serological survey for H5, H7 and H9 antibodies to AI-subtype viruses in wild birds in the state of São Paulo , Brazil. Serum samples were tested using the hemagglutination-inhibition assay. Out of the 31 wild birds sampled between January and December of 2006, seven (22.58%), were seropositive for H5, H7 and H9; four (12.90%) were seropositive for H5 and H7; 13 (41.94%), were seropositive only for H7; three (9.7%), were seropositive only for H9; and four (12.90%) were negative for all three hemagglutinin subtypes. These results indicate that AI viruses belonging to H5, H7 and H9 subtypes circulate among wild birds in the state of São Paulo in the form of either concurrent or consecutive infections. This study contributes to the knowledge of AI epidemiology in Brazil, and stresses the need of further detailed and long-term epidemiological and ecological investigation to determine the current status of this virus.(AU)

Zooplankton community structure of two marginal lakes of the River Cuiabá (Mato Grosso, Brazil) with analysis of Rotifera and Cladocera diversity

In the present study, two small lakes on the margins of the River Cuiabá were analyzed regarding taxonomic composition and population densities of the zooplankton. Diversity was evaluated for two groups, Rotifera and Cladocera; sampling was carried out on two dates: 2 March 1999, in the rainy season, and 25 August 1999, in the dry season. Seventy-nine rotifer taxa, 30 cladoceran taxa, and 6 copepod taxa were found. Comparing the species identified in the present study with those recorded by other authors for several water bodies in Mato Grosso and Mato Grosso do Sul states, it was found that 9 species of Cladocera, 2 of Copepoda, and 14 of Rotifera are new records for the region. The most abundant rotifer species were Keratella cochlearis, Brachionus angularis, Polyarthra vulgaris, and Keratella americana. Moina minuta and Bosminopsis deitersi were dominant among the cladocerans, and Notodiaptomus transitans and N. devoyorum among the copepods. Comparing both lakes, the greatest species richness of both Rotifera and Cladocera was observed in Lake Souza Lima, during the rainy season. This is probably linked to the fact that the littoral region of this lake is densely colonized by macrophytes. The lake also has better environmental conditions since it does not receive domestic sewage inputs, as does Lake Parque Atalaia. The diversity of the Rotifera was markedly low in Lake Parque Atalaia, during the dry season, again perhaps linked domestic sewage input found in this water body.

Este trabalho se baseia no estudo das comunidades zooplanctônicas de duas lagoas marginais ao rio Cuiabá, próximas às cidades de Cuiabá e Várzea Grande, e teve por objetivo analisar a composição de espécies, a abundância das populações zooplanctônicas e a diversidade dos Rotifera e dos Cladocera. Realizaram-se duas campanhas para amostragens, com coletas efetuadas nos dias 2/3/1999, no período chuvoso, e 25/8/1999, no período seco. Foram identificados no total 115 táxons, distribuídos em 79 táxons de Rotifera, 30 táxons de Cladocera e 6 táxons de Copepoda. Comparando-se as espécies registradas no presente estudo com aquelas já registradas por diferentes autores para os Estados de Mato Grosso e Mato Grosso do Sul, observa-se que 9 espécies de Cladocera, 2 espécies de Copepoda e 14 espécies de Rotifera são novas ocorrências para esses Estados ou região. As espécies mais abundantes foram Keratella cochlearis, K. americana, Brachionus angularis e Polyarthra vulgaris para Rotifera, Moina minuta e Bosminopsis deitersi entre os Cladocera e Notodiaptomus transitans e N. devoyorum entre os Copepoda. Comparando-se ambas as lagoas, observa-se que a maior riqueza de espécies foi registrada para a lagoa Souza Lima durante a estação chuvosa, em relação aos Rotifera e aos Cladocera, o que pode estar relacionado ao fato de a região litorânea dessa lagoa ser densamente colonizada por macrófitas e não receber esgoto doméstico, como observado na lagoa Parque Atalaia. A diversidade de Rotifera foi notadamente baixa na lagoa Parque Atalaia durante a estação seca, o que também pode estar relacionado à entrada de esgoto doméstico nesse corpo d'água.