Expansion of hantavirus infection during the SARS-CoV-2 pandemic in Bosnia and Herzegovina, 2021.

Introduction. Bosnia and Herzegovina (B and H) has been recognized for decades as a country with a high risk of diseases caused by hantaviruses.Gap statement. The severe acute respiratory syndrome-associated coronavirus 2 (SARS-CoV-2) pandemic has diverted attention from many pathogens, including hantavirus.Aim. To provide a socio-demographic, temporal, geographical and clinical laboratory overview of the expansion of hantavirus infection cases during the SARS-CoV-2 pandemic in B and H in 2021.Methodology. The RecomLine HantaPlus IgG, IgM immuno-line assay (Mikrogen, Germany) was used to detect IgG and IgM antibodies to hantavirus serotypes in human sera from clinically suspected cases.Results. In 2021 (January-October), the number of confirmed cases of hantavirus infection and tested persons (92/140; 65,71 %) was higher than in the previous 2 years, 2020 (2/20; 10.00 %) and 2019 (10/61; 16.39 %). Most of the infected persons were men (84/92; 91.30 %). Hantavirus infections were recorded from January to October 2021, and the peak was reached in July (25/92; 27.17 %). Six out of 10 cantons in the Federation of Bosnia and Herzegovina (FB and H) were affected, namely Sarajevo Canton, Central Bosnia Canton, Neretva Canton, Zenica-Doboj Canton, Posavina Canton and Bosnian-Podrinje Canton Goražde, in descending order. Of the 38/92 (41.30 %) infected patients with characteristic clinical manifestations of haemorrhagic fever, including renal (mainly) or pulmonary syndrome, 32/92 (34.78 %) were hospitalized in the Clinical Center of the University of Sarajevo. Two cases were detected with dual infection, hantavirus (Puumala) with Leptospira in one and SARS-CoV-2 in another case. The largest number of infections was related to Puumala (PUUV) (83/92; 90.22 %), while the rest of the infections were caused by the hantavirus Dobrava serotype (DOBV).Conclusion. The reported infections were probably caused by exposure of individuals to at-risk areas inhabited by contaminated rodents as natural reservoirs of hantavirus. As a highly endemic area, B and H requires continuous monitoring and increased awareness of this problem.