This installment of the infectious disease puscast, covering late August 2016 literature, addresses several contemporary ID topics, prioritizing efficiency and skepticism regarding common practices and guidelines. Key points include the proven effectiveness of hand hygiene (HH) countered by the unethical nature of covert observation methods; a comparison of IV Zenamavir and oral Oseltamivir for influenza; and the growing crisis of rising endocarditis rates linked to the opioid epidemic. The host is highly critical of clinical guidelines that mandate expensive, low-yield testing (like ophthalmic exams for all candidemia patients) and practices based on poor data, such as using oral vancomycin prophylaxis for C. difficile or administering routine anti-anaerobic therapy for aspiration events in HAP/VAP. The episode also touches on pathogen evolution (Red Queen Hypothesis applied to Pneumococcus) and concerning findings of multi-drug resistance transfer via imported seafood.
Summary of the Infectious Disease Puscast (Late August 2016)
0:42 Debunking Historical Biological Warfare: The claim that Russians catapulted plague victims into Raval in 1710 is likely false. As far as the evidence shows, they dumped corpses into a stream; the intent and infection status remain unclear.
1:56 Hand Hygiene (HH) Efficacy and Ethics: A direct correlation exists between increasing HH compliance (from 82% to 95.9% in one study) and decreasing infection rates (from >6 to >4 per 1,000 patient days). However, the premise of covert observation to measure adherence is profoundly unethical, as it allows healthcare providers to actively endanger patients by not correcting failures in real-time.
4:02 IV vs. Oral Flu Treatment: An abstract suggests IV Zenamavir (300/600mg) is comparable to oral Oseltamivir. Zenamavir showed slightly faster symptom resolution but a slightly higher (non-significant) mortality rate. This IV option is useful for critically ill ICU patients where oral drug reliability is questionable.
5:16 HIV Transmission Prevention: Immediate Antiretroviral Therapy (ART) in serodiscordant couples resulted in a 93% decrease in HIV transmission. It is not 100%, but combined with PrEP and condoms, transmission could be effectively halted.
6:25 HPV in Older Women: In sexually active women aged 25–65, only about two-thirds of HPV infections were new acquisitions, suggesting that much of the benefit of vaccination is lost because "the horse is probably already a little bit out of the barn."
9:52 Rising Endocarditis in IDU: Hospitalizations for endocarditis in young people doubled between 2000–2013, predominantly associated with injection drug use (IDU). White females were identified as a specific high-risk subgroup, linked to the opiate addiction crisis.
11:13 NSAIDs and Severe Infection: The use of NSAIDs is associated with the subsequent development of severe infections (e.g., necrotizing fasciitis, peritonsillar abscesses, empyema). Causality is suspect—maybe sicker people take more NSAIDs—but the association suggests inflammation might be protective.
12:16 Rejecting Prophylactic Oral Vancomycin: A retrospective study suggested oral vancomycin prophylaxis prevents C. difficile (reducing rates from 26% to 4%). This is a terrible idea; it risks VRE/VRSA and subsequent long-term resistance. The study is flawed as it used an overly sensitive PCR method, likely counting asymptomatic carriage. The future for C. difficile prevention is "poop pills," not prophylactic antibiotics.
15:38 HAP/VAP Guidelines (100% Dumbass): Updated IDSA guidelines for HAP/VAP do not recommend anaerobic coverage. Treating aspiration events with anti-anaerobic therapy is "absolutely totally 100% dumbass every time it's done," and clinicians should immediately stop this practice.
16:30 Applied Evolution (Red Queen Hypothesis): Vaccination against Pneumococcus (PCV7/PCV13) caused non-vaccine strains to proliferate, filling the ecological niche. This evolutionary pressure is why infectious disease is complex. I predict resistance in the new dominant strains will start creeping back up.
20:13 Challenging Candidemia Guidelines: Guidelines recommending routine ophthalmologic exams for all candidemia patients are excessive and based on "crappy evidence." Only 4.8% of patients developed endophthalmitis, and most symptomatic patients can communicate their findings. Screening should be limited to comatose/ICU patients or those with symptoms.
21:35 Helminths and Metabolic Syndrome: Helminth infection is associated with a 50% lower chance of metabolic dysfunction, lower glucose, and reduced insulin resistance. While interesting, I don't care to consume worms, even though naturopaths will inevitably try to sell this as a Type 2 diabetes cure.