[Catalytic model analysis of HAV and HBV infection rate in a PLA population]

Mathematical model can be used to express the quantitative relationship between the factors of epidemiologic processes. In this paper, we tried to analyze the data of HAV and HBV infection rates obtained in a cross-section study in a Navy aviation school in December 1983, using simple and reversible catalytic models. It was shown that the expected HAV prevalence rate was not significantly different from the observed HAV infection rate and the observed incidence density of HAV new infection (111.8/1000 person-year) found during follow-up period of one and-a-half years was nearly identical to the theoretical value (111.7/100 person-year). The result of reversible model fitted the HBV prevalence rate well, not significantly different from the data of the cross section study, but the revalue was a little different from that observed in the follow-up period. The results suggest that mathematical model is very useful in the analysis of the HAV and HBV prevalence rates in a fixed population. The catalytic model can be used to predict the average infection rates. To make the models fitting better, a long-time follow-up study or multivariable analysis is required and the formula needs further improvement.