A Case Report of Two Kala-azar Cases in China Diagnosed by Metagenomic Next-Generation Sequencing

Abstract

BackgroundLeishmaniasis being a local disease, as kala-azar this particular form is a visceral form. It is transmitted by sandflies, and is a parasitic disease involving the reticuloendothelial system of mononuclear macrophages. Due to its poor prognosis and high fatality rate, the fatality rate of patients without effective treatment can exceed 95%. Thereby, early diagnosis and treatment can significantly improve its prognosis. The metagenomic next-generation sequencing (mNGS) has the advantage of being able to find pathogens that cannot be detected by traditional methods. More importantly, it can conduct nucleic acid detection of pathogens covering a wide range in a short time. For infectious diseases like kala-azar, which is clinically complicated and difficult, mNGS detection provides a basis for accurate etiological diagnosis.Case ReportWe report 2 cases of kala-azar in West China Hospital, Chengdu, China. The first case is a 47-year-old male patient who had recurrent fever for 4 months, accompanied by reduction of red blood cell, white blood cell, and blood platelet. He was detected by mNGS and clinically diagnosed as kala-azar (Leishmania detection), finally died of multiple organ failure. The second patient was a 15-year-old male who had fever for more than 10 days. He was detected by mNGS and clinically diagnosed as kala-azar (Leishmania detection). He recovered and discharged quickly after treatment with sodium stibogluconate.ConclusionEfforts should be made to improve early etiological diagnosis in order to improve patient prognosis. mNGS detection is beneficial to the diagnosis and treatment of infectious diseases with unknown causes in the early stage of emergency treatment.

A Case Report of Cutaneous Anthrax Diagnosed by Using a Metagenomic Next-Generation Sequencing (mNGS) Approach

“…infections with specific pathogens. 8,[19][20][21][22][23] However, any pathogen test can only be used as an adjunct to an infection and the final diagnosis must be clinically based. Detection of mNGS can be a diagnostic tool for microorganisms that are difficult to find in the regular environment, such as B. anthracis.…”

Case report: Application of metagenomic next-generation sequencing in the diagnosis of visceral leishmaniasis and its treatment evaluation

“…Due to its unbiased and hypothesis-free characteristics, mNGS has emerged as a vital method in identifying complex microorganisms to culture and diagnosing infectious diseases with low incidence. As recently reported, mNGS allows for Leishmania detection and early diagnosis of visceral leishmaniasis, improving the prognosis of the patients (10). In this case report, two patients with fever of unknown origin were enrolled, with some abnormal items in their physical examinations, including blood biochemistry, liver function, and blood routine.…”

Case report: Diagnosis of visceral leishmaniasis using metagenomic next-generation sequencing and bone marrow smear

“…Patients may be asymptomatic in the initial stage of the disease, and the incubation period typically lasts several weeks to more than one year (van Griensven and Diro, 2019;Scarpini et al, 2022). The case fatality rate is more than 95% in individuals with symptomatic disease, if untreated or if treatment is delayed (Gao et al, 2022). As the disease is rare in China and its clinical symptoms are atypical, its diagnosis is often incorrect, missed, or delayed.…”