Open Forum Infectious Diseases

BackgroundRespiratory syncytial virus (RSV) is a major cause of lower respiratory tract infections in children, often leading to hospitalisation in infants. In low-resource settings where routine RSV diagnostics are unavailable, clinical overlap with bacterial pneumonia frequently results in unnecessary antibiotic use, contributing to antimicrobial resistance. ObjectiveTo evaluate the frequency and clinical determinants of antibiotic use among RSV-positive children under two years at a tertiary...

BackgroundHeartland virus (HRTV) is an emerging tick-borne virus capable of causing severe illness and death. The burden of disease is likely underestimated due to limited seroprevalence studies, lack of commercially available diagnostic tests, and an overlapping clinical syndrome with more commonly diagnosed bacterial diseases such as spotted fever group rickettsiosis or ehrlichiosis. MethodsActive surveillance for Heartland virus disease was conducted at a large academic center from March to ...

From 2021 to 2025, MRSA emerged as a major multidrug-resistant pathogen in the study area. Among 545 S. aureus isolates, 67.2% were MRSA, disproportionately affecting children under five (26.5%) and males (55.5%). Case incidence more than doubled by 2025, suggesting rising transmission or resistance. Most isolates were hospital-associated (85.2%), predominantly from outpatients (88.5%), with middle ear discharge as the main source (67%). Gentamicin showed the highest susceptibility (72.1%), whil...

BackgroundMycoplasma genitalium (MG) is an emerging sexually transmitted infection (STI) associated with pelvic inflammatory disease and tubal factor infertility. Its relationship with impaired fecundity remains unclear and is rarely examined in the context of co-seropositivity with other STIs. MethodsWe conducted a secondary analysis of the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial, a prospective preconception cohort of women with proven fecundity and prior pregnancy loss....

The rapid diagnosis of Campylobacter infections is important for the management of infectious gastroenteritis. Although stool culture is considered the gold standard, its sensitivity is limited and it requires prolonged incubation times. We performed a prospective multicenter study at nine healthcare facilities in Japan to evaluate a Campylobacter rapid antigen test using stool specimens between March 2024 and August 2025. Patients with suspected infectious gastroenteritis were consecutively enr...

BackgroundCandidemia is a rare but life-threatening bloodstream infection that remains difficult to predict using conventional risk stratification approaches, highlighting the need for improved predictive strategies. As a result, empiric antifungal therapy is often delayed even in high-risk patients. MethodsWe developed a deep learning model (PyTorch_EHR) to predict 7-day candidemia risk by using electronic health record data from two large cohorts (Houston Methodist Hospital System [HMHS] and ...

The emergence of vaccine covered serotypes causing invasive pneumococcal disease (IPD) is a serious concern worldwide. We investigated the unexpected rise of serotype 4 causing IPD primarily in non-vaccinated young adults after the COVID-19 pandemic that further spread to adults [≥] 65 years in recent years. For this purpose, we conducted a retrospective study of serotype 4 IPD cases (n=827) reported in Spain between 2009 and 2024. Whole-genome sequencing was performed to assess clonal lineag...

Sepsis caused by drug-resistant pathogens remains a major contributor to under-five mortality in low- and middle-income countries, threatening progress toward Sustainable Development Goal (SDG) 3.2. Blood culture, the gold standard for sepsis diagnosis and antimicrobial stewardship, remains underutilised in routine pediatric care. This study assessed the extent and determinants of blood culture utilisation among hospitalised children under five years with suspected sepsis at four antimicrobial r...

BackgroundIn trials, three-month weekly rifapentine and isoniazid (3HP) showed higher adherence and completion than the six-month daily isoniazid (6H) regimen for TB preventive treatment (TPT). However, programmatic outcome data remain limited. MethodologyWe evaluated the TPT cascade among people with HIV (PWH) aged >15 years newly enrolled in HIV care in western Kenya. Initiation and completion of 6H (Jan to Sept 2022) were compared to 3HP (Oct 2022-Sept 2023) using Chi-square tests. Correlate...

Serological surveillance is fundamental to infectious disease research and informed public-health decision making. Immunoassays used in the study of pathogen-specific immunity have historically relied on the collection of venous blood. While critical for many public-health applications, this sample collection method is invasive and resource intensive. The costs and logistical barriers associated with venous blood collection are exacerbated in resource-limited regions, and the shift to less invas...

Understanding host susceptibility to Mycobacterium tuberculosis (Mtb) is critical for the development of new vaccines. Certain individuals "resist" becoming infected with Mtb despite intensive exposure; however, it is unknown whether there is a genetic basis for "resistance" to Mtb infection across populations. Here we conducted a genome-wide association study (GWAS) of resistance to Mtb infection by carefully characterizing exposure to TB patients among 4,058 close contacts in India, Brazil, an...

BackgroundSustained retention in HIV care is essential for achieving durable viral suppression and controlling the HIV epidemic. Loss to follow-up (LTFU) remains a persistent challenge in sub-Saharan Africa and shows substantial geographic variation. However, nationally representative analyses of routine monitoring data remain limited. Pharmacy refill data provide a scalable and objective approach for identifying individuals at risk of disengaging from care. We assessed the magnitude, spatial di...

BackgroundNeonatal jaundice management increasingly relies on transcutaneous bilirubinometry (TcB), yet discrepancies with serum bilirubin (TSB) have limited its clinical reliability. This study introduces Skin Residual Bilirubin Volume (SRBV) as a physiologically grounded framework to enhance TcB interpretation. ObjectiveTo evaluate SRBV as an explanation for TcB-TSB discordance and assess whether incorporating SRBV improves the interpretability and reliability of TcB measurements during diagn...

Linezolid is a critical last-resort antimicrobial for multidrug-resistant Enterococcus faecium, particularly against vancomycin-resistant lineages where therapeutic options are severely limited. While resistance has historically arisen through de novo chromosomal mutations, the global emergence of transferable resistance mechanisms threatens to render more infections untreatable. Here, we characterise a recent (2023-2024) hospital-associated outbreak of linezolid-resistant E. faecium in Queensla...

Background: Schistosoma mansoni is a leading cause of hepatosplenic disease in sub-Saharan Africa. Yet, associations with current Schistosoma mansoni infections and hepatosplenic organometry remain unclear in the context of widespread mass drug administration and co-endemic infections. Methods: From January to February 2024, we conducted a community-based, cross-sectional study nested within the SchistoTrack cohort in three districts of Uganda. Liver and spleen dimensions were assessed via point...

BackgroundCambodia has made great progress in reducing malaria transmission and is targeting elimination. While this progress is particularly marked for Plasmodium falciparum, the situation is different for Plasmodium vivax. It is generally assumed that symptomatic patients are effectively diagnosed using rapid diagnostic tests (RDTs), regardless of transmission intensity. MethodsIn 2023 we conducted a cross-sectional survey among 986 treatment-seeking patients in 6 provinces of Cambodia with v...

Strengthening in-country sequencing capacity generated 28 Lassa virus genomes from human clinical cases, expanding our knowledge of Lassa fever in Guinea. Phylogeographic analysis revealed cross-border exchange between Liberia and the NZerekore region, and a Sierra Leone introduction into the Gueckedou area. Enhanced genomic surveillance is crucial to guide future public health actions.

BackgroundElimination of Plasmodium vivax is challenging due to its dormant liver stages (hypnozoites), which can reactivate weeks or months after the primary infection, causing relapses and ongoing transmission of the parasite. Despite these challenges, P. vivax clinical case numbers have declined over the past decade in Cambodia. We used parasite genotyping to assess whether the decline in case numbers was reflected in parasite diversity and relatedness as a proxy to transmission. MethodsGeno...

Because of its recent regulatory approval in southern and eastern Africa, CAB PrEP represents a scientific advancement with unknown implementation costs in most African countries. To our knowledge, this paper is the first study comparing PrEP costs in health facilities where clients had a choice between three PrEP methods. We collected and analyzed the direct service delivery costs for each method using the same costing approach and assumptions at three facilities in Lesotho and six facilities i...

Background Antibiotic pricing is a key determinant of access and stewardship in low- and middle-income countries (LMICs), yet empirical evidence on how prices are formed within pharmaceutical markets remains limited. However, there is little longitudinal evidence on how antibiotic prices behave within national pharmaceutical supply systems. This study evaluated the patterns and determinants of systemic antibiotic pricing in Tanzania using national regulatory import permit data. Methods We conduc...