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Clinical Microbiology and Infection

Elsevier BV

Preprints posted in the last 30 days, ranked by how well they match Clinical Microbiology and Infection's content profile, based on 60 papers previously published here. The average preprint has a 0.04% match score for this journal, so anything above that is already an above-average fit.

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Impact of prescription-free access to sexually transmitted infection screening tests in medical-biological laboratories: cross-sectional analysis of data from clinical laboratories in France.

Gil-Salcedo, A.; Gazzano, V.; Arsene, S.; Durand, A.; Roger, S.; Prots, L.; Laurencin, N.; Chanard, E.; Duez, A.; Le Naour, E.; Bausset, O.; Ghali, B.; Strzelecki, A.-C.; Felloni, C.; Levillain, R.; Fargeat, C.; Lefrancois, S.; Feuerstein, D.; Visseaux, B.; Escudie, L.; Visseaux, C.; Leclerc, C.; Haim-Boukobza, S.

2026-04-24 public and global health 10.64898/2026.04.23.26351562 medRxiv
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Background: Since September 2024, France has implemented a national reform allowing prescription-free access (PFA) to sexually transmitted infection (STI) screening in medical biological laboratories (MBLs). This study aims to characterize the populations undergoing STI testing according to their access modality and evaluate the probability of test positivity in relation to testing pathway, sex, and age groups. Methods: We conducted a cross-sectional analysis of all individuals screened for Chlamydia trachomatis, Gonorrhoea, human immunodeficiency virus (HIV), hepatitis B virus (HBV), and syphilis by treponemal-specific immunoassay (TSI) in Cerballiance MBLs between Mars 2025 and February 2026. Multivariable logistic regression models stratified by sex and adjusted for age and region assessed associations between screening modality and STI positivity. Results: Among 1,008,737 individuals included, 27.8% were under PFA and 72.2 under prescription-based access (PBA). PFA users were more frequently male (47.4% vs. 36.3%, p<0.001) and aged 20-39 years (34.0%, p<0.001). Overall positivity rates differed by modality: PFA was associated with higher detection of Chlamydia (4.6% vs. 3.6%). PBA group showed more positive cases of syphilis (3.4% vs. 1.2%), HBV (1.3% vs. 0.4%), and HIV infections (0.3% vs. 0.2%, all p<0.001). Co-infection and gonorrhoea proportions did not significantly differ between modalities. Conclusions: PFA substantially increased STI screening uptake, particularly among young adults and men, and enhanced detection of bacterial STIs. PBA remains essential for diagnosing viral and chronic infections. These findings highlight the complementary roles of both access strategies and support PFA screening as an effective public health intervention to broaden STI detection and reduce transmission.

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Assessing Compliance with Reporting Requirements in European Phase II to IV Clinical Trials: A Cross-Sectional Observational Study

Bruckner, T.; Dike, C. E.; Caquelin, L.; Freeman, A.; Aspromonti, D. A.; DeVito, N.; Song, Z.; Karam, G.; Nilsonne, G.

2026-04-05 health policy 10.64898/2026.04.03.26350111 medRxiv
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Objectives: To assess the availability of key clinical trial registration data and compliance with legal reporting requirements for all Phase 2-4 drug trials registered on the new European Clinical Trial Information System (CTIS) registry. This study is the first ever assessment of data quality and legal compliance with reporting requirements on CTIS. Design: Cross-sectional observational study of CTIS registry data combined with manual review of results documents. Setting: Cohort of all 7,547 Phase II-IV clinical trials registered on CTIS as of November 2025. Main outcome measures: Number and proportion of missing data points in CTIS registration data. Proportion of completed clinical trials that are compliant with regulatory reporting requirements. Results: Trial registration data quality was high overall with more than 99% of expected data present. Of 234 clinical trials legally required to report results, fewer than half (49.6%) fully reported results within the required timeframe, 20 trials (8.5%) fully reported results late, and 98 trials (41.9%) failed to fully report results. Legal compliance was similar for adult trials (79/158) and paediatric trials (37/76). Conclusions: Sponsor compliance with legal reporting requirements is weak. Current efforts by European regulators to monitor and enforce compliance appear to be insufficient. New results reporting functions currently being set up by trial registries worldwide will require quality assurance processes. Trial registration: Study protocol prospectively registered on OSF: https://osf.io/sn4j2/overview

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Invasive cervical cancers after an HPV-negative test: insights from screening histories

Hassan, S. S.; Nordqvist-Kleppe, S.; Asinger, N.; Wang, J.; Dillner, J.; Arroyo Muhr, L. S.

2026-04-13 public and global health 10.64898/2026.04.11.26350679 medRxiv
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Human papillomavirus (HPV) testing is the primary method for cervical cancer screening, and a negative HPV test is associated with a very low subsequent risk of invasive cancer. Nevertheless, a small number of cervical cancers are diagnosed following an HPV-negative testing result, posing challenges within HPV-based screening pathways. Using nationwide Swedish registry data of HPV testing, we identified women diagnosed with invasive cervical cancer between 2019 and 2024 and reconstructed HPV testing histories from the National Cervical Screening Registry (NKCx). The most recent HPV test prior to diagnosis was defined as the index test, and longitudinal HPV testing trajectories were classified among women with an HPV-negative index test. Of 3,000 women diagnosed with invasive cancer, 243 (8.1%) had an HPV-negative index test. These women were older at diagnosis and more frequently diagnosed at advanced stages compared with women with an HPV-positive index test. Most HPV-negative index tests (66.3%) were performed in the peri-diagnostic period (+/- 30 days). Among women with an HPV-negative index test, 52.7% (128/243) had no prior HPV testing recorded, while the remainder had consistently HPV-negative histories (33.3%, 83/243) or evidence of prior HPV positivity before the index negative test (14%, 32/243). Possible recurrent HPV positivity following an intervening negative test was rare (0.4%, 1/243). HPV-negative screening results preceding invasive cancer reflect heterogeneous screening histories and cannot be explained solely by test failure. Findings highlighting the importance of reaching women earlier in screening programs and show that fluctuating HPV detectability is rare.

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Risk Factors for Antimicrobial Resistance in Cancer Patients and Cancer Survivors: An Electronic Health Record Study

Hu, F.; Wei, J.; Muller-Pebody, B.; Hope, R.; Brown, C.; Carreira, H.; Demirjian, A.; Walker, A. S.; Eyre, D. W.

2026-04-25 infectious diseases 10.64898/2026.04.17.26351097 medRxiv
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Objectives: To identifiy risk factors for antimicrobial resistance (AMR) in seven pathogen-antimicrobial combinations in patients with cancer and cancer survivors. Methods: Using data from patients with recent or past cancer diagnostic codes in Oxfordshire, UK, we examined associations between 22 potential risk-factors and AMR in blood culture isolates, collected between 1-April-2015 and 31-March-2025. Results: Among 5,975 bacteraemias in 4,365 adults, we analysed 3,141 (52.6%) due to Enterobacterales and 620 (10.4%) due to Enterococcus faecalis/faecium in 2,752 patients. Fourteen risk-factors for antimicrobial-resistant bacteraemia were identified, varying across pathogen-antimicrobial combinations. Compared with no previous antimicrobial susceptibility test result, prior resistance to the same antibiotic in any culture in the last year was strongly associated with AMR across all pathogen-antimicrobial combinations (all p<=0.001). Prior antibiotic exposure and younger age were also positively associated with AMR in four and five combinations, respectively. Cancer type showed modest effects; lymphoid/haematopoietic malignancies were associated with higher odds (vs colorectal cancer) of trimethoprim-sulfamethoxazole-resistant Enterobacterales (aOR=2.07 95%CI 1.40-3.06) and vancomycin-resistant Enterococcus bacteraemia (aOR=6.68, 1.21-36.91). Conclusions: Previous resistance was the greatest risk factor for bacteraemia with AMR in cancer patients and survivors, with prior antibiotic exposure and age also contributing. Lymphoid/haematopoietic malignancies increased risk of resistance to specific antimicrobials. Keywords: antimicrobial resistance, bacteraemia, cancer, risk factors

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Tongue swab Xpert MTB/RIF Ultra testing for tuberculosis in adolescents: a cross-sectional study of diagnostic accuracy and acceptability

MacLean, E. L.; Ma, T. T.; Chuong, L. H.; Minh, K. H.; Hoddinott, G.; Pham, Y. N.; Tiep, H. T.; Nguyen, T.-A.; Fox, G.; Nguyen, N. T.

2026-04-25 infectious diseases 10.64898/2026.04.17.26351119 medRxiv
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Introduction Improved diagnostics are needed for people at risk of tuberculosis, especially adolescents. Tongue swab (TS) molecular testing has emerged as a promising strategy for tuberculosis diagnosis. We evaluated diagnostic accuracy and acceptability of Xpert MTB/RIF Ultra (Xpert) using TS samples for tuberculosis detection among adolescents. Methods We conducted a cross-sectional diagnostic accuracy study with consecutive recruitment in Vietnam. Adolescents aged 10-19 who were recommended to undergo investigation for tuberculosis and had not received tuberculosis treatment in the past years were eligible. Participants provided TS and sputum samples and completed a structured survey regarding sampling experiences. TS was tested on Xpert, with sputum tested on Xpert and liquid culture. We utilised a composite reference standard of a positive result on sputum Xpert or sputum culture to define disease status. Sensitivity, specificity, and diagnostic yield were calculated for TS Xpert. Results From July to December 2025, we enrolled 225 adolescents from Can Tho and An Giang provinces in southern Vietnam. Fewer than half (96/225, 43%) the participants exhibited a tuberculosis -like symptom, and the majority (157/225, 70%) were close contacts of a person recently diagnosed with tuberculosis. TS were collected from all adolescents, while 116 (52%) could provide mucopurulent sputum. Tuberculosis prevalence was relatively low (12/225, 5.3%). TS Xpert sensitivity (90% CI) and specificity (90% CI) were 58.3% (35.6, 78.0) and 99.5% (97.9, 99.9), respectively. Diagnostic yield among all diagnosed was 58.3% (7/12). TS sampling was highly acceptable to adolescents; the short time and simplicity of collecting TS were considered favourably. Conclusions The sensitivity and diagnostic yield of TS Xpert was relatively low among adolescents recommended for tuberculosis investigation, which includes asymptomatic individuals who may not provide high quality sputum. Specificity was excellent, and everyone could provide a TS. TS high acceptability indicates it remains a promising sample for diagnostic algorithms.

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Epidemiology and Predictors of Fluoroquinolone Resistance in ESBL-Producing Escherichia coli: Implications for Empirical Therapy in Mexico

Gallardo Mejia, A.; Almeida, J.

2026-04-22 infectious diseases 10.64898/2026.04.21.26351439 medRxiv
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Urinary tract infections (UTIs) are among the most common infectious diseases worldwide, with Escherichia coli being the predominant uropathogen. The increasing prevalence of extended-spectrum beta-lactamase (ESBL)-producing strains and their association with fluoroquinolone resistance pose a significant challenge to empirical therapy, particularly in community settings. The aim of this study was to determine the epidemiology and predictive factors associated with ESBL-producing E. coli and its concomitant fluoroquinolone resistance in community-acquired clinical isolates. A retrospective cross-sectional study was conducted analyzing 244 clinical E. coli isolates. Demographic and microbiological data were collected, including age, sex, sample type, and antibiotic susceptibility. Associations between variables and ESBL production were assessed using Pearsons chi-squared test, and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Of the isolates, 165 (68%) were ESBL-producing. A significant association was observed between age group and ESBL production (p < 0.001), with the highest frequency in the 20-39 age group. Most ESBL-positive isolates were obtained from women (73%), although odds ratio (OR) analysis suggested a non-significant trend toward a higher probability in men (OR = 1.29; 95% CI: 0.72-2.31). High rates of fluoroquinolone resistance were identified among the ESBL-producing isolates, with 30% resistance to levofloxacin and 35% to ciprofloxacin (p < 0.001). Urine samples showed the highest concentration of ESBL-positive isolates, with a significant association between sample type and resistance (p < 0.001). The high prevalence of ESBL-producing E. coli and its concomitant resistance to fluoroquinolones highlight a critical challenge for the empirical treatment of urinary tract infections in Mexico, underscoring the need to strengthen antimicrobial use management and local surveillance strategies.

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AI/ML-based prediction of TB treatment failure: A systematic review and meta-analysis

Kamulegeya, R.; Nabatanzi, R.; Semugenze, D.; Mugala, F.; Takuwa, M.; Nasinghe, E.; Musinguzi, D.; Namiiro, S.; Katumba, A.; Ssengooba, W.; Nakatumba-Nabende, J.; Kivunike, F. N.; Kateete, D. P.

2026-04-22 infectious diseases 10.64898/2026.04.16.26350453 medRxiv
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BackgroundTuberculosis (TB) remains a leading cause of infectious disease mortality worldwide, and treatment failure contributes to ongoing transmission, drug resistance, and poor clinical outcomes. Artificial intelligence and machine learning approaches have attracted growing interest for predicting tuberculosis treatment outcomes, but the literature is heterogeneous and lacks a comprehensive synthesis. MethodsWe conducted a systematic review and meta-analysis of studies that developed or validated machine learning models to predict TB treatment failure. We searched PubMed/MEDLINE and Embase from January 2000 to October 2025. Studies were eligible if they developed, validated, or implemented an artificial intelligence or machine learning model for the prediction of TB treatment failure or a closely related poor outcome in patients receiving anti-TB treatment. Risk of bias was assessed using the Prediction model Risk Of Bias Assessment Tool. Random-effects meta-analysis was performed to pool area under the curve values, with subgroup analyses and meta-regression to explore heterogeneity. ResultsThirty-four studies were included in the systematic review, of which 19 reported area under the curve values suitable for meta-analysis (total participants, 100,790). Studies were published between 2014 and 2025, with 91% published from 2019 onward. Tree-based methods were the most common algorithm family (52.9%), and multimodal models integrating three or more data types were used in 41.2% of studies. The pooled area under the curve was 0.836 (95% confidence interval 0.799-0.868), with substantial heterogeneity (I{superscript 2} = 97.9%). In subgroup analyses, studies including HIV-positive participants showed lower discrimination (pooled area under the curve 0.748) compared to those excluding them (0.924). Only eight studies (23.5%) performed external validation, and only one study (2.9%) was rated as low risk of bias overall, primarily due to methodological concerns in the analysis domain. Eggers test suggested publication bias (p = 0.024). Major evidence gaps included underrepresentation of high-burden countries, HIV-affected populations, social determinants, pediatric TB, and extrapulmonary disease. ConclusionsMachine learning models for predicting TB treatment failure show promising discrimination but are not yet ready for routine clinical implementation. Performance varies substantially across populations and settings, and methodological limitations, including inadequate validation, poor calibration assessment, and high risk of bias, limit confidence in current estimates. Future research should prioritize rigorous external validation, calibration assessment, and development in underrepresented populations, particularly HIV-affected and high-burden settings. Author SummaryTB kills over a million people annually. While curable, treatment failure remains common and drives ongoing transmission and drug resistance. Researchers increasingly use artificial intelligence and machine learning to predict which patients will fail treatment, but it is unclear if these models are ready for clinical use. We reviewed 34 studies including nearly 1.1 million participants from 22 countries. On average, models correctly distinguished patients who would fail treatment from those who would not 84% of the time, a performance generally considered good. However, this average hid enormous variation. Models developed in populations including HIV-positive people performed substantially worse, suggesting prediction is harder with HIV co-infection. Worryingly, only one study used high-quality methods; 97% had serious flaws in handling missing data, checking calibration, or testing in new populations. Only eight studies validated their models in different settings. To conclude, we found that machine learning is promising in predicting TB treatment failure, but it is not ready for clinical use. Researchers should prioritize validation in high-burden settings, include social determinants, and improve methodological rigor before these tools can help patients.

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Antibiotic Seeking Pathways and Patterns of Usage among Patients with Productive Coughs Attending Selected Chest Clinics in Nairobi County, Kenya

MWABU, A. K.; Mutai, W. C.; Jaoko, W.; Mwaniki, J. N.; kiiru, J. N.

2026-04-06 infectious diseases 10.64898/2026.04.04.26350147 medRxiv
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Introduction: Antibiotic misuse is a major driver of antimicrobial resistance (AMR), contributing to an estimated 1.27 million deaths globally. In Kenya, inappropriate antibiotic use is shaped by health-seeking behaviors and sociodemographic factors. However, little is known about how adults with productive coughs seek and use antibiotics, or how sociodemographic factors underpin these practices. This study explored antibiotic-seeking pathways, usage patterns, and the sociodemographic factors influencing these practices among adults with productive coughs attending selected chest and tuberculosis clinics in Nairobi County, Kenya. Methodology: A facility-based cross-sectional study was conducted among 400 adults ([&ge;]18 years) with productive coughs. Data were collected using a structured questionnaire on sociodemographic characteristics, antibiotic-seeking pathways, and use patterns. Results: Most participants were male (65.0%) and employed (67.0%), with 68.3% earning below Ksh 10,000 (approximately USD 80) monthly and 35.8% having basic education. A history of smoking (37.3%), tuberculosis (32.0%), or other comorbidities (29.8%) was common. Among 347 (86.7%) antibiotic users, 46.4% obtained antibiotics through general practitioners (GP) only, 31.4% via both GP and over-the-counter (OTC) sources, 15.3% from OTC only, and 6.9% through self-medication. Females were more likely to self-medicate (13.3% vs. 3.2%) and had higher odds of antibiotic use (cOR: 2.00; 95% CI: 1.04-4.10). Tuberculosis history was linked to greater GP reliance (61.7% vs. 37.4%). Low-income participants mainly used GP-only sources, while higher-income earners favored GP plus OTC routes (RRR: 2.67; 95% CI: 1.41-5.05). Empirical use was common (71.1%), dominated by Amoxicillin (90.8%), with multiple antibiotic use reported by 67.2% of the participants. Conclusion: Antibiotic use among adults with productive coughs in Nairobi was widespread and largely empirical, dominated by Amoxicillin and Amoxicillin/Clavulanic acid. Self-medication, unregulated antibiotic access, and inappropriate use highlight the urgent need for stricter prescription enforcement and strengthened stewardship programs to promote rational antibiotic use and curb AMR.

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Diagnostic Accuracy and Potential Resource Savings of Pooled Sputum Testing with Xpert MTB/RIF Ultra for Tuberculosis among adults in Vietnam: A Cross-Sectional Study

Nguyen, H. T.; Codlin, A. J.; Vo, L.; Nguyen, N.; Forse, R.; Dang, H.; Nguyen, L. H.; Hoa, N. B.; Dinh, L. V.; Doan, H. T.; Nguyen Van, H.; Creswell, J.; Garg, T.; Cubas Atienzar, A. I.; Byrne, R. L.; Iem, V.; Squire, B.; Forsman, L. D.; Wingfield, T.

2026-04-01 infectious diseases 10.64898/2026.03.31.26349825 medRxiv
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Objectives: A pooled testing algorithm for tuberculosis (TB), in which sputum specimens from multiple individuals are tested in pools with individual testing of positive pools, can optimise diagnostic resources. This study evaluated the diagnostic accuracy and cartridge savings of pooled testing with the Xpert MTB/RIF Ultra assay (Xpert Ultra) relative to individual Xpert Ultra testing. Methods: We conducted a cross sectional study among 2,396 adults (aged above 15 years) with presumptive TB enrolled between July 2024 and February 2025, through facility based case finding (FBCF) and community based case finding (CBCF). Participants submitted two sputum specimens. The first underwent individual Xpert Ultra testing; remnant specimens were combined into four specimen pools and tested again with Xpert-Ultra. The second specimen was used to inoculate liquid culture (BACTEC MGIT). Data were used to simulate an up-front pooled testing strategy; sensitivity and specificity of this approach was estimated against culture, and cartridge use was compared with individual Xpert-Ultra testing. Results: Of 2,396 participants, 395 (16.5%) had a positive Xpert Ultra and/or culture, including 360/912 (39.5%) in FBCF and 35/1484 (2.4%) in CBCF. The pooled testing approach had sensitivity of 82.4% (95% confidence interval [CI], 77.9; 86.3) and specificity of 98.5% (97.8; 99.0) compared to culture, with lower sensitivity than individual Xpert-Ultra testing (86.5%, 82.4; 89.9) but high specificity (98.1%, 97.4; 98.7). Sensitivity of pooled testing was lower in CBCF (59.1%, 36.4; 79.3) than in FBCF (84.0%, 79.5;87%), whereas cartridge savings were greater in CBCF (69.1% vs 9.6%). The pooling strategy reduced Xpert-Ultra cartridge use by 46.5%, saving USD 14,447. Conclusions: Pooled Xpert-Ultra testing among adults appears resource-efficient for TB screening in Vietnam. As sensitivity is lower compared to individual Xpert Ultra testing, particularly for paucibacillary disease, these losses should be carefully weighed against gains in affordability and expand access to molecular testing. Careful, context-specific implementation is essential to maximise programmatic benefit while minimising missed persons with TB.

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Peer support boosted Hepatitis C treatment access among marginalised populations in England: A Bayesian causal factor analysis.

Schmidt, C.; Samartsidis, P.; Seaman, S.; Emmanouil, B.; Foster, G.; Reid, L.; Smith, S.; De Angelis, D.

2026-04-22 health policy 10.64898/2026.04.20.26351261 medRxiv
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To minimise health disparities, equitable access to medical treatment is paramount. In a pioneering intervention, National Health Service Englands Hepatitis C virus (HCV) programme has implemented country-wide peer support to boost treatment access. Peer support workers (peers) are individuals with relevant lived experience, who promote testing and treatment in marginalised populations underserved by traditional health services. We evaluated the English peers intervention, exploiting its staggered rollout and rich surveillance data between June 2016 and May 2021. Peers increased HCV cases identified by 13{middle dot}9% (95% credible interval (95% CrI) [5{middle dot}3, 21{middle dot}7]), sustained viral responses by 8{middle dot}0% (95% CrI [-4{middle dot}4, 18{middle dot}6]), and drug services referrals by 8{middle dot}8% (95% CrI [-12{middle dot}5, 22{middle dot}6]). The interventions effectiveness was magnified during the first COVID-19 lockdown and individuals supported by peers typically belonged to populations with poor treatment access. Our findings indicate that peers can boost equity in treatment access on a national scale.

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RNase HII-assisted amplification (RHAM) for rapid point-of-care monkeypox detection

Kamhieh-Milz, J.; Kamhieh-Milz, S.; Schwarz, F.; Michel, J.; Nitsche, A.; Puyskens, A.

2026-04-02 infectious diseases 10.64898/2026.04.01.26349928 medRxiv
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Mpox poses an ongoing global public health threat, with case numbers rising beyond traditionally endemic regions in Central and Western Africa. Rapid detection of the causative agent, the Monkeypox virus (MPXV), is critical for outbreak control, yet laboratory infrastructure and trained personnel remain scarce in many affected areas. Point-of-care molecular diagnostics offer a practical solution by enabling timely testing without specialized equipment or elaborate nucleic acid extraction. We evaluated the performance of an extraction-free RNase HII-assisted amplification (RHAM) assay for MPXV detection by Pluslife Biotech, a novel isothermal amplification technology providing results in under 30 minutes. The Pluslife RHAM test demonstrated pan-MPXV clade reactivity, detecting all four MPXV clades (Ia, Ib, IIa, IIb) with high analytical sensitivity and no cross-reactivity to other poxviruses or other clinically relevant pathogens. The assay proved compatible with diverse clinical specimen types, including lesion swabs, oropharyngeal swabs, rectal swabs, urine, semen, and wound exudate. As part of routine diagnostics at the German Consultant Laboratory for Poxviruses, in a comprehensive evaluation of 206 clinical specimens against diagnostic real-time PCR, the Pluslife RHAM test achieved a diagnostic sensitivity of 94.2% (95% CI: 85.8-98.4%) and a specificity of 100% (95% CI: 97.3-100%). Notably, samples with higher viral loads (Ct <30) showed 100% sensitivity. Time-to-result correlated significantly with viral load, enabling faster diagnosis in high-viral-load cases. The Pluslife RHAM test represents a practical, sensitive, and rapid point-of-care solution for MPXV detection in resource-limited settings, combining strong analytical performance with operational simplicity to support timely outbreak response and clinical decision-making.

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Analytical performance of a multi-target open real-time PCR assay for simultaneous detection of tuberculosis, non-tuberculous mycobacteria, and drug resistance in a high-burden setting

Sidiq, Z.; Tyagi, P.; Anand, A.; Dwivedi, K. K.; Rajpal, S.; Chopra, K. K.

2026-04-24 infectious diseases 10.64898/2026.04.23.26351557 medRxiv
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Abstract Background Timely diagnosis of tuberculosis and drug resistance remains a cornerstone of effective disease control. Multiplex open molecular platforms capable of simultaneously detecting Mycobacterium tuberculosis complex (MTBc), non-tuberculous mycobacteria (NTM), and resistance to first-line anti-tuberculosis drugs could streamline diagnostic pathways. Methods We conducted a laboratory-based evaluation of two multiplex real-time PCR assays (MTBc/NTM R-Gene and MTB-RIF/INH R-Gene) using 300 well-characterized samples, including 150 MTBc-positive culture isolates (including rifampicin-resistant, isoniazid-resistant, and drug-susceptible strains) and 150 MTBc-negative samples (50 NTM isolates and 100 mycobacteria-negative specimens). Composite reference standards included culture, MPT64 antigen testing, and line probe assay corroborated by phenotypic drug susceptibility testing for resistance profiling, with NTM speciation performed using a dedicated line probe assay. DNA extraction was performed using the QIAamp DNA Mini Kit (QIAGEN, Germany), followed by amplification on a real-time PCR platform according to manufacturer instructions. The diagnostic performance was assessed against composite reference standards. Results The analytical performance for detecting MTBc demonstrated 100% sensitivity and specificity (150/150). NTM detection showed 70.0% sensitivity (35/50) and a specificity of 100%, highlighting limitations in coverage of NTM species. Rifampicin resistance was detected with a sensitivity of 96.0% (48/50) and specificity of 100%, whereas isoniazid resistance detection was 100% sensitive and specific (50/50). Agreement with established reference standards was high ({kappa}=0.76-1.00) within this analytical context. Interpretation This analytical validation demonstrates that multiplex open real-time PCR assays can accurately and simultaneously detect MTBc, NTM, and rifampicin and isoniazid resistance using culture isolates. While these platforms offer potential advantages in flexibility and expanded resistance profiling, additional studies on clinical diagnostic accuracy, cost-effectiveness analyses, and operational feasibility are required to determine their practical utility and programmatic impact in high-burden settings

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High Perforation Rates in Jejunal Diverticulitis: A Single-Center Retrospective Review

Florescu, N.; Thomas, E. C.; Charles, A.; Aunchman, A.; An, G.

2026-04-06 surgery 10.64898/2026.04.05.26350210 medRxiv
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Background: Jejunal diverticulitis is an uncommon but increasingly recognized cause of acute abdomen. It can present with a range of CT findings, including peridiverticular inflammation, bowel wall thickening, and fecalized small bowel content, with perforation or abscess occurring as complications in roughly 6% of cases. Case reports note varied presentations with jejunal and ileal involvement, treatment ranging from nonoperative management with antibiotics to urgent surgical intervention. Though rare, small bowel diverticulitis, particularly involving the jejunum, can result in significant morbidity, including peritonitis and sepsis, requiring heightened clinical suspicion in elderly or immunocompromised patients. Methods: We conducted a single center retrospective review of patients diagnosed with jejunal diverticulitis in a single academic center's Emergency General Surgery registry between December 2017 and December 2024. Of 42 patients initially identified, 34 had confirmed diagnoses on chart review. Data abstracted included age, sex, imaging modality, presence of perforation, serial physical exams, lab values (CBC, lactate), ICU admission, length of stay (LOS), antibiotic duration, operative status and timing, distance of residence from our institution, disposition after index admission, and readmission within one year. Results: Of the 34 confirmed cases, 24 (71%) were perforated: 2 presented with small bowel obstruction, 16 with abscesses and/or contained perforations, and 1 with both. 19 of the 24 perforated patients required operative intervention: 9 proceeded directly to the OR, 3 on hospital day one, and 2 as late as hospital day six. Among non-operative patients treated with antibiotics alone, the average LOS was 6 days (range: 2-23). Two patients were readmitted within one year: neither had undergone surgery during their index admission and neither were related to their index admission. Overall, three patients died: two during the index admission (both perforated and operated on) and one on readmission. Conclusion: Compared to the 6% complication rate reported in prior literature, our series demonstrates a notably higher rate of perforation (71%) among patients diagnosed with jejunal diverticulitis. Operative intervention was common, though a subset of patients was successfully managed non-operatively with antibiotics. Mortality was limited to patients with significant comorbidities and complex presentations. These findings underscore the heterogeneity in presentation and outcomes and highlight the need for a standardized approach. Development of practice guidelines incorporating clinical, radiographic, and laboratory parameters may improve diagnostic accuracy and guide timely, evidence-based management of this rare but serious condition.

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Streptococcus agalactiae, a frequent but not so well-known cause of bone and joint infections: a Multicentric observational study 2014-23

Jamard, S.; Le Moal, g.; Plouzeau-Jayle, c.; Arvieux, C.; Ressier, S.; Lecomte, r.; Corvec, S.; Ansart, S.; Lamoureux, C.; Abgueguen, P.; Chenouard, R.; Lartigue, M. F.; Lemaignen, A.

2026-03-31 infectious diseases 10.64898/2026.03.30.26349534 medRxiv
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Abstract Introduction: Streptococcus is the second genus involved in bone and joint infections (BJIs) after Staphylococcus. Streptococcus agalactiae is the predominant Streptococcus species implicated in BJIs. However, unlike Staphylococcus-related BJIs, data on S. agalactiae infections remain scarce. Methods: We conducted a retrospective cohort study from the West Region cohort of the CRIOAc registry among six university hospitals including all microbiologically confirmed streptococcal BJI in adults between 2014 and 2023. Results: 1454 patients were included, with a median age of 67 years and 65% male. S. agalactiae was the predominant streptococcal species involved 423/1454(29%). The most prevalent comorbidities identified were obesity (378/1454;26%) and diabetes mellitus (343/1454;24%). Prosthetic joint infections (PJIs) were the most common (653/1454;45%), although diabetic foot osteitis was less prevalent overall, it was significantly more associated with S. agalactiae infections (48/423;11% versus 70/1031;7%, p=0.05). S. agalactiae BJIs were more frequently lower-limb infections and chronic infections (240/423;57% versus 502/1031;49%, p=0.04). Half of the cohort had a polymicrobial infection and were slightly more frequent with S. agalactiae BJIs (235/423;56% versus 498/1031;48%, p=0.1). These results were consistent with a sensitivity analysis excluding diabetic foot related osteitis. Logistic regression analysis identified arteriopathy (OR: 4.16; IC95:1.64-11.24, p=0.003), and obesity (OR: 2.57; IC95: 1.41-4.78, p=0.002) as specific risk factors for S. agalactiae BJIs. Conclusion: S. agalactiae emerges as a prominent and distinct pathogen in complex streptococcal BJIs, with specific risk factors such as arteriopathy, obesity and diabetes mellitus, and more chronic infections.

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Clinical mechanism of ribavirin action in Hepatitis C treatment: insights from the STOPHCV-1 randomised trial

Moradi Marjaneh, M.; Badhan, A.; Chai, H.; Hadfield, O.; Chen, Y.; Wang, Z.; Thomson, E. C.; Taylor, G. P.; Walker, A. S.; Ansari, M. A.; Barnes, E.; Cooke, G. S.

2026-04-15 infectious diseases 10.64898/2026.04.14.26350846 medRxiv
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Background: Ribavirin is a guanosine analogue with clinical antiviral activity against a range of RNA viruses including hepatitis C virus (HCV), respiratory syncytial virus and Lassa virus. Several potential mechanisms of action have been proposed, but there is limited data supporting them clinically. Methods: We studied 196 HCV-infected participants from a trial of short-course directly antiviral therapy (STOPHCV-1) which included a factorial randomisation to ribavirin versus no ribavirin. Deep sequencing of the HCV genome was performed on samples with detectable viremia from three time-points: baseline (n = 191), day 3 of treatment (n = 25) and post-treatment failure (n = 47). Results: Ribavirin exposure significantly increased total mutational load at treatment failure (P = 0.0065) and enriched classical ribavirin-associated transitions, including G->A (P = 0.026) and C[-&gt;]U (P = 0.004), along with other key changes including A->G (P = 0.005), U->C (P = 0.023), C->G (P = 0.010), and U->A (P = 0.026). The resulting mutational signature was broad, not dominated by G-related changes. Region-specific analyses demonstrated this increase was broadly distributed across the viral genome, without strong evidence for protection of specific regions. Non-synonymous to synonymous mutation ratios (dN/dS) rose at day 3 (P = 5.5e-5) before declining at failure (P = 8.5e-7), with trends toward higher dN/dS in the ribavirin group at day 3 (P = 0.06). Conclusions: Ribavirin acts as a potent in vivo mutagen, driving viral populations toward genome-wide diversity rather than selecting a few highly fit drug-resistant clones. These findings support an error-catastrophe model.

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Development of a Monoclonal Antibody and a Sandwich-ELISA for the Detection of Mucormycosis in Humans

Thornton, C. R.; Davies, G. E.

2026-04-23 infectious diseases 10.64898/2026.04.23.26351301 medRxiv
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Background: Mucormycosis is a rapidly progressive and often fatal invasive fungal infection caused by moulds in the order, Mucorales. Early diagnosis is essential for effective clinical management; however, conventional diagnostic approaches such as culture and histopathology are slow, insensitive, and require specialist mycological expertise. Although molecular methods are available for disease detection, they are not widely accessible. At present, no enzyme immunoassay (EIA) exists for the detection of mucormycosis. Methods: A murine IgG1 monoclonal antibody (mAb), FH12, was generated against extracellular polysaccharides (EPSs) produced by Mucorales pathogens during active growth. The antibody was characterised for specificity, epitope stability, and antigen localisation using ELISA, immunoblotting, and immunofluorescence techniques. The mAb was incorporated into a Sandwich-ELISA and evaluated using culture filtrates, purified EPSs spiked into human serum, and tissue homogenates from a patient with cutaneous mucormycosis caused by Lichtheimia ramosa. Results: mAb FH12 demonstrated pan-Mucorales specificity and no cross-reactivity with other clinically relevant yeasts and moulds. The epitope recognised by FH12 is periodate-insensitive and moderately heat-stable. The Sandwich-ELISA detected EPS antigens in human serum with limits of detection ranging from pg/mL to low ng/mL levels, and successfully identified the EPS biomarker in patient tissue homogenates. Conclusion: The FH12-based Sandwich-ELISA shows high sensitivity and specificity, and has the potential to be used as a laboratory-based adjunct diagnostic test for the detection of mucormycosis in humans.

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Tracking cross-border transmission of Rwandas successful dominant rifampicin-resistant Mycobacterium tuberculosis clone using genomic markers

Cuella-Martin, I.; Mulders, W.; Keysers, J.; Hakizayezu, F.; Niyompano, H.; Runyambo, D.; de Rijk, W.-B.; Phelan, J.; Mucyo Habimana, Y.; Migambi, P.; Sawadogo, M.; Mambo Muvunyi, C.; C. de Jong, B.; Ngabonziza, J. C. S.; Rigouts, L.; Meehan, C.

2026-03-31 infectious diseases 10.64898/2026.03.29.26349652 medRxiv
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Background: In Rwanda, genomic surveillance identified a dominant multidrug-resistant tuberculosis (MDR-TB) strain, the R3clone, responsible for approximately 70% of rifampicin-resistant TB cases. Its presence beyond Rwanda remains unexplored. Methods: Unique genetic signatures of the R3clone were defined using whole-genome sequencing of MDR-TB isolates from Rwanda. We developed a targeted qPCR assay detecting a clone-specific single-nucleotide polymorphism. With these tools, we screened isolates from neighbouring countries and public genomic repositories. Results: We identified 375 R3clone isolates, including 264 from historical Rwandan collections (1991-2021), 49 from recent Rwandan diagnostic routine (2021-2024), 25 from historical Burundi isolates (2002-2013), and 37 among public repositories from several countries. The R3clone-specific qPCR showed 100% specificity in distinguishing the R3clone from other MTBC (sub-)lineages. Transmission analysis revealed cross-border transmission of the R3clone within the Great Lakes Region. Conclusion: This study comprehensively assesses cross-border transmission of a dominant MDR-TB strain, highlighting the need for coordinated international surveillance.

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Long-read sequencing of Mycobacterial tuberculosis is comparable to short-read sequencing for antimicrobial resistance prediction and epidemiological studies.

Colpus, M.; Baker, C. S.; Roghi, E.; Hong, H. N.; Trieu, P. P.; Thu, D. D. A.; Hall, A.; Fowler, P. W.; Walker, T. M.; Spies, R.; Webster, H.; Westhead, J.; Thai, H.; Turner, R. D.; Peto, T. E.; Quang, N. L.; Thuong, N. T. T.; Omar, S. V.; Crook, D. W.

2026-04-08 microbiology 10.64898/2026.04.08.717216 medRxiv
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BackgroundShort-read genetic sequencing technologies (mainly Illumina) have been extensively used for around a decade for Mycobacterium tuberculosis complex (MTBC) outbreak analysis and genomic drug susceptibility testing (gDST) with the result that Illumina has become the de facto gold standard. Long-read sequencing, as exemplified by Oxford Nanopore Technologies (ONT), offer the prospect of faster, simpler, and portable sequencing. In this work, we carry out the largest to date comparison of how well Illumina and ONT technologies sequence MTBC samples, making use of R10.4 ONT flowcells, updated basecalling models and deep-learning variant calling. MethodsA total of 508 samples were sequenced using both short and long-read platforms. All samples originated from South Africa or Vietnam and were over-selected for drug resistance and also included several local outbreaks and a range of lineages. The South African and Vietnamese samples had already been Illumina sequenced. Samples with [&ge;]50 read depth by Illumina were selected for sequencing by ONT using one of the GridION or PromethION platforms. Bioinformatics processing was done using a modified online cloud platform which included reference-based variant calling, catalogue-based gDST and identified related samples via SNP counting to inform outbreak detection. The lineages and gDST predictions obtained by short-and long-sequencing were compared for all samples as were all putative clusters identified via SNP counting. For convenience Illumina was used as the reference method. FindingsOf the 508 samples, 425 (83.7%) had sufficient read depths to permit comparison between the two sequencing technologies. The assigned lineages were identical for 407/425 (95.8%) samples and all discordances were due to mixed lineages being identified by one technology. Evidence of non-tuberculous mycobacterium (NTM) subpopulations were found in nine samples. Using Illumina as the reference method, the very major error (VME) rate of ONT for predicting resistance to all 15 drugs is 1.0% (0.6-1.5%) whilst the major error (ME) rate is 1.7% (1.3-2.2%) with an unclassified rate of 6.9% (6.3-7.5%). This is below the thresholds specified by the CLSI. Considering each of the 15 drugs individually they had VME and ME point estimates below [&le;]3% in 29/30 cases; and most 25/30 below [&le;]1.5%. Filtering out all samples containing mixtures left 382 isolates. By appropriate masking of the reference genome we were able to obtain a mean SNP distance between the two platforms of 0.13 (median of zero) for the same sample and for 376/382 samples (98.4%, CI:96.6-99.4%) the difference was [&le;]1 SNPs. The high concordance in SNP identification ensured that few differences in the 43 putative clusters among 172 isolates were observed. InterpretationThe differences between the two sequencing platforms for the key clinical outputs is so small that it is now within the tolerances set by regulatory agencies. Provided the sequencing is of sufficient quality, we have therefore reached a threshold whereby sequencing data from long-and short-read platforms can be aggregated. This will enable large scale analyses by national and international public health agencies whilst allowing the MTBC community to take advantage of the portability and speed of long-read sequencing. FundingThe NIHR Health Protection Research Unit: Healthcare Associated Infections and Antimicrobial Resistance at University of Oxford (NIHR200915), a partnership between the UK Health Security Agency (UKHSA) and the University of Oxford, the National Institute for Health and Care Research Biomedical Research Centre: Oxford (BRC) and the Ellison Institute of Technology, Oxford Ltd. The CRyPTIC project was funded by Wellcome [214560/Z/18/Z], a Wellcome Trust/Newton Fund-MRC Collaborative Award (200205/Z/15/Z); and the Bill & Melinda Gates Foundation Trust (OPP1133541). Research in contextO_ST_ABSEvidence before this studyC_ST_ABSWe conducted a PubMed Central full text search for "tuberculosis" AND ("drug resistance prediction" OR "drug susceptibility prediction") AND ("genome" OR "genomic" OR "geno-typic") AND ("ont" OR "oxford nanopore") between 2022 and 2026 (conducted 1 April 2026). This returned 62 papers; of which, six used both Illumina and ONT sequencing. One of these, published in 2023, directly compared the performance of the two platforms on 151 M. tuberculosis isolates oversampled for resistance. The investigation yielded comparative results for the earlier generation ONT flow cell (R9{middle dot}4{middle dot}1) and base-caller (guppy version 5{middle dot}0{middle dot}16). Another, published in 2026, investigated a targeted next-generation sequencing panel of 20 amplicons using ONT sequencing on R10.4.1 flow cells with guppy 6{middle dot}4{middle dot}6. They compared the results on 71 isolates against phenotypic data and Illumina whole genome sequencing (for 53 isolates) but had low rates of resistance, with all drugs but isoniazid being limited to under five resistant isolates. Two other small studies (10 and 13 samples, respectively) conducted feasibility studies comparing ONT with Illumina, also using earlier generation flow cells and base-calling technology from ONT. Two further studies compared Illumina with ONT for direct sputum sequencing and did not investigate the comparative performance of the two platforms for variant call accuracy, resistance prediction, and outbreak detection. Illumina sequencing technology is widely used for genomic sequence analysis in research, and clinical and public health contexts. Consequently, it has become the de facto reference standard for generating whole genome sequence data. Whilst previous studies established the promise and limitations of long-read (ONT) sequencing as an alternative to short-read sequencing (mainly Illumina), the enhanced performance arising from newer flowcells (e.g. R10.4.1), V14 chemistry, and the latest basecallers (dorado v4.3.0/5.0.0) has not been analysed. Neither has any ONT analysis incorporating the new deep-learning variant callers been evaluated in a large-scale comparative study. Thus, it is currently unclear whether data generated by either platform can be used safely in aggregated analyses for research and clinical or public health service. Added value of this studyWe compared how well short-(Illumina) and long-read (ONT) sequencing platforms identify the genetic variants in M. tuberculosis, predict antituberculous drug resistance and recog-nise outbreaks. The long-reads were generated using the latest generation ONT R10.4.1 flows cells, V14 chemistry, super high accuracy basecalling (dorado v4.3.0/5.0.0) and a bioinformatics analysis pipeline built using the Clair3 deep-learning based variant caller. A total of 508 clinical samples were sequenced using both technologies, substantially more than previous studies. The sampling frame was much larger than previously investigations and included a large proportion of isolates with resistance to first-line and second-line antibiotics as well as bedaquiline. Thus, providing greater statistical power for resistance prediction than before. In particular, the inclusion of bedaquiline resistance provided evidence useful for predicting resistance to this newly deployed drug for treating multi-drug resistant (MDR) TB. We find that the differences between technologies are small meaning that either technology can be used alone safely, and services using both technologies can confidently aggregate the data for analysis. Implications of all the available evidenceThis will be a benefit to local, regional and international organisations, particularly public health agencies, which often have a mix of the two main sequencing technologies for characterising TB whole genome sequences. It also opens up the sequence based diagnostic market to greater competition, particularly if the observed performance can be replicated for other pathogen species.

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Abscess Complications and Prolonged Care in Five-Biomarker-Defined Hypervirulent Klebsiella pneumoniae Bloodstream Infection

Watanabe, N.; Watari, T.; Otsuka, Y.; Matsumiya, T.

2026-04-11 infectious diseases 10.64898/2026.04.10.26350004 medRxiv
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Background Five-biomarker-defined hypervirulent Klebsiella pneumoniae (hvKp) causes invasive infections, but its burden in bloodstream infections versus classical K. pneumoniae (cKp) is unclear. Methods This retrospective cohort study at a tertiary hospital in Japan included K. pneumoniae bloodstream infection episodes from January 2022-December 2024. hvKp was defined by the presence of all 5 genotypic biomarkers (rmpA, rmpA2, iucA, iroB, and peg-344). The primary outcome was abscess complications, and secondary outcomes were length of stay and antibiotic duration. Whole-genome sequencing was performed for 164 isolates. Results Among the 207 episodes, 28 (14%) were of hvKp. Abscess complication occurred in 17 (61%) hvKp versus 23 (13%) cKp episodes (adjusted odds ratio 10.7; 95% CI, 4.36-26.2). Median length of stay in hvKp versus cKp was 28 versus 14 days (adjusted ratio 1.60; 95% CI, 1.18-2.16) and median antibiotic duration was 43 versus 14 days (adjusted ratio 2.13; 95% CI, 1.64-2.77). These associations were attenuated after adjusting for abscess-related complications. No significant difference in 30-day mortality was observed, although the study was underpowered. Multidrug resistance was less frequent in hvKp strains than in cKp strains (11% vs. 30%; P = .040). Among the sequenced hvKp episodes, abscess rates varied across lineages, from 9 of 10 in ST23 to 1 of 4 in ST412. Conclusions Five biomarker-defined hvKp strains delineated a bloodstream infection subgroup with frequent abscess complications and prolonged care. hvKp and cKp present distinct clinical challenges; diagnostic tools distinguishing these subgroups may aid abscess evaluation and source control.

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A prospective cohort study of the clinical profile of Acinetobacter baumannii infections in Thailand

Freeouf, S.; Palethorpe, S.; Fairhead, C.; Kewcharoenwong, C.; Khemla, S.; Wiboonsuntie, N.; Juhongf, S.; Wren, B.; Edwards, T.; Lertmemongkolchai, G.; Brown, J.

2026-03-27 infectious diseases 10.64898/2026.03.26.26349299 medRxiv
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Objectives: To better define the clinical features of Acinetobacter spp. infection in Northern Thailand, including a comparison of hospital- and community-acquired infections (HAIs and CAIs). Methods: A prospective clinical study of Acinetobacter spp. infections at two Northern Thailand hospitals from 2019 to 2022, collecting data on sample sources, patient demographics, comorbidities, antimicrobial resistance profiles, and outcomes. Results: Of 129 enrolled patients, 81.4% had Acinetobacter spp. isolated from a respiratory sample. A significant minority (25.6%) of infections were CAIs, 33.3% of which were admitted to ITU within 24 hours of admission. Compared to HAIs, CAIs were significantly more likely to be caused by blood (15.2%, p=0.0258), wound (21.2%, p=0.0120), or urine infections (12.1%, p=0.0370). Acinetobacter spp. HAIs mainly occurred after admission to ITU (87.7%, p<0.0001) and were more likely to be multidrug-resistant than CAIs (76.3% vs. 34.4%, p<0.0001). Overall, the median length of hospital stay was 27 days and there was a 27.1% in-hospital mortality, which was increased in patients with CVA/brain (p=0.005), and multidrug-resistant (p=0.010) or carbapenem-resistant infections (p=0.003). Conclusions: These data define the clinical profile of Acinetobacter spp. infections in Northern Thailand, confirming their high mortality and demonstrating CAIs are a significant proportion of all cases.