Viral hepatitis A in residents of Novosibirsk: clinical, epidemiological and laboratory characteristics

Introduction. Viral hepatitis A (VHA) remains an urgent problem due to its widespread prevalence in the world, including Russia, high incidence among adults, characteristic epidemic outbreaks, and polymorphism of clinical forms. The world is conventionally divided into countries with high, medium, low, and very low endemicity. Russia is classified as a medium-endemicity country, and there is uneven distribution of cases of the disease across individual territories of the country. In the Novosibirsk region, the incidence of hepatitis A virus (HAV) infection in 2015–2023 was uneven, often explosive, and its rates varied from 28 to 239 cases, which occurred under approximately equal sanitary and epidemiological conditions in the region. The maximum rise in the incidence of HAV infection was recorded in 2017, 2019, and 2023. The incidence rate in 2023 (3,04 per 100 000) exceeded the hepatitis A incidence rate in the Russian Federation by 20,4%. Aim. To evaluate clinical, epidemiological and laboratory parameters in VHA patients hospitalized in the City Infectious Clinical Hospital No. 1 in Novosibirsk from February to April 2024. Materials and methods. Clinical, epidemiological and laboratory parameters were analyzed in 56 patients with VHA hospitalized from February to April 2024. The distribution of patients by gender was as follows: 22 men (41,4%), 34 women (58,6%). The median age was 30.3 (15; 62) years. The diagnosis of HAV infection was verified by enzyme immunoassay. To exclude viral hepatitis B and C, hepatitis C total antibodies, hepatitis B antigens and antibodies were determined in the blood serum. Hemogram and blood biochemistry indices were analyzed. Ultrasound examination was used to diagnose pathology of the abdominal cavity organs. When assessing the severity of HAV infection, we followed the criteria of the Clinical Recommendations of the Ministry of Health of the Russian Federation. Results. The dominant age group was represented by individuals aged 15 to 20 years (25%), patients aged 30 to 62 years accounted for 46%, and women predominated. In 19,2% of patients, the contact route of transmission was identified, in 80,8% – the food-borne transmission route. Four outbreaks of VHA were registered. The icteric form of hepatitis A prevailed (87.5%); the severe form was diagnosed in 37% of cases. A relationship between the route of transmission and severity of the disease was found – the severe form was more often observed in food-borne transmission. The clinical picture of VHA was characterized by a typical cyclical course with the presence of influenza-like syndrome, asthenia and dyspeptic syndrome during the pre-icteric phase. In 9% of patients during the pre-icteric phase, abdominal pain was noted, which was a reason for differential diagnosis with surgical pathology. Variability of cytolysis and cholestasis parameters was revealed. In severe cases of VHA, there were manifestations of hepatocellular insufficiency syndrome (hypoalbuminemia down to 24 g/l, a decrease in the prothrombin index down to 33%). Conclusion. Activation of the epidemic process was observed in a season that was not typical for hepatitis A (February – April). The food-borne transmission route was predominant; 46% of patients were over 30 years old. The icteric form prevailed in hospitalized patients (87,5%), and the severe form was observed in 37%. Significant variability in cytolysis and cholestasis syndromes parameters was noted. Hepatocellular insufficiency syndrome was observed in patients with the severe form of hepatitis A.