The Risk of Virus Infection and Behavioral Factors on Pathogen Transmission from Macaques to Humans
|macaque human pathogen transmission risk behavioral factors
Zoonosis is one of the major diseases that endanger human health. There are more than200types of zoonoses and150kinds of parasitic diseases can be transmitted directly or indirectly to humans from animals or animal products, which leading to human disease and even death. Zoonoses are serious threats to the stability of social economy and ecological security, and it can also cause serious damage to human health and public health. There are many times of outbreak of zoonoses in the history, such as smallpox, plague, cholera, rabies, SARS, avian influenza, and HIV/AIDS, which brought huge disaster to human beings. As human closely related species, nonhuman primates are similar with humans in morphological structure, physiology, biochemistry, metabolic function, genetic structure and ecological behavior. However, this similarity is associated with the sensitivity of the pathogen, that is, relative to zoonoses from other species of animals, zoonoses from nonhuman primates are more likely to infect human beings, which pose a threat to human health.There are22species of nonhuman primates in China, which second only to Madagascar, Indonesia and Brazil. Meanwhile, China is a big country with large population density and frequent foreign communication. With the fast development of economy and the acceleration of internationalization, nonhuman primates have become as the main objects in aquaculture, tourism and scientific research activities. In mis situation, the interaction between humans and nonhuman primates becoming more and more frequent. If the zoonoses from nonhuman primates infected human beings in large scale, it will affect economic development and social stability, and even panic in the world. At present, the domestic research in this respect is relatively weak, thus to carry out the research in this area is more and more targeted and urgency. The first step is to understand the kinds of microorganism and virus infection situation in both nonhuman primates and staff that related to nonhuman primate management work. At the same time, it should be carried out the behavior study and behavior survey between humans and nonhuman primates. Preliminary assess the risk of pathogen transmission from nonhuman primates to humans in our country. And make the prevention and control measures to avoiding pathogen transmission from nonhuman primates to humans.From September,2008to June,2010, we conducted this study in Anhui province, China, in three different contexts in which human-macaque interactions are known to occur:1) Tibetan macaques (Macaca thibetana) at Huangshan Monkey Center,2) Japanese macaques (Macaca fuscata) at Hefei Wildlife Zoo and3) Rhesus macaque (Macaca mulatto) at Anhui Laboratory Monkey Center. We used scan sampling and continuous recording (using a digital voice recorder) to collect data about interactions between humans and monkeys, including numbers, sexes and age classes. All-occurrence sampling was used to record the frequency of the monkeys’aggressive behaviors. Blood samples were analyzed by enzyme-linked immunosorbent assay (EL1SA) for the presence of immunoglobulin antibodies to Herpes B Virus (BV), Hepatitis A virus (HAV), Simian foamy virus (SFV), Simian pox virus (SPV), Simian retrovirus (SRV) and Simian T-cell lymphotrophic virus-1(STLV-1). The main results are as follows,(1) We observed more varied interaction behavior types at Huangshan Monkey Center compared to Hefei Wildlife Zoo and Anhui Laboratory Monkey Center (P<0.05). The frequency of interaction behavior and macaque aggressive behavior was also the highest at Huangshan Monkey Center (P<0.05).(2) There has no significant difference about interaction behavior between tourists and macaques at both Huangshan Monkey Center and Hefei Wildlife Zoo (.P>0.05). The frequency of proximity behavior at Hefei Wildlife Zoo was higher than that at Huangshan Monkey Center (P<0.05).(3) Questionnaire survey showed that the frequency of interaction behavior between staff and macaques were much higher than that in tourists and local residents (P<0.05). But the difference between tourists and local residents was not significant.(4) The difference about interaction behavior types with macaques among staff, tourists and local residents was not significant (P>0.05). There has no significant difference about safeguard measures when scratched or bitted by macaques among staff, tourists and local residents (P>0.05).(5) Our results showed that Macaca thibetana were tested positive for all six types of virus antibodies, Macaca mulatta were tested five types of virus antibodies, and Macaca fuscata were three types of virus antibodies.(6) The most highest seroprevalence antibodies to BV is37.5%in Macaca fuscata, to HAV is13.6%in Macaca mulatta, to SPV is27.3%in Macaca mulatta, to SFV is18.8%in Macaca thibetana, to SRV is25%in Macaca fuscata, and to STLV-1is6.3%in Macaca thibetana. The difference between seroprevalence antibodies and age distribution among macaques was not significant (P>0.05).(7) We had not detected seroprevalence antibodies to macaques virus in staff except HAV. The seroprevalence antibodies to HAV is57.1%at Huangshan Monkey Center, and then is33.3%at Hefei Wildlife Zoo, and is10%at Anhui Laboratory Monkey Center.(8) There have two I risk level (high risk level, that is, BV and SPV), one Ⅱ risk level (middle risk level, that is, HAV, SFV and SRV) and one Ⅲ risk level (low risk level, that is, STLV-1) at Huangshan Monkey Center. There have two I risk level (that is BV), one Ⅱ risk level (that is SPV), and four Ⅲ risk level (that is SRV) at Hefei Wildlife Zoo. There have two I risk level (that is, BV and SPV), one Ⅱ risk level (that is HAV), and three Ⅲ risk level (that is SFV and SRV) at Anhui Laboratory Monkey Center.Our results showed that the monkey virus types and infection frequency were in accordance with the degree of closed environment. The route of pathogen transmission from macaques to humans through blood, body fluids, and feces and so on. We had not detected seroprevalence antibodies to macaque virus in staff. The results showed that the pathogen transmit from macaques to humans is unlikely, but there has still a risk of virus infection. The effective methods to prevent infecting virus is avoid direct body contact with macaques. Meanwhile, the key action is to avoid contact with the macaque pollutants or intake of contaminated food and water. According to the results of this study, it is suggested that take the following measures: (1) conduct quarantine to macaques regularly,(2) raise awareness of ecological protection in public and improve the relationship with the macaques,(3) prevent the interaction between wild macaques and domestic animals to avoid mutual spreading pathogens,(4) carry out the vaccine strategies for captive macaques to reducing virus infection rate among macaques.Potential pathogen transmission from nonhuman primates to humans pose a serious and increasing threat to human public health and welfare in the world, but there has no enough attention in public about this in China. Our study is a first step to characterizing the disease’s emergence status in macaques and behavioral interactions between humans and nonhuman primates in China, which will be critical pieces of information for developing strategies to minimize potential transmission risk from macaques to humans.