Search

The presence of Borrelia burgdorferi sensu lato (the agent of Lyme disease) in Ixodes ricinus ticks removed from wild birds and questing ticks was investigated. A total of 345 ticks from 75 infested birds belonging to 10 species and 274 questing ticks collected from the surrounding vegetation were examined by PCR for Borrelia burgdorferi s. l. Pathogen DNA was found in 8.1% (28/345) of the bird-feeding ticks - 10.9% (11/101) in larvae and 7.0% (17/244) in nymphs. Prevalence of infection was 9.4% in ticks from the Eurasian blackbird (Turdus merula), 4.0% in ticks from the song thrush (T. philomelos) and 16.6% from the European robin (Erithacus rubecula). Detection of infected larvae (13.3%) collected from the Eurasian blackbird suggests that this species might contribute to the transmission to the vector I. ricinus. The overall prevalence of B. burgdorferi in the questing nymphs was 10.6%. This is the first report of B. burgdorferi s. l. infection in I. ricinus from wild birds in Bulgaria. [ABSTRACT FROM AUTHOR]

Lyme borreliosis (LB), a tick-borne infection caused by bacteria in the Borrelia burgdorferi sensu lato complex, is increasingly prevalent on the Balkan Peninsula, including Bulgaria, where it is the most common tick-borne disease. This study aimed to assess the seroprevalence of LB across Bulgaria by analyzing 1892 serum samples for specific IgG antibodies using a two-tier testing protocol involving an ELISA and immunoblot methods. The results revealed an overall seroprevalence rate of 5.4%, with significant variation based on age, sex, and residence. Seroprevalence increased with age, peaking at 8.4% in individuals over 65 years. Males had a seroprevalence of 8.4% compared to 3.3% in females, and rural residents showed higher seroprevalence (10.2%) compared to urban residents (4.4%). Regional analysis indicated that seroprevalence ranged from 0.0% to 20.0%, with higher rates in northern provinces such as Gabrovo (18.9%) and Targovishte (20.0%). This study highlights the importance of two-step testing protocols for accurate diagnosis and underscores the need for increased awareness and further research to enhance public health measures and the management of LB in Bulgaria. [ABSTRACT FROM AUTHOR]

Crimean-Congo haemorrhagic fever is endemic in Bulgaria where the primary vector and reservoir are ticks Hyalomma marginatum. The present study examined the role of ticks Hyalomma aegyptium parasitizing on tortoises Testudo graeca in circulation of Crimean-Congo haemorrhagic fever virus. A total of 81 ticks H. aegyptium were collected from 23 specimens of T. graeca in Kardzhali District, SE Bulgaria. Real-time RT-PCR was performed for the detection of CCHFV RNA. CCHFV genome was detected in 10 specimens of H. aegyptium collected from two T. graeca hosts (infection rate 12.3 %). Further studies on H. aegyptium and their hosts are needed to assess their role as CCHFV vectors and reservoirs in SE Bulgaria. [ABSTRACT FROM AUTHOR]

To the Editor: West Nile virus (WNV) is a mosquitoborne flavivirus. Approximately 80% of human infections are asymptomatic, 10%-20% are characterized by an acute febrile illness, and Since then, and [...]

Introduction: Toscana virus (TOSV) is an arthropod-borne virus transmitted by sandflies and is mainly found in countries around the Mediterranean basin. In this article, we present the findings of a seroprevalence study on TOSV in Bulgaria. We aim to assess the current epidemiological situation regarding TOSV in the country and raise clinical awareness. Methods: Serum samples ( n = 1892) were collected in December 2023. Serological tests were performed using a commercial anti-TOSV ELISA kit. Results: Specific immunoglobulin G (IgG) antibodies were detected in 6.4% (121/1892) of the participants. A significantly higher seropositivity rate was found in the age group over 65 years compared with the age groups 18-29 and 40-64 (11.8% vs. 3.9% vs. 3.4%), as well as in males compared with females (8.0% vs. 5.3%). The seroprevalence rates in districts ranged from 0% to 18.5%. Higher seropositivity was found in the southern and northern regions. Conclusions: The seroprevalence rate of TOSV in Bulgaria, found in this study, is a significant decrease compared with the seropositivity rate of 24.5% reported in the country in 2018. The reasons for this are unknown and could possibly be related to the COVID-19 pandemic and the constantly changing environmental conditions. There is also a possibility that the higher seropositivity detected in 2018 together with the rise in clinical cases reported from endemic countries around that time might have been due to an unrecognized TOSV outbreak taking place in this period. Continued clinical awareness and surveillance are necessary for recognition and management of potential cases of TOSV neuroinfection, especially during summer.