Cotton rats (Sigmodon hispidus): an animal model to study the pathogenesis of measles virus infection.

Measles is still the most lethal infectious disease of infants worldwide. In spite of research efforts, two major problems associated with measles virus (MV) infection have not been resolved. One is the marked immune suppression leading to subsequent (often lethal) opportunistic infections and the second is waning of maternal antibodies which do not protect against wild type virus infection any longer, but impair vaccination. Monkeys are an animal model in which MV infection most closely resembles the human disease. The use of monkeys is restricted by ethical and financial reasons and their availability. A cost-effective alternative is the cotton rat (Sigmodon hispidus). Cotton rats are the only rodents which replicate measles virus in lung tissue after intranasal infection. Our research has shown that cotton rats are a valid model to study MV induced immune suppression and to test vaccine candidates. It is also useful for comparing various wild type measles virus strains as well as recombinant measles viruses.