Caihua Chang, Wen Song, Yingcai Zhang, Xiaojun Yang, Yongping Zhang
This study demonstrates that mNGS can serve as a valuable adjunct for the rapid etiological diagnosis of VL, particularly when conventional tests are negative. Nevertheless, its current use is largely restricted to endemic areas where advanced laboratory infrastructure is available; therefore, mNGS should be regarded as a complementary diagnostic tool rather than a substitute for routine assays. Broader implementation in clinical practice will require further studies on cost‑effectiveness and operational feasibility.
BACKGROUND: Kala-azar, or visceral leishmaniasis (VL), is a parasitic disease caused by Leishmania protozoa. Conventional diagnostic modalities for visceral leishmaniasis-including microscopy, in vitro culture, and serological assays-are constrained by suboptimal sensitivity, invasive sampling, and prolonged turnaround times.
METHODS: We report two cases of visceral leishmaniasis-related hemophagocytic lymphohistiocytosis, in which no Leishman-Donovan bodies were detected by conventional assays. Metagenomic next-generation sequencing (mNGS) successfully identified Leishmania pathogens, and the diagnosis was confirmed by the rK39 rapid test.
RESULTS: mNGS successfully identified Leishmania pathogens in both patients. Targeted anti-leishmanial treatment led to rapid clinical improvement in both patients.
CONCLUSION: This study demonstrates that mNGS can serve as a valuable adjunct for the rapid etiological diagnosis of VL, particularly when conventional tests are negative. Nevertheless, its current use is largely restricted to endemic areas where advanced laboratory infrastructure is available; therefore, mNGS should be regarded as a complementary diagnostic tool rather than a substitute for routine assays. Broader implementation in clinical practice will require further studies on cost‑effectiveness and operational feasibility.