Six-Year Study on Cutaneous Leishmaniasis in Al-Muthanna, Iraq: Molecular Identification Using ITS1 Gene Sequencing

Abstract

Background: The current study aimed to determine the prevalence of cutaneous leishmaniasis (CL) in Al-Muthanna province (Iraq) and to characterize the Leishmania species that cause cutaneous lesions through conventional polymerase chain reaction techniques in some patients during the first 7 months of the year 2020.

Materials and methods: Medical information on patients with CL was obtained from archived records at the Al-Muthanna Health Office's Public Health Department (2015-2020). In the Al-Hussein Teaching Hospital laboratory, 95 CL samples were collected and examined microscopically for molecular characterization using Giemsa staining.

Results: Between 2015 and 2020, 2,325 patients (1,184 men and 1,141 women) were enrolled. Although CL occurred across all age groups, those aged range of 5-14 years had the highest proportion of infections (53.0%). This study found that most infections occurred between December and February, peaking in January. Only 63 of 95 CL samples were positive for the Internal Transcribed Spacer 1 region. L. tropica was found in 39 samples (61.9%), whereas L. major was found in 24 samples (38.1%), in CL patients. Although dermal lesions develop in all body regions, a single lesion is the most common. The upper limbs (13 of 16 samples, 33.3%)were infected with L. tropica, whereas the lower limbs (9 of 14 samples, 37.5%) were infected with L. major. In contrast to L. major, most L. tropica lesions occur in urban areas.

Conclusion: Our study indicates that CL is endemic in the Al-Muthanna province and that two Leishmania spp. coexist in the province. Molecular diagnosis is a vital component in determining many clinical symptoms of the Leishmania parasite as well as implementing suitable therapeutic, epidemiological, and control strategies.

Keywords: Baghdad boil; Dermal lesion; Internal Transcribed Spacer 1; Leishmania major; Leishmania tropica.

Figure 1. Study area (A) Administrative boundaries of Al-Muthanna Province, (B) Locations of samples collection.

Figure 2. Distribution of CL monthly infections, illustrated by month over the period 2015–2020.

CL, cutaneous leishmaniasis.

Figure 3. Positive samples of the ITS1-ribosomal RNA gene, (A) samples in lanes 1–5 positive for Leishmania tropica and (B) samples in lanes 1–5 positive for L. major at 202 and 569 bp. (M: marker [100–1,500 bp]).

ITS1, Internal transcribed spacer 1.