The appropriate group of people to review this topic, given that it is a conversational review of current Infectious Disease (ID) literature, would be Infectious Disease Specialists, particularly those engaged in clinical practice, hospital epidemiology, and antimicrobial stewardship. They are the only ones who care about the highly specific references, the nuances of Yersinia pestis pathophysiology, or the zero-data basis of counting duration from the last negative blood culture.
Abstract
This "puscast" reviews the Infectious Disease literature from the first half of August 2020, covering evolving COVID-19 data, antimicrobial resistance, and general ID management principles. Key findings include skepticism regarding probiotics (shown ineffective in reducing antibiotic use in nursing homes) and the limited, expensive benefit of copper-impregnated surfaces for hygiene.
COVID-19 topics focus on high bloodstream infection (BSI) rates (up to >50% at 30 days) in critically ill patients in overwhelmed Italian ICUs, and the confirmation that Hydroxychloroquine (HCQ) is useless for post-exposure prophylaxis. Seroprevalence data from Oregon confirmed significant underdiagnosis (10x official cases).
The review also highlights the high stakes of future Avian Influenza pandemics, the independent cardiovascular risks of seasonal influenza, and the confirmed uselessness of screening for asymptomatic bacteriuria (pyuria) before surgery. Furthermore, it challenges the widespread, unsupported practice of counting antibiotic duration from the last negative blood culture.
Summary of Infectious Disease Literature Review (August 2020)
0:41 Copper Surfaces for Hygiene: A study suggests copper-impregnated surfaces decrease microbial counts by half (from $\sim 60$ CFU to $\sim 25.5$ CFU) on high-touch surfaces in acute care.
Takeaway: Surfaces still harbor bacteria; copper is not a substitute for hand hygiene. Given the high cost of copper and concerns about its availability, this seems like an inefficient solution for a marginal benefit, as far as I can tell.
2:07 Probiotics Efficacy: A study examining the use of probiotics in nursing home patients found they did not decrease the subsequent need for antibiotics.
Critique: This confirms the overall skeptical trend. I lack the prior plausibility to believe Lactobacillus and Bifidobacterium do much of anything.
3:47 Bloodstream Infections (BSI) in COVID-19: A study out of Italy reported extremely high rates of BSI in critically ill COVID-19 patients: 25% at 15 days, rising to over 50% at 30 days.
Note: These rates are higher than seen elsewhere, potentially reflecting the high patient volumes and resulting compromised care standards in overwhelmed settings.
4:36 Nucleic Acid Amplification Tests (NAAT) for COVID-19: Overall sensitivity is estimated between 82% and 97% (average $\sim 95%$).
5:21 Seroprevalence and Underdiagnosis: Data from Oregon indicated that the actual number of COVID-19 cases was approximately 10 times the diagnosed case count, confirming a consistent finding across the US.
6:49 Sunlight Inactivation of SARS-CoV-2: Simulated sunlight inactivates 90% of the virus in 20 minutes (fall light) or 8 minutes (summer light). Relevant for assessing risk during brief outdoor contacts (e.g., passing on a hiking trail).
7:32 Hydroxychloroquine (HCQ) Prophylaxis: A trial published in the NEJM confirmed that HCQ is ineffective for post-exposure prophylaxis against COVID-19.
Takeaway: Unsurprising.
7:54 Avian Influenza Pandemic Risk: The speaker maintains that Avian Flu (Bird Flu) remains the greatest threat, capable of causing a 1918-1919 level pandemic with high mortality, especially if it jumps to humans similar to COVID-19.
9:42 Influenza Complications: Influenza is an independent risk factor for myocardial infarction (MI) and hospital readmission up to a year later. Vaccination is crucial for preventing these severe downstream complications.
12:02 Hepatitis B and HCC Treatment: Patients with Hepatitis B-related hepatocellular carcinoma (HCC) undergoing chemoembolization (TAE) experienced prolonged survival if they were simultaneously treated for their active Hepatitis B infection.
18:35 Vancomycin vs. Metronidazole for VRE Risk: A large VA study ($>86,000$ patients) found that using oral Vancomycin did not increase the risk of developing Vancomycin-Resistant Enterococcus (VRE) compared to Metronidazole.
Takeaway: While no antibiotic is the best antibiotic for resistance prevention, Vancomycin is apparently not a unique driver of VRE, which confirms my bias.
19:24 Single-Dose Aminoglycosides in Sepsis: Combining a beta-lactam with a single dose of Gentamicin for community-acquired sepsis/septic shock was associated with decreased mortality and no increased risk of Acute Kidney Injury (AKI).
Opinion: Supports the idea that the therapeutic benefit of aminoglycosides is largely achieved with the initial dose.
21:09 Compression Therapy for Cellulitis: Compression therapy (not necessarily just stockings) is beneficial in preventing the recurrence of cellulitis in patients with chronic edema.
22:35 Enterococcal Endocarditis Duration: Four weeks of Ceftriaxone plus Ampicillin may suffice for enterococcal endocarditis, provided symptoms have been present for less than a week and there is no ring abscess.
23:57 Duration Counting Dogma: Reject the premise that antibiotic duration must be counted from the last negative blood culture.
Critique: This practice wastes resources and has zero supporting data. I don't care if it's tradition; it needs to stop.
24:32 Pre-Operative Pyuria Screening: Screening and treating asymptomatic pyuria prior to surgery is useless. It does not improve surgical outcomes but significantly increases the risk of C. difficile infection.
Takeaway: Only treat symptomatic UTIs. Pyuria is not a symptomatic infection.
30:24 Outpatient Antibiotic Therapy (Dalbavancin): Discharging patients after a dose of Dalbavancin, replacing the final week of inpatient IV therapy, saved an estimated $9,600 per patient.
Questionable Premise: I am skeptical that the full course was necessary in the first place. Did they actually need that final week? Probably not.