Study on mNGS Technique in Diagnosing Pneumocystis jirovecii Pneumonia in Non-HIV-Infected Patients.

To investigate the value of metagenomic Next-Generation Sequencing (mNGS) in diagnosing Pneumocystis jirovecii pneumonia (PJP) in non-human immunodeficiency virus (HIV)-infected patients. In this retrospective study, non-HIV-infected patients with PJP and those diagnosed with non-PJP from August 2022 to December 2024 were selected as subjects. The presence of Pneumocystis jirovecii (PJ) and other co-pathogens in bronchoalveolar lavage fluid (BALF) was analyzed, and the diagnostic efficacy of NGS, polymerase chain reaction (PCR) and serum 1,3-β-D-glucan (BDG) in PJP was compared with the reference standard of clinical compound diagnosis. Eighty-nine non-HIV-infected patients were recruited, with dyspnea as the primary symptom (69.66%) and solid malignant tumor as the most common underlying disease (20.22%). Taking clinical compound diagnosis as the reference standard, the sensitivity, specificity, negative predictive value and positive predictive value of mNGS were higher than those detected by PCR and serum BDG. Among 42 non-HIV-infected patients with PJP who underwent mNGS and conventional pathogen detection of BALF, 6 had simple PJ infection and 36 had combined PJ infection. The detection rate of mNGS in mixed infections was significantly higher than that of conventional pathogen detection (85.71 vs 61.70%, P = 0.012). A total of 127 pathogens were detected in BALF using mNGS, among which fungi had the highest detection rate (46.46%). The fungi, viruses and bacteria detected were mainly Pneumocystis jirovecii, human gammaherpesvirus 4 and Acinetobacter baumannii. mNGS is highly effective in diagnosing non-HIV-infected patients with PJP and exhibits ideal performance in the detection of co-pathogens. In addition, it has certain value for clinical diagnosis and guidance of targeted anti-infective drug treatment.

Li S ，Han X ，Ma J ，Huang GH ，Yang ST ，Wang CM ... -  《Infection and Drug Resistance》

Metagenomic next-generation sequencing promotes diagnosis and treatment of Pneumocystis jirovecii pneumonia in non-HIV infected children: a retrospective study.

Metagenomic next-generation sequencing (mNGS) excels in diagnosis of infection pathogens. We aimed to evaluate the performance of mNGS for the diagnosis of Pneumocystis jirovecii pneumonia (PJP) in non-HIV infected children. Totally 36 PJP children and 61 non-PJP children admitted to the pediatric intensive care unit from March 2018 to December 2021 were retrospectively enrolled. Clinical features of PJP children were summarized. 1,3-β-D glucan (BDG) test and bronchoalveolar lavage fluid (BALF) mNGS were used for evaluation of PJP diagnostic performance. Antimicrobial management modifications for PJP children after the mNGS results were also reviewed. Pneumocystis jirovecii was detected in all PJP children by mNGS (36/36), and the sensitivity of mNGS was 100% (95% confidence interval [CI]: 90.26-100%). The sensitivity of BDG was 57.58% (95% CI: 39.22-74.52%). Of the 26 (72.2%) PJP patients with mixed infection, twenty-four (66.7%) were detected by BALF-mNGS. Thirteen patients (36.1%) had their antimicrobial management adjusted according to the mNGS results. Thirty-six PJP children included 17 (47.2%) primary immunodeficiency and 19 (52.8%) secondary immunodeficiency, of whom 19 (52.8%) survived and 17 (47.2%) died. Compared to survival subgroup, non-survival subgroup had a higher rate of primary immunodeficiency (64.7% vs. 31.6%, P = 0.047), younger age (7 months vs. 39 months, P = 0.011), lower body weight (8.0 kg vs. 12.0 kg, P = 0.022), and lower T lymphocyte counts. The mortality rate of PJP in immunosuppressed children without HIV infection is high and early diagnosis is challenging. BALF-mNGS could help identify PJP and guide clinical management.

Zhang Z ，Liu T ，Ming M ，Shen M ，Zhang Y ，Chen H ，Chen W ，Tao J ，Wang Y ，Liu J ，Zhou J ，Lu G ，Yan G ... -  《BMC Pulmonary Medicine》

Diagnostic value of metagenomic next-generation sequencing using bronchoalveolar lavage fluid samples for pathogen detection in children with severe or refractory pneumonia.

Zhao M ，Shi Y ，Zhang C ，Lu M ，Shen M ，Xie L ，Wang L ，Lu A ... -  《-》

Diagnostic tests performance in detecting Pneumocystis jirovecii: A systematic review and meta-analysis.

Pneumocystis jirovecii (Pj) pneumonia (PJP) is a life-threatening opportunistic infection primarily affecting immunocompromised individuals. Detecting Pj is challenging, particularly in distinguishing between Pj colonization (PJC) and infection. We aimed to systematically evaluate the diagnostic accuracy of various tests in differentiating Pj colonization from infection. Systematic reviews and meta-analyses were performed. Searches were conducted in PubMed, Embase, and Web of Science. Original clinical studies reporting sensitivity and specificity data for diagnostic tests such as quantitative polymerase chain reaction (qPCR), nested PCR, (1,3)-Beta-D glucan (BDG), metagenomic next-generation sequencing (mNGS), and digital PCR (ddPCR) to differentiate PJC from PJP were included. Quality assessment was performed using QUADAS-2 tool, and data processing followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Diagnostic performance was evaluated using either a random-effects or fixed-effects model. Twenty-eight studies (2,550 patients, 1,445 with PJP) were included, with moderate methodological quality. The pooled sensitivity of these diagnostic tests was 0.80 (95% CI 0.77-0.82) and specificity was 0.83 (95% CI 0.81-0.85), with a diagnostic odds ratio (DOR) of 23.12. Among the individual tests, BDG (5 studies) showed high pooled sensitivity (0.83, 95% CI 0.77-0.88) but lower specificity (0.78, 95% CI 0.69-0.85). mNGS (3 studies) had the highest performance, with pooled sensitivity and specificity both at 0.87 (95% CI 0.80-0.92 and 95% CI 0.77-0.94, respectively), and the highest DOR of 41.57. qPCR (19 studies) demonstrated adequate pooled sensitivity (0.78, 95% CI 0.76-0.81) and high specificity (0.83, 95% CI 0.81-0.86), with a DOR of 20.44. While BDG has low specificity and mNGS is costly with no standardized interpretation, along with the limited number of relevant studies in BDG and mNGS, this meta-analysis concluded that qPCR remains valuable for distinguishing P. jirovecii infection from colonization. A well-designed randomized clinical trial that standardizes the technical aspects of the qPCR protocol is needed to assess its effectiveness and provide a solid basis for clinical diagnosis.

Zhang L ，Zheng C ，Sun Y ，Chen X ，Wang Y ，Xiang H ，Liang Y ，Wei F ，Zhang Y ... -  《-》

Insights into Pneumocystis jirovecii pneumonia in South Africa (2018-2022).

Pneumocystis jirovecii causes P. jirovecii pneumonia (PJP)-a leading opportunistic infection among persons with advanced human immunodeficiency virus. Furthermore, individuals with underlying conditions such as cancer and transplant recipients are susceptible to PJP. Most data on PJP come from other countries, with limited knowledge about its prevalence in Africa. The aim was to describe changes in the proportion of positive PJP tests in South Africa from 2018 to 2022. A 5-year retrospective study was conducted on patients with suspected P. jirovecii, detected by polymerase chain reaction. Data were obtained from the National Health Laboratory Service, where laboratory diagnostics were done as part of routine patient care. Mann-Whitney test and Χ2 tests were used to compare the age, sex, and wards with both the negative and positive results of PJP. From 2018 to 2022, a total of 8110 patients' results were retrieved, and 8059 met the inclusion criteria. The positive test proportions of PJP in South Africa were 32.66%, 29.93%, 34.02%, 24.98%, and 25.78%, respectively. The median age was 35 years, with interquartile range of 24-43 years (P = .002). Female patients had a higher positive test proportion than males (59.39% vs. 38.74%, P < .001). The proportion of positive PJP tests was higher in general wards (48.54%) and intensive care units (18.99%) (P = .012). The epidemiology of PJP in South Africa is similar to that of other countries in some respects but is influenced by unique factors specific to the country. These findings are crucial for public health planning, emphasising the need for targeted PJP prevention strategies considering sex- and age-specific vulnerabilities in South Africa.

Nkosi MP ，Hoog KJ ，Lowe M 《-》