Analysis Of The Dynamic Transmission Characteristics Of Malaria In Anhui Province

Malaria is a typical vector-borne disease.By the beginning of the 21 st century,the malaria epidemic in most areas of China has been controlled.However,the malaria vector species including Anopheles are still widespread in Anhui,Hainan,Yunnan and other provinces.Therefore,it is necessary to further explore the transmission dynamics of malaria and analyze the risk of malaria resurgence in China.The understanding of malaria transmission will provide guidance for effective control measures for malaria.Taking Anhui Province as an example,we used ARIMA model and Gibbs sampling method to study the “break point” of the transmission dynamics of P.vivax malaria and P.falciparum malaria in recent ten years.The Susceptible Infected Recovered-Susceptible Infected(SIR-SI)human-mosquito coupled model was adopted for the transmission dynamics of local P.vivax malaria.The mosquito biting rate and the transmission rate over time were estimated.Then we established a multiple linear regression model to explore the effects of temperature and precipitation on mosquito biting rate and P.vivax malaria transmission rate.For imported P.falciparum malaria,we studied the potential reasons for the significant increase in the incidence of P.falciparum malaria.Finally,nonparametric statistical method was used to analyze the resurgence risk of local malaria.The results show that: 1)the “break point” of the transmission dynamics of P.vivax malaria and P.falciparum malaria in Anhui Province occurred in 2010.The reason for the sharp increase of imported P.falciparum malaria cases after the “ break point ” is the increase of Anhui Province's annual investment in Africa.2)The mosquito biting rate and transmission rate of local P.vivax malaria had significant annual seasonality with amplitude of 42.4%;temperature(p value= 7.23e-11)and precipitation(p value = 0.004)had significant effects on the transmission rate of P.vivax malaria.3)The number of the Infected of p.vivax malaria not only had one year small cyclic pattern,but also showed multi-year cyclic pattern due to long-term change in the number of the Susceptible.Affected by the widespread existence of malaria vectors,the long-term trend of climate factors,the increasing number of imported malaria cases year by year and the trend of the number of susceptible people,we should be alert to the possibility of malaria resurgence in eliminated areas.