Bionic Computer Model for Rabies-Oriented Ecological Infectious Diseases (Preprint)
Authors: Huang Yihao , Li Mingtao 
Published: March 2020

BACKGROUND

Rabies is a zoonotic acute infectious disease of the central nervous system caused by the rabies virus. Because rabies patients have outstanding clinical manifestations of being afraid to drink water, this disease is also called "water phobia". However, diseased animals do not have this characteristic. The main clinical manifestations are peculiar mania, fear of anxiety, fear of wind and water, salivation and pharyngeal muscle spasm. Eventually, paralysis will endanger life. The various lengths of the incubation period are one of the characteristics of this disease. Most cases occur within 3 months, with 4% to 10% occurring in more than half a year, and about 1% in cases exceeding 1 year. The longest case in the literature is 10 years. Factors that affect the length of the incubation period are age (shorter in children), wound site (head and facial occurring earlier), depth of wound (the deep occurring earlier), number of virus invasions, the virulence of the strain, and whether formalized debridement processing and rabies vaccine prevention are performed. Others such as trauma, cold, and overwork may contribute to early onset.
The earliest country to propose the term rabies was Ancient Babylon. At that time, there was no effective rabies control method, and the pain was unbearable at the onset with a high lethal rate. Therefore, many people chose to commit suicide after being bitten by dogs. There are more than 150 countries in the world that have caused a large number of deaths due to the wild spread of rabies. At present, only one-quarter of the country can effectively control the occurrence of rabies. Especially in some countries with severe health conditions, the number of rabies cases is far ahead and difficult to control. In Asia, India is the country with the most severe rabies situation, with an annual incidence of 20,000 cases, followed by Southeast Asia and most parts of Africa.
The vaccination rate of dogs in China is relatively low, especially in rural areas, free-range dogs are rarely vaccinated. Therefore, the death toll from rabies is still huge. The number of people who died of rabies in China in the past two decades has shown a trend of rising first and then falling. The number of rabies deaths rose rapidly in the 1990s, reaching a peak in 2007. After the unremitting efforts of relevant personnel in China, the number of rabies deaths has slowly decreased and has decreased by about 76% in 2013. At present, there are still a considerable number of wild dogs foraging outside in China. Garbage yards and schools are all places where wild dogs may gather. Thus, during the transmission of rabies, wild dogs are an important source of infection that cannot be ignored. In addition, wild dogs lack human domestication, and the situation that wild dogs bite humans is constantly occurring. Therefore, this paper conducts a comprehensive study of domestic dogs, wild dogs, and humans in studying the spread of rabies.

OBJECTIVE

This paper is to study the ecological transmission mode of rabies to make theoretical contributions to the suppression of rabies in China.

METHODS

A mathematical model is constructed aiming at the transmission mode of rabies. During the construction of the mathematical model, the relevant data comes from the officially published data in China and the research data of previous literature. According to this model, this study performs the fitting of the number of rabies patients and the prediction of the number of rabies patients in the future. Also, it studies the effectiveness of different rabies suppression measures.

RESULTS

The results of the study indicate that the number of people infected with rabies rises in the first stage, and then decreases. In about 10 years, the number of rabies cases will be controlled within a relatively stable range. According to the prediction results of the model in this paper, the number of rabies will eventually be controlled to about 500 people every year. Controlling the birth rate of domestic and wild dogs as well as increasing the level of rabies immunity in domestic dogs are relatively effective rabies suppression programs.

CONCLUSIONS

The basic reproductive number of rabies in China is still greater than 1 after the study in this paper. Therefore, in terms of rabies control, China still needs many studies, policy formulation, and grassroots implementation. In addition, the research on rabies transmission mode and control measures in this paper can provide theoretical support for rabies control in China.