US flu activity continues slow rebound
Flu activity continued to rise in most of the nation last week, with three more pediatric flu deaths reported, but markers are still below epidemic baselines, the US Centers for Disease Control and Prevention (CDC) said today in its latest update.
The national percentage of outpatient visits for flulike illness rose slightly, to 1.7%. The level had reached a season high at the end of 2021 and was declining until early February, when it started to creep up again. Oklahoma reported high flu activity, another measure of clinic visits for flu, while Arkansas and Idaho reported moderate activity.
The percentage of respiratory specimens that were positive for flu at clinical labs was 6.8% last week, up from 5.8% the week before. The CDC said the highest positivity rates at the labs were in the central and south-central regions of the country. At public health labs, all specimens were influenza A, and, of subtyped samples, all were the H3N2 strain.
Hospital admissions rose for the sixth straight week, but the cumulative rate is still lower for this time of year that the last four pre-COVID flu seasons.
The 3 pediatric flu deaths occurred between the middle of January and early March. All involved unsubtyped influenza A viruses. So far, 13 pediatric flu deaths have been reported to the CDC this season.
Mar 18 CDC FluView update
High-path avian flu found in Michigan waterfowl, other states
In ongoing surveillance in wild birds to monitor the spread of highly pathogenic H5N1 avian flu, the US Department of Agriculture (USDA) reported nine more positives, including the first in Michigan, according to an update.
The positive H5 sample from Michigan was from a mute swan harvested in Monroe County, which is located in the far southeastern part of the state on the Lake Erie shore, according to an update from the USDA's Animal and Plant Health Inspection Service (APHIS). Earlier this month, Michigan reported an outbreak, its first, in a backyard flock in Kalamazoo County.
The other new H5 positives in wild birds were from already affected states: Florida, New Hampshire, Iowa, and Illinois.
So far, the USDA has confirmed 385 positive wild bird detections and 38 appearances in poultry flocks since the middle of January. They involve the Eurasian H5N1 strain that has fueled outbreaks in wild birds and poultry in a number of world regions and resulted in one human case—involving a person who had very close contact with infected birds.
USDA APHIS wild bird avian flu detection page
Study finds dramatic drop in antimicrobial use in Japan in 2020
Japan saw a marked reduction in antimicrobial use (AU) in 2020 that's linked to the COVID-19 pandemic but could also reflect increased antimicrobial stewardship, according to a study yesterday in the International Journal of Infectious Diseases.
Using nationwide antimicrobial sales data, researchers from Japan's National Center for Global Health and Medicine examined annual and monthly trends in AU from 2016 to 2020 according to the World Health Organization AWaRe (Access, Watch, and Reserve) classification system and administration route (oral and injectable). They compared AU trends in 2020 with those observed from 2016 to 2019. To assess the impact of the pandemic, they compared actual AU in 2020 to a hypothetical scenario in which the pandemic did not occur.
The analysis showed a general decline in the use of oral antimicrobials from 2016 through 2020, especially those in the Watch category (from 9.69 defined daily doses per 1,000 inhabitants per day [DID] in 2016 to 7.22 DID in 2020), with substantially lower AU in 2020 that exceeded the downward trend observed from 2016 to 2019.
The analysis of monthly trends showed a significant drop in overall AU in May 2020 that was not observed in the same month in previous years. In addition, AU for both oral (1.10 DID to 0.59 DID) and injectable antimicrobials (10.6 DID to 6.62 DID) fell in May 2020, as did AU for Access (2.36 DID to 1.56 DID) and Watch (9.14 DID to 5.54 DID) antimicrobials.
When compared with the scenario of no pandemic, the reductions for AU in total antimicrobials and Watch antimicrobials for 2020 were greater than predicted.
"The observed reduction in AU in 2020 was likely due to the COVID-19 pandemic, which led to a decline in hospital visits and lower incidences of other infectious diseases," the study authors wrote. "However, AU had been decreasing every year before 2020, which might reflect an increase in antimicrobial stewardship measures following the National Action Plan on AMR [antimicrobial resistance]."
Mar 17 Int J Infect Dis study