In this episode of Infectious Disease Puscast, Dr. Daniel Griffin and Dr. Sarah Dong review recent literature across viral, bacterial, fungal, and parasitic infections. Key discussions include the waning of MPOX antibody responses post-vaccination compared to natural infection, the promising intestinal mucosal immunity generated by a novel oral polio vaccine in newborns, and the identification of a new tick-borne Oz virus associated with fulminant myocarditis. The efficacy of baloxavir in reducing influenza transmission within households is examined, alongside risk factors for Pseudomonas aeruginosa bloodstream infection mortality and the impact of a blood culture bottle shortage. Unexpectedly, commonly used non-antibiotic medications are shown to enhance E.coli's antimicrobial resistance development. Geographic shifts in blastomycosis (Upper Midwest) and histoplasmosis (Southern US) epidemiology are highlighted, and a novel biological control strategy for schistosomiasis using African catfish is presented.
Exploring Recent Advances in Infectious Disease Research
0:00 Introduction & Hosts: Dr. Daniel Griffin and Dr. Sarah Dong host Infectious Disease Puscast episode 89, recorded on September 15, 2025, from Micro TV, discussing recent infectious disease literature.
2:10 MPOX Antibody Responses Post-Vaccination vs. Infection: A multicenter prospective cohort study published in Open Forum Infectious Disease revealed that MPOX antibody responses remain sustained for two years after natural infection, but decline more rapidly following MVABN vaccination. Vaccination led to significantly lower odds of retaining seropositivity (Odds Ratio 0.18) compared to infection, though the clinical implications for reinfection or booster needs are yet to be fully understood.
4:33 Novel Oral Polio Vaccine (nOPV2) Efficacy in Newborns: Results from a randomized, placebo-controlled phase 2 clinical trial in Bangladesh, published in C. difficile, demonstrated that two doses of a novel oral polio vaccine type 2 (nOPV2) induced strong intestinal mucosal antibody responses in healthy newborns. At 8 weeks (four weeks after the second dose), 90% of vaccinated newborns showed positive PV2-specific neutralization in stool.
6:39 Oz Virus Linked to Fulminant Myocarditis: The New England Journal reported a case of fulminant myocarditis in a woman in her 70s caused by the newly recognized Oz virus (also known as Goto virus), a tick-borne pathogen discovered in Japan in 2018. The patient developed severe symptoms and ultimately died, with viral gene fragments identified by metagenomic sequencing and viral particles confirmed via electron microscopy.
9:00 Baloxavir Treatment for Influenza Transmission Prevention: A multi-country phase 3B trial published in the New England Journal of Medicine investigated a single dose of baloxavir to prevent influenza transmission from index patients to household contacts. It reduced lab-confirmed flu transmission by 32% (9.5% vs. 13.4% in placebo, adjusted OR 0.68) by day five, but did not significantly reduce symptomatic transmission. Drug resistance emerged in 7.2% of index patients.
11:37 Risk Factors for Pseudomonas aeruginosa Bloodstream Infections (BSI): A multicenter retrospective cohort study in Italian hospitals, published in the Journal Infection, identified older age, presence of sepsis (OR ≈3x), septic shock (OR ≈6.5x), and high-risk infections (OR ≈2.7x) as significant risk factors for 30-day mortality in P. aeruginosa BSI. Importantly, appropriate empirical therapy was associated with improved survival (OR 0.39).
14:24 Impact of Nationwide Blood Culture Bottle Shortage: A study in C. difficile assessed the clinical impact of the 2024 BD BACTEC blood culture bottle shortage in US healthcare facilities. It found that almost half of the responding facilities were affected, with BD BACTEC users experiencing a median 33% decrease in culture rates during the shortage, and an increase in solitary cultures.
16:12 Non-Antibiotic Medications (NAMS) Enhance Antimicrobial Resistance (AMR): Research in the Nature journal Antimicrobials and Resistance demonstrated that common NAMS, such as ibuprofen and acetaminophen, significantly increased ciprofloxacin-induced mutagenesis and high-level ciprofloxacin resistance in E.coli at gut-relevant concentrations. Ibuprofen led to an approximately 15-fold increase in mutational frequency, highlighting an overlooked driver of AMR.
19:15 Pre-operative Entro Signatures Predict Surgical Site Infections (SSIs): A prospective cohort study in C. difficile introduced "entro signatures" (ES) to characterize pre-operative rectal microbiota. A "firmicutes ES" was identified as a significant risk factor for SSIs after abdominal surgery, while a "prevotella ES" was associated with reduced risk. Their combined ratio showed an even stronger predictive association, offering a potential novel biomarker for identifying high-risk patients.
23:01 Duration of Candidemia Impacts Clinical Outcomes: A retrospective multicenter study published in CID (using the Pinky AI healthcare database) found that candidemia lasting more than one day was associated with significantly higher in-hospital mortality (increasing by 3% for each additional day), longer hospital stays (one extra day per additional day of candidemia), and increased hospital costs (an additional $3,000 per day).
24:48 Updating Epidemiology of Blastomycosis and Histoplasmosis: An analysis of national electronic health record data (2013-2023) published in JID revealed significant shifts in the epidemiology of these fungal infections. Blastomycosis incidence has risen sharply since 2017, with a concentration in the Upper Midwest (e.g., Minnesota, Wisconsin, Michigan). Histoplasmosis is also increasing in the Southern US (e.g., Texas, Louisiana, Mississippi), challenging the traditional Ohio River Valley dominance. Older, male patients remain at higher risk for both.
27:59 African Catfish for Biocontrol of Schistosomiasis Snail Vectors: Research in PLOS NTDs demonstrated that restoring African catfish populations in Lake Victoria, Eastern Africa, provided effective biological control of freshwater snails that transmit Schistosoma mansoni. This restoration led to reduced snail vector abundance and a decrease in schistosomiasis transmission risk in the human population.