April 9, 2026

MS Risk in EBV-associated Mono

Risk of Multiple Sclerosis Among Persons With Epstein-Barr Virus–Positive Mononucleosis A Population-Based Study
Investigators conducted a population-based retrospective cohort study using medical records from the Rochester Epidemiology Project. They identified individuals with serologic evidence of EBV infection and an associated infectious mononucleosis (IM) diagnosis (EBV-positive IM; exposed cohort) between 1998 and 2022. Age-matched (±1 year) and sex-matched individuals without evidence of IM (3:1 match) comprised the unexposed cohort. Incident MS cases were verified through blinded expert chart review. A total of 4,721 persons had EBV-positive IM (exposed cohort: 55% female, 70% < 20 years). The referent cohort included 14,163 persons without EBV-positive IM (55% female, 70% < 20 years). During follow-up (median, 6 years for exposed; 8 years for referents), MS developed in 8 individuals with EBV-positive IM (0.17%) and 10 referents (0.07%). EBV-positive IM was associated with a >3-fold increased risk of MS (adjusted hazard ratio: 3.14, 95% confidence interval: 1.18–8.34).

COVID: The Late Phase/PASC/Long COVID

Association of Nasopharyngeal Dolosigranulum pigrum and Corynebacterium Species with Post-acute Sequelae of SARS-CoV-2 in a Longitudinal Cohort
Microbiota composition was assessed for a cohort of healthy participants (n = 25), influenza patients (n = 24), and patients with moderate (n = 50) and severe (n = 57) COVID-19. Samples were collected at two time points: during the acute infection phase and at approximately three-month follow-up. They identified differential abundance of specific species, such as Dolosigranulum pigrum and various Corynebacterium species, whose profiles correlated with PASC development. Furthermore, the analysis of microbial co-associations identifies commensal species, including D. pigrum and Corynebacterium species, which are less abundant in patients who develop PASC, consistent with a potential protective role suggested by experimental studies. Antibiotic use was associated with lower levels of key protective taxa, which may increase susceptibility to PASC in case of superinfection. This is consistent with other studies.