Urine excreted antibodies significance in the hemorrhagic fever with renal syndrome specific diagnosis

Abstract

Relevance. Hemorrhagic fever with renal syndrome (HFRS) is an acute viral zoonosis. Being widespread in Eurasia, it holds a leading place in Russia among natural focal human diseases. The vast majority of HFRS cases in Russia, about 98%, are associated with Puumala virus. The disease is characterized by a wide range of clinical manifestations. Early specific diagnostics appears to be of a great importance for starting timely pathogenic therapy. The aim of the study was to clarify the diagnostic value of detecting hantavirus antibodies in the HFRS suspected patient urine. Materials and methods. Blood sera and urine samples from 68 patients at the Infectious Diseases Hospital in the city of Ufa, obtained with a 2-day interval, as well as urine and blood serum samples from 15 convalescents 1, 2, 3 and 6 months after disease onset were examined for hantavirus antibodies. 53 blood sera and urine samples from patients residing in Moscow, Moscow and Samara regions collected at different time points during the disease course were investigated in parallel. Antibodies were detected by the indirect immunofluorescence method. Results. On day 3, 4, 5 and 6 of disease, while specific antibodies were detected in the blood serum, antibodies in the urine were found in 85.7%, 89.4%, 93.1% and 100% of patients, respectively. The peak quantity of antibodies was excreted in the urine from days 5 to 11, which corresponds to the oliguric stage of the disease. In the convalescent period, antibodies were still detected in urine 1, 2 and 3 months afterwards in 86.7%, 46% and 20% of cases, respectively, but not detected 6 months later, which probably reflects the process of long-term restoration of the kidneys function. A moderate positive correlation between specific antibodies in serum and urine was observed only in the oliguric period of the disease. Conclusions. Detection of hantavirus antibodies simultaneously in blood serum and urine of febrile patients instead of paired blood sera allows to conduct HFRS diagnostics within the very first days of hospitalization and prevent severe complications due to timely pathogenic therapy.