Iowa has announced its second measles case, an adult male from the eastern part of the state who was vaccinated and whose travel history is still under investigation. This is the third measles case in Iowa this year. Iowa last identified measles in 2019.

Health officials in Montana's Gallatin County also confirmed two more measles cases, including one person who was exposed to an earlier case and another who likely acquired the virus through community transmission. Several Bozeman stores, restaurants, and a middle school flag football game are listed as spots of possible exposure. The county now has 12 cases of measles this year. 

New Mexico detection hints at ongoing transmission 

Finally, New Mexico's health department today announced a positive measles sample in wastewater from Chaves County. The last confirmed measles case in Chaves County was in early April. The wastewater sample was collected in early June, suggesting the possibility of ongoing silent transmission there.

"While wastewater testing cannot tell us the timing, location or number of people infected with measles, this detection tells us there was at least one person infectious with measles in Roswell around June 3 and puts us on notice there may be more cases in Chaves County in the coming days,” Daniel Sosin, MD, a medical epidemiologist for the state, said in a press release. 

Despite widespread recommendations for use among kids at risk for complications from influenza infection, including children under 5 years and those with certain underlying medical conditions, antivirals were prescribed for only one-third of at-risk children, according to a study based on data from the New Vaccine Surveillance Network from 2016 to 2020. 

The study was published yesterday in Influenza and Other Respiratory Viruses. It included information on children presenting to the emergency department (ED) with confirmed flu at one of seven pediatric academic centers. Characteristics of children prescribed antivirals were compared to those who were not.

In total, 2,472 children enrolled in the study tested positive for influenza, of which 1,931 (78%) were at high risk for severe flu. Of those at risk, 622 (32%) received an antiviral. Oseltamivir (Tamiflu) was the only antiviral prescribed.
 

Clinical testing associated with antiviral use 

Children prescribed an antiviral had a shorter duration of symptoms (2 days) before presenting to the ED than those not prescribed the drug. Older children were less likely to be prescribed antivirals, and significant differences in prescribing were seen across several states. 

The factor most associated with antiviral use was clinical testing. Children who underwent clinical testing for flu had higher odds of being prescribed antivirals than those who did not (adjusted odds ratio, 18.10; 95% confidence interval, 12.97 to 25.25).

Influenza antivirals for children continue to be under-prescribed in the ED, including for children at higher risk of severe influenza.

“Influenza antivirals for children continue to be under-prescribed in the ED, including for children at higher risk of severe influenza,” the authors concluded. “Our study highlights the concerning gap in evidence-based influenza treatment of children in the ED setting, similar to that in hospitalized children with influenza, and underscores the need for implementation research to increase adherence.”

Antibiotic exposure during pregnancy or early childhood is associated with increased risk of childhood atopic dermatitis (AD), according to a study published yesterday in eClinicalMedicine.

In a review and meta-analysis, Chinese researchers examined 39 cohort studies involving expectant mothers and young children younger than 5 years old to explore the association between antibiotic exposure and the risk of childhood AD, a chronic skin condition characterized by inflammation, eczema-like lesions, and severe itching. 

While studies in mice have suggested that antibiotics can induce AD-like pathology, clinical studies and meta-analyses have reported inconsistent results in children who've had early antibiotic exposure. 

The meta-analysis of the 39 studies, which involved more than 7.4 million children, found that antibiotic exposure was associated with a 22% increased risk of childhood AD (pooled odds ratio [OR], 1.22; 95% confidence interval [CI], 1.17 to 1.28). Subgroup analysis showed that early childhood exposure to antibiotics demonstrated a stronger association with AD (OR, 1.23; 95% CI, 1.13 to 1.34) compared with exposure during pregnancy (OR, 1.09; 95% CI, 1.05 to 1.13). 

Antibiotic exposure frequency, antibiotic type may play a role

Further subgroup analyses revealed that increased risk of AD following antibiotic exposure was affected by the diagnostic criteria of AD, that increased risk of AD was higher in American/European children than Asian children, and that both the antibiotic exposure frequency and type of antibiotic appear to influence the increased risk of AD.

"Taken together, our study supports that antibiotic exposure during pregnancy and early childhood increases the risk of AD," the study authors wrote.

The authors caution that because of the presence of biases in the reviewed studies (such as selection and publication bias) and uncontrolled confounding factors, more high-quality studies with larger sample sizes are needed.

"Future studies should consider variables including different types and dosages of antibiotic exposure, the influence of breast milk, specific conditions in rural areas, and medication compliance," they concluded.

A decline in the sale of antibiotics for use in food-producing animals in the United Kingdom was associated with a significant decrease in indicators of antimicrobial resistance (AMR) in pigs and poultry, researchers reported last week in the Journal of Antimicrobial Chemotherapy.

From 2014 through 2021, antibiotic sales for food-producing animals in the United Kingdom were cut in half, declining from 59.27 milligrams per population correction unit (mg/PCU) to 29.14 mg/PCU. The decrease was spurred by 2014 report from the UK government that called for reductions in the use of antibiotics in humans and animals. 

To analyze associations between the decrease and AMR in food-producing animals, researchers from the UK's Animal and Plant Health Agency and Veterinary Medicines Directorate assessed the prevalence of non–wild-type Escherichia coli (strains that have acquired resistance) in pigs and poultry (broilers and turkeys)—the sectors that have contributed the most to the reductions in antibiotic sales.

Significant drop in resistant E coli

Over the study period, the percentage of non–wild-type E coli isolates with resistance to any antibiotic tested (the primary AMR indicator) fell from 82% to 61%, and the percentage of isolates showing multidrug resistance (the secondary indicator) fell from 56% to 31%. 

Logistic regression models showed a significant association between decreasing antimicrobial sales and declines in the percentage of any non–wild-type E coli (odds ratio [OR], 2.69; 95% confidence interval [CI], 1.70 to 4.27) and declines in the percentage of E coli displaying multidrug resistance (OR, 2.58; 95% CI, 1.78 to 3.74).

Although analysis of the direct impact of the findings on human health in the United Kingdom was beyond the scope of the study, the study authors note previous studies have shown links between food-animal antibiotic use and resistant E coli in people.

"Sustaining efforts of antimicrobial stewardship, together with ongoing surveillance, will be important to maintain progress in the control of AMR," the authors wrote. "To further reduce the spread of AMR, funding other areas of research will be beneficial, such as investigating best farm practices (while supporting animal welfare standards, which in itself can affect disease resilience) at [the] individual-farm level."