Features of the long-term dynamics of virus contamination of non-centralized water supply in the Russian Federation

Microbiological contamination of sources of non-centralized water supply can lead to high risks of the spread of certain infectious diseases. Sources of non-centralized water supply, as a rule, are characterized by the absence of sanitary protection zones for water sources, lack of preliminary water treatment, contributing to water contamination by microorganisms and infection with human viruses. The aim is to study the spectrum of viruses contained in the water of non-centralized water supply, using laboratory diagnostic methods regulated to determine the normalized indicators. During 2014-2023, water samples from the non-centralized water supply system were taken annually (n=8279). The dynamics and structure of contamination of water in a non-centralized water supply system with hepatitis A (HAV), rotavirus group A (Rotavirus A), enterovirus (Enterovirus), norovirus genogroup 2 (Norovirus GII), astrovirus (Astrovirus) and adenovirus group F (Adenovirus F) viruses have been described using a molecular genetic method. According to the conducted research, it was found that for the period 2014-2023, the average specific weight of water samples from non-centralized water supply that did not meet sanitary and hygienic standards in the Russian Federation for the period from 2014 to 2023. in terms of the presence of viruses, it was 1.3% (95% CI 1.03-1.52). The proportion of non-centralized water supply samples in terms of Rotavirus A content was 1.78 samples (95% CI 1.36–2.29), Enterovirus - 0.70% of samples (95% CI 0.47-0.99), Adenovirus F - 0.30% of samples (95% CI 0.01-1.67), HAV – 0.30% of samples (95% CI 0.10-0.69), Norovirus GII - 0.29% of samples (95% CI 0.09-0.67), Astrovirus - 0.13% of samples (95% CI 0.02-0.47).). The structure of virus contamination of water in the centralized water supply system for 2018-2023. Rotavirus A (52.6±1.1%), Adenovirus F (30.2±2.5%), Norovirus GII (28.6±1.1%), HAV (26.0±1.3%), Astrovirus (12.9±0.9%), Enterovirus (12.0±0.5%) were represented. The conducted studies have established that today there is still a need to monitor virus contamination and use disinfection methods in water treatment of non-centralized water supply.