Viral hemorrhagic fevers in the Voronezh Region: epidemiological, clinical and laboratory features of HFRS in the natural focus and imported dengue fever

Hemorrhagic fever with renal syndrome is a common natural focal zoonotic infection of the Voronezh region. In the initial period of the disease, diagnosis is difficult due to the absence of pathognomonic symptoms. Epidemiological data are important for the detection of HFRS - the prevalence of cases in the summer and autumn period, due to patients' contact with natural objects, and an increase in the number of cases in the winter season. Able-bodied men living in the city prevail among the patients. The HFRS clinic is characterized by an acute onset, high fever with intoxication, kidney damage and hepatosplenomegaly. In the early stages of the disease, there are no characteristic signs - hemorrhagic syndrome, dry mouth and visual disturbances. To confirm the diagnosis of HFRS, laboratory data must be taken into account, including thrombocytopenia, an increase in red blood cells and hemoglobin, an increase in urea, creatinine, proteinuria, and isohypostenuria. A detailed analysis of the epidemiological features and clinic of HFRS is important for differential diagnosis with other viral hemorrhagic fevers, including dengue fever. From 2010 to 2019, 12 cases of hemorrhagic dengue fever were registered in the Voronezh Region, imported from Southeast Asia, mainly Thailand. The disease was more often diagnosed in people under 40 years of age. The clinical picture included high fever, myalgia, arthralgia, gastrointestinal disorders, hypotension, bradycardia, increased liver transaminases, leukopenia and thrombocytopenia. Clinical features: late appearance of rash, absence of lymphadenopathy and mild hemorrhagic syndrome, which makes diagnosis difficult. When patients with signs of acute infectious disease are admitted after visiting endemic territories, it is necessary to carefully analyze the data of the epidemiological history for timely and accurate differential diagnosis of dengue fever with other diseases by a practicing physician.