Reemerging Rabies and Lack of Systemic Surveillance in People's Republic of China
Reemerging Rabies and Lack of Systemic Surveillance in People's Republic of China
Rabies is a reemerging disease in China. The high incidence of rabies leads to numerous concerns: a potential carrier-dog phenomenon, undocumented transmission of rabies virus from wildlife to dogs, counterfeit vaccines, vaccine mismatching, and seroconversion testing in patients after their completion of postexposure prophylaxis (PEP). These concerns are all scientifically arguable given a modern understanding of rabies. Rabies reemerges periodically in China because of high dog population density and low vaccination coverage in dogs. Mass vaccination campaigns rather than depopulation of dogs should be a long-term goal for rabies control. Seroconversion testing after vaccination is not necessary in either humans or animals. Human PEP should be initiated on the basis of diagnosis of biting animals. Reliable national systemic surveillance of rabies-related human deaths and of animal rabies prevalence is urgently needed. A laboratory diagnosis–based epidemiologic surveillance system can provide substantial information about disease transmission and effective prevention strategies.
The record of rabies in Chinese history dates back to 556 bc in Master Zuo's tradition of the Spring and Autumn annals. He wrote, "In the eleventh month, people in the capital of Song were chasing a rabid dog. It entered the house of Hua Chen". Sporadic descriptions of overt clinical signs of rabies can be found in records of various ancient civilizations. However, robust scientific investigation of the disease began only after 1885, with Louis Pasteur's discovery of postexposure vaccination against rabies. In the 1930s, a rabies virus (RABV) 3aG strain was isolated in Beijing and was eventually developed into a vaccine for human immunization. In the 1950s, another RABV strain (CTN) was isolated in Shandong Province and was characterized and attenuated as a vaccine for humans. However, to date, no dog RABV isolates in China have been developed into animal vaccines. Few domestically licensed vaccines for animal rabies exist, according to the Regulations for Veterinary Biologics in China (www.ivdc.gov.cn). The disconnection between human and dog rabies in China reflects a lack of awareness of the concept of one medicine, or health without regard to species, in approaches to rabies control in the public health system.
Although great progress has been made internationally in rabies control and prevention, >55,000 persons still die of rabies annually worldwide. In China, at least 108,412 persons died of rabies from 1950 through 2004. A rabies epidemic occurs every 10 years in China. Despite high human mortality rates, only ≈30 rabies virus isolates have been recorded and partially characterized by sequencing. Therefore, human rabies is mainly reported without confirmatory laboratory diagnosis in most of China. Few statistics are available for dog rabies, indicating that a diagnosis and surveillance system for animal rabies is not fully functional. Obvious inconsistencies exist in published results of human rabies diagnosis. China is now facing another wave of rabies outbreaks resulting from the combined consequences of rapid economic development, a profitable domestic pet industry, and continuing family planning, resulting in increased numbers of family pets. Reemerging rabies in China has led to a carrier-dog myth, strict pet population control policies, counterfeit vaccines (low antigen, generating <0.5 IU of virus-neutralizing antibodies after administration), vaccine matching, seroconversion testing with an ELISA after completion of postexposure prophylaxis (PEP) in humans, virus–neutralizing antibody titration in vaccinated animals because of inferior vaccines, and other related issues. We discuss these issues and suggest a new approach to prevention and control of rabies when the disease reemerges in an unprepared country like China.
Abstract and Introduction
Abstract
Rabies is a reemerging disease in China. The high incidence of rabies leads to numerous concerns: a potential carrier-dog phenomenon, undocumented transmission of rabies virus from wildlife to dogs, counterfeit vaccines, vaccine mismatching, and seroconversion testing in patients after their completion of postexposure prophylaxis (PEP). These concerns are all scientifically arguable given a modern understanding of rabies. Rabies reemerges periodically in China because of high dog population density and low vaccination coverage in dogs. Mass vaccination campaigns rather than depopulation of dogs should be a long-term goal for rabies control. Seroconversion testing after vaccination is not necessary in either humans or animals. Human PEP should be initiated on the basis of diagnosis of biting animals. Reliable national systemic surveillance of rabies-related human deaths and of animal rabies prevalence is urgently needed. A laboratory diagnosis–based epidemiologic surveillance system can provide substantial information about disease transmission and effective prevention strategies.
Introduction
The record of rabies in Chinese history dates back to 556 bc in Master Zuo's tradition of the Spring and Autumn annals. He wrote, "In the eleventh month, people in the capital of Song were chasing a rabid dog. It entered the house of Hua Chen". Sporadic descriptions of overt clinical signs of rabies can be found in records of various ancient civilizations. However, robust scientific investigation of the disease began only after 1885, with Louis Pasteur's discovery of postexposure vaccination against rabies. In the 1930s, a rabies virus (RABV) 3aG strain was isolated in Beijing and was eventually developed into a vaccine for human immunization. In the 1950s, another RABV strain (CTN) was isolated in Shandong Province and was characterized and attenuated as a vaccine for humans. However, to date, no dog RABV isolates in China have been developed into animal vaccines. Few domestically licensed vaccines for animal rabies exist, according to the Regulations for Veterinary Biologics in China (www.ivdc.gov.cn). The disconnection between human and dog rabies in China reflects a lack of awareness of the concept of one medicine, or health without regard to species, in approaches to rabies control in the public health system.
Although great progress has been made internationally in rabies control and prevention, >55,000 persons still die of rabies annually worldwide. In China, at least 108,412 persons died of rabies from 1950 through 2004. A rabies epidemic occurs every 10 years in China. Despite high human mortality rates, only ≈30 rabies virus isolates have been recorded and partially characterized by sequencing. Therefore, human rabies is mainly reported without confirmatory laboratory diagnosis in most of China. Few statistics are available for dog rabies, indicating that a diagnosis and surveillance system for animal rabies is not fully functional. Obvious inconsistencies exist in published results of human rabies diagnosis. China is now facing another wave of rabies outbreaks resulting from the combined consequences of rapid economic development, a profitable domestic pet industry, and continuing family planning, resulting in increased numbers of family pets. Reemerging rabies in China has led to a carrier-dog myth, strict pet population control policies, counterfeit vaccines (low antigen, generating <0.5 IU of virus-neutralizing antibodies after administration), vaccine matching, seroconversion testing with an ELISA after completion of postexposure prophylaxis (PEP) in humans, virus–neutralizing antibody titration in vaccinated animals because of inferior vaccines, and other related issues. We discuss these issues and suggest a new approach to prevention and control of rabies when the disease reemerges in an unprepared country like China.