Leishmania species

Rioux, Jean-Antoine, Gramiccia, Marina, Léger, Nicole, Desjeux, Philippe & Depaquit, Jérôme, 2020, Leishmaniasis and phlebotomine sand flies in Oman Sultanate, Parasite (Paris, France) 27 (68), pp. 1-13 : 8-9

Leishmaniases and Leishmania species identification

Skin tests

A total of 213 students (114 boys and 99 girls) from the school of Kafaïfa (Ibra province) underwent skin tests. Among them, 17 (8%) were positive. They exhibited an erythematous and pruritic papule of 1 or more cm in diameter. Girls were more susceptible to the disease (13.3%) than boys (10.1%). A low positivity rate seems to be due to a weak interaction between the young population and the Leishmania parasite in this focus (20 km from Ibra). It could be related to low density of sandfly vectors or their weak anthropophilia.

Human CL case reports, sampling and cultures

Four suspected human CL cases were observed, and 3 Leishmania strains were cultured and identified.

Case LCO 1:

Female, 17 years old, from the Muscat area (Sharqiyah region). Lesion on the right leg, beginning two years before. The CL diagnosis was confirmed by the presence of amastigotes in the lesion by microscopical examination. Treatment by intramuscular sodium stibogluconate (Pentostam ®). Improvement but relapse. New hospitalisation for skin graft. Currently pretibial lesion: round-shaped ulcer of 4 cm diameter with a red/purplish elevated border and necrotic surface. Intralesional treatment by sodium stibogluconate (Pentostam ®). In 1998, on September 28, biopsy under local anaesthesia. Direct examination: negative, in vitro culture on NNN medium: positive at the 2nd subculture. Strain MHOM / OM /98/IBM-103- ISS 1783. MLLE identification: L. donovani ZMON-31 (= ZROM-24), L. donovani species identification was confirmed by molecular analyses.

Case LCO 2:

Female, 35 years old, living in Rowda (Ibra province, Sharqiyah region). Ulcero-scabby lesion on the left cheekbone, 3 cm in diameter with ulcerated centre and with an elevated and infiltrated border of 3–4 cm. In 1998, on September 16, consultation at Ibra hospital. CL diagnosis confirmed parasitologically by Giemsa stained smear. Local cryotherapy (pregnant woman). In 1998, on October 4, biopsy ( Fig. 5 ). Direct microscopical examination of cutaneous smear and in vitro culture on NNN medium: positive. Strain MHOM / OM /98/IBM-104- ISS 1790. MLLE identification: L. donovani ZMON-31 (= ZROM-24), L. donovani species identification was confirmed by molecular analyses.

Case LCO 3:

Boy, 12 years old, observed at Kafaïfa school, 20 km North of Ibra (Sharqiyah region). In the middle of the forehead, scabby lesion of 1 cm diameter, initiated 3 months before. Leishmanin skin test positive (1.5 cm). Cutaneous biopsy: direct microscopical examination and in vitro culture in NNN medium: negative.

Case LCO 4:

Girl, 4 years old, living in Ghadow on the southern slopes of Djebel Qara (Dhofar region), altitude: 500 m. The disease began 7 months before, by an erythematous lesion at the top of the nose. Treatment by intramuscular sodium stibogluconate (Pentostam ®, 10 injections) was initiated on September 9. Examination at Salalah hospital on October 21: red and purplish infiltrated lesion (2 cm) at the top of the nose. Sample obtained by scraping with curette. Direct microscopical examination

and in vitro culture in NNN medium: positive. Strain MHOM / OM /98/IBM-105- ISS 1793. MLLE identification: L. tropica ZROM-102 ( MDH 100, ME 100, ICD100, PGD95, G6 PD 85, GLUD 100, DIA 100, NP(1)450, NP(2)100, GOT(1)135, GOT (2)90, PGM 100, FH 100, MPI101, GPI 76. The ZMON more similar was MON-39 with 4 variable isoenzymes ( ME 100, G6 PD 85, GLUD 100, NP(2)100). The L. tropica species identification was confirmed by molecular analyses.

Animal leishmaniases

No Leishmania strain was isolated from canids.

Figures

Figure 5. Ulcero-scabby lesion of case LCO 2.