Pediatric visceral leishmaniasis in Austria: diagnostic difficulties in a non-endemic region

Visceral leishmaniasis is usually fatal if left untreated. In Europe it is mainly caused by Leishmania infantum which is endemic in the whole Mediterranean region. While visceral leishmaniasis classically affects children, adults increasingly suffer infections in regions which are known to be endemic for HIV. Nowadays up to 70% of the patients with visceral leishmaniasis in southern Europe are HIV-infected adults. The diagnosis is known to be especially difficult to establish in this group of patients because of a frequently atypical clinical presentation, but even in non-HIV-infected patients visceral leishmaniasis often represents a diagnostic challenge particularly when the patient is living in a non-endemic region. We report on four children with visceral leishmaniasis diagnosed at St. Anna Children's Hospital, Vienna, in the last decade. Diagnostic difficulties arose (1) from inexperience with this rare disease, (2) from a long incubation period (6 to 8 months) and (3) from a travel history apparently unsuspicious for the contraction of what is considered a 'tropical' disease. In one case, specific problems resulted (4) from clinical appearance and laboratory data mimicking hemophagocytic lymphohistiocytosis. Consequently even in regions where leishmaniasis is not endemic, diagnostic efforts should be undertaken to rule out this disease especially in patients with the presumptive diagnosis of hemophagocytic lymphohistiocytosis.