Evaluation of feline leukemia virus control measures.
A susceptible-infected-recovered-susceptible (SIRS) model of the epidemiology of feline leukemia virus is formulated and analysed. The dynamics of the disease are dramatically different in no-risk, low-risk and high-risk subpopulations of asocial, free roaming, and multiple cat household cats. Among low risk (<1% prevalence) free roaming cats, the model predicts that an effective immunization rate of 4% year-1, or an effective removal rate of 8% year-1 are adequate to control the disease completely. Under higher risk (10% prevalence) conditions, an effective immunization rate of 23-72% year-1 or a removal rate of 69-145% year-1 are required for control. At very high (30%) prevalence rates, even heroic measures may not suffice to substantially reduce disease prevalence: a vaccination rate of 100% year-1 even if attainable, would only slightly reduce disease prevalence from 30% to 29%. We conclude that the current estimated effective feline leukemia virus immunization rate of 11-19% of the general population is inadequate to provide herd immunity in the subpopulation of cats which are genuinely at risk of infection. A substantial increase in the vaccination rate and/or intensification of test and removal efforts in the at risk population would be required to attain an effective level of protection.
Lubkin
S R
SR
Department of Applied Mathematics, University of Washington, Seattle, USA. lubkin@amath.washington.edu
Romatowski
J
J
Zhu
M
M
Kulesa
P M
PM
White
K A
KA
D000818:Animals; D002415:Cats; D004198:Disease Susceptibility; D005069:Evaluation Studies as Topic; D007114:Immunization / Q000662:veterinary*; D016582:Leukemia, Feline / Q000453:epidemiology / Q000517:prevention & control*; D008954:Models, Biological; D011156:Population Density; D015995:Prevalence; D012931:Social Environment