Diagnóstico sorológico de influenza A subtipo H1 na avicultura familiar da região metropolitana de Belo Horizonte,Minas Gerais e Santa Maria,Rio Grande do Sul.

Abstract

Serum samples (n=704) were collected from Gallus gallus domesticus and Cairina moschata (Anatidae) for the investigation of antibodies to influenza A virus. Samples were collected from birds of family poultry of the surrounding counties of Santa Maria/RS and the metropolitan region of Belo Horizonte/MG totaling twenty different counties and seventeen ducks including free-living and domestic birds. The chosen tests for the survey were agar gel immunodiffusion (AGID) for antibodies to influenza A virus nucleoprotein (N) and haemagglutination inhibition (HI) for the H1 subtype, with protocols as described by the World Organisation for Animal Health (OIE). Out of the 704 tests performed by AGID, eight (8/704) were revealed positive for antibodies to N (1.13%), with six (6/704) of these retested positive (0.85%) by HI for H1 subtype specific antibodies. Two samples tested positive by AGID were shown to be not reactive in the H1 subtype specific HI, suggesting responses to other subtype. A low occurrence of antibodies to influenza A was found and most were specific to subtype H1, although 0.25% were specific to an unknown subtype. One anatid bird was shown reagent in both tests. The low occurrence of antibodies may suggest a low activity of influenza A virus during the period of study.