Stewardship / Resistance Scan for Mar 17, 2021

News brief

Indian scientists isolate Candida auris in the environment

A team of Indian scientists yesterday reported the detection of Candida auris isolates from two sampling sites on islands in the Indian Ocean—the first time the multidrug-resistant yeast has been isolated in a natural environment. The discovery was reported in mBio.

Since it was first identified in a Japanese patient in 2009, C auris has spread to hospitals around the world, and has been declared an urgent health threat by the US Centers for Disease Control and Prevention. Because the yeast is capable of growing at higher temperatures and can tolerate hypersaline environments more than other Candida species, scientists in recent years have hypothesized that it may have existed in wetlands before becoming a clinically relevant pathogen, and that its emergence could be linked to global warming's effects on wetlands.

To further explore this hypothesis, scientists from the University of Delhi collected 48 samples of sediment and seawater from coastal wetlands, sandy beaches, tidal marshes, and mangrove swamps around the Andaman Islands in the Bay of Bengal. The climate of these islands is tropical, with hot and humid conditions.

The team isolated C auris from samples at two sites, with two isolates found in a salt marsh wetland and 22 on a sandy beach. Antifungal susceptibility testing showed that one of the salt marsh isolates and all 22 from the beach—which was high in human activity—were multidrug resistant. Whole-genome sequencing revealed that the isolates were genetically distinct from C auris isolates from Indian hospitals but broadly related to clade 1, which includes isolates from South Asia.

"The isolation of C. auris from this natural environment is noteworthy considering that until now this yeast has not been identified outside hospital environmental settings," the authors wrote.

They add that the significance of the discovery, its connection to human infections, and whether the pathogen exists in other ecological niches, need to be further explored.
Mar 16 mBio study


VA study links contact precautions with reduced MRSA transmission

Department of Veterans Affairs (VA) hospitals that conducted contact precautions for patients with methicillin-resistant Staphylococcus aureus (MRSA) had a nearly 50% reduction in MRSA transmission, researchers reported this week in JAMA Network Open.

In the study, researchers from the VA Salt Lake City Health Care System and the University of Utah School of Medicine applied mathematical models to data from patients admitted to VA acute care hospitals from January 2008 through December 2017 to determine whether contact precautions for MRSA carriers had any impact on patient-to-patient transmission. Contact precautions, which involve the use of gloves and gowns by healthcare staff when interacting with MRSA carriers and their environment, are one element of the MRSA Prevention Initiative introduced by the VA in 2007, but their effectiveness has been questioned. Other elements include surveillance and hand hygiene.

The cohort included 108 hospitals with more than 2 million unique patients, and over the study's duration, they had more than 5.6 million admissions and 8.4 million MRSA surveillance tests (9.3% positive). Among all admissions, 14.1% required contact precautions during their stay based on a positive MRSA test result. Pooled estimates found associations between contact precautions and transmission to be stable from 2008 through 2017, with estimated transmission reductions ranging from 43% (95% credible interval [CrI], 38% to 48%) to 51% (95% CrI, 46% to 55%). Over the entire 10-year study period, contact precautions reduced transmission by 47% (95% CrI, 45% to 49%).

Larger hospitals and those with higher admission screening compliance saw additional reductions in transmission associated with contact precautions compared with smaller hospitals with lower screening compliance. VA hospitals in the southern states saw less transmission reduction linked to contact precautions compared with facilities in other regions.

The study authors say the results provide an explanation for the decline in MRSA acquisition rates in VA hospitals since the MRSA Prevention Initiative began.
Mar 15 JAMA Netw Open study

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News Scan for Mar 17, 2021

News brief

Race, Medicaid status tied to higher COVID-19 rates in US nursing homes

Among 3,008 US nursing homes in counties in the top quartile of COVID-19 prevalence, those with larger proportions of racial minority residents, Medicaid participants, and fewer direct patient care hours experienced more coronavirus infections amid the pandemic, according to a research letter published yesterday in JAMA Network Open.

The study, led by researchers from the University of Pennsylvania in Philadelphia, involved analysis of data from the Centers for Medicare & Medicaid Services (CMS) Nursing Home COVID-19 Public File, the 2017 Long-term Care: Facts on Care in the US database, the USAFacts website, and the 2017 American Community Survey.

The 752 nursing homes in the highest quartile of COVID-19 prevalence had, on average, 677.1 coronavirus cases per 1,000 residents, in contrast with 6.7 cases per 1,000 residents in the 755 homes in the lowest quartile.

Adjusted estimates showed that residents of nursing homes with higher numbers of COVID-19 cases were older, had higher activities of daily living scores, and were less likely to be White and more likely to have Medicaid coverage. The homes had lower occupancy rates and fewer direct patient care hours per day and were more likely to employ an advanced practitioner than those with fewer cases.

The nursing homes had a total of 255,923 residents with a mean age of 78.4 years. Of all residents, 64.7% were women, and 61.8% had Medicaid insurance.

"These data sets represent the most comprehensive accounting of [nursing home] COVID-19 cases and characteristics available as of October 11, 2020," the authors wrote. "Interventions such as increasing staff support and directing more resources toward [nursing homes] with disproportionate shares of racial minorities and Medicaid participants may reduce disparities in COVID-19 morbidity among [nursing home] residents."
Mar 16 JAMA Netw Open research letter


Less COVID death seen in wealthier parts of Europe, United States

COVID-19 mortality rates have decreased during the pandemic's second wave in most western European countries and the northeastern United States, according to a study published yesterday in Chaos. The analysis points out similarities between the two regions, such as their high case numbers (and subsequent lockdowns) during the first wave and their wealthier and more developed statuses. However, the researchers acknowledge that an underreporting of cases or a higher number of elderly deaths during the first wave could have affected the results.

Using time series- and algorithm-based mathematics, the researchers looked at the ratio of mortality and case numbers between the two COVID waves, excluding Russian and the See of Rome. Overall, the average case number ratio between the first and second waves was 7.39 for entities with a significantly improved second-wave mortality rate, while those who did not significantly improve had a rate ratio of 2.94.

In Europe, countries with at least 10-fold reductions in mortality were the Netherlands (16.17), Denmark (14.25), France (13.67), and Belgium (11.25), which supports the researchers' correlations with development level and wealth. The two notable exceptions to this were Sweden and Germany, with a 3.6 and 3.8 mortality rate ratio, respectively. Only Belarus experienced more mortality, with a rate ratio of 0.72, but other less developed European countries such as Romania also showed less improvement.

As for the United States, much of the wealthier northeastern states had better mortality rates. For instance, Vermont had the highest mortality rate change at 9.17, and New Jersey (8.23), New York (7.41), and Connecticut (6.67) had the next highest mortality rate reductions. Arkansas (mortality rate ratio, 0.69) and Tennessee (0.88) were the two states that have exhibited worse mortality rates during the second COVID-19 wave.

"While similarity exists between Western European countries and Northeastern U.S. states, there is no such close relationship between other European countries, such as less developed Eastern European countries, and other U.S. states outside the northeast," the researchers note.
Mar 16 Chaos study


Household income associated with COVID-19 risk, hospitalization

Household income was the most associated with COVID-19 risk and hospitalization when compared with population density and household size, according to a study published this week in the Annals of the American Thoracic Society. While it has been well documented that the COVID-19 burden is higher in minorities, the researchers wanted to look at some of the socioeconomic factors that may be driving this.

In two retrospective cohorts, the researchers looked at 15,473 adults tested for COVID-19 from Mar 1 through Jul 23, 2020, at University of Miami hospitals and clinics. Overall, 8.1% were positive, and 1.9% were hospitalized, leading to 47 deaths. While the researchers did not find any racial or ethnic associations with mortality or ventilation needs, they did find correlation with infection and hospitalization rates.

After adjustment, Black people were 2.55 times more likely to get infected than non-Hispanic White people (95% confidence interval [CI], 2.05 to 3.17); Hispanic Black, 2.25 (95% CI, 2.21 to 7.93); Hispanic White, 2.04 (95% CI, 1.69 to 2.45). Similarly, COVID-infected minorities were at greater hospitalization risk when compared with non-Hispanic White people, ranging from 3.81-fold (95% CI, 2.84 to 5.21, Hispanic White) to 4.74 (95% CI, 3.38 to 6.76, Black).

This cohort was stratified across median household income, median household size, and population density, which were linked to 27%, 20%, and 17% of the positive COVID-19 diagnoses, respectively. Although the data do not prove causality, the researchers write that improving socioeconomic factors could plausibly alleviate burden.

"We found that all three socioeconomic factors were associated with higher odds of test positivity, regardless of race or ethnicity," lead author Hayley Gershengorn, MD, said in an American Thoracic Society press release. "For example, after accounting for other differences, individuals of all races and ethnicities living in the highest population density neighborhoods had 2.5-fold higher odds of test positivity than those living in areas with the lowest population density."

The study adds, "Even if too late for COVID-19, improvements in the social situation of all patients living in more crowded, less well-off communities may pay dividends for their health when the next pandemic, or the next season of influenza, hits [particularly with similarly transmitted diseases]."
Mar 15 Ann Am Thorac Soc study
Mar 17 American Thoracic Society press release


H5N8 avian flu detected in seals and fox at UK wildlife refuge

Veterinary officials in the United Kingdom reported highly pathogenic H5N8 avia influenza in seals and a fox that died at a wildlife rescue center in Runnymede district in Surrey county, where mute swans died from the virus in November, according to a notification from the World Organization for Animal Health (OIE).

The examination of the five seals and one fox, done after postmortem evaluation, found lesions that suggested systemic viral infection. Testing found H5N8, and genetic sequencing found that the virus was nearly identical to that from the dead mute swans from the facility.

Coexisting conditions in the seals and fox weren't investigated, and it's possible that other factors influenced disease severity, the report said.

H5N8 has been detected in seals before. In December 2019, researchers described the detection of the virus in lung samples from gray seals stranded off the Baltic coast of Poland in 2016 and 2017. The virus was closely related to H5N8 circulating in European birds at the time.
Mar 15 OIE report on H5N8 in the UK
Dec 2019 Emerg Infect Dis report

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