Host condition and individual risk of cowpox virus infection in natural animal populations: cause or effect?
Recent studies have provided evidence that endemic pathogens may affect dynamics in animals. However, such studies have not typically considered that infected individuals might have a preceding underlying poor condition. We examined whether individuals in poor condition are more likely to become infected by an endemic pathogen, using as a system the dynamics of cowpox virus in field voles. With data from monthly sampled vole populations, a nested case-control study evaluated whether susceptible individuals with poorer condition had higher probabilities of contracting cowpox. The influence of condition was found to be considerable, especially for males. At times when a susceptible male with good body condition had a relatively low probability of becoming infected, a susceptible male with poor body condition was twice as likely to contract cowpox; if this male was also anaemic, the chances were almost quadrupled. We discuss the care needed when interpreting the findings of wildlife disease studies.
Beldomenico
P M
PM
School of Biological Sciences, University of Liverpool, UK. pbeldome@fcv.unl.edu.ar
Telfer
S
S
Lukomski
L
L
Gebert
S
S
Bennett
M
M
Begon
M
M
D000740:Anemia / Q000150:complications / Q000662:veterinary* / Q000821:virology; D000818:Animals; D003411:Arvicolinae; D016022:Case-Control Studies; D015605:Cowpox / Q000150:complications / Q000453:epidemiology / Q000662:veterinary*; D019353:Endemic Diseases / Q000662:veterinary*; D005260:Female; D008297:Male; D011157:Population Dynamics; D011159:Population Surveillance; D012737:Sex Factors; D014197:Trees; D006113:United Kingdom / Q000453:epidemiology