Diagnostic approaches for oculoglandular tularemia- advantages of PCR

¹ National Center of Infectious and Parasitic Diseases, Bulgaria

^* To whom correspondence should be addressed. E-mail: ppadeshki{at}yahoo.com.

Accepted 1 April 2007

	Abstract

Purpose: The current report describes a diagnostic approach that proved to be particularly valuable in rare cases of ocular tularemia registered during the tularemia outbreak 1997-2005 in Bulgaria. Herein we describe the laboratory findings and the diagnosis of four cases with oculoglandular form of infection.

Methods: Several different specimens from each patient were analyzed. Oculoglandular tularemia was diagnosed in four patients either by culture, immunofluorescent antibody analysis (IFA), serology or by a polymerase chain reaction (PCR) assay.

Results and Discussion: Three F. tularensis strains were isolated and characterized. One of these was isolated from an conjuctival swab specimen obtained from a seronegative patient. We report for the first time a successful application of diagnostic PCR performed directly on conjuctival swab specimen. From all analyzed specimens the IFA was diagnostically effective only in case of lymph node aspirates but not sensitive enough for conjuctival swabs or blood samples. We also describe the histological picture of a conjunctival granuloma in course of infection. All patients were successfully treated with ciprofloxacin.

Conclusions: Some of the proposed laboratory diagnostic strategies (swab PCR) are not invasive and could represent a new approach for resolving rare and hard-to-diagnose cases of oculoglandular tularemia.

Keywords: Francisella tularensis, PCR analysis of eye swab, Parinaud�s syndrome, histology of conjunctival granuloma, oculoglandular tularemia

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