The South Dakota Department of Agriculture and Natural Resources (DANR) and the state's Animal Industry Board today announced that tests have confirmed highly pathogenic avian influenza (HPAI) in a South Dakota dairy herd, a first for the state.

Testing was done by the US Department of Agriculture (USDA) National Veterinary Services Laboratory in Ames, Iowa. The detection in South Dakota dairy cows raises the number of affected states to eight and comes 1 day after animal health officials in North Carolina announced that state's first HPAI detection in dairy cows.

Marv Post, chairman of South Dakota Dairy Producers, said, "South Dakota Dairy Producers encourage all dairy producers to closely monitor their herd and contact their herd veterinarian immediately if cattle appear symptomatic." He added that the USDA continues to emphasize that pasteurization kills viruses and that milk and dairy products are safe to consume.

Similar to the North Carolina announcement, South Dakota officials did not say if the affected herd had received cows from an earlier-affected state.

A study of patients who developed infections after spinal surgery found that for most, the bacteria causing the infection was present on their skin before surgery, researchers reported yesterday in Science Translational Medicine.

The study, conducted by researchers at the University of Washington School of Medicine, examined 210 adult patients undergoing spinal fusion. The researchers wanted to explore why surgical site infections (SSIs), which occur in roughly 1 in 30 surgical procedures, have not significantly declined despite adherence to infection-prevention measures like environmental cleaning and sterile processing. To get a better understanding of where the bacteria causing SSIs might originate, they combined multiple forms of genomic analysis to compare preoperative patient microbiomes with postoperative SSI isolates.

Of the 210 patients studied, SSI developed in 14 (6.8%), and preoperative nasal, rectal, and skin specimens were obtained from 204 (97.1%). Skin swabs were collected on the day of surgery from the region directly overlying the planned incision area. Whole-genome sequencing analysis of 22 SSI isolates found that 19 (86%) were genomically similar to a bacterial strain present in one or more preoperative patient samples. 

Furthermore, when the researchers analyzed an additional 59 SSIs that occurred in patients who underwent surgery in the same environment during the study period, they found that none of the SSIs were caused by a common bacterial strain.

"This finding indicates that spine SSIs in our population were not caused by exogenous strains originating from shared reservoirs within the hospital environment at any measurable frequency," the study authors wrote.

Implications for infection-prevention strategy

The analysis also found that 59% of SSI isolates were resistant to the prophylactic (preventive) antibiotic administered before surgery, and their resistance phenotypes correlated with the patient's preoperative resistome.

The authors say the findings and methodologic framework carry practical implications for SSI prevention strategies.

"If these findings are replicated in other procedural cohorts, this model of SSI pathogenesis could drive important shifts in infection prevention strategy and enable more individualized and patient-centered approaches," they wrote.

Carbapenem-resistant and difficult-to-treat (DTR) gram-negative priority pathogens are increasing in most regions of the world, according to an analysis of global surveillance data published yesterday in the Journal of Global Antimicrobial Resistance.

Using isolates collected by the Antimicrobial Testing Leadership and Surveillance (ATLAS) global surveillance program from 157 medical centers in 49 countries from 2018 to 2022, an international team of researchers conducted antimicrobial susceptibility testing on 79,214 Enterobacterales, 30,504 Pseudomonas aeruginosa, and 13,500 Acinetobacter baumannii-calcoaceticus complex isolates, which are all on the World Health Organization's list of critical priority pathogens. 

They focused on carbapenem resistance and the DTR phenotype, defined as non-susceptibility to all first-line antibiotics used to treat serious infections.

Percentages of carbapenem-resistant Enterobacterales (CRE) resistance increased in the Asia Pacific, Europe, Latin America, Middle East-Africa regions but declined in North America, while annual DTR percentages increased in all five regions. Rates of carbapenem-resistant P aeruginosa (CRPA) and carbapenem-resistant A baumannii-calcoaceticus complex (CRAB) remained stable across all regions, but rates of CRAB and DTR A baumannii-calcoaceticus complex were consistently more than 25 percentage points lower in North America.

Analysis of countries from each region found significant and consistent increases in CRE (10.3% in 2018 to 35.6% in 2022) and CRPA (16.5% to 55.6%) in Brazil, high CRAB rates (more than 84% each year), and increasing detection of CRE (4.4% to 15.4%) in South Africa. For all regions except North America, most changes in CRE rates could be attributed to hospital-acquired infections.

'Decisive action' needed

The study authors say that while the findings may have been influenced by the COVID-19 pandemic, which saw increased inappropriate antibiotic use and disruption of infection prevention and control (IPC) measures, the global increase in gram-negative antimicrobial resistance indicates that current antimicrobial stewardship and IPC initiatives aren't getting the job done.

"Decisive action is needed to prevent and control the spread of antimicrobial-resistant pathogens," they wrote. "All initiatives to curb antimicrobial resistance must be supported by continued surveillance at local, national, regional, and global levels."

Chronic wasting disease (CWD) has been confirmed in Jefferson County, West Virginia, for the first time, according to a West Virginia Division of Natural Resources (WVDNR) news release.

Four white-tailed deer tested positive for the fatal neurodegenerative disease. Jefferson County, the easternmost county in the state, is the first previously unaffected West Virginia County to detect CWD since 2018. Cases have also been identified in Berkeley, Mineral, Morgan, and Hampshire counties.

"Jefferson County has been part of the CWD containment area for several years because it lies adjacent to CWD-positive counties in West Virginia, Virginia and Maryland," Paul Johansen, MS, WVDNR Wildlife Resources Section chief, said in the release. "While there is no evidence that CWD is harmful to humans, it is important that hunters abide by the carcass transport regulations to ensure the proper wildlife management and reduce risk factors that may affect our deer population."

The WVDNR has placed restrictions on baiting and feeding deer and on transporting high-risk carcass parts from the CWD containment area. 

Ongoing threat to cervids

Found in deer and other cervids such as moose and elk, the infectious illness is caused by misfolded proteins known as prions. The disease poses an ongoing threat to cervids, given that CWD can spread from animal to animal and through environmental contamination. No human cases have been reported, but health officials urge people to avoid eating the meat of infected animals and to take precautions when field-dressing or butchering cervids.