News Scan for Sep 14, 2021

News brief

Review finds elevated rates of antibiotic resistance in aquatic animals

A review and meta-analysis of point-prevalence surveys conducted in Asia over the past two decades found concerning levels of resistance to first-line and last-resort antibiotics in foodborne pathogens isolated from aquatic animals, researchers reported late last week in Nature Communications.

The systematic review identified 749 point-prevalence surveys reporting antimicrobial resistance (AMR) in aquatic food animals (fish and shrimp) in Asia published from 2000 to 2019, a period that saw substantial growth in aquaculture. From 2000 to 2018, the percentage of antimicrobial compounds with resistance exceeding 50% (P50) in each survey plateaued at 33% in cultured aquatic animals and declined from 52% to 22% in wild-caught aquatic animals. The study authors suggest the decline in wild-caught aquatic animals could be associated with reduced exposure to human and livestock fecal pollution.

Among the foodborne pathogens isolated (Escherichia coli, Vibrio spp, Aeromonas spp, and Streptococcus spp), resistance was highest to penicillins (60.4%), macrolides (34.2%), sulfonamides (32.9%), and tetracyclines (21.5%). In Vibrio and Aeromonas species, resistance to colistin was 42.7% and 51.5%, respectively; carbapenem resistance in Vibrio climbed from 5.1% before 2010 to 51.1% after 2010.

Predicted hot spots of multidrug resistance in freshwater environments, based on geospatial modeling, included eastern Turkey, southern India, the Yangtze River in China, and the lower reaches of the Mekong River and its delta in southern Cambodia and Vietnam. In marine environments, the highest rates of AMR were identified in northeastern China on the Yellow and East China seas; southern China and Central Vietnam on the South China Sea; southern India on the Arabian Sea and the Bay of Bengal between southern India and northern Sri Lanka; and the eastern Mediterranean Sea on the coast of Lebanon.

"This study identified elevated rates of antimicrobial resistance in bacteria isolated from aquatic animals intended for human consumption in Asia," the authors wrote. "A growing aquatic food animal production industry may serve as an important pathway for transmission of resistance along the food chain with potential consequences for human health."

The authors say their findings could help direct the prioritization of future surveillance efforts and inform planning for the sustainable development of the aquaculture industry.
Sep 10 Nat Commun study

Research: CWD has spread fivefold in Kansas in 11 years

Researchers at the University of Missouri have found that chronic wasting disease (CWD) has spread fivefold among Kansas counties, expanding from 6 counties in 2009 to 32 counties with confirmed positive cases in 2020.

The information came from the University of Missouri's Veterinary Medical Diagnostic Laboratory, which analyzed more than 1,900 samples from 2020’s deer hunting season. Those samples identified CWD in seven eastern Kansas counties where the disease was previously undetected.

The spread has several researchers and officials concerned. Students and professors at the University of Missouri said they will continue to sample deer across the state and test for CWD and solicit samples from taxidermists, wildlife biologists, game wardens, and individual hunters who collect and send the lymph nodes of hunted deer to the university.

"This project not only helps us track the spread of the disease, it also helps raise awareness for hunters because we want them and their families to stay as safe as possible," said Zoe Koestel, a doctoral student, in a university press release. "Hunters are the world's original conservationists, and they often ask how they can help our efforts. The more samples we receive from hunters, the better we can track the spread of chronic wasting disease."

CWD is a deadly prion disease that affects cervids. It was first identified in North America in 1967 and has since spread across much of the United States and Canada. Though no humans have confirmed CWD infections related to consuming infected animals, some experts fear CWD could follow the trajectory of bovine spongiform encephalopathy, or mad cow disease.
Sep 13 University of Missouri press release

Measles cases prompt pause in Afghan refugee arrivals

After four measles cases were detected in evacuated Afghans who recently arrived in the United States, inbound refugee flights will be paused for at least until Sep 20, White House officials said yesterday, according to CNBC.

At press briefings yesterday, officials said those infected with measles will be housed separately and that the Centers for Disease Control and Prevention (CDC) is conducting contact tracing. They also added that the refugees from Afghanistan will be soon be given critical immunizations, including those against measles, mumps, and rubella (MMR), while they are overseas and awaiting transfer to other countries.

The United States expects to admit about 65,000 refugees through Operation Allies Welcome. All are required to be vaccinated against measles as an entry condition.

Measles is highly contagious, and infected people can spread the virus from 4 days before the rash appears. In 2019, the United States reported 1,282 cases, with outbreaks reported in pockets of undervaccinated people that were triggered by those who contracted the virus in foreign countries. COVID-19 measures and the impacts on surveillance resulted in few numbers of known cases. So far this year, the United States has reported only two cases.
Sep 13 CNBC story
CDC measles background

COVID-19 Scan for Sep 14, 2021

News brief

Severe COVID linked to more self-attacking antibodies, study says

Hospitalized COVID-19 patients were more likely to have autoantibodies, or self-attacking antibodies, than those without COVID-19, according to a study today in Nature Communications.

The researchers looked at March and April 2020 blood samples from 147 COVID-19 patients at Stanford-affiliated hospitals, as well as 48 patients from Kaiser Permanente in California, although most of the study's assessments didn't involve the whole cohort.

By using three protein arrays to look at immunoglobulin G (IgG) autoantibodies, the researchers found that about 50% of patients had autoantibodies, compared with less than 15% of samples from healthy controls collected pre-pandemic from donors. Longitudinal analysis from 48 patients also showed that about 20% of patients had new autoantibodies within a week of COVID-19 hospitalization.

Data indicated that antibodies recognizing nonstructural COVID-19 proteins were positively correlated with autoantibodies and that autoantibodies were produced out of proportion to the total IgG serum concentration. Also, in most people, only a small number of autoantigens were targeted.

Some of the autoantibodies have also been seen in relatively rare connective tissue diseases and are not typically measured. Others were anti-cytokine antibodies (ACAs) that the researchers say may have been triggered by SARS-CoV-2 infection or an inflammatory immune response to it; about 60% to 80% of the cohort had at least one ACA.

"It's possible that, in the course of a poorly controlled SARS-CoV-2 infection—in which the virus hangs around for too long while an intensifying immune response continues to break viral particles into pieces—the immune system sees bits and pieces of the virus that it hadn't previously seen," said senior author PJ Utz, MD, in a Stanford Medicine press release. "If any of these viral pieces too closely resemble one of our own proteins, this could trigger autoantibody production."

Vaccinations, he adds, cause significantly less inflammation in patients than SARS-CoV-2 infection.
Sep 14 Nat Commun study
Sep 14 Stanford press release

Gabon may have had lower COVID-19 severity, analysis suggests

An analysis of the single hospital treating COVID-19 patients in Gabon showed that from March to June 2020, 62.6% of patients were asymptomatic, 33.7% had mild symptoms, and 3.7% had severe illness, according to a study today in JAMA Network Open. The mortality rate was 1.4%.

By the end of the study period, the researchers say 3,463 patients in the country had COVID-19, but the study consisted only of the 837 admitted to the Armed Forces Hospital in Libreville, Gabon. Most (68.3%) were men, and the median age was 35 years. COVID-19 severity was associated with older age (mean age 46.1 years vs 41.3, but 35.7 years in mild and asymptomatic cases). Diabetes was also seen more frequently in patients with severe COVID-19 (16.1% of 31), compared with patients with mild (3.9% of 282) or asymptomatic illness (0.9% of 524).

Flu-like symptoms were more common in patients with mild symptoms (20.2%) than in patients with severe symptoms (0%) or those who were asymptomatic (0%). Also, while there was no significant difference between men's and women's advanced thoracic computed tomography scores for stages I to III, men were more likely to have a stage IV score than women (6.7% of 193 vs 1.0% of 196; odds ratio, 6.9).

The researchers suggest that the lower rates of severe illness may be due to the country's smaller number of older and more vulnerable people. However, as a related commentary by Igho Ofotokun, MD, and Anandi N. Sheth, MD, points out, these findings must be taken into context with its early timeframe in the pandemic, the country's limited COVID-19 testing, and the study's single-site design.

"The silver lining in this report and the African COVID-19 experience is that the window of opportunity still exists to protect one of the most vulnerable regions of the world from the catastrophes of this pandemic through massive and rapid vaccination," Ofotokun and Sheth conclude.
Sep 14 JAMA Netw Open study and commentary