China has the second highest number of reported rabies cases in the world, but numbers of human deaths have been decreasing. According to the WHO, the Chinese authorities are forecasting national rabies elimination by 2025. Most of the cases are reported from the country’s Southeastern provinces. A new study reports on ongoing transmission of rabies in Northwestern China, highlighting challenges and opportunities pertinent to the elimination efforts.
Rabies virus continues to cross carnivorous species and to infect humans and livestock in China. Rabies vaccination of the principal reservoir animals is even being neglected in most regions of China, resulting in continuous expansion of rabies epidemics. Since there is no oral vaccine for stray dogs and wild animals and no inactivated vaccine for large domestic animals, rabies is not currently controlled in China. Rabies outbreaks are caused by bites of dogs and wild foxes and the long-term effects on protection against rabies using canine inactivated vaccines in domestic camels and cattle. At least three separate phylogenetic groups of rabies virus consistently exist and spread throughout Northwest China. Local canine vaccine products can be used to induce levels of virus neutralizing antibodies indicative of protection against rabies in cattle and camels, however licensed oral and inactivated vaccines for reservoir carnivores and large domestic animals are urgently needed for elimination of rabies in China.
Rabies Outbreaks and Vaccination in Domestic Camels and Cattle in Northwest China. (2016) PLoS Negl Trop Dis 10(9): e0004890. doi:10.1371/journal.pntd.0004890
In contrast to many countries where rabies has been well controlled in humans and livestock, even in wildlife, rabies is still endemic in almost regions of China. In Northwest China, rabies transmitted by stray dogs and wild foxes has caused heavy economic losses to local herdsmen, as well as causing numbers of human cases. In this study, as part of an investigation of ways to prevent rabies epidemics in livestock, we report an analysis of domestic cattle and camel rabies cases in Ningxia Hui (NHAR) and Inner Mongolia Autonomous Region (IMAR) and the immune efficacy of canine inactivated rabies vaccines in these ani- mals. We found that rabies viruses from these animals are closely related to dog-hosted China I and fox-associated China III lineages, respectively, indicating that the infections originated from two different sources (dogs and wild foxes). As well as the previously reported Arctic and Arctic-related China IV lineage in IMAR, at least three separate phylogenetic groups of rabies virus consistently exist and spread throughout Northwest China. Since there is no licensed oral vaccine for wild foxes and no inactivated vaccine for large livestock, local canine inactivated vaccine products were used for emergency immunization of beef and milk cattle and bactrian (two-humped) camels in local farms. Compared with a single injection with one (low-efficacy) or three doses (high-cost), a single injection of a double dose of canine vaccine provided low-price and convenience for local veterinarians while inducing levels of virus neutralizing antibodies indicative of protection against rabies for at least 1 year in the cattle and camels. However, licensed vaccines for wildlife and large domestic animals are still needed in China.