Contrastive prevalence of feline retrovirus infections between northern and southern Vietnam.

The prevalence of infections with three feline retroviruses; feline leukemia virus (FeLV), feline immunodeficiency virus (FIV) and feline foamy virus (FeFV), was examined in domestic cats (Felis catus) and leopard cats (Felis bengalensis) in southern Vietnam in 1998. We then compared this data with our previous study in northern Vietnam in 1997. None of the cats had FeLV antigens in both the northern and southern areas. In contrast, there is a great distinction in the seropositivity of FIV. Twenty-two percent of domestic cats had FIV antibodies whereas no FIV positive cats were detected in northern area. FIV may have entered southern Vietnam recently and spread rapidly. FeFV infections were found in both areas, suggesting that FeFV might be present in the cat populations in Vietnam from the earliest time.