Surveillance of feral cats for influenza A virus in north central Florida

Abstract

Background: Transmission of highly pathogenic avian influenza and the recent pandemic H1N1 viruses to domestic cats and other felids creates concern because of the morbidity and mortality associated with human infections as well as disease in the infected animals. Experimental infections have demonstrated transmission of influenza viruses in cats.

Objectives: An epidemiologic survey of feral cats was conducted to determine their exposure to influenza A virus.

Methods: Feral cat sera and oropharyngeal and rectal swabs were collected from November 2008 through July 2010 in Alachua County, FL and were tested for evidence of influenza A virus infection by virus isolation, PCR, and serological assay.

Results and conclusions: No virus was isolated from any of 927 cats examined using MDCK cell or embryonated chicken egg culture methods, nor was viral RNA detected by RT-PCR in 200 samples tested. However, 0.43% of cats tested antibody positive for influenza A by commercial ELISA. These results suggest feral cats in this region are at minimal risk for influenza A virus infection.

Figure 1

Characteristics of cats sampled stratified by the quarter of year in which samples were collected. Between 40 and 60 samples were collected every month between November 2008 and July 2010, except for August 2009 and April 2010. Urban, suburban, and rural environments reflect the general location where the cats were trapped.