A tularemia outbreak in an extended family in Tokat Province, Turkey: observing the attack rate of tularemia

SummaryObjectiveWe report the first tularemia epidemic occurring in Tokat Province, located in the Middle Black Sea Region of Turkey, and some features of the cases. This epidemic has allowed the calculation of the attack rate of this disease because of its appearance in a single large family.MethodsThe clinical and laboratory features of patients were examined. For serological diagnosis, microagglutination assays were done on serum samples from patients and other members of the family.ResultsSeven members of the family developed overt clinical disease (one ulceroglandular, six oropharyngeal). Three patients had conjunctivitis in addition to oropharyngeal involvement. All patients had a microagglutination titer above 1/160. As eight out of 16 members of the extended family were found to be positive for tularemia serology, the attack rate was calculated to be 50%.ConclusionsTularemia is highly infectious and different clinical forms can occur in a single epidemic.