News Scan for Oct 27, 2021

News brief

Infant formula linked to more antibiotic resistance genes

Formula feeding is associated with a 70% increase in antibiotic resistance gene (ARG) abundance in the gut microbiome of infants compared with breast milk, US and Finnish researchers reported this week in the American Journal of Clinical Nutrition.

To determine the impact of early exposure to infant formula on the ARG load in newborns and infants born either pre- or full-term, the researchers cross-sectionally sampled the gut metagenomes of 46 infants born prematurely to build a generalized linear model and collected extensive data on the infants' diet during the first month of life.

They then cross-validated the model using 242 infant gut metagenomes from public databases. Their hypothesis was that diet causes a selective pressure that influences the microbial community of the infant gut and that formula might carry an abundance of bacterial species that carry ARGs.

The researchers found that formula-feeding increases the ARG load compared with an exclusively human milk diet. The relative abundance of ARGs carried by gut bacteria was 69% higher in infants receiving formula (fold change, 1.69; 95% confidence interval [CI], 1.12 to 2.55) compared with those who received human milk only. Several ARGs in formula-fed infants were enriched, including extended-spectrum beta-lactamase (ESBL) genes and genes encoding resistance to methicillin and erythromycin in Staphylococcus aureus.

Formula-fed infants also had a higher relative abundance of opportunistic pathogens, including S aureus, Staphylococcus epidermis, Klebsiella pneumoniae, Klebsiella oxytoca, and Clostridioides difficile, and significantly less bacterial species typically found in the gut, such as bifidobacteriaceae.

The study authors note that they did not follow up on the infants to determine whether those who were fed formula or had higher ARG abundance had more infections caused by antibiotic-resistant bacteria and that they could not confirm whether the ARGs were functional. But they say the findings suggest that the changes in formula-fed infants' intestinal environment may result in more ARG-carrying bacteria.

"Infants born prematurely are at particular risk of acquiring severe and life-threatening infections," they wrote. "Thus, increased ARG loads in formula-fed infants and the enrichment of potentially pathogenic bacteria are concerning."
Oct 22 Am J Clin Nutr abstract

CDC confirms aromatherapy spray as source of melioidosis

The Centers for Disease Control and Prevention (CDC) confirmed yesterday that bacteria in aromatherapy spray found in the home of a Georgia melioidosis patient genetically matches the bacterial strain that caused the patient's infection and three other infections.

The agency announced late last week that a bottle of Better Homes & Gardens aromatherapy spray—Lavender & Chamomile Essential Oil Infused Aromatherapy Room Spray with Gemstones—found in the home of the Georgia patient had tested positive for Burkholderia pseudomallei, the bacteria that causes melioidosis. But they had not determined at that point that the genetic fingerprints of the bacteria in the spray matched those in the patient or the three other melioidosis patients in Minnesota, Kansas, and Texas—two of whom died.

The genomic testing results enable the CDC to confirm that the spray or one of its ingredients caused the four melioidosis infections, which are extremely rare in the United States.

"When you think about the thousands of things people come in contact with around their homes, it's remarkable we were able to identify the source and confirm it in the lab," Inger Damon, MD, PhD, director of CDC's Division of High-Consequence Pathogens and Pathology, said in a CDC press release. "CDC scientists and our partners found the proverbial needle in the haystack."

The CDC says that its scientists are working to confirm the extent of contamination in other bottles and whether other scents of the spray may also be contaminated. The agency also says that anyone who has a bottle of the spray, which is made in India but sold at 55 Walmart stores and on the Walmart website, should not pour the contents down the drain or throw the bottle in the trash but should stop using it immediately, double-bag and box it, and return it to Walmart.
Oct 26 CDC press release
Oct 22 CIDRAP News scan

H5N6 avian flu hospitalizes another person in China

In a steady stream of H5N6 avian flu infections in China, the country reported its 25th case of the year, the Hong Kong Centre for Health Protection (CHP) said in a statement today.

The latest patient is a 66-year-old man who works as a farmer in Yongzhou, a city in the southern Hunan province. An investigation revealed he had contact with domestic poultry before he got sick.

His symptoms began on Sep 25, and he was admitted to the hospital on Sep 27, where he is listed in critical condition.

Since 2014 when the first human cases were detected in China, the country has reported 49 cases. H5N6 is known to circulate in poultry, primarily in Asian countries. So far human cases, which are often severe or fatal, have only been reported from China and Laos.
Oct 27 CHP statement

H5N1 avian flu outbreaks strike birds in Germany, Denmark

Germany and Denmark reported highly pathogenic H5N1 avian flu in poultry in wild birds, as UK officials warned that the virus is spreading through migration routes and could lead to more winter activity.

In notifications from the World Organization for Animal Health, Germany reported an H5N1 outbreak at a goose farm in the far north Schleswig-Holstein state that began on Oct 21, killing 10 of 663 birds. It also reported two outbreaks involving waterfowl, one in Lower Saxony state and the other in Bavaria state.

Elsewhere, Denmark reported two H5N1 outbreaks, which affected two separate locations in the Southern Denmark region.

In a related development, the UK Department for Environment, Food, and Agriculture (DEFRA) yesterday posted one of its regular risk assessments for highly pathogenic avian influenza and said the spread of H5N1 along bird migration paths could portend wider spread in the coming months. Genetic characterization of the virus is needed to assess if it marks a new incursion or is related to outbreaks last winter that involved many different H5 subtypes, the department adds.

The risk assessment also detailed events since the middle of September, which included outbreaks in turkeys in Italy, game birds in Finland, and backyard and village birds in Russia and Ukraine. A number of European countries have reported recent detections in wild birds as well. While DERFA raised the risk of spread via wild birds from low to medium, it said the overall risk of poultry and captive bird exposure is still low.
Oct 25 OIE report on H5N1 in German poultry
Oct 25 OIE reports on H5N1 in German wild birds (Lower Saxony, Bavaria)
Oct 26 OIE report on H5N1 in Denmark
Oct 26 UK DEFRA statement

COVID-19 Scan for Oct 27, 2021

News brief

COVID-mitigating behavior didn't change after vaccination, study says

COVID-mitigating behavior such as physical distancing and mask use didn't change after receipt of vaccination prior to government exemptions, according to a research letter published yesterday in JAMA Network Open.

The researchers looked at the self-reported behaviors of 80,305 people who were fully vaccinated, partially vaccinated, or not vaccinated at all from Feb 23 to Jun 1. Respondents were from Canada, Denmark, France, Germany, Israel, Italy, Norway, Singapore, Spain, Sweden, the United Kingdom, and the United States, of whom 51.8% were women. The mean age was 47.8 years.

Regression modeling showed no difference in physical distancing between those with one or no vaccination dose across country and region matching (βs = –0.02 and –0.02, respectively). The models showed a difference among those who received two doses compared with those who had fewer, however. Those who were fully vaccinated physically distanced less than respondents with one dose (significant β for country matching [–0.08] but not region matching) and those who hadn't received any dose (βs = –0.07 for country matching and –0.12 for region matching).

No significant differences were seen regarding mask use in the aggregated sample.

The researchers note that when President Joe Biden said fully vaccinated adults didn't need to wear masks or physically distance, behavior still followed the same patterns.

"Despite occasional significant results, all of small magnitude, overall, this cross-sectional study found no substantial reduction in physical distancing or mask use associated with receipt of COVID-19 vaccine doses," write the researchers. "This suggests that until early June, people generally did not engage in concerning levels of risk compensation as they acquired immunity."
Oct 26 JAMA Netw Open research letter

Facemask ventilation in surgery may not be aerosol-generating procedure

Facemask ventilation of patients during routine surgery should not be considered an aerosol-generating procedure, according to a study published yesterday in Anaesthesia. If facemask ventilation lost this designation, it would not require extra personal protective equipment nor the sometimes half-hour delay between surgeries while the operating theater's air is ventilated.

The researchers compared 11 UK patients' aerosol generation during 60 seconds of tidal breathing and three coughs with aerosol generation during facemask ventilation with and without a deliberate leak. Breathing or coughing had a median of 191 particles per liter, while facemask ventilation with a leak produced 3 particles per liter, an almost 64-fold difference.

When the procedure included a deliberate facemask leak, aerosol generation was 17 times lower than normal breathing or coughing, at 11 particles per liter. Furthermore, coughing produced 1,260 particles per liter, while peak levels for regular facemask ventilation with or without an international leak were 120 and 60 particles per liter, respectively.

"The low concentration of aerosol detected during facemask ventilation with an intentional leak is also reassuring given that this represents a worst-case scenario," write the researchers. "On the basis of this evidence, we argue facemask ventilation should not be considered an aerosol-generating procedure," write the researchers.

In a press release by the Association of Anaesthetists of Great Britain and Ireland (AAGBI), its president Mike Nathanson, MBBS, MRCP, FRCA, added, "As we enter another winter, and with a high prevalence of Covid, the backlog of surgical cases is increasing. Anaesthetists will wish to carry on working for as many of their patients as possible. As the authors suggest, this research will inform the debate on how we can work safely."

The cohort consisted of six women and five men who had a mean age of 60.0 years and an average body mass index of 27.1 kilograms per square meter.
Oct 26 Anaesthesia study
Oct 26 AAGBI press release