IN THIS ISSUE
Floor swabs might predict long-term-care COVID outbreaks
Pandemic medical-device shortages (almost) over
Pathogens in new places or with new threats
New and Noteworthy
Pathogens blooming in new locations or with new threats
It’s spring! Okay, now that we’ve gotten the good news out of the way, here’s the bad news: A flurry of recent disease outbreaks caused by pathogens in new places or with new, concerning traits:
Mosquito- and tick-borne diseases, including West Nile and Lyme, increase in the spring and summer every year, but levels in 2021 were particularly high. Arizona alone reported 127 deaths.
Tanzania just reported its first outbreak of Marburg virus, a hemorrhagic virus related to Ebola - just a month after Equatorial Guinea also reported its first case of the disease.
Shigella, a relatively common bacteria (450,000 US cases a year), spreads via contact with feces. What’s worrisome is that 5% of cases now appear to be drug-resistant.
Candida, a fungus most often found in nursing homes and long-term-care facilities, saw a doubling of cases in 2021. While the total annual number is still relatively small (fewer than 1500), an increasing number of cases look to be drug-resistant - and this microbe spreads easily via asymptomatic people.
More to come on this issue in the future, especially on antimicrobial resistance.
What goes up must come down - and you can test for it.
A study done in 10 Canadian long-term-care homes between September 2021 and November 2022, printed in the New England Journal of Medicine, showed that floor swabs could be used as an early warning indicator of COVID outbreaks. The percentage of positive swabs tended to increase before outbreaks began, with eight of the 10 homes showing “floor swab positivity exceeding 10% five or more days before the outbreak was identified.”
Commentary: An unexpected result, given our understanding that SARS-CoV-2 doesn’t last long on most surfaces. If it holds up, we agree with the authors’ assessment that floor swabs could be a useful complement to wastewater testing for COVID surveillance purposes, particularly for long-term-care facilities and other places where people live together in close quarters (dorms, correctional facilities).
Pandemic supply chains stabilizing
Another sign that the emergency phase of the pandemic is winding down: The FDA predicts that most of the COVID-related shortages of medical devices and supplies will be over by the end of 2023. PPE has left the agency’s list of device shortages altogether (gloves were the last holdouts as of December 2022), and nearly all testing supplies are predicted to be back to normal levels by mid-year. Some ventilation, cardiac, and standard ICU supplies are still thin on the ground, as well as clinical sample concentrators.
Food for Thought
The COVID origin debaters are missing the point.
There’s been a lot of breathless discussion about the origin of SARS-CoV-2 in the last month. In late February, the US Energy Department came down on the lab-leak side, while other federal agencies stuck to the zoonotic-transmission side - all without releasing any evidence as a basis for their differing conclusions. Then on March 4, an international group of scientists identified several newly released (GISAID) sequences taken from Wuhan’s Huanan Seafood Wholesale Market back in 2019. These samples were promptly analyzed and found to contain both SARS-CoV-2 virus and raccoon dog genetic material, suggesting early infections in these wet-market animals as a (the?) source of the global pandemic. Alternatively, it is quite possible the raccoon dog mtDNA and viral RNA had different sources but ended up in the same place. Then on March 11, the sequences “disappeared” from GISAID, increasing the mystery, and fueling calls for greater disclosure/transparency from China’s CDC.
Commentary: Geopolitical objectives clearly work against the data transparency that is essential for science-based public health. We hate to dismiss both sides of the debate, but really, does the answer matter? Many have said that we need to know because we have to either increase security around labs doing research on dangerous pathogens or pay more attention to potential zoonotic diseases and the human-animal interactions that can cause them.
But the mere fact that this level of debate exists tells us one critical thing: both sources are a potential future risk to global health. That means we don’t have a choice at all - we need to do both. Public and private labs / research centers need to strengthen their procedures and provide strict oversight of compliance. AND we have to acknowledge that increasing viral transmission from wild animals to humans (zoonosis) is a huge and growing threat to global human health (e.g., HIV, SARS, MERS) that can only be mitigated by minimizing wild animal/human exposure, combined with systematic early warning testing wherever wild animals and humans can come in close proximity.
Quick Hits
Rebound is a COVID problem, not a Paxlovid problem, according to the FDA. In their analyses of Pfizer’s clinical trial data, “Viral RNA rebound and symptom rebound were observed in both PAXLOVID and placebo recipients, and at frequencies that were generally similar in both arms across multiple analyses.”
Rats in New York City are infected with wild-type SARS-CoV-2, according to a study published in mBio. The study adds to the list of human-adjacent mammals who could potentially be sources of new variants.
Omicron’s duration of transmission is not different from previous variants, per a recent meta-study. Omicron transmission lasted for an average of 5.2 days (up to a maximum of 15 days), while PCR test positivity continued for an additional 5.6 days - during which transmission is unlikely to occur. There was no statistical difference between symptomatic and asymptomatic people.