The Value of Metagenomic Next-Generation Sequencing in Leishmaniasis Diagnosis: A Case Series and Literature Review

Background Leishmaniasis is a zoonotic disease caused by Leishmania spp. and spreads through sandfly bites. Owing to the wide range of nonspecific clinical symptoms, patients with leishmaniasis are frequently misdiagnosed or underdiagnosed. Methods The study participants were 7 metagenomic next-generation sequencing (mNGS)-diagnosed patients with leishmaniasis who could not be diagnosed using conventional methods. Clinical data were retrospectively collected and analyzed. When searching PubMed for mNGS and leishmaniasis, 8 peer-reviewed case reports in English were retrieved. Results A total of 7 patients with recurrent fever, pancytopenia, and significant splenomegaly were included in this study. Only 3 individuals tested positive for rK39. Two individuals, 1 of whom was HIV-positive, had Leishmania amastigotes identified in their bone marrow. However, all patients' blood mNGS findings pointed to Leishmania infection, and they were finally diagnosed with leishmaniasis. Sodium stibogluconate therapy with a short course of amphotericin B was administered to all patients. The prognosis for the remaining patients was good, except for 1 who died of multiple organ failure. Conclusions mNGS could be used to identify leishmaniasis, particularly in patients who are difficult to diagnose using conventional approaches.