Chapter 10 - Lactate Dehydrogenase-Elevating Virus

Abstract

This chapter discusses the parameters of lactate dehydrogenase-elevating virus (LDV) infection. LDV is unusual in its extreme host specificity. To date, LDV is known to infect only mice. The virus replicates rapidly in all strains of mice so far tested, producing a persistent infection. Even though a high titer of infectivity is continually present in the blood, no clinical disease is normally observed in mice infected with LDV. The infection is characterized by elevated levels of certain serum enzymes. This characteristic was actually responsible for the original discovery of the virus and is utilized currently for the assay of its infectivity. Although, LDV has been referred to in the literature by a number of names, including Riley virus and enzyme-elevating factor, it is now commonly referred to as either lactate or lactic dehydrogenase-elevating virus. Currently, LDV is classified as a togavirus , but its characteristics distinguish it from members of the four named groups of togaviruses: the alphavirus, flavivirus, rubivirus, and pestivirus groups. It seems most similar to a few ungrouped togaviruses such as the hog cholera virus, bovine diarrhea virus, and equine arteritis virus. Although LDV replicates rapidly once it enters its host, it is not readily transferred from one mouse to another by natural means. No insect vector for this virus has been identified, nor is anything known about its incidence in wild mouse populations. LDV has been found in association with more than 50 different transplanted murine tumors.