US celebrity Twitter posts—especially those from politicians and news anchors—likely influenced the increasingly negative US public attitudes toward efforts to combat the COVID-19 pandemic, according to a study published this week in BMJ Health & Care Informatics.

A team led by University of Tennessee researchers analyzed the sentiments of more than 45,000 COVID-related tweets from 34,000 unique users from January to March 2022 that mentioned a well-known vaccine skeptic. The tweets garnered more than 16.3 million likes, with the most popular one earning 70,000.

The skeptics included podcaster Joe Rogan, TV host Tucker Carlson, political commentator Candace Owens, broadcaster Phil Valentine, football player Aaron Rodgers, tennis player Novak Djokovic, musicians Nicki Minaj and Eric Clapton, and politicians Rand Paul, Donald Trump, Ted Cruz, and Ron DeSantis.

Messages downplayed COVID risks

While sentiments varied slightly, the researchers said the overall tone was negative and polarizing. News anchors had a wide sphere of influence, with more than 14,000 likes among them.

So, too, did politicians. "The spread, reaction and engagement by the public to posts made by politicians online was indicative of a strong level of influence, suggesting politicians play key roles in ensuring population health and should be committed to promoting health-protective behaviours rather than sensational falsehoods," the authors wrote.

Our findings suggest that polarised messages from societal elites may downplay these risks, unduly contributing to an increase in the spread of COVID-19.

Further research, they added, could help public health officials and policymakers combat misinformation about COVID-19 and future outbreaks through targeted social media messaging.

"The risk of severe negative health outcomes increases with failure to comply with health-protective behaviour recommendations set forth by public health officials, such as vaccination, and our findings suggest that polarised messages from societal elites may downplay these risks, unduly contributing to an increase in the spread of COVID-19," the authors wrote.

A California law that banned the routine use of medically important antibiotics for disease prevention in food-animal production was associated with a reduction in one type of antibiotic-resistant infection in people, researchers reported yesterday in Environmental Health Perspectives.

To assess the impact of SB27, a bill enacted in 2018 that required all use of medically important antibiotics in food animals in California to have a veterinary prescription and limited the preventive use to extraordinary circumstances, a team of US researchers analyzed state-level data on antibiotic-resistance patterns in Escherichia coli isolated from human urinary tract infection (UTI) samples from 2013 through 2020. Previous research has suggested a link between antibiotic use in food-producing animals such as poultry and resistant UTIs in people.

Tested antibiotic classes included aminoglycosides, extended-spectrum cephalopsorins (ESCs), fluoroquinolones, and tetracyclines. Using an augmented synthetic control method (ASCM), the researchers compared resistance patterns in the California E coli samples before and after 2018 to a scenario in which California had not passed the law. They used resistance data from 32 states with no similar law to create this "synthetic California."

Less extended-spectrum cephalosporin resistance

From 2013 to 2017, the median E coli resistance percentages in UTIs in California were 11.9%, 13.8%, 24.6%, and 7.9% for aminoglycosides, ESC, fluoroquinolones, and tetracyclines, respectively. The ASCM analysis showed that implementation of SB27 was associated with a 7.1% reduction in ESC resistance in California compared with synthetic California, but no difference in resistance to aminoglycosides, tetracyclines, or fluoroquinolones.

A 7% reduction—for a bill where we aren't sure about its implementation quality—it's pretty exciting.

The study authors say the results are limited by the fact that California has not published data on antibiotic sales in food-producing animals since SB27 was implemented and note that factors other than the legislation may have contributed to the reduced ESC resistance. Still, they say the findings are encouraging.

"A 7% reduction—for a bill where we aren't sure about its implementation quality—it's pretty exciting," lead study author Joan Casey, PhD, of the University of Washington, said in a university press release. "I'm hopeful that this can spur other states to consider similar bills."