Treatment failure of gentamicin in pediatric patients with oropharyngeal tularemia

Abstract

Tularemia is a zoonotic infection, and the causative agent is Francisella tularensis. A first-line therapy for treating tularemia is aminoglycosides (streptomycin or, more commonly, gentamicin), and treatment duration is typically 7 to 10 days, with longer courses for more severe cases. We evaluated 11 patients retrospectively. Failure of the therapy was defined by persistent or recurrent fever, increased size or appearance of new lymphadenopathies and persistence of the constitutional syndrome with elevation of the levels of the proteins associated with the acute phase of infection. We observed fluctuating size of lymph nodes of 4 patients who were on the 7th day of empirical therapy. The therapy was switched to streptomycin alone and continued for 14 days. The other 7 patients, who had no complications, were on cefazolin and gentamycin therapy until the serologic diagnosis. Then we evaluated them again and observed that none of their lymph nodes regressed. We also switched their therapy to 14 days of streptomycin. After the 14 days on streptomycin therapy, we observed all the lymph nodes had recovered or regressed. During a follow-up 3 weeks later, we observed that all their lymph nodes had regressed to the clinically non-significant dimensions (<1 cm). All patients were first treated with gentamicin, but were than given streptomycin after failure of gentamicin. This treatment was successful in all patients. The results of our study suggest that streptomycin is an effective choice of first-line treatment for pediatric oropharyngeal tularemia patients.