The Role of Rodents in the Transmission of Viral and Bacterial Diseases of Livestock

Abstract

Rodents are the most successful and abundant mammals on earth. The commensal behaviour of some of the rodents has made them important in the epidemiology and ecology of many viruses and bacteria pathogenic to livestock and humans. Rodents may act as vectors, carriers, or passive (mechanical) transmitters of pathogens. Diseases actively transmitted by rodents may involve a territory, a region or even across continents as they observe no internationally recognized boundaries. These diseases may be "classified as (a) those which affect rodents as well as other mammals (e.g. rabies, lymphocytic choriomeningitis, typhus, Q fever, plague, salmonellosis) (b) those for which rodents act as reservoirs and affects other mammals (e.g. leptospirosis, foot and mouth disease, African horse sickness, ehrlichiosis). Mechanical transmission of disease causing agent through rodent’s hairs, claws and mouthparts although frequent, is usually limited to a farm or a household. Certain pathogens (e.g. pox viruses, salmonella) and various fungal and bacterial spores may b-e transmitted this way. Rodents also act as intermittent hosts for arthropods and arachnids, which themselves are primary hosts for diverse parasitic microorganisms of animals and humans. This paper describes briefly, the most important livestock (and human) diseases of viral and bacterial origin which are transmitted directly or indirectly by rodents.