This Puscast reviews infectious disease literature from late August 2015, focusing on therapeutic efficacy, public health issues, and diagnostic challenges.
Key findings include strong evidence supporting early initiation of antiretroviral therapy for HIV patients regardless of CD4 count, and new data on HPV vaccine dosing intervals showing improved efficacy against genital warts with longer spacing between the first two doses. The discussion highlights ongoing concerns regarding hospital hygiene (tracing Pseudomonas outbreaks to water sources and increased MDRO transmission due to poor room cleaning) and the global rise of antibiotic resistance, evidenced by the selection of chlorhexidine-resistant Staphylococcus due to antiseptic use. Furthermore, the video presents conflicting data on the use of macrolides and steroids for community-acquired pneumonia, suggesting immunomodulatory benefits may influence treatment outcomes, while criticizing the routine overuse of diagnostics like urinalysis. As far as I can tell, the central theme is the continuous failure of clinical practice to align with evolving evidence, particularly concerning antimicrobial stewardship.
Puscast Summary: Infectious Disease Literature Review (August 2015)
0:45 CV Padding Critique: The host dismisses common publication strategies: useless surveys on alternative medicine use and culturing random surfaces (door knobs, lanyards) to report bacteria, which merely proves the world is filthy.
2:01 Nosocomial Sources: Emphasis on finding water sources in hospital outbreaks, citing Pseudomonas from a drinking fountain. Also stresses that poor environmental cleaning increases acquisition risk for MDROs (MRSA, VRE, etc.) for subsequent room occupants.
3:44 Anti-Vaccine Rhetoric: Directly criticizes "antivaccine whackaloons" for using "only" to describe human deaths.
4:20 Influenza and Pregnancy: 12% of pregnancy-related deaths (110 total) during the 2009-2010 period were due to influenza (rate of 2.2/100,000 live births). A preventable risk, obviously.
5:12 Tick-Borne Diseases: Review of Colorado Tick Fever (a viral, non-doxycycline-responsive illness) and a comprehensive list of US tick-borne pathogens (e.g., Lyme, Powassan, Anaplasma).
6:38 Travel Medicine & Ebola: Caution against "premature closure" when diagnosing fever in travelers from Ebola endemic areas (e.g., Sierra Leone). Most fevers are due to mundane causes like malaria, influenza, or UTIs.
7:48 Early HIV Treatment: Patients starting antiretroviral therapy (ART) early (CD4 >500) had better outcomes (fewer AIDS/non-AIDS serious illnesses) than those waiting for CD4 <350. The take-home message is clear: start therapy immediately upon diagnosis.
9:49 HPV Vaccine Dosing: A longer interval between the first and second HPV vaccine dose (6 months vs. 4 months) increased efficacy against genital warts (63% vs. 45%).
11:08 HSE Oral Therapy: Adding a three-month course of oral acyclovir/valacyclovir after standard IV treatment for Herpes Simplex Encephalitis showed no benefit for neuro-psychological testing.
12:11 Scrub Typhus Mortality: Untreated mortality for Scrub Typhus (Orientia tsutsugamushi) is estimated at 6% (range 0β70%). Fevers last over 14 days without treatment.
13:03 Lyme Disease Incidence: CDC estimates 329,000 annual cases of Lyme disease in the US (106.6/100,000 population).
14:39 Plague vs. Ebola: The host dismissively notes the 11 US plague cases in 2015 compared to Ebola, asserting plague is far deadlier historically ("Ebola is a wimp"). I don't care why the panic differential exists; the data speaks for itself.
15:40 Macrolides and Resistance: While inappropriate antibiotics generally increase mortality (17% vs 11%), macrolide resistance in S. pneumoniae did not impact patient outcome. Suggests the benefit of macrolides may be due to their immunomodulatory, rather than direct antimicrobial, effects.
17:16 Steroids for CAP: Meta-analysis supports the use of corticosteroids for Community Acquired Pneumonia: 3% decrease in mortality, 5% reduction in mechanical ventilation need, and a 1-day shorter hospital stay. However, steroids increase mortality in influenza, complicating co-infection treatment.
19:49 CSF Lactate Utility: CSF lactate is suggested as a useful marker to differentiate bacterial from viral meningitis. Although a 3.5 mg/dL cutoff was touted as 100% sensitive/specific, I reject that premise entirely; real-world data is likely half as robust, as far as I can tell.
21:06 Antibiotic Misuse & MRSA: Unnecessary antibiotic prescriptions (e.g., for sore throats) increase the likelihood of patients carrying resistant organisms, specifically MRSA.
21:29 Chlorhexidine Resistance: Use of chlorhexidine for decolonization is linked to the development of chlorhexidine-resistant Staphylococcus via a transferable plasmid (QACA efflux pump). This is depressing and suggests chlorhexidine/mupirocin resistance is imminent.
22:52 Urinalysis Critique: Routine urinalysis in asymptomatic elderly ER patients is criticized as leading to unnecessary antibiotics and increased cost. The rule for asymptomatic bacteriuria should be "don't ask, don't tell."
26:06 Antibiotics & Diabetes: Epidemiologic data shows a 53% increased risk of Type 2 Diabetes in patients on antibiotics. This is a potential mechanism for discouraging unnecessary outpatient antibiotic use.
27:06 Tigecycline Safety/Efficacy: Meta-analysis confirms that Tigecycline is generally inferior to comparators, associated with more adverse events and higher all-cause mortality. It should not be used as a first-line drug.