Analysis of the infection system of human T-cell leukaemia virus type I based on a mathematical epidemic model.

Abstract

Human T-cell leukaemia virus type I (HTLV-I) is a retrovirus that causes adult T-cell leukaemia (ATL). HTLV-I has existed in Japanese people for thousands of years. In order to prevent an epidemic of HTLV-I, it is important to explain the infection system by a mathematical approach. By considering the main infection routes in Japan, that is: (i) mother-to-child transmission; (ii) male (husband)-to-female (wife) transmission; and (iii) female (wife)-to-male (husband) transmission, a mathematical model for describing the time-dependent change of the infection proportion can be constructed. An upper bound of the present infection rate per year in male-to-female transmission and that in female-to-male transmission is given by the model, and theoretical results related to HTLV-I infection are also deduced from the mathematical model. A simulation study based on the present model demonstrates the theoretical results relating to the HTLV-I infection.