ABSTRACT
INTRODUCTION: This present research study presents the analytic results of an outbreak of tularemia (Francisella tularensis) that occurred in the Northwest areas of Castilla y León in Northern Spain in late June 2007. PATIENTS AND METHODS: Serum was obtained from 302 patients from a West Valladolid health area, attended in the University Hospital of Río Hortega of the Castilla y León Health Care Service, with suspicion of tularemia. A tube agglutination test was performed in all of them to detect anti-F. tularensis antibodies. RESULTS: Anti-F. tularensis antibodies were detected in 59 (19%) of reported cases (302 sera). The most frequent clinical presentations of the disease suggest that the main transmission pathway was through inhalation of the bacteria. CONCLUSIONS: When the 2007 outbreak of human tularemia was compared with that which occurred in 1997, we observed a lower number of positive cases in the recent outbreak as well as a difference in the transmission pathway and predominant form of clinical presentation of the disease.