DOMESTIC CATS AS HOSTS FOR HUMAN INFLUENZA A AND B VIRUSES IN BRAZIL

Studies on the host range of influenza viruses have been of great importance to prove the role of some animals that were already considered as unlikely links, in the virus transmission chain. This study aimed to investigate the circulation of the influenza virus in cats in Brazil. Domestic cats, assisted at the clinic of the Faculty of Veterinary Medicine at the University of Sao Paulo, were grouped according to gender and age (young and adult). Serum samples were collected and analyzed for antibodies to influenza A and B viruses by the haemagglutination inhibition (HI) test using the corresponding antigens from the circulating viruses in Brazil. Twenty per cent of the cats aged between 6 and 20 years old responded with high antibody titers (≥ 640 HIU/25 µL) against human influenza A (H1N1) virus. Lower percentages of the animals in the same age group, 11% and 8%, presented the same high titers in response to human influenza A (H3N2) and B virus samples respectively. When the animals were classified by gender, 17 % of males and 8% of females showed a poor antibody response against the influenza A (H1N1) virus (titers of ≤ 20 HIU/25 µL). For the first time in Brazil, protective antibody titers against human influenza viruses revealed the presence of virus infection possibly transmitted to the domestic cats by man. In conclusion, our results show that domestic cats, like other mammals, may play a role in interspecies transmission and spread of the influenza virus. DOI:  http://dx.doi.org/10.17525/vrr.v15i2.43