Tularemia in Bursa, Turkey: 205 cases in ten years S. Helvacõ, S. GedikogÆlu, H. Akalõn & H.B. Oral Department of Microbiology and Infectious Diseases, Uludag Æ University, School of Medicine, Bursa, Turkey Accepted in revised form 23 November 1999 Abstract. Tularemia is a zoonotic disease caused by the coccobacillus F. tularensis. Small epidemics and sporadic cases were seen around Bursa since No- vember 1988. In this study, a total of 205 cases of tularemia were observed. All the cases were diag- nosed on clinical, bacteriological and serological grounds. The epidemics were thought to be water- borne. The majority of the patients were young and female. In most of the cases the disease presented itself in oropharyngeal form (83%). Analysing sera from the patients with microagglutination method demonstrated that titers were P1:160 in approxi- mately 85% of the cases, including the ones in sub- clinical form. Five of ten patients from who the bacteria was isolated were seronegative. Streptomy- cin was given to the most of the patients by combining with tetracycline, doxycycline or chlor- amphenicol. The early administration of these anti- biotics (before the third week of disease) was found to be much more eective to resolve the infection. As a result, the main mode of transmission of F. tularensis is waterborne in our region. In our region, tularemia should be considered in dierential diagnosis for the cases with fever, tonsillopharyngitis and cervical lymphadenopathy to make an early diagnosis and to design relevant treatment. Key words: Francisella tularensis, Tularemia, Waterborne epidemic Introduction Tularemia is a zoonotic disease caused by Francisella tularensis. Biovar tularensis (Jellison type A), one of F. tularensis serovars, has been only isolated in North America. It is originated from rodents and highly virulent. F tularensis biovar palaearctica (Jellison type B) leads to more mild disease with the mortality rate of less than 1% in the cases who did not even receive any treatment. Infections with the latter biovar are commonly seen in European and Asian countries. F. tularensis biovar palaearctica can be detected in water itself and/or in rodents living in water [1]. Francisella tularensis may enter into body from skin, respiratory system and mucous membranes such as conjunctiva and oropharynx [2, 3, 4]. The clinical picture may vary dependent upon several factors that include the route of transmission, virulence of the microorganism strain and the immune condition of the host [3, 4]. The disease may develop in ulceroglandu- lar, glandular, oculoglandular, oropharyngeal, pneu- monic or typhoid forms [2, 5]. Ulceroglandular form is the most common clinical picture, and characterized by fever, formation of pustule or ulcer in the inocula- tion region and lymphadenitis in the regional lymph nodes [6]. In pneumonic form pneumonia is seen; fe- ver, ulcerative pharyngitis and cervical lymphaden- opathy in oropharyngeal form; acute conjunctivitis, preauricular and cervical lymphadenopathy in oculo- glandular form; and systemic ®ndings in typhoid form are predominantly found. It may also rarely occur in a subclinical manner [2]. Tularemia may cause outbreaks in many regions of the world [3, 6]. Small epidemics of tularemia were reported from dierent regions of Turkey between 1936 and 1953 [7±9]. After quite a long interlude, Tularemia has proceeded with small epidemics and sporadic cases around Bursa since November 1988. In this report, we evaluate 205 cases of tularemia with regard to the clinical and microbiological features, and discuss the outcome of antimicrobial therapy. Materials and methods A total of 205 patients were included in this study. These patients had been admitted to the Department of Infectious Diseases in UludagÆ University School of Medicine, Bursa, directly or through other clinics to which the patients were admitted with cervical lym- phadenopathy. In addition, some patients were examined and followed up in their villages by regular visits. Diagnosis of tularemia was accepted: (i) if tularemia serological tests were positive in the context of a compatible clinical illness; (ii) if the bacteria was isolated with the accompaniment of a compatible clinical illness; (iii) if sustained high titres (1:80 and above) or a four-fold increased titer in paired serum samples taken at dierent time points were observed in tularemia agglutination test. European Journal of Epidemiology 16: 271±276, 2000. Ó 2000 Kluwer Academic Publishers. Printed in the Netherlands.