Introduction With their remarkable flight capabilities, wild and captive birds play a pivotal role in the global dissemination of zoonotic pathogens including Chlamydia psittaci, Avian Influenza viruses (AIV), Chikungunya virus (CHIKV), Usutu virus (USUV), and West Nile virus (WNV). They function both as hosts and reservoirs responsible for transporting the mentioned infectious agents across vast geographic regions. Additionally, captive birds and birds inhabiting urban environments, particularly in tourist destinations, present significant public health concerns due to facilitated close interactions with humans. Methods A total of 358 samples originating from fifteen bird species were collected across 21 locations in Sarajevo Canton, over three consecutive years (2022–2024). Upon collection, the samples were subjected to molecular analysis to detect the presence of zoonotic pathogens. For detection of Chlamydia spp., and C. psittaci, real-time PCRs (qPCR) were used following established protocols. Additionally, reverse transcriptase real-time PCR (RT-qPCR) were utilized for the detection of emergent viral pathogens including avian influenza viruses, Chikungunya, Usutu, and West Nile virus. Results Chlamydia spp. was detected in 29.9% (95% CI: 25.2–34.9) of samples. Further, C. psittaci was identified in 10.3% (95% CI: 5.2–17.7) of positive samples originating from captive birds and birds inhabiting urban environments. One sample (0.3%) originating from a wild bird was positive to West Nile Virus. None of the samples tested positive for Avian Influenza viruses, Chikungunya and Usutu virus. Discussion The identification of C. psittaci and West Nile virus highlights the increased likelihood of zoonotic transmission. This underscores the imperative for bolstered biosecurity measures and public health strategies aimed at mitigating the risk associated with both environmental exposure and direct contact, especially in areas characterized by substantial tourist activity.

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which led to the COVID-19 pandemic, has significantly impacted global public health. The proper diagnosis of SARS-CoV-2 infection is essential for the effective control and management of the disease. This study investigated the SARS-CoV-2 infection using RT-qPCR tests from laboratories in Bosnia and Herzegovina. We performed a retrospective study of demographic data and Ct values from 170,828 RT-qPCR tests from April 2020 to April 2023, representing 9.3% of total national testing. Samples were collected from 83,413 individuals across different age groups. Of all tests, 33.4% were positive for SARS-CoV-2, with Ct values and positivity rates varying across demographics and epidemic waves. The distribution was skewed towards older age groups, although lower positivity rates were observed in younger age groups. Ct values, indicative of viral load, ranged from 12.5 to 38. Lower Ct values correlated with higher positive case numbers, while higher Ct values signaled outbreak resolution. Additionally, Ct values decreased during epidemic waves but increased with the dominance of certain variants. Ct value-distribution has changed over time, particularly after the introduction of SARS-CoV-2 variants of interest/concern. Established Ct value trends might, therefore, be used as an early indicator and additional tool for informed decisions by public health authorities in SARS-CoV-2 and future prospective pandemics. Moreover, they should not be overlooked in future epidemiological events.

Dermacentor (D.) reticulatus ticks carry and transmit a wide range of pathogens to vertebrate hosts. Limited information is available about the existence of emerging tick-borne pathogens and the distribution of D. reticulatus in Bosnia and Herzegovina. The study aimed to investigate the occurrence and distribution of D. reticulatus and to detect the presence of Anaplasma spp., Borrelia (B.) burgdorferi s.l., Rickettsia spp., and Babesia spp. in samples originating from questing ticks and ticks collected from domestic animals in various regions of Bosnia and Herzegovina. A total of 402 collected D. reticulatus ticks were widely distributed throughout the country. Of the 41 pools consisting of 205 individual D. reticulatus ticks, 21 (51.2%) indicated the presence of Rickettsia spp., 17 (41.4%) of Babesia spp., 2 (4.8%) of Anaplasma spp., and 1 (2.4%) of B. burgdorferi s.l. after real-time PCR screening. Our study indicates that D. reticulatus has significantly expanded its distribution and host range in Bosnia and Herzegovina. Moreover, our results represent the first detection of Babesia spp. in D. reticulatus in Bosnia and Herzegovina. Given the demonstrated presence of emerging pathogens in questing and feeding ticks, there is an urge to establish a surveillance system for ticks and tick-borne pathogens in Bosnia and Herzegovina.