Reemerging rabies and lack of systemic surveillance in People's Republic of China

Evolutionary dynamics of rabies viruses highlights the importance of China rabies transmission in Asia

Rabies in Asia is emerging as a serious public health issue. To explore the possible origin, phylogenetic relationships, and evolutionary dynamics of Asian Rabies viruses (RABV), we examined 200 complete nucleoprotein (N) gene sequences from RABV isolates in the region. Phylogeny supported the classification of Asian RABVs into five distinct clusters in lyssavirus genotype 1. Our geospatial and temporal analyses demonstrated that China appears to be the prime source of Asian RABVs. Understanding of rabies transmission and associated human activities, such as dog translocation, can help rabies control and elimination in Asia through collaborative efforts or programs.

Transmission dynamics of rabies in China over the last 40 years: 1969-2009

BACKGROUND

Rabies is a serious reemerging zoonosis in China. The molecular evolution and transmission patterns of rabies virus inferred from historical data can provide guidelines for better disease control and prevention in the future.

OBJECTIVES

To investigate the epidemiology and evolutionary dynamics of the rabies virus in China.

STUDY DESIGN

The molecular evolution of 132 viral glycoprotein gene sequences of Chinese rabies viruses collected in 17 provinces and 3 municipalities between 1969 and 2009 was analyzed.

RESULTS

Phylogenetic analysis revealed that Chinese rabies viruses are subdivided into 6 lineages (A-F) within Lyssavirus genotype 1. Lineage A represents the widely dispersed cosmopolitan lineage while lineage B is closely related to Arctic-like rabies viruses. The remaining lineages (C-F) are typical of those circulating across much of Southeast Asia. The evolutionary rate for Chinese rabies virus was 1.532 x 10(-4) substitutions per site per year, and the corresponding common ancestor was in about 1115.

CONCLUSIONS

The phylogeographic structure demonstrated Chinese rabies viruses have been transmitted intra-provincially and extra-provincially due to human-related activities.

Genetic evidence for domestic raccoon dog rabies caused by Arctic-like rabies virus in Inner Mongolia, China

An outbreak of rabies affected domestic raccoon dogs on an animal farm in Inner Mongolia, China in 2007. A study was conducted to characterize the aetiological agent and clarify the origin of the rabies virus. Brain tissues were obtained from five rabid raccoon dogs. Viral nucleoprotein antigen was detected in the brain tissues and five rabies viruses were isolated from these rabid animals. Phylogenetic analysis of the N and G gene sequences showed that these isolates were closely related to Arctic-like rabies viruses isolated from the far-eastern region of Russia and South Korea, but distinct from the rabies viruses that are widely distributed in endemic areas in China. Epidemiological data suggested that the likely source of infection was from one wild raccoon dog that was captured and placed in the same type of pen used for domestic raccoon dogs.

Re-emergence of rabies in dogs and other domestic animals in eastern Bhutan, 2005-2007

We report a major outbreak of rabies in dogs and other domestic animals that occurred in eastern Bhutan between May 2005 and November 2007. The outbreak peaked in February 2006 and subsided by the end of April 2006 with sporadic cases reported until November 2007. Rabies affected 18 of the 40 sub-districts in the three eastern districts of Bhutan. There were reportedly one human and 256 domestic animal fatalities. The outbreak affected cattle (n = 141, 55%), dogs (n = 106, 41%), horses (n = 7, 3%) and cats (n = 2, 1%). Rabies was primarily diagnosed by clinical signs but 36 cases were confirmed by fluorescent antibody test of brain samples. High densities and movements of free-roaming dogs might have been responsible for the rapid spread and persistence of the infection for a longer period than expected in dogs in eastern Bhutan.

Epidemiological investigations of human rabies in China

BACKGROUND

The epidemic of rabies showed a rising trend in China in recent years. To identify the potential factors involved in the emergence, we investigated and analyzed the status and characteristics of human rabies between 1996 and 2008. Moreover, the status of rabies infection and vaccination in dogs, and prophylaxis of humans after rabies exposure were analyzed.

METHODS

Human rabies data in China between 1996 and 2008 collected from the annual reports of Chinese Center for Disease Control and Prevention (China CDC) were analyzed. To investigate the status of dogs and postexposure prophylaxis (PEP) of humans, brain specimens of domestic dogs were collected and detected, and the demographic details, exposure status and PEP of rabies patients were obtained in 2005 and 2006 in Guangxi, Hunan and Guizhou provinces.

RESULTS

The results showed 19,806 human rabies cases were reported in China from 1996 to 2008, with an average of 1,524 cases each year, and the incidence almost was rising rapidly, with the peak in 2007 (3,300 cases). It was notable that nearly 50% of the total rabies cases nationwide were reported in Guangxi, Hunan and Guizhou provinces. In these three provinces, the rabies infection rate in dogs was 2.3%, and 60% investigated cities had a dog vaccination rate of below 70%; among the 315 recorded human cases, 66.3% did not receive any PEP at all, 27.6% received inadequate PEP, and only 6.0% received a full regime of PEP.

CONCLUSIONS

In recent years, rabies is reemerging and becoming a major public-health problem in China. Our analysis showed that unsuccessful control of dog rabies and inadequate PEP of patients were the main factors leading to the high incidence of human rabies in China, then there are following suggestions: (1) Strict control of free-ranging dogs and mandatory rabies vaccination should be enforced. (2)Establishing national animal rabies surveillance network is imperative. (3) PEP should be decided to initiate or withhold according to postmortem diagnosis of the biting animal. (4) The cost of PEP should be decreased or free, especially in rural areas. (5)Education of the public and health care staff should be enhanced.