Influenza virus

From Felipedia

PCR identification of H5N1 requires oral swabs from suspect cats

Though a rare disease in cats, H5N1 infections (Swine flu) have been reported as sporadic outbreaks in the USA and Asia, and can mimic symptoms of Cat flu.

Cats are rarely reported to show seropositivity for human seasonal influenza virus. These results indicate that infection and transmission of seasonal human influenza viruses to cats are generally self-limiting. However, in the case of highly pathogenic H5N1 viruses, Felidae species, including domestic cats and tigers, became victims during outbreaks in domestic poultry^[1].

Subsequent experiments have shown that these species are highly susceptible to the recently circulating H5N1 viruses^[2]. Systemic infection was confirmed by pathological examination, and viral antigen was found in parenchymal cells, including immune cells, in infected organs. The main viral targets in the lungs were bronchiolar and alveolar epithelium of the lower respiratory tract. These data indicate that cats are susceptible to systemic infection if they are heavily exposed to certain types of H5N1 viruses.

Virus transmissions appears to occur primarily through direct contact of cats with infected poultry or poultry meat^[3].

Clinical signs usually appear within 1-2 days following contact with virus, although asymptomatic cases have been reported^[4].

Although diagnostic tests exist for detection of H5N1 antibodies in feline serum, diagnosis usually requires isolation of the H5N1 virus via PCR^[5]. Symptomatic therapy, utilising broad-spectrum antibiotics or antiviral drugs such as oseltamivir have given mixed result. Mortality rates in cats are high, compared with other felids^[6].

Control of outbreaks are aimed at minimizing contact with poultry or poultry products. There are presently no licensed vaccines available for prophylactic use in cats^[7].

References

1. ↑ Thanawongnuwech R, et al (2005) Probable tiger-to-tiger transmission of avian influenza H5N1. Emerg Infect Dis 11:699–701
2. ↑ Kuiken T, et al (2004) Avian H5N1 influenza in cats. Science 306:241
3. ↑ Keaw, J et al (2004) Avian influenza H5N1 in tigers and leopards. Emerg Infect Dis 10:2189
4. ↑ Leschnik, M et al (2007) Subclinical infection with avian influenza A (H5N1) virus in cats. Emerg Infect Dis 13:243
5. ↑ Marshall, J Schulz, B & Hartmann, K (2008) Evaluation of a point-of-care influenza antigen test for the detection of highly pathogenic avian influenza H5N1 virus in cats. Transbound Emerg Dis 55:315
6. ↑ Hartmann, K & Marschall, J (2010) Influenza infections. In August, JR (Ed): Consultations in feline internal medicine. Vol 6. Elsevier Saunders, Philadelphia. pp:13-18
7. ↑ Karaca, K et al (2005) Immunogenicity of fowlpox virus expressing the avian influenza virus H5 gene (TROVAC AIV-H5) in cats. Clin Diag Lab Immunol 12:1340