This "Puscast" provides a concise, though highly informal and anecdotal, review of infectious disease literature from early August 2011. The speaker, an infectious disease specialist, focuses heavily on emerging virology (including Arenaviruses, Cowpox, Merkel Cell Polyomavirus, Pumala virus, and a novel Reovirus) and critical re-evaluations of clinical practice. Key findings reject common medical dogma: steroids significantly increase mortality in H1N1, and Cefazolin is shown to be non-inferior (and safer) than Nafcillin for MSSA bacteremia. The video strongly advocates for early antiretroviral therapy as a highly effective method of HIV prevention and condemns the fallout from vaccine misinformation.
Summary of the Puscast: Infectious Diseases Update (August 2011)
0:09 Delivery Style: The podcast is recorded outside and is highly informal, no longer accredited for Continuing Medical Education (CME)—a decision the host finds efficient.
1:38 Arenaviruses: The Trecareb sero complex of arenaviruses (including Tamiami and Bear Canyon viruses) is a common, though often undiagnosed, cause of febrile illness and CNS disease in the US.
3:04 Cowpox Risk: Due to the discontinuation of smallpox vaccination, the population is increasingly susceptible to Cowpox. The virus, found in various animals (llamas, cats, etc.) across Europe, typically causes self-limited localized disease but is dangerous in immunocompromised patients.
3:54 Merkel Cell Polyomavirus (MCPyV): This virus, linked to Merkel cell carcinoma (a rare skin cancer), is common. Seroconversion occurs at a rate of about 7% per year in high-risk groups (e.g., gay/bisexual men) but is usually asymptomatic and not linked to HIV progression.
5:13 Pumala Virus: A Hantavirus primarily found in Northern Europe (spread by bank voles) causing hemorrhagic fever with renal syndrome. CNS complications appear to disproportionately affect young male patients.
6:19 Rabies/Climate Threat: A fatal case of vampire bat rabies acquired in Mexico suggests that, due to climate change, these vectors might migrate north. As far as I can tell, the US border security is not optimized for infectious bat control.
7:54 Steroids in H1N1: Contraindicated: Early use of steroids in H1N1 significantly increased rates of death or critical illness (71% versus 39% in the non-steroid group). This confirms steroids harm patients in this context. The speaker stresses that unproven therapies often do more harm than good.
10:35 Early ART Prevents HIV Transmission: Early antiretroviral therapy (ART) in the seropositive partner of discordant couples dramatically decreased transmission rates (1 transmission vs. 38 transmissions in the later therapy group). Early treatment is highly effective prevention.
12:59 Hepatitis E (HEV): Despite about 20% of Americans being seropositive, HEV is rarely tested for. It can cause serious complications like polyradiculopathy. The speaker notes testing rarely goes beyond "D."
13:34 Wakefield Condemnation: Fraudulent claims linking the MMR vaccine to autism resulted in low vaccination rates (61% in London), directly causing massive measles outbreaks (25,000 cases in Bulgaria after being imported from Germany).
14:42 Norovirus Epidemiology: The common Norovirus strain shifted to the G2.4 New Orleans strain, accounting for over 50% of outbreaks. Molecular testing suggests Norovirus causes significantly more gastroenteritis (15.7%) than standard testing (7%).
16:00 Varicella Vaccine Efficacy: Implementation of the single-dose Varicella vaccine led to a dramatic reduction in US death rates (from 0.41 to 0.05 per million).
20:20 Procalcitonin (PCT) Use: A systematic review found that using PCT to guide antibiotic duration in the ICU safely resulted in shorter ICU lengths of stay, but did not significantly change mortality or relapse rates. I don't care much for its necessity if basic clinical judgment suffices.
21:52 Prosthetic Joint Infection (PJI) Management: Joint salvage was associated with a one-stage procedure (surprisingly) and crucially, the inclusion of Rifampin with a beta-lactam or quinolone.
22:50 Vancomycin MIC and Mortality: High Vancomycin MICs (MIC > 1.5) correlated with increased mortality (15% difference), regardless of whether the infection was MRSA or MSSA (and appropriately treated with a beta-lactam). This suggests MIC > 1.5 indicates a poor prognostic factor intrinsic to the organism or host, separate from Vancomycin’s direct efficacy.
26:14 Cefazolin vs. Nafcillin for MSSA: A retrospective study found no difference in failure rates for MSSA bacteremia between Cefazolin and Nafcillin. Cefazolin is superior due to significantly fewer adverse events (0% vs. 17%). Reject the premise that Nafcillin is necessary.
30:13 Microbiota and Obesity: Obesity is associated with changes in gut flora, including depletion of M. smithi. While association is not causation, this might explain anecdotal links between antibiotic use (like Vancomycin) and weight gain.
31:40 Miscellaneous: The host briefly mentions West Nile in a whale, Salmonella from peanut butter, and E. coli O157 from strawberries contaminated by deer feces (31:54).