This episode of the Infectious Disease Puscast (#83) reviews recent literature in infectious diseases, covering viral, bacterial, fungal, and parasitic infections. Key discussions include new perspectives on the Milwaukee Protocol for rabies, 2023 arboviral disease surveillance data, and the critical role of neonatal gut microbiota in preventing severe viral respiratory infections. The hosts also delve into a large diphtheria outbreak in Europe, novel antibiotic prophylaxis for recurrent UTIs, and the impact of empiric therapy for Enterococcal bloodstream infections. Updates on fungal disease burden (Coccidioidomycosis), a new antifungal agent (olorofim), and Candida endocarditis treatment are provided. Finally, the episode explores the intriguing link between schistosome infection and host behavior via the gut-brain axis, alongside findings of Toxoplasma gondii contamination in ready-to-eat salads.
Infectious Disease Puscast #83: A Review of Latest ID Literature
0:00 Introduction & Host Welcome: Dr. Daniel Griffin and Dr. Sarah Dong introduce episode 83, recorded on June 23rd, 2025, providing a brief personal anecdote about a heatwave and AC issues.
2:23 Viral Section - Milwaukee Protocol (Rabies): Discusses a "Dear Editor" correspondence titled "Premature Demise of the Milwaukee Protocol," optimistically rebutting claims of its failure by highlighting instances of survival without neurological devastation, and noting ongoing development of broad-spectrum antivirals, biologics, and gene therapies.
3:57 Viral Section - Arboviral Diseases (US 2023): Summarizes 2023 data from the ArboNET surveillance system, reporting 2,770 human cases of nationally notifiable arboviral diseases (West Nile, Powassan, Lacrosse, etc.). West Nile virus accounted for 95% of cases, with most occurring from July to September. Cases were up from 2022 but lower than 2021.
6:26 Viral Section - Neonatal Gut Microbiota & Viral RTIs: Presents a study from Lancet Microbe showing that greater gut microbiota diversity in the first week of life is linked to lower rates of lower respiratory tract infection hospitalizations in infants. A specific "cluster three" microbiota, dominated by beneficial Bifidobacterium longum and found only in vaginally born babies, significantly reduced infection risk threefold, suggesting potential for microbiome "optimization" for C-section babies.
11:15 Viral Section - Mpox Guidelines (WHO May 2025): Highlights updated WHO guidelines for clinical management and infection prevention for Mpox. Recommendations include enhanced supportive care in healthcare facilities for complicated cases, home management for mild cases, and updated isolation advice (no longer required if lesions are fully covered and patient wears a mask). Mothers with Mpox are encouraged to continue breastfeeding with precautions, and HIV-positive patients should start ART without delay.
13:07 Bacterial Section - Corynebacterium diphtheriae Outbreak (Europe 2022): Discusses a large outbreak in migrant populations across 10 European countries. Out of 263 patients, 78% had cutaneous diphtheria (often overlooked but important for transmission), and only 15% had respiratory forms. Whole genome sequencing showed widespread cross-border transmission, emphasizing the importance of genomic data sharing and linking the outbreak to low vaccination coverage in unstable regions.
18:28 Bacterial Section - Weekly Oral Cycling Antibiotic Treatment (WACA) for Recurrent UTIs: A small quasi-experimental study (34 women) explored a new regimen where two different oral antibiotics are alternated weekly (e.g., fosfomycin and nitrofurantoin). This approach resulted in a significant 7-fold reduction in annual UTI episodes (from a median of 7.5 to 1), with few adverse events. This method offers a promising alternative to continuous low-dose prophylaxis but requires larger trials.
22:42 Bacterial Section - Enterococcal Bloodstream Infections & Empirical Therapy: A retrospective multicenter study (758 patients) investigated the impact of empiric anti-enterococcal therapy within 48 hours on 14- and 30-day mortality. While a trend towards improved outcomes was noted, the study found no significant mortality benefit, suggesting that comorbidities and uncontrolled infection sources might be more significant predictors of mortality than early empiric coverage. VRE cases were notably low (6%).
27:18 Fungal Section - The Last of Us Season 2: A brief mention about the show.
27:56 Fungal Section - Estimated Burden of Coccidioidomycosis (US 2019): A cross-sectional study estimates that the true burden of symptomatic coccidioidomycosis in the US in 2019 was 10 to 18 times higher (26,000-360,000 cases) than national surveillance reported, with substantial hospitalizations and deaths. This highlights the urgent need for better awareness, diagnostic practices, and reporting to improve patient outcomes.
30:08 Fungal Section - Olorofim for Invasive Fungal Diseases (Phase 2B Study): Presents results from a single-arm, open-label Phase 2B study of olorofim, a novel oral antifungal. It showed a successful global response rate of 29% at day 42 in patients with few therapeutic options (including azole-resistant Aspergillus and coccidioidomycosis). Liver function test changes were a significant safety concern (10% of cases). The study provides valuable data for difficult-to-treat invasive fungal infections, though longer follow-up is often needed to assess full therapeutic effect.
35:30 Fungal Section - Antifungal Therapy in Candida Infective Endocarditis: A retrospective Swedish cohort study compared outcomes of echinocandin, amphotericin, and azole backbone therapies for Candida infective endocarditis. While no statistically significant difference in in-hospital mortality, relapse, or one-year mortality was found, the azole group (small N=8) showed higher raw mortality rates (62% primary outcome, 60% one-year mortality), cautioning against definitive conclusions due to small sample sizes.
37:40 Parasitic Section - Does Schistosome Infection Affect Behavior Through the Gut-Brain Axis?: A study in mice found that schistosome-infected mice exhibited higher anxiety, reduced spatial learning, and altered memory retention. This behavioral modulation was associated with significant changes in their fecal microbiomes, suggesting the parasite might influence host behavior by manipulating the gut-brain axis through microbial shifts.
41:22 Parasitic Section - Molecular Detection of Toxoplasma gondii in Ready-to-Eat Salads (Europe 2021-2022): A multi-country survey found Toxoplasma gondii in 4.1% of 3,293 ready-to-eat salad mixes. Detection was associated with winter season sampling, packaging in Northern Europe, and salads grown in Western Europe. This highlights a non-meat transmission route and encourages washing "ready-to-eat" salads, particularly for high-risk individuals like pregnant or immunocompromised patients.
44:56 Conclusion & Call to Action: Daniel and Sarah wrap up the episode, reminding listeners that references are available at microbe.tv, and encouraging subscriptions, likes, comments, and financial support for their science shows.