Chronic cutaneous leishmaniasis: Leishmania parasites in blood

Failure to Detect Leishmania in the Blood of Patients with Old-World Cutaneous Leishmaniasis: Implications for Blood Donation

Cutaneous leishmaniasis (CL) is endemic in Israel, caused mainly by Leishmania major (L. major) and L. tropica. In addition, returning travelers import another leishmanial species such as L. braziliensis. Although we are dealing with a skin disease, the blood bank in Israel does not accept blood donations from people infected with CL in cases of multiple lesions due to the possibility of transfusion. Our purpose was to investigate the prevalence of Leishmania in the blood of patients with active or previous CL. This pilot study screened patients with active or previous CL for parasites in their blood. All patients were infected in Israel or were returning travelers with leishmaniasis acquired in Latin America. Patients were seen at the Sheba Medical Center. In addition, patients were seen at their homes in L. tropica and L. major endemic regions in Israel. Blood samples were taken from each patient for culture and polymerase chain reaction (PCR). Altogether 62 blood samples were examined (L. tropica = 26, L. major = 33, and L. braziliensis = 3). Twenty-seven patients had an active disease and 35 were recovered. All blood cultures and PCR were negative for parasites except one blood sample that was PCR positive for L. braziliensis. The findings of our study, although a small sample, suggest that people with active or recent CL caused by L. major and L. tropica, do not harbor parasites in their blood. Thus, their exclusion from blood donation should be revisited. Further studies are needed with larger sample size and highly sensitive tests.

Cutaneous leishmaniasis following local trauma: a clinical pearl

Cutaneous leishmaniasis is acquired from the bite of an infected sand fly and can result in chronic skin lesions that develop within weeks to months after a bite. Local trauma has been implicated as a precipitating event in the development of skin lesions in patients who have been infected with Leishmania species. Here we report a case series and review the literature on patients who developed cutaneous leishmaniasis after local trauma, which may familiarize clinicians with this presentation.

The epidemiology of leishmaniases in Lebanon

The prevalence of leishmaniasis in Lebanon was studied in 1993-97 for a Lebanese population sample of about 81,000 subjects (60% rural and 40% urban) constituting roughly 3.4% of the total population. The prevalence of cutaneous leishmaniasis was found to be 0.18% in the rural versus 0.41% in the urban areas. Visceral leishmaniasis was practically non-existent in both environments. In addition, skin tests were done and anti-Leishmania antibodies were sought in a sample of the population at risk in the rural area. Skin tests were positive in 2.5% of the tested subjects, and 1% of the normal population had elevated levels of anti-Leishmania antibodies. The difference between the prevalence of clinical disease and positive skin testing and/or antibodies may be due to the existence of past or present subclinical disease. An unexpected finding was that the prevalent dermotropic parasite in Lebanon belongs to the L. donovani complex. Further characterization of the isolates by molecular techniques and definition of the transmission cycle of this parasite may explain our epidemiological findings.

Leishmania donovani invasion of the blood in a child with dermal leishmaniasis

Cutaneous leishmaniasis is highly endemic in eastern Mediterranean countries. The causative organisms are Leishmania tropica or Leishmania major but, further west, variants of Leishmania infantum frequently cause cutaneous leishmaniasis. We report a young girl from Beirut with an acute cutaneous leishmaniasis in whom the causative organism was cultured from both the skin lesion and the blood in the absence of any signs or symptoms typical of systemic involvement. The parasite was found to have a zymodeme typical of organisms belonging to the L. donovani complex. With the negative past history and in the absence of anti-Leishmania antibodies in her serum, post-kala-azar dermal leishmaniasis is an unlikely possibility, especially in view of the rarity of the complication in this part of the world. The infection was probably acquired during a recent visit to Aleppo, where cutaneous leishmaniasis is hyperendemic as similar cases have not been reported in Beirut. This case indicates the need to consider L. infantum strains in addition to L. tropica in cutaneous disease in Aleppo. This case also demonstrates that L. infantum can spread by the haematogenous route, even in a child without evidence of the immunosuppression, which usually predisposes to such spread.