Haemonchus contortus is a globally significant parasitic nematode in ruminants, with widespread resistance to benzimidazole due to its excessive and prolonged use. Given the extensive use of benzimidazole anthelmintics in Bosnia and Herzegovina, we hypothesized that resistance is prevalent. The aim of this study was to identify the presence of anthelmintic resistance to benzimidazole in H. contortus from naturally infected sheep, goats and cattle in Bosnia and Herzegovina through the detection of the Phe/Tyr polymorphism in the amino acid at position 200 of the β-tubulin protein. From 19 locations in Bosnia and Herzegovina, a total of 83 adult H. contortus were collected from the abomasum of ruminants. Among these, 45 H. contortus specimens were isolated from sheep, 19 from goats and 19 from cattle. Results showed that 77.8% of H. contortus in sheep exhibited homozygous resistant genotypes at position 200 of the β-tubulin gene, with 15.5% being heterozygous. In goats, all tested H. contortus (100%) were homozygous resistant, and no heterozygous resistant or homozygous sensitive genotypes were found. Cattle had 94.7% homozygous resistant H. contortus, with no heterozygous resistant genotypes detected. In H. contortus from sheep and cattle, 6.7% and 5.3%, respectively, displayed homozygous sensitive genotypes. This study, for the first time, highlights the presence of a resistant population of H. contortus in sheep, goats and cattle in Bosnia and Herzegovina, using the rt-qPCR method. The resistance likely spread from sheep or goats to cattle, facilitated by shared pastures and the practice of transhumance, indicating a widespread and growing issue of anthelmintic resistance.

Echinococcus multilocularis has been spreading through Central Eastern Europe but has not yet been reported in Bosnia and Herzegovina (B&H). Recently, this parasite is confirmed in Croatia suggesting the movement of the parasite's distribution limit further south. Given that there is no surveillance or monitoring system for echinococcosis in B&H, our study was designed as a pilot study of E. multilocularis. A total of 57 red foxes originating from 24 localities all over the country were collected during the routine rabies monitoring, autopsied and examined for the presence of echinococcosis. Based on intestinal scraping technique and microscopy, E. multilocularis adult worms have been detected in one (1/57, 1.75%) red fox. To verify this finding and to differentiate Echinococcus spp., DNA extracted from adult worms was subjected to species-specific PCR targeting part of the mitochondrial 12S ribosomal RNA gene. E. multilocularis PCR-positive samples were further confirmed by NGS sequencing of a 203 bp amplified fragment of 12S rRNA, which has been deposited in GenBank (Accession no.: OP047920). This finding represents the first detection of E. multilocularis in B&H, strongly suggesting its presence in the country. The confirmation of the parasite in the same locality where migrants/refugees temporarily stay on their route to Western Europe highlights the need for a One Health approach in addressing all future questions. Moreover, the first detection of E. multilocularis in B&H warrants the need for the implementation of an appropriate state surveillance program.

The infection with SARS-CoV-2 virus in cats and dogs raised issue of human-to-animal transmission of SARS-CoV-2 in domestic pets in close contacts with their owners. Our study was designed to research this in the framework of Bosnia and Herzegovina. Using ELISA, AFIAS fluorescent immunoassay, RT-qPCR and WGS on Nanopore MinION platform with ARTIC Network Amplicon sequencing protocol for SARS-CoV-2, we showed that three out of thirteen dogs and one out of five cats from the households with confirmed human cases of COVID-19 in Bosnia-Herzegovina were infected with SARS-CoV-2. The high viral RNA load was detected in samples collected from a 4-year-old male Havanese (Ct = 12.52), a 6-year-old German Shepherd (Ct = 21.36) and a 9-year-old female American Staffordshire terrier (Ct = 25.74). The antibody response in dogs and one cat was observed. The viral genetic sequences from dogs were identical to the sequences detected in the owners suggesting the human-to-animal transmission of the virus. These findings, especially the low initial Ct values detected, from the public health perspective additionally stress the need for precautionary measures to protect both humans and animals.

Background: Crimean–Congo haemorrhagic fever (CCHF) is a widespread tick‐borne zoonosis with reported detection of virus and/or virus‐specific antibodies from over 57 countries across Africa, Asia, Europe and the Middle East and is endemic in the Balkans. Detection of Crimean–Congo Haemorrhagic Fever Virus (CCHFV) antibodies in domestic ruminants has been important in providing initial evidence of virus circulation and in localising CCHFV high‐risk spots for human infection.Objectives: The present study investigated the possible exposure of sheep to CCHFV in Bosnia and Herzegovina (B&H).Methods: To investigate the presence of anti‐CCHFV antibodies in sheep, all sera (n = 176) were tested using multi‐species double antigen enzyme‐linked immunosorbent assay (ELISA). Reactive sera were further complementary tested by adapted commercial indirect immunofluorescence assay (IFA) using FITC‐conjugated protein G instead of anti‐human immunoglobulins.Results: CCHFV specific antibodies were detected in 17 (9.66%) animals using ELISA test. All negative sera were determined as negative by both tests, while 13 out of 17 ELISA‐positive reactors were also determined as unambiguously positive by IFA test. The age group with the highest proportion of seropositive rectors were the oldest animals.Conclusions: This is the first report of anti‐CCHFV antibodies in sheep from B&H providing the evidence of CCHFV circulation in the country's sheep population. So far, these findings indicate the circulation of the virus in the westernmost region of the Balkans and point to the potential CCHFV spread further out of this endemic area.

The prime significance of species belonging to the genus Culicoides Latreille, 1809 (Diptera: Ceratopogonidae) is their ability to transmit viruses such as bluetongue virus (BTV) to wild and domestic ruminants. Prior to 1998, BTV was considered exotic in Europe, but according to recent history of its outbreaks, it has become endemic in southern and eastern European countries circulating beyond its expected historical limits, into the Balkan region. The wind-borne long-distance dispersal of Culicoides spp. over water bodies and local spreading between farms emphasize the necessity of filling in the information gaps regarding vector species distribution. In most Balkan countries, data on Culicoides fauna and species distribution are lacking, or information is old and scarce. During this study, 8586 specimens belonging to 41 species were collected. We present the first faunistic data on Culicoides species in the former Yugoslav Republic of Macedonia (FYROM), Kosovo, Montenegro and Serbia. For other countries (Bosnia and Herzegovina, Bulgaria and Croatia), all historical records were compiled for the first time and then expanded with our findings to various extents. In all countries, confirmed or suspected BTV vector species belonging to the subgenera Avaritia and Culicoides were collected. The total number of species sampled during our field collections was 20 in Bosnia and Herzegovina (15 new records), 10 in Bulgaria (2 new records), 10 in Croatia (5 new records), 13 in FYROM, 9 in Kosovo, 15 in Montenegro, and 28 in Serbia. Of these, 14 species were registered for the first time in this part of the Balkans. This paper provides the first data about Culicoides fauna in FYROM, Kosovo, Montenegro and Serbia, as well as new records and an update on the checklists for Bosnia and Herzegovina, Bulgaria and Croatia. These findings provide preliminary insights into the routes of BTV introduction and spreading within the Balkans, and present a valuable contribution to further research related to Culicoides-borne diseases in Europe.

Red foxes are the most abundant wild carnivore species in Europe commonly exposed to pathogenic Leptospira and Hepatozoon canis. Despite high seroprevalence, the clinical disease caused by these pathogens in red foxes has never been reported. Herein, we report the first-ever case of a fatal Leptospira spp. and H. canis coinfection in a two-month-old red fox cub with acute haemolytic anaemia, mild bronchopneumonia, intraalveolar haemorrhage, and tubulonephrosis. The presence of pathogenic Leptospira spp. DNA was detected in the kidney and lung tissues of the infected animal. In contrast to our previous knowledge, we believe that such fatal cases due to concomitant infection by Leptospira spp. and H. canis, especially in young animals, may commonly occur in nature. However, further studies are required to identify other factors that possibly contribute to the severity and the pathogenic effect of Leptospira spp. and H. canis infections in red foxes.