Detection of Dobrava hantavirus RNA in Apodemus mice in Bulgaria.

Several Hantaviruses cause hemorrhagic fever with renal syndrome (HFRS) in Europe: Dobrava-Belgrade virus (DOBV), Puumala, Saaremaa, Sochi, and Seoul virus. Although HFRS is endemic in Bulgaria, genome sequences of hantaviruses have never been detected in wild rodents. To identify rodent reservoirs, a total of 691 rodents from three endemic regions were trapped in 2011-2012 and screened by TaqMan RT-PCR for detection of hantaviral genomic RNA. Partial small (S) and/or large (L)-segment sequences were recovered from six Apodemus mice: five of the species A. flavicollis and one A. agrarius. Phylogenetic analysis revealed that all recovered sequences belonged to DOBV. On the phylogenetic trees, the novel Bulgarian hantavirus sequences clustered together with sequences of established previously DOBV variants recovered from Bulgarian HFRS patients and also with variants found in wild rodents trapped in Slovenia, Greece, and Slovakia. One of the novel Bulgarian DOBV S-sequences from A. agrarius was related closely to DOBV sequences recovered from A. flavicollis, suggesting a spillover of DOBV from its natural host to A. agrarius mice. The results of this study confirmed the circulation of DOBV in wild rodents in Bulgaria. The complexity of the epidemiological situation in the Balkans requires further studies of hantaviruses in rodent hosts and human HFRS cases.

Seroprevalance of Crimean-Congo haemorrhagic fever in Bulgarian livestock.

Crimean-Congo haemorrhagic fever (CCHF) is a tick-borne zoonotic disease. Over the past decade, CCHF cases in humans have emerged in Turkey and reemerged in the Balkan countries, Ukraine and Tajikistan. Occupational contact with infected livestock has been recognized as a common cause of the disease. A cross-sectional seroprevalence study in livestock was conducted in farming communities of an endemic area in Bulgaria, southeastern Europe. Overall, 72% of the tested animals were positive for IgG antibodies to CCHF virus. By the time the animals were one-year old almost 50% had serologic evidence of CCHF infection, and by two years already 80% of them had been infected. The data obtained in this study reflect current situation of CCHF virus infection among livestock in Bulgaria. The results showed active CCHF virus circulation that poses risk for humans to be infected during contacts with animals and requires public health awareness.

Fatal outcome of coinfection of Crimean-Congo hemorrhagic fever and malaria.

Here, we report a case of a Bulgarian patient with imported falciparum malaria that manifested 6 days after his arrival in Bulgaria, which was complicated by bloody diarrhea 2 days later. Blood smear revealed high parasitemia, with annular forms and gametocytes of Plasmodium falciparum. In addition, RNA of the Crimean-Congo hemorrhagic fever (CCHF) virus was detected in the blood sample by real-time reverse transcription (RT)-PCR and nested RT-PCR. The obtained sequence was found to be clustered within the Europe 1 lineage close to the other Bulgarian strains. Notably, the two infectious diseases may appear with many similar symptoms that are difficult to distinguish.

Serologic evidence of Crimean-Congo hemorrhagic fever virus infection in Hungary.

Crimean-Congo hemorrhagic fever virus (CCHFV) is a typical tick-borne pathogen that causes an increasing number of severe infections in many parts of Africa, Asia, the Middle East, and the Balkans, as well as in some other parts of Europe. The virus is transmitted primarily by Hyalomma spp., and the spectrum of natural hosts for CCHFV is broad, including wild and domestic animals. Although, the presence of CCHFV was hypothesized in Hungary, no significant research activity has been carried out in the past 30 years. In the present study, we provide serological evidence of CCHFV infection in Lepus europeus using newly developed antibody detection assays. Of 198 samples, 12 (6%) were positive for immunoglobulin G antibody against CCHFV, with 2 independent detection assays. This observation indicates a need for a large-scale surveillance to estimate the potential public health risk of CCHFV in Hungary.