Tularemia in Bulgaria 2003-2004

Abstract

Introduction: Tularemia is an uncommon but potentially fatal zoonosis. А second outbreak of tularemia in Bulgaria, about 40 years after the first, occurred in 1997 in two western regions, near the Serbian border. In 2003 tularemia reemerged in the same foci. This retrospective study aimed to evaluate the clinical characteristics and the efficacy of antibiotic therapy in a tularemia resurgence in the Slivnitza region in 2003-2004.

Methodology: A total of 26 cases were evaluated. Using medical records, the following data were collected for all patients: symptoms, physical signs, and microbiology results of agglutination tests, cultures and PCR assays.

Results: Twenty-four of 26 suspected tularemia patients were laboratory confirmed by agglutination test and/or culture. Fifteen (57.7%) patients had clinical presentation compatible with oropharyngeal, 8 (30.8%) with glandular, and 3 (11.5%) with oculoglandular tularemia. The most frequent symptoms were swollen neck (84.6%) and sore throat (76.9%). Lymphadenopathy (100%) was the most common finding. Francisella tularensis (F. tularensis) was detected by PCR, providing a definitive diagnosis in 82.3% of the cases. All the patients were treated with antibiotics considered effective against F. tularensis; however, therapeutic failure was observed in 23.1% of the cases, which was related to a delay in the initiation of antibiotics.

Conclusion: The tularemia outbreak in west Bulgaria near the Serbian border was probably food-borne, associated with a surge in the rodent population. The oropharyngeal form was the most common. Although the disease runs a benign course, late initiation of antimicrobial therapy might delay complete recovery.