Complex approach to assess the epidemiological risk of hepatitis A in the current conditions
Hepatitis A is a common cause of viral hepatitis. The pronounced autonomy of the epidemic process of infection, the polymorphism of its clinical symptoms and other factors make it difficult to apply universal approaches to predict the morbidity of hepatitis A. The aim of the study was to develop a complex approach for epidemiological risk assessment of hepatitis A. Short-term prediction of hepatitis occurrence rate was carried out with maximum stability and regression equation methods in Nizhny Novgorod during the 1994-2017 period. Concentration of the pathogen in waste water samples was made by adsorption method using non-woven bags with macroporous glass. Viral RNA was detected by real-time PCR method. Anti-HAV IgG prevalence rate was studied by ELISA (enzyme-linked immunosorbent assay) method among the relatively healthy population in the age from 1 to 60 years in Nizhny Novgorod. Accuracy of mathematic prediction of hepatitis A morbidity rate has been ineffective in the current conditions. It is necessary to supplement the analysis of recorded morbidity data by monitoring the activity of activation signs of the pathogen circulation and parameters of specific population immunity for an adequate assessment of the epidemiological risk of hepatitis A in current conditions. Such precursors are an increase in the detection rate of anti-HAV above a threshold value in the indicator age groups of children 1-4 years old and 5-9 years old, as well as the detection of pathogen RNA in wastewater before treatment.