Molecular identification of Leishmania tropica and L. infantum isolated from cutaneous human leishmaniasis samples in central Morocco

BACKGROUND & OBJECTIVES

Cutaneous leishmaniasis (CL) in Marrakesh-Safi region located in the central-south part of Morocco is a public health problem. This study assessed the efficiency of a microscopic examination method in establishing the diagnosis of CL and PCR for the characterization and identification of the circulating Leishmania strains in different CL foci of the study area.

METHODS

A total of 297 smears obtained from cutaneous lesions of suspected patients with CL were stained with May-Grünwald Giemsa (MGG) for microscopic examination. For each positive smear, genomic DNA was extracted and PCR-analysed, targeting the small subunit ribosomal ribonucleic acid (ssu rRNA) gene to detect Leishmania DNA. Then, the internal transcribed spacer 1 (ITS1) was amplified and sequenced in order to identify the Leishmania species. The sensitivity and specificity of the conventional microscopy with ssu rRNA gene were compared by Leishmania nested PCR (LnPCR) and ITS1 gene by ITS-PCR.

RESULTS

A total of 257 smears were positive in the microscopic examination, i.e. the detection rate of amastigotes by optical microscopy was 86.53% (257/297). The LnPCR was found to have a specificity and a sensitivity of 100%, each. Interestingly, the sequencing results showed that 99.61% (256/257) of the isolates had Leishmania tropica and 0.39% (1/257) had L. infantum infection.

INTERPRETATION & CONCLUSION

Though, classical microscopic examination is useful and economical, it is not sensitive enough, especially in endemic regions where several Leishmania species coexist. In such situations, PCR constitutes a complementary method for the identification of the causal species. The results indicate that both the L. tropica (dominant) and L. infantum are the causative agents of CL in the Marrakesh-Safi region. The rate of CL infection is high in Imintanout, and Chichaoua provinces. Hence, early diagnosis and prompt treatment of CL patients is necessary to prevent its extension to neighboring localities.

Risk mapping of human HIV-Leishmaniasis co-infection in Morocco

Background

HIV/AIDS is frequently associated with opportunistic diseases such as leishmaniasis. Hence, the co-infection HIV-Leishmania spp. is the result of the geographical overlap between leishmaniasis and HIV/AIDS cases. To the best of our knowledge, this is the first report describing the spatial distribution of HIV-Leishmaniasis co-infection in Morocco where both infections are endemic.

Methods

In the current study, we discuss the HIV-Leishmania spp. co-infection vulnerability in Morocco by using the cartography tools. Thus, epidemiological data of both infections (Leishmaniasis and HIV/AIDS) in different administrative regions of Morocco were collected and co-registered for Digital maps making.

Results & conclusion

The results showed a high risk of HIV-Leishmania infantum co-infection in northern and central regions in Morocco. These results should be taken into account for efficient control strategies and epidemiological surveillance of HIV –Leishmania spp. co-infection in Morocco.

Asymptomatic carriers of Leishmania infantum in patients infected with human immunodeficiency virus (HIV) in Morocco

In Morocco, visceral leishmaniasis (VL) is a parasitic disease caused by the flagellated protozoan parasite Leishmania infantum. L. infantum is transmitted by the bite of female phlebotomine sandflies, and its main reservoir hosts are domestic dogs. Asymptomatic infection with L. infantum is more frequent than clinically apparent disease. In HIV-infected patients, the risk of clinical VL is increased due to immunosuppression that may reactivate latent infections. However, coinfected subjects do not necessarily develop VL and may remain as asymptomatic carriers depending on their immune status. The present study investigates the asymptomatic carriers of L. infantum in HIV-infected patients in central Morocco, where human cases of visceral leishmaniasis by L. infantum have been reported. A total of 200 HIV-infected patients attending the Infectious Diseases Unit of the Ibn Zohar Hospital of Marrakech participated in the study. Parasitological and serological blood analyses included a direct microscopic examination (DME), culture in Novy-McNeal-Nicolle (NNN) medium, and serology by indirect immunofluorescence (IFI). We found prevalence rates of 5% (10/200) by IFI, 3% (6/200) by DME, and 2.5% (5/200) by culture. The parasite was identified as L. infantum by PCR from positive cultures.