МОДЕЛИРОВАНИЕ ДИНАМИКИ ЭПИДЕМИИ ВИЧ-ИНФЕКЦИИ С ИСПОЛЬЗОВАНИЕМ ЧАСТОТЫ ВСТРЕЧАЕМОСТИ РАННИХ СЛУЧАЕВ ЗАРАЖЕНИЯ

Errors in forecasting the expected number of HIV patients lead to organizational and economic problems. In particular, the budgetary funding of the purchases of drugs and diagnostic means may turn out to be inadequate to a real epidemiological situation. Study objective: To ascertain the accuracy of modeling of HIV infection based on standard epidemiological data supplemented with the incidence of early HIV cases. The expediency of this task is determined by the necessity to find approaches to making more accurate prognoses. Materials and methods: Retrospective modeling of the dynamics of HIV epidemic was carried out for the period of 2010 to 2014 with account of the incidence of new HIV cases and HIV-related mortality rate. The coef- ficient of HIV increment in the study population was used. This parameter is determined from empirical data by calculating the incidence of the early HIV cases are assumed to be those that have negative or uncertain results of immunoblotting for p24 antigen and some p24-positive cases selected based on additional criteria. The use of parameters accounting of the time elapsed from HIV contraction made it possible to calculate the probable number of the cases of newly acquired HIV based on the incidence of early HIV cases in the population. On average, one «missed» HIV case may result in infecting 0,64 + 0,09 (p<0,05) persons annually. The difference between this estimate and HIV-related mortality rate provides for calculating the increment coefficient, which characterizes the rate of HIV spread and determines the short-time trend of HIV epidemic. The mean error of this prognosis relative to the actual number of HIV cases found was 4% vs. 26% found in the case of using the least squares method. The incidence of the early HIV cases may be used as a criterion of the effectiveness of preventive interventions and for calculating the minimal scope of screening that can make the trend of HIV epidemic be declining.