Journal of Infection in Developing Countries最新文献

{"title":"Analysis of bacteriological characteristics of nosocomial infections in preterms based on Gram-negative infection factors.","authors":"Junjie Xiang, Yuanxin Kuang, Qian Cheng, Keqian Zhang, Xindie Hu, Binghong Zhang, Yanyan Shang, Zhiyue Deng","doi":"10.3855/jidc.21965","DOIUrl":"https://doi.org/10.3855/jidc.21965","url":null,"abstract":"<p><strong>Introduction: </strong>Nosocomial infections (NIs) in the neonatal intensive care unit (NICU) are a significant cause of disability or death in preterm infants. This study focused on the bacteriological characteristics of NIs in preterm infants based on blood culture, and the factors related to Gram-negative bacterial infection.</p><p><strong>Methodology: </strong>This retrospective study was conducted at the NICU in Renmin Hospital of Wuhan University from January 2020 to June 2024. The patients were divided into Gram-negative and Gram-positive bacteria groups based on Gram staining results. Logistic regression analysis was performed to identify the factors influencing Gram-negative bacterial infection, and the diagnostic value was evaluated based on the area under the receiver operating characteristic curve (AUC).</p><p><strong>Results: </strong>A total of 54 strains (54/95, 56.84%) of Gram-positive bacteria and 41 strains (41/95, 43.16%) of Gram-negative bacteria were detected in the blood cultures of the 95 patients diagnosed with late-onset sepsis. The proportion of Gram-negative bacteria in the past 5 years exhibited a trend of initially decreasing and then increasing. Use of mechanical ventilation, decreased monocyte count, and elevated lactate levels were identified as factors predicting Gram-negative bacterial infection (p < 0.05). The AUC values of these factors for predicting Gram-negative bacterial infection were 0.56 (p < 0.05), 0.71 (p < 0.05), and 0.71 (p < 0.05), respectively.</p><p><strong>Conclusions: </strong>The proportion of Gram-negative bacterial infections showed a trend of initially decreasing and then increasing from 2020 to 2024. The use of mechanical ventilation, decreased monocyte counts, and elevated lactate levels were factors influencing Gram-negative bacterial infection.</p>","PeriodicalId":49160,"journal":{"name":"Journal of Infection in Developing Countries","volume":"20 8","pages":"1217-1224"},"PeriodicalIF":1.3,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148920430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative evaluation of a novel saliva collection strip and nasopharyngeal swab for SARS-CoV-2 validated by in-house RT-qPCR.","authors":"Ahmet C Orbay, Tuba Kuruoglu, Derya Bayirli Turan, Emine H Erdeniz, Demet Gur Vural, Deniz Kirac","doi":"10.3855/jidc.22270","DOIUrl":"https://doi.org/10.3855/jidc.22270","url":null,"abstract":"<p><strong>Introduction: </strong>The most commonly used sample collection method for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is nasopharyngeal swab; however, sample collection, especially from pediatric patients, is difficult. Therefore, the aim of this study was to design a saliva collection strip and to compare the effectiveness of this strip with the nasopharyngeal swab. Additionally, the performance of different isolation procedures before real time quantitative polymerase chain reaction (RT-qPCR) were investigated and an in-house RT-qPCR assay was developed.</p><p><strong>Methodology: </strong>A total of 200 samples was collected from patients and 92 samples were confirmed as SARS-CoV-2 positive. In the first technique, nucleic acid from the samples were isolated using different isolation methods, and then analyzed by RT-qPCR. In the second technique, the samples were analyzed directly by RT-qPCR without any isolation process. Additionally, in-house RT-qPCR assay was performed and the results were compared with conventional RT-qPCR.</p><p><strong>Results: </strong>The cycle threshold (Ct) values were compared between the techniques, and very similar results were obtained with all of the methods. This reveals that both sample collection methods, both isolation methods, and both RT-qPCR assays had comparable accuracy.</p><p><strong>Conclusions: </strong>In this study, in-house optimization, validation, and integration of the SARS-CoV-2 assay with both isolation-based and extraction (direct lysis) workflows were compared. In addition, its compatibility with the newly designed saliva strip collection system was analyzed. Very similar results were obtained from all of the methods. Therefore, the sample collection strip and in-house assay can be useful tools for detecting SARS-CoV-2.</p>","PeriodicalId":49160,"journal":{"name":"Journal of Infection in Developing Countries","volume":"20 8","pages":"1114-1121"},"PeriodicalIF":1.3,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148920903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal, seasonal, and spatial patterns of Mpox in the DRC, 2002-2022: longitudinal surveillance study.","authors":"Dominique Muteba Bapebabo, Trésor Zola Matuvanga, Thierry Kalonji Mukendi, Charlotte Jackson, Aaron Aruna, Joachim Kalubi Kabi, Vivi Maketa Tevuzula, Oriol Mitja, Felix Mulangu, Ali Judd, Carlo Gianquito, Patrick Mitashi Mulopo, Hypolite Muhindo-Mavoko","doi":"10.3855/jidc.21745","DOIUrl":"https://doi.org/10.3855/jidc.21745","url":null,"abstract":"<p><strong>Introduction: </strong>Mpox has shown increasing incidence and geographic spread since its first identification in the Democratic Republic of the001 Congo (DRC) in 1970.</p><p><strong>Methodology: </strong>We analyzed weekly mpox surveillance data reported from 2002-2022 in the DRC. Temporal trends were assessed using time-series decomposition to separate secular trends, seasonal patterns, and residual variation. Change-point analysis identified distinct transmission phases. Spatial trends were analyzed through thematic mapping of incidence rates across Health Zones.001 RESULTS: Between 2002 and 2022, a total of 55,072 suspected mpox cases and 1,297 deaths were reported, corresponding to an overall case fatality rate (CFR) of 2.4% and a mean CFR of 2.15% (95% CI: 1.8-2.5). Incidence increased progressively, with marked rises after 2010 and further intensification after 2015. Recurrent seasonal peaks were observed at the beginning of the year (February) and during mid-year (May-July). Change-point analysis identified four distinct transmission phases, during which annualized incidence increased from 0.78 to 2.67 cases per 100,000 population, alongside a steady geographic expansion from 56 to 159 health zones. By the most recent phase (2018-2022), approximately 30% of health zones nationwide had reported mpox cases. While CFRs declined during the intermediate phases, they increased again in recent years, reaching 2.63% in Phase IV.</p><p><strong>Conclusions: </strong>Mpox remains persistently endemic in the DRC, with progressive geographic expansion. These findings underscore the need for sustained surveillance, strengthened community engagement, and targeted prevention strategies embedded within a broader One Health framework to address zoonotic and ecological drivers of transmission.</p>","PeriodicalId":49160,"journal":{"name":"Journal of Infection in Developing Countries","volume":"20 8","pages":"1225-1234"},"PeriodicalIF":1.3,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148921479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lack of association between unhealthy vaginal pH and bacterial vaginosis positive status.","authors":"Ntombizethu Msomi, Nonkululeko Mabaso, Makandwe Nyirenda, Nathlee Abbai","doi":"10.3855/jidc.20098","DOIUrl":"https://doi.org/10.3855/jidc.20098","url":null,"abstract":"<p><strong>Introduction: </strong>Bacterial vaginosis (BV) remains highly prevalent worldwide. Although vaginal pH has been suggested to be a good predictor of BV, findings are conflicting. This study investigated the prevalence and risk factors associated with BV and the association between BV and vaginal pH in women from Durban, South Africa.</p><p><strong>Methods: </strong>This was a cross-sectional study that included 150 pregnant and non-pregnant women. BV was diagnosed using Nugent scoring and vaginal pH was measured using Lovibond® pH strips. Vaginal pH results were compared with Nugent scores. Statistical analyses were performed in STATA 17.1 using 95% confidence intervals and a significance level of 0.05.</p><p><strong>Results: </strong>According to Nugent's criteria, BV prevalence was 29.33%, while an additional 29.33% of the women had intermediate BV. Women aged 31-39 years were more likely to have BV than younger women (odds ratio [OR]: 7.27; 95% CI 1.40- 37.85; p = 0.018). Women with intermediate BV had a 2.4-fold higher likelihood of vaginal dysbiosis (OR: 2.42; 95% CI: 1.07-5.45; p = 0.033). Significant associations were observed between BV status and the presence of BVAB-1 (p = 0.016), BVAB-2 (p = 0.009), BVAB-3 (p = 0.048), Atopobium vaginae (p = 0.029), and Sneathia sanguinegens (p < 0.001). However, vaginal pH was not significantly associated with the prevalence of BV-associated microorganisms (p > 0.05).</p><p><strong>Conclusions: </strong>BV was common among women in Durban, South Africa; however, vaginal pH was not associated with BV or BV-associated bacteria, indicating that it was a poor predictor of BV in this population.</p>","PeriodicalId":49160,"journal":{"name":"Journal of Infection in Developing Countries","volume":"20 8","pages":"1187-1198"},"PeriodicalIF":1.3,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148921487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of Toxoplasma gondii seroprevalence in patients with cardiac diseases.","authors":"Şehriban Yürektürk, Yemlihan Ceylan, Abdurrahman Ekici, Canan Yenitürk Baydar, Selahattin Aydemir, Gülüm Sarğın","doi":"10.3855/jidc.21626","DOIUrl":"https://doi.org/10.3855/jidc.21626","url":null,"abstract":"<p><strong>Objective: </strong>To determine the prevalence of toxoplasmosis in cardiac patients and investigate the relationship between toxoplasmosis and cardiac diseases.</p><p><strong>Methodology: </strong>The study included 170 patients followed up in the cardiology department (patient group) and 167 individuals without any disease who were not receiving any immunosuppressive treatment (control group). Blood samples obtained from the study participants were analyzed for anti-Toxoplasma gondii immunoglobulin G (IgG) levels via enzyme-linked immunosorbent assay.</p><p><strong>Results: </strong>Anti- T. gondii IgG was detected in 41.2% of the patient group and 29.3% of the control group. Statistical analysis showed a significant correlation between anti- T. gondii IgG seropositivity in the patient and control groups. In the patient group, anti- T. gondii IgG was detected in 65.7% of those with a history of myocardial infarction (MI), 49.4% of those undergoing coronary angiography, and 48.6% of those undergoing stenting. In the statistical evaluation of patients with a history of coronary angiography, stenting, and MI, and toxoplasmosis seropositivity, significant relationships were found separately (p = 0.016, p = 0.014, and p = 0.001, respectively).</p><p><strong>Conclusions: </strong>Patients with cardiac diseases were found to be at a higher risk for toxoplasmosis compared to healthy individuals. In individuals with cardiac diseases, it is recommended that patients should be monitored for toxoplasmosis at regular intervals and necessary precautions should be taken, considering that latent infection may be reactivated in case of immune system failure.</p>","PeriodicalId":49160,"journal":{"name":"Journal of Infection in Developing Countries","volume":"20 8","pages":"1249-1253"},"PeriodicalIF":1.3,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148921555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comparison of phenotypic methods for the detection of carbapenemase in Klebsiella pneumoniae.","authors":"Betül Günaydın, Nuri Kiraz","doi":"10.3855/jidc.22219","DOIUrl":"https://doi.org/10.3855/jidc.22219","url":null,"abstract":"<p><strong>Introduction: </strong>Carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates are increasingly spreading in the community and pose a serious public health threat. Rapid and accurate detection of these isolates is therefore critical. This study aimed to evaluate the performance of combined disc method, the carbapenem inactivation method (mCIM) and its modifications.</p><p><strong>Methodology: </strong>A total of 100 K. pneumoniae isolates collected from various clinical samples between 2018 and 2021 were included. Carbapenemase production was investigated using the combined disc method, mCIM (19 mm and 22mm), and aCIM (19 mm and 22 mm). Carbapenemase types were determined using the combined disc method, eCIM, and mCIMplus. Resistance genes were detected by real-time PCR, which was used as the reference method to evaluate the performance of phenotypic tests.</p><p><strong>Results: </strong>For carbapenemase detection, the sensitivities of combined disc method, mCIM-19 mm, mCIM-22 mm, aCIM-19 mm, and aCIM-22 mm were 100%, 84.8%, 95.7%, 83.7% and 95.7%, respectively, while the specificities are 62.5%, 100%, 25%, 100%, and 62.5%. For carbapenemase species detection, the sensitivities of the combined disc method, eCIM-19 mm, eCIM-22 mm, and mCIMplus were 98,9%, 75.4%, 84% and 26.1%, respectively; the specificities were 62.5%, 48.8%, 42% and 100%. No significant differences were observed between the mCIM and aCIM tests. (p value:1 for 19 mm, p value:0.37 for 22 mm).</p><p><strong>Conclusions: </strong>The combined disc method provided the most effective balance of performance and practicality. However, phenotypic methods may be insufficient for isolates harboring multiple resistance genes.</p>","PeriodicalId":49160,"journal":{"name":"Journal of Infection in Developing Countries","volume":"20 8","pages":"1106-1113"},"PeriodicalIF":1.3,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148921603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinical Utility of Targeted Third-Generation Sequencing for Pathogen Detection in Community-Acquired Pneumonia: A Real-World Comparative Study of China.","authors":"Nianhong Lu, Jin Guo, Caihong Liu, Jiangyuan Wang, Danhua Wang, Xue Li, Ye Yuan","doi":"10.3855/jidc.22870","DOIUrl":"https://doi.org/10.3855/jidc.22870","url":null,"abstract":"<p><strong>Objective: </strong>To evaluate the diagnostic performance and clinical utility of targeted third-generation sequencing (tTGS) for pathogen detection in community-acquired pneumonia (CAP), compared with targeted next-generation sequencing (tNGS) and conventional culture.</p><p><strong>Methodology: </strong>We conducted a real-world, retrospective study including 356 CAP patients who were tested in parallel with culture, tNGS, and tTGS. Diagnostic sensitivity, pathogen spectrum, mixed-infection detection, and antimicrobial resistance (AMR) gene profiling were compared across methods. Clinical relevance was assessed by analyzing treatment adjustments informed by sequencing results.</p><p><strong>Results: </strong>tTGS demonstrated the highest overall sensitivity (99.16%), surpassing tNGS (96.35%, p < 0.05) and culture (50.27%, p < 0.01). Across all samples, tTGS identified 135 microbial species - substantially more than tNGS (84 species) and culture (27 species) - including fastidious, rare, and slow-growing pathogens. tTGS also showed an improved ability to detect mixed infections (86.24% vs. 87.64% with tNGS; culture detected none). AMR gene detection was significantly higher with tTGS than with tNGS (58.99% vs. 48.88%, p = 0.008), and long-read sequencing enabled the identification of composite resistance patterns that tNGS missed. Among patients without underlying diseases, sequencing-guided therapeutic adjustment occurred in 67.87% of cases, with nearly 80% of AMR-positive patients demonstrating clinical improvement following regimen optimization.</p><p><strong>Conclusions: </strong>tTGS provides markedly enhanced pathogen detection, greater sensitivity, and more comprehensive AMR profiling than both tNGS and culture. Its strong performance in identifying mixed infections and actionable determinants of resistance supports its incorporation into clinical diagnostic workflows for CAP. Further large-scale, prospective studies are warranted to validate its clinical impact and optimize its integration into routine practice.</p>","PeriodicalId":49160,"journal":{"name":"Journal of Infection in Developing Countries","volume":"20 8","pages":"1122-1132"},"PeriodicalIF":1.3,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148920450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emergence of NDM and OXA-48-like producing Enterobacterales in Northern Morocco.","authors":"Majda El-Hassouni, Asmae Hazzaz, Reda A Souhli, El Mehdi El Ghorba, Hanaa El Mamouny, Kawtar El Harrak, Nouhaila Chahid, Youssra Amekran, Karima Rissoul","doi":"10.3855/jidc.22277","DOIUrl":"https://doi.org/10.3855/jidc.22277","url":null,"abstract":"<p><strong>Introduction: </strong>Carbapenemase-producing Enterobacterales (CPE) have widely emerged as a global health threat due to the spread of resistance genes such as New Delhi metallo-β-lactamase (blaNDM) and oxacillinase-48-like β-lactamases (blaOXA-48-like). Data on the molecular epidemiology of CPE in northern Morocco remain limited. Hence, this study aimed to report the epidemiological profile of carbapenem-resistant Enterobacterales and their molecular analysis.</p><p><strong>Methodology: </strong>A prospective study was conducted from July 2024 to July 2025 at Mohammed VI University Hospital, Tangier. Ninety-two non-duplicate Enterobacterales isolates were collected across different departments. Species were identified via the matrix-assisted laser desorption/ionization - time-of-flight (MALDI-TOF MS) technique and antimicrobial susceptibility testing was performed according to the guidelines of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Carbapenemase production was screened using GeneXpert® Carba-R (Cepheid, Sunnyvale, USA). Associations between clinical, microbiological, and molecular data were assessed using Chi square or Fisher's exact tests.</p><p><strong>Results: </strong>Klebsiella pneumoniae dominated across all isolates (75/92; 81.5%), followed by Escherichia. coli (8/92; 8.7%). BlaNDM was found in 65/92 (70.6%), blaOXA-48-like in 17/92 (18.5%), and both in 10/92 (10.9%). Most cases occurred in neonatal (38%) and intensive care units (31.5%). Resistance exceeded 70% for several major antibiotics; 29.3% were colistin-resistant. Mortality was 46.7%. Diabetes (p < 0.01) and severe burns (p < 0.01) were significantly associated with carbapenemase carriage.</p><p><strong>Conclusions: </strong>CPE, especially NDM-producing Klebsiella pneumoniae, represent a major threat in northern Morocco, notably in neonatal and critical care units. Their high resistance and mortality highlight the urgent need for reinforced infection control, molecular surveillance, and rapid diagnostics.</p>","PeriodicalId":49160,"journal":{"name":"Journal of Infection in Developing Countries","volume":"20 8","pages":"1179-1186"},"PeriodicalIF":1.3,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148921289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Re-emergence of Ebola and Marburg virus diseases and recent activity in Africa - the need to shift to more proactive emergency responses.","authors":"Hermenegildo O Chitumba","doi":"10.3855/jidc.22746","DOIUrl":"https://doi.org/10.3855/jidc.22746","url":null,"abstract":"<p><p>Ebola virus disease and Marburg virus disease are severe, highly lethal infections caused by filoviruses, characterized by rapid transmission, complex clinical management, and major socio-economic impact. A narrative review of recent outbreaks between 2021 and 2025 underscores persistent systemic gaps that compromise early detection and effective containment. The recurrence of Ebola and Marburg outbreaks demonstrates that, although progress has been made since the 2014-2016 West African epidemic, substantial vulnerabilities persist.</p>","PeriodicalId":49160,"journal":{"name":"Journal of Infection in Developing Countries","volume":"20 8","pages":"1104-1105"},"PeriodicalIF":1.3,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148921465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of the DNA methylation of seven genes contributes to monitoring recovery from COVID-19.","authors":"Xiao Xiao, Ren Xu, Chaoxiang Du, Jun Yin, Beibei Xin, Zhonghe Ke, Xiyan Li, Hao Zhang, Xinyu Chen","doi":"10.3855/jidc.21864","DOIUrl":"https://doi.org/10.3855/jidc.21864","url":null,"abstract":"<p><strong>Introduction: </strong>DNA methylation might influence the expression of genes that regulate coronavirus disease 2019 (COVID-19) progression. This work explored the significance of DNA methylation of 7 genes (TAC1, CDO1, HOXA9, ZFP42, SOX17, RASSF1A, and SHOX2) in blood circulating free DNA (cfDNA) in differentiating COVID-19 infections and recoveries. The correlation with changes in the proportion of immune cell populations in the recovery period was analyzed.</p><p><strong>Methodology: </strong>18 COVID-19-infected, 65 COVID-19-recovered, and 11 uninfected individuals were included. DNA methylation expression was determined by quantitative multiplex methylation-specific PCR (qMSP). The immune function of the recovered group versus uninfected group was evaluated by full-spectrum flow cytometry.</p><p><strong>Results: </strong>The infected population showed a higher methylation positivity rate for 7 genes compared to the uninfected/recovered population. A model was constructed to distinguish the infected patients from uninfected/recovered individuals using the methylation status of 7 genes, with a sensitivity, specificity and area under curve (AUC) of 0.889, 0.842 and 0.931, respectively. The results of flow cytometry revealed that CD8+ T cells and CD38+ CD8+ T cells were significantly upregulated in recovered individuals compared to those in uninfected individuals. DNA methylation was correlated with immune cell changes, with a significant increase in the percentage of T cells, PD-1+ function CD4+ T cells, TCRγδ+ cells, and CD38+ NKT cells upon an increase in 7 gene methylation positivity.</p><p><strong>Conclusions: </strong>This work revealed the significance of 7 gene methylation in the diagnosis of COVID-19 recovery, and demonstrated that these genes were significant in evaluating the immune function during the recovery period.</p>","PeriodicalId":49160,"journal":{"name":"Journal of Infection in Developing Countries","volume":"20 7","pages":"944-953"},"PeriodicalIF":1.3,"publicationDate":"2026-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148690218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}