Studies describe Candida auris outbreaks in COVID-19 patients
Two new studies highlight the threat posed by the multidrug-resistant yeast Candida auris to hospitalized COVID-19 patients.
In a case report today in Morbidity and Mortality Weekly Report (MMWR), investigators with the Centers for Disease Control and Prevention and the Florida Department of Health describe an outbreak of C auris in a COVID-19 specialty care unit of an acute care hospital in Florida.
After the hospital alerted Florida health officials about four C auris infections in the unit in July 2020, staff conducted a unit-wide point-prevalence survey from Aug 4 through Aug 18 to identify additional patients colonized with the pathogen. The results showed that, among 67 patients admitted to the unit, 35 (52%) were positive, and 6 later had clinical cultures that grew C auris.
Eight of the colonized patients died within 30 days of screening, but it’s unclear whether C auris contributed to those deaths.
Investigators concluded that use of multiple layers of gloves and gowns by healthcare workers, and repeated doffing and donning of secondary layers, may have led to contamination of base layers, which in turn could have contributed to C auris transmission. They also suggest lapses in cleaning and disinfection of shared medical equipment, along with lapses in adherence to hand hygiene, may have played a role.
Jan 8 MMWR case report
In the other study, published today in Clinical Microbiology and Infection, researchers in Mexico describe the clinical and microbiologic characteristics of 12 patients with severe COVID-19 and C auris co-infection at a Mexican hospital in August.
All patients were under mechanical ventilation and had peripherally inserted central lines and urinary catheters. C auris was isolated from blood in 6 patients, urine in 8, and from both sites in two 2. Five of the six patients with bloodstream infections died.
Antifungal susceptibility testing revealed that 8 of 15 isolates (12 from patients and 3 environmental isolates) were multidrug-resistant.
The authors of the study say use of multiple antibiotics and central venous catheters may have contributed to C auris co-infection in these patients, but they also suggest that factors specifically associated with COVID-19, such as excessive corticosteroid use, which can have an immunosuppressive effect, might have also contributed to the problem.
Jan 8 Clin Microbiol Infect study
Cats infected with SARS-CoV-2 show immunity, long-term lesions
Nine domestic cats inoculated with SARS-CoV-2, the virus that causes COVID-19, showed lung lesions and other long-term inflammation in the respiratory tract after the virus had cleared from their system, reports an Emerging Infectious Diseases research letter published yesterday. Despite these lingering effects, however, six cats who were re-infected showed protection against the disease.
Previous studies have proved that domestic cats can transmit COVID-19 among themselves, and the researchers similarly found that the virus efficiently replicated in the upper respiratory organs (nasal passages and trachea), showing up in organ and lung samples on days 3 and 6 post-infection but absent by day 10 (detectable levels were 10 plaque-forming units per gram of tissue).
No animal showed symptoms of respiratory illness during the entire process, but three cats who were euthanized postinfection day 28 showed persistent lung lesions that shared characteristics with chronic peribronchiolar fibrosis (scarring) and vascular proliferation. One cat had severe pneumonia, as well.
Even with these long-term effects, SARS-CoV-2 infection appeared to give cats at least some level of protection against reinfection. When the researchers re-infected the six remaining cats about 4 weeks after the initial infection, they found that those euthanized 3 days after reinfection didn’t have any detectable SARS-CoV-2 in their organs or lungs. Cats euthanized 21 days after reinfection had lung lesions comparable to those observed from the first cohort of cats, but the alveolar septa suffered less thickening.
“Because SARS-CoV-2 did not cause acute lethal respiratory disease in the cats in our study, cats are a compelling animal model for studying the long-term effects of nonfatal infections,” write the researchers. “These results suggest that virus infection by natural transmission between cats, as well as by experimental inoculation, induces protective immunity against a second SARS-CoV-2 infection.”
Jan 7 Emerg Infect Dis research letter
Black populations lack COVID-19 testing, study finds
To have an equitable COVID-19 testing strategy in seven counties around St. Louis, 30.4% of tests would have to be reallocated, according to a research letter published today in JAMA Open Network. The researchers defined equitable testing as “the balance between the number of tests and the actual disease burden,” but only 22.9% of COVID-19 tests took place in the 23 zip codes that held 50% of the region’s hospitalizations.
Almost three quarters of these zip codes (73.9%) had a population of at least 50% blacks. Even with the same zip code, black residents had consistently lower rates of tests per hospitalization compared with their white neighbors.
The researchers collected data from Mar 14 through Aug 10 and used an adapted Lorenz curve to measure the number of tests, the disease burden, and a color-coded line that varied depending on the racial makeup of a particular zip code. During the study period, 404,904 COVID-19 tests and 4,059 hospitalizations took place in the region, which has a total population of 2,149,222.
“Equitable testing is paramount to a successful COVID-19 response and is essential for early case detection, self-isolation, and overall prevention of onward transmission,” the researchers write. “Lorenz curves provide straightforward metrics that can also be easily tracked over time to quantify these disparities.”
Jan 8 JAMA Netw Open research letter