Impact of cross-border migration on disease epidemics: Case of the P. falciparum and P. vivax malaria epidemic along the Thai-Myanmar border

Abstract

The transmission of Plasmodium falciparum and Plasmodium vivax malaria in a mixed population of Thais and migrant Burmese living along the Thai-Myanmar border is studied through a mathematical model. The population is separated into two groups: Thai and Burmese. Each population in turn is divided into susceptible, infected, recovered and in case of vivax infection, a dormant subclass. The model is then modified to allow for some of the Burmese (given as a fraction P) to be infectious when they enter into Thailand. The behaviour of the modified model is obtained using a standard dynamical analysis. A new basic reproduction number is obtained. Numerical simulations of the modified model show that when P ≠ 0 and the same set of parameter values used in the initial model are used, the Thai population will be in the epidemic state. In other words, the repeated introduction of infectious Burmese (no matter how small of a number) will result in a malaria epidemic among the Thais irregardless of the public health practice undertaken by the Thai government. In the presence of the infected Burmese, the Thai government would have to increase the facilitites to treat the people who are infected by the malaria. © 2010 World Scientific Publishing Company.