Wesselsbron virus - a virus not previously described, associated with abortion in domestic animals

Abstract

1. There has been isolated from a lamb a pantropic virus with neurotropic properties and a well-marked affinity for embryonic tissue. 2. In the field the vectors are mosquitoes which have yet to be identified accurately. 3. In sheep infection with the virus causes a febrile reaction after a short incubation period of about one to four days, the mortality rate not being high. Pregnant ewes may abort during the febrile reaction in which case virus could not be isolated from the foetuses. Subsequently the virus invades the foetus causing death usually with abortion. The mortality amongst foetuses carried to full term and new-born lambs is very high (practically 100%). New born lambs suckling reacting ewes did not become infected by contact with the reacting ewe. 4. In addition to sheep, cattle, horses, pigs, mice, rabbits, guinea-pigs and man are susceptible. 5. Infant and adult mice are equally susceptible to intracerebral inoculation, the mortality being 100%. Infant mice are fully susceptible to intraperitoneal infection but in adult mice the reaction is at most inapparent.