News Scan for Mar 24, 2022

News brief

NFL games didn't contribute to county COVID-19 spread, study suggests

National Football League (NFL) games played with fans in the 2020 season, with mask mandates and physical distancing in place, had no effect on COVID-19 infections in the surrounding county, suggests a new study in the Proceedings of the National Academy of Sciences (PNAS).

Led by Massachusetts Institute of Technology (MIT) researchers, the study estimated the effects of games played from September 2020 to early January 2021, well before the emergence of the highly transmissible Delta and Omicron SARS-CoV-2 variants. Of 29 stadiums, 13 were closed throughout the season, and 16 opened with reduced capacity, mask requirements, distanced seating, mobile ticketing, and enhanced cleaning.

The researchers tracked COVID-19 cases in counties surrounding the stadiums and compared them with those in simulated counties without stadiums but with similar patterns of COVID-19 leading up to the season.

They found no difference in COVID-19 case trajectories between counties that did and didn't host NFL games. To ensure that their method didn't miss case spikes, the team tested it on the August 2020 Sturgis Motorcycle Rally in South Dakota, a superspreader event. The analysis detected the case spike in surrounding Meade County in the 2 weeks after the rally.

"These results show that the measures adopted by the NFL were effective in safely opening stadiums," senior author Anette Hosoi, PhD, said in an MIT press release. "If case counts start to rise again, we know what to do: mask people, put them outside, and distance them from each other."

Of note, some counties hosting NFL games saw a slight dip in COVID-19 cases. "These are football communities with dedicated fans," Hosoi said. "Rather than stay home alone, those fans may have gone to a sports bar or hosted indoor football gatherings if the stadium had not opened."

Another finding is that counties with similar COVID-19 patterns had comparable political proclivities. For example, infection counts in Ohio in 2020 strongly predicted the state's electoral map in the presidential election. "That is not a coincidence," Hosoi said. "It tells us that local political leanings determined the temporal trajectory of the pandemic."
Mar 22 PNAS study
Mar 23 MIT press release


Rapid PCR tests for suspected Strep A infections tied to less antibiotic use

Implementation of point-of-care (POC) polymerase chain reaction (PCR) tests for patients with acute pharyngitis symptoms as part of a broader antibiotic stewardship initiative was associated with a significant reduction in inappropriate antibiotic use at outpatient clinics in California, researchers reported today in Open Forum Infectious Diseases.

The retrospective before-and-after study assessed the impact of switching from a rapid antigen detection test (RADT) to a rapid POC PCR assay for patients with suspected group A beta-hemolytic Streptococcus pyogenes (Strep A) infection at 15 outpatient clinics in the University of California (UC) Davis health system. RADTs are the standard-of-care for Strep A, but because they have low sensitivity and negative results require time-consuming microbiologic culture confirmation, patients frequently receive inappropriate empiric antibiotic therapy.

Using patient medical records, UC Davis researchers compared antibiotic use when RADTs were used (the control period, June 2017 to May 2018) with the first complete season when the POC PCR testing strategy was implemented (the intervention period, June 2018 to May 2019).

Analysis of 10,081 eligible patient records showed that rates of antibiotic prescribing within 14 days of the initial clinic visit were similar during the intervention and control period (25.1% vs 26.2%, respectively). But among the patients who had a negative POC PCR result, the researchers recorded a 44.1% reduction in the number of antibiotics prescribed during the intervention period (10.1% vs 18%, respectively). Rates of antibiotic prescribing varied across sites, ranging from 10.7% to 33.8% during the intervention period and 12.4% to 34.4% during the control period.

The use of POC PCR tests had no impact on prescription rates in patients with positive results compared with RADTs (76.2% vs 76.5%, respectively).

"The prescribing changes between the intervention and control periods demonstrate that the greater diagnostic accuracy of the POC PCR, compared with that of the RADT, allows clinicians to have greater certainty in the result, and reduces the likelihood of the clinician resorting to empiric antibiotic therapy," the authors write, adding that adherence to an algorithm directing appropriate management of suspected Strep A also likely played a role in the reduced prescribing.
Mar 24 Open Forum Infect Dis abstract

Flu Scan for Mar 24, 2022

News brief

South Dakota and Maine report more high-path avian flu outbreaks

South Dakota reported three more highly pathogenic avian flu outbreaks on commercial poultry farms, while Maine reported another detection in a backyard flock, according to the latest updates from the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS).

The outbreaks in South Dakota raised the state's total to eight. The three new ones all occurred on turkey farms that have a total of 189,250 birds. Locations include two counties that have already reported similar outbreaks: Charles Mix and Hanson. The third event struck birds in Beadle County near Huron in the east central part of the state.

In Maine, the virus was found in a backyard flock for the eighth time, this time in a Cumberland County location that houses 150 mixed species of birds. Cumberland County is in the southern part of the state on the Atlantic coast.

The outbreaks are part of ongoing activity involving the Eurasian H5N1 strain, which has infected poultry in multiple parts of the world and has been implicated in one human infection, an individual who had very close contact with poultry. In the United States, the virus has led to the loss of about 13.4 million birds in 17 states since January.
USDA APHIS poultry outbreak page


WHO: Flu levels trend up again in parts of Northern Hemisphere

Flu levels, after peaking at the end of 2021, are creeping up again in some Northern Hemisphere countries, mainly due to the H3N2 strain, the World Health Organization (WHO) said in its latest global flu update, which covers the end of February and the first week of March.

In temperate parts of the Northern Hemisphere, flu activity rose or remained stable. For example, in North America, flu activity has increased over the past weeks, but is still at levels lower for this time of year for typical pre–COVID-19 pandemic seasons. Europe's levels also rose, mainly due to H3N2, while an increase in China was mainly from the influenza B Victoria lineage.

Tropical African countries reported ongoing flu spread in the eastern region from both H3N2 and influenza B. Meanwhile, in temperate Southern Hemisphere countries, flu remained low overall, but with some ongoing H3N2 detections in parts of South America.

Of the respiratory samples that tested positive for flu at national labs during the latest reporting period, 74.2% were influenza A and 25.8% were influenza B. Of the subtyped influenza A samples, 88% were H3N2. And of the characterized influenza B samples, all belonged to the Victoria lineage.
Mar 21 WHO global flu update

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