The field vole (Microtus agrestis) is a known maintenance host of Mycobacterium microti. Previous studies have shown that infected animals develop tuberculosis. However, the disease is also known in cats and is sporadically reported from humans and other mammalian species. We examined trapped field voles from an endemic area, using a range of diagnostic approaches. These confirmed that a combination of gross and histological examination with culture is most appropriate to identify the true prevalence of the disease, which was shown to be more than 13% at times when older animals that have previously been shown to be more likely to develop the disease dominate the population. The thorough pathological examination of diseased animals showed that voles generally develop systemic disease with most frequent involvement of spleen and liver, followed by skin, lymph nodes, and lungs. The morphology of the lesions was consistent with active disease, and their distribution suggested skin wounds or oral and/or aerogenic infection as the main portal of entry. The demonstration of mycobacteria in open skin lesions, airways, and salivary glands indicated bacterial shedding from the skin and with sputum and saliva. This suggests not only the environment but also direct contact and devouring as likely sources of infection.

In this study a total of 2230 sheep (one-three years of age) were serologically surveyed in three selected areas in Libya (Western, Middle and Southern areas) to specify foci of infection and determination of the prevalence of ovine brucellosis using Rose Bengal Plate Test and Rivanol test. Prevalence of brucellosis in this study revealed 4%, 0%and 0%, respectively. Only the western area showed positive cases, while the Middle and Southern areas showed no serological evidence of brucella infection.