Polymerase chain reaction detection of Leishmania DNA in skin biopsy samples in Sri Lanka where the causative agent of cutaneous leishmaniasis is Leishmania donovani.

Leishmania donovani is the known causative agent of both cutaneous (CL) and visceral leishmaniasis in Sri Lanka. CL is considered to be under-reported partly due to relatively poor sensitivity and specificity of microscopic diagnosis. We compared robustness of three previously described polymerase chain reaction (PCR) based methods to detect Leishmania DNA in 38 punch biopsy samples from patients presented with suspected lesions in 2010. Both, Leishmania genus-specific JW11/JW12 KDNA and LITSR/L5.8S internal transcribed spacer (ITS)1 PCR assays detected 92% (35/38) of the samples whereas a KDNA assay specific forL. donovani (LdF/LdR) detected only 71% (27/38) of samples. All positive samples showed a L. donovani banding pattern upon HaeIII ITS1 PCR-restriction fragment length polymorphism analysis. PCR assay specificity was evaluated in samples containing Mycobacterium tuberculosis, Mycobacterium leprae, and human DNA, and there was no cross-amplification in JW11/JW12 and LITSR/L5.8S PCR assays. The LdF/LdR PCR assay did not amplify M. leprae or human DNA although 500 bp and 700 bp bands were observed in M. tuberculosis samples. In conclusion, it was successfully shown in this study that it is possible to diagnose Sri Lankan CL with high accuracy, to genus and species identification, using Leishmania DNA PCR assays.

Polymerase chain reaction detection of LeishmaniaDNA in skin biopsy samples in Sri Lanka where the causative agent of cutaneous leishmaniasis is Leishmania donovani

Leishmania donovani is the known causative agent of both cutaneous (CL) and visceral leishmaniasis in Sri Lanka. CL is considered to be under-reported partly due to relatively poor sensitivity and specificity of microscopic diagnosis. We compared robustness of three previously described polymerase chain reaction (PCR) based methods to detectLeishmania DNA in 38 punch biopsy samples from patients presented with suspected lesions in 2010. Both, Leishmaniagenus-specific JW11/JW12 KDNA and LITSR/L5.8S internal transcribed spacer (ITS)1 PCR assays detected 92% (35/38) of the samples whereas a KDNA assay specific forL. donovani (LdF/LdR) detected only 71% (27/38) of samples. All positive samples showed a L. donovani banding pattern upon HaeIII ITS1 PCR-restriction fragment length polymorphism analysis. PCR assay specificity was evaluated in samples containing Mycobacterium tuberculosis, Mycobacterium leprae, and human DNA, and there was no cross-amplification in JW11/JW12 and LITSR/L5.8S PCR assays. The LdF/LdR PCR assay did not amplify M. leprae or human DNA although 500 bp and 700 bp bands were observed in M. tuberculosis samples. In conclusion, it was successfully shown in this study that it is possible to diagnose Sri Lankan CL with high accuracy, to genus and species identification, using Leishmania DNA PCR assays.

Liquid nitrogen cryotherapy on Leishmania donovani cutaneous leishmaniasis.

OBJECTIVE: To evaluate the efficacy and the safety of liquid nitrogen cryotherapy (LN) on Leishmania donovani cutaneous leishmaniasis and on type V skin. METHODS: LN was applied to 65 patients (121 lesions) using cotton swabs attached to ekels. Cryosessions were performed for 15-20 seconds, two per site, weekly for 1-3 weeks, fortnightly for 4-5 weeks and then monthly until cure. Patients were followed-up for 6 months after cure. RESULTS: A total of 91.7% of patients were cured within one to seven cryosessions; mean 3.57. With one to four cryosessions, papules ≤ 1 cm in diameter showed rapid healing (90.5%) in comparison with those of > 1 cm diameter (64.28%). The cure rates for lesions on the head (84.61%) and upper limb (82.6%) were greater than those for the lower limbs (71.42%) and trunk (66.66%). With LN, local pain lasted for 15-30 minutes; ulceration (33%), depigmentation (46.9%) and scarring (43%) were noticed. During 6 months of follow-up there was one (1.6%) recurrence. CONCLUSIONS: LN (77.15% cure within one to four cryosessions) is an alternative to intralesional sodium stibogluconate in the treatment of papules measuring ≤ 1 cm. In type V skin, LN should be avoided on the face, and on patients who have a tendency to form keloids. We recommend giving cryotherapy using cryoguns (instead of cotton swabs attached to ekels) fortnightly (not weekly), which may minimize ulceration, and therefore scarring.