Genotypic and phylogenic analyses of cutaneous leishmaniasis in Al Ahsa, Eastern Saudi Arabia during the coronavirus disease 2019 pandemic: First cases of Leishmania tropica with the predominance of Leishmania major

Abstract

During the coronavirus disease 2019 lockdown period, a surge in sandflies and cutaneous leishmaniasis (CL) cases was observed in Al-Ahsa, Saudi Arabia. Skin punch biopsies were obtained from 100 patients clinically diagnosed with CL in Al-Ahsa who had no travel history in the last 6 months. Impression smears were used following a three-step polymerase chain reaction (PCR) protocol using genus-specific primers targeting kDNA and ITS1. Leishmania speciation was determined by ITS1 PCR/nested PCR-restriction fragment length polymorphism and sequencing. A phylogenetic tree was constructed. The associated patient characteristics were analyzed. Using internal transcribed spacer one (ITS1)-PCR/nested PCR, 98 cases were considered true-positive CL. Leishmania major was the predominant species, and Leishmania tropica was identified in three cases. Microscopy had poor sensitivity and perfect specificity. Direct ITS1-PCR missed nine cases. Sex, residence, and treatment outcome were significantly associated with the occurrence of Leishmania; distribution of skin lesion(s) and treatment outcome were significantly associated with Leishmania genotype. This is the first time that L. tropica was identified as a cause of CL in human in Al-Ahsa, in addition to the predominant zoonotic species, L. major. We recommend using ITS1-nested PCR for negative cases by ITS1-PCR. Further exploration of Leishmania transmission dynamics in vectors and reservoir animals is essential for designing effective preventive measures.

Molecular identification of Leishmania major species in phlebotomine sand flies from Al Ahsa, Eastern KSA

“… 14 , 20 In our study, we applied a protocol combining ITS1 PCR and ITS1 nPCR for samples with initial negative results for the collected female Phlebotomus sand flies ( Figure 1 ). 8 , 16 Other protocols have been used for identification of Leishmania species in collected sand flies. El-Beshbishy et al.…”

“…The ITS1 nPCR was conducted with two sets of two pairs of primers: the primer pair R221 and R332 targeting small subunit ribosomal RNA (SSU rRNA) in the first PCR reaction, and the nested primer pair LITS and L5.8S targeting ITS1 in the second reaction ( Table 1 ). 8 , 16 Figure 1 shows the PCR protocol.…”

“… 7 Several Saudi provinces are considered CL endemic areas, including Al-Madinah Al-Munawwarah, Al Qassim, and Al-Ahsa oasis. 8 Multiple surveys in KSA have defined the prevalence and geographical distribution of phlebotomine species. 9 , 10 , 11 , 12 , 13 A total of 25 species have been reported in KSA, and Phlebotomus papatasi has been found to predominate in all explored regions of the country.…”

Leishmaniasis: Recent epidemiological studies in the Middle East

“…A molecular study detected human cases of anthroponotic L. tropica in Al-Ahsa, an eastern region in Saudi Arabia, for the first time (Al-Rashed et al, 2022). This may be accounted for by sandfly migration from regions outside Al-Asha during the COVID-19 lockdown, which caused vector-borne disease prevention programs and sandfly surveillance to shut down.…”

“…Leishmania donovani sensu lato was the main VL parasite in the region; feral dogs are the reservoir, and P. alexandri and P. orientalis are suspected as main vectors ( Sirdar et al, 2018 ). A molecular study detected human cases of anthroponotic L. tropica in Al-Ahsa, an eastern region in Saudi Arabia, for the first time ( Al-Rashed et al, 2022 ). This may be accounted for by sandfly migration from regions outside Al-Asha during the COVID-19 lockdown, which caused vector-borne disease prevention programs and sandfly surveillance to shut down.…”