An analysis of reported non-typhoidal Salmonella (NTS) infections in the United States suggests international travel is a significant risk factor for antibiotic resistance, US researchers reported today in the Journal of Infectious Diseases.

Although most of the 1.35 million NTS infections that occur each year in the United States don't require antibiotic treatment, antibiotics are needed for more severe invasive infections, and roughly 16% of reported NTS infections are antibiotic resistant. To assess the documented links between international travel and antibiotic-resistant NTS infections, a team led by researchers with the Centers for Disease Control and Prevention analyzed NTS infections reported to the Foodborne Diseases Active Surveillance Network during 2018-2019 that were screened for resistance genes, including those conferring resistance to first-line agents (ciprofloxacin, ceftriaxone, or azithromycin). They used multivariable regression analysis to estimate the contribution of international travel to drug-resistant NTS infections.

Among 9,301 NTS infections with sequenced isolates and known travel status, 1,159 (12%) occurred after recent international travel. Among 1,220 infections with predicted resistance to first-line antibiotics, 30% were among travelers and 19% were estimated to be attributable to international travel during the 7 days before illness began.

Adjusted for age, sex, and season, NTS infections following recent travel were more likely to have predicted resistance for first-line antibiotics compared with non-travelers (adjusted odds ratio [aOR], 3.7; 95% confidence interval [CI], 3.2 to 4.3). The odds of predicted resistance to first-line antibiotics were highest among travelers to Asia (aOR, 7.2; 95% CI, 5.5 to 9.5). The highest incidence of infections resistant to first-line antibiotics was in Latin America and the Caribbean (3 per 100,000 travelers).

The study authors say the association between travel and antibiotic resistance could be related to increased selection pressure for resistance genes in particular regions from use of antibiotics in human medicine but could also be linked to antibiotic use in animals. They also say that use of whole genome sequencing for NTS surveillance can help track resistant strains.

"Understanding risks of resistant infection could help target prevention efforts," they concluded.

Following a Gold Medal flour recall due to Salmonella, the Centers for Disease Control and Prevention (CDC) yesterday posted an update connecting the product to an ongoing outbreak that has now sickened at least 13 people in 12 states.

Three people have been hospitalized, but no deaths have been reported. Two people have been sickened in Illinois, and one person each in Oregon, California, Nebraska, Minnesota, Iowa, Missouri, Tennessee, Ohio, Virginia, New York, and New Jersey. Sick people range in age from 12 to 81 years, with a median age of 64, and 92% are female.

The CDC said the outbreak is likely significantly bigger than what has been reported. Illness-onset dates range from December 6, 2022, to March 1, 2023.

Of eight people interviewed, seven (88%) reported eating raw dough or batter before they got sick. All six patients who knew brand information reported buying Gold Medal flour, made by General Mills of Minneapolis.

Late last week, General Mills recalled 2-pound, 5-pound, and 10-pound bags of Gold Medal bleached and unbleached all-purpose flour with "better if used by" dates of March 27, 2024, and March 28, 2024.

The recall happened after the Food and Drug Administration conducted a trace-back investigation and identified a single production facility of the flour consumed by sick people, the CDC said. The facility was in Kansas City, Missouri.

The CDC recommends throwing away all stored flour that may be contaminated, and to avoid eating uncooked flour in products such as cookie dough.