COVID-19 Scan for Feb 10, 2021

News brief

COVID associated with more hospitalizations, ICU care, mortality than flu

Hospitalized adults with COVID-19 are 3.5 times more likely to die than adults with the flu, reports a study today in CMAJ. The study also found that those with COVID were 1.5 times more likely to be admitted to the intensive care unit (ICU) and have 1.5 times longer hospital stays.

The researchers collected data from seven hospitals in Toronto and Mississauga in Canada and found that, from November 2019 through June 2020, 763 patients were admitted 783 times with the flu and 972 patients were admitted 1,027 times with COVID-19—the latter making up 23.5% of all hospitalizations during the study's duration.

Unadjusted in-hospital mortality for COVID and flu patients was 19.9% and 6.1%, respectively, and COVID patients similarly had higher rates of ICU admittance (26.4% vs 18.0%) and longer hospital stays (8.7 vs 4.8 median days). The adjusted relative risk for COVID patients was 3.46 for death, 1.50 for ICU use, and 1.45 for length of hospital stay.

Thirty-day readmission was not significantly different between COVID and flu patients at 9.3% and 9.6%, respectively.

More than 1 in 5 COVID hospital admissions (21.2%) were for adults younger than 50; this group made up 24.0% of COVID ICU admissions and almost 1 in 10 COVID readmissions, according to a CMAJ press release. In general, those with COVID were more likely to have no comorbidities (54.1% vs 38.8%) and reside in long-term care (11.7% vs 4.5%) than those with the flu. Lower-income residents made up disproportionately high percentages of hospital patients for both illnesses (34.2% vs 31.7%).

"These differences may be magnified by low levels of immunity to the novel coronavirus compared with seasonal influenza, which results from past infections and vaccination," said first author Amol Verma, MD, in the release. "Hopefully, the severity of COVID-19 will decrease over time as people are vaccinated against the virus and more effective treatments are identified. There is, unfortunately, also the possibility that variants of the virus could be even more severe."
Feb 10 CMAJ study
Feb 10 CMAJ press release


Fluid dynamics highlight role of air conditioning in indoor COVID spread

Computational fluid dynamics can help assess transmission risk of airborne COVID-19 particles, according to a study published yesterday in Physics of Fluids. The researchers, from the University of Minnesota, found that their modeling of a January 2020 COVID outbreak in a restaurant in Guangzhou, China, supports the idea that air conditioning contributed to disease transmission.

After mapping out the general layout of the restaurant, its ventilation systems, and its occupants, the researchers discerned that the cyclical flow of air from the four heating, ventilation, and air conditioning (HVAC) units along the wall was disrupted by factors including hemispherical hot regions above each table due to food heat, the restaurant's occupants, and the presence of a fifth, floor-level HVAC unit on the adjacent wall.

Recirculation zones were found throughout the restaurant, such as one above one table created by the interaction between the walls and ceiling, the table, and the thermal differences between empty space and occupied space. Additionally, they found that particles from the HVAC units were projected laterally from the unit before sinking down to be carried by currents underneath the tables before being sucked up vertically into the units again.

"Our work highlights the need for more preventive measures, such as shielding more properly underneath the table and improving the filtration efficiency of air conditioners," senior author Jiarong Hong, PhD, said in an American Institute of Physics (AIP) press release.

Based on their results, the researchers write, "Aerosols can contribute as high as 30% to the total infection risk in some ventilation and thermal settings."
Feb 9 Phys Fluids study
Feb 9 AIP
press release


COVID-19 aerosol load associated with infection, age, obesity

The number of COVID-19 aerosol droplets a person exhales is positively associated with infection, age, and obesity, finds an observational study published yesterday in the Proceedings of the National Academy of Sciences.

The researchers looked at 194 healthy people to measure general aerosol rates as well as 8 COVID-infected nonhuman primates (NHPs) to look at how infection progression affected aerosol quantity and size. Human participants were asked to spend up to 30 minutes per session breathing into a mouthpiece connected to a particle detector.

The NHPs (rhesus macaques and African green monkeys) were infected with SARS-CoV-2, the virus that causes COVID-19, and the researchers collected biosamples from them and had them breathe into a modified pediatric face mask connected to a particle counter.

Among the human group, which consisted of 74 food workers in North Carolina and 120 students, staff, and faculty at a community college in Michigan, aerosol creation appeared to follow the 20:80 superspreader rule, with 35 exhaling 80% of the aerosols. The researchers write that aging, diet, and lung quality are all accepted factors of mucus composition. They found that the 73 people with the lowest BMI-years (age multiplied by BMI, or body mass index) exhaled less aerosol compared with the 73 with the highest BMI-years.  

The NHP portion of the study indicated that aerosol production followed SARS-CoV-2 viral replication patterns by increasing around day 3 post-infection, peaking at about day 7, declining rapidly by day 14, and undetectable by day 27. Aerosol sizes were at their smallest during peak infection.

To assess another respiratory infection, the researchers gave four rhesus macaques tuberculosis and found similar results.

The researchers conclude, "These findings suggest that quantitative assessment and control of exhaled aerosol may be critical to slowing the airborne spread of COVID-19 in the absence of an effective and widely disseminated vaccine."
Feb 10 Proc Natl Acad Sci study

News Scan for Feb 10, 2021

News brief

Antibiotic prescribing in telehealth can be appropriate with guidance, study finds

Telemedicine visits in Brazil performed under rigorous adherence to antibiotic stewardship guidelines were associated with appropriate antibiotic prescribing for patients with low-risk conditions, Brazilian and Australian researchers reported yesterday in the International Journal of Infectious Diseases.

While some studies have suggested that antibiotic prescribing rates for people who consult telemedicine services may be higher than those who have face-to-face visits with providers, most of these studies have not specified the protocols and guidelines accessible to providers or how telemedicine providers should be trained and monitored for antibiotic stewardship.

In this study, researchers assessed antibiotic prescribing at a hospital in Sao Paulo, where all telemedicine providers were required to be trained on international antibiotic stewardship protocols based on the best current evidence, and senior supervisors monitored prescription rates.

The study included all patients 18 and older who sought telemedicine consultations for acute but non-urgent symptoms through the hospital from January 2019 through February 2020. Diseases for which an antibiotic might be required were classified into five diagnostic groups: upper respiratory tract infection (URI), acute pharyngotonsillitis (PT), acute sinusitis (AS), urinary tract infection (UTI), and acute diarrhea (AD).

Of the 2,328 patients included, 2,085 (89.6%) received telemedicine consultations alone, and 243 (10.4%) were referred for face-to-face consultation. Among the telemedicine patients, 472 (22.6%) received an antibiotic. The antibiotic prescribing rates per diagnostic group were 2.5% for URI, 35% for PT, 51.8% for AS, 1.6% for UTI, and 1.6% for AD. In most cases, these prescriptions were in line with international stewardship protocols, and the prescribing rates were low compared with other telemedicine programs, the authors concluded.

"This study shows that using technology and proper antibiotic stewardship may mitigate the apprehension that video visits may lead to a high antibiotic prescription rate," they wrote.
Feb 9 Int J Infect Dis abstract


Macrolide resistance found in 40% of US Strep pneumoniae isolates

A surveillance study published last week in Open Forum Infectious Diseases found macrolide resistance in 40% of Streptococcus pneumoniae isolates from adult ambulatory and inpatient settings in US hospitals.

Using microbiology laboratory data from the BD (Becton, Dickinson and Company) Insights Research Database, researchers evaluated S pneumoniae blood or respiratory cultures with antibiotic susceptibility test results collected at 329 US hospitals from October 2018 through September 2019. The pathogen is the most common bacterial cause of community-acquired pneumonia (CAP), an illness that results in more than 1 million emergency department visits and an estimated 750,000 to 1 million hospitalizations annually.

Isolates with resistance to azithromycin, clarithromycin, or erythromycin were considered macrolide-resistant. The researchers used US Census geographic regions and ZIP code tabulation areas to determine the regional distribution of resistant isolates.

The overall rate of macrolide resistance among 3,626 S pneumoniae isolates analyzed was 39.5%, with a significantly higher resistance rate found in respiratory isolates (47.3%) than in blood isolates (29.6%). Isolates from ambulatory settings had a higher rate of resistance than isolates from inpatients (45.3% vs 37.8%).

Evaluation of regional resistance found the highest rate of macrolide resistance in the West North Central region (54.2%), followed by the South Atlantic (48.0%). Although geographic variations were observed, most regions had overall macrolide resistance rates higher than 25%, and more than 25% of respiratory isolates in all regions were macrolide-resistant.

The authors say the results, along with other recent US or North American studies showing high macrolide resistance in S pneumoniae, may explain recent findings of high failure rates (21%) with macrolide monotherapy in patients with CAP. They say ongoing surveillance efforts are needed to track resistance trends in S pneumoniae and suggest that clinicians in most parts of the country consider alternatives to macrolide monotherapy as empiric therapy for suspected CAP.
Feb 4 Open Forum Infect Dis abstract


Officials confirm 4 more MERS cases in Saudi Arabia, 2 fatal

Saudi Arabia's health ministry reported four new MERS-CoV cases in four areas since the start of the new year, two of which were fatal, according to three recently posted weekly updates.

The first MERS-CoV (Middle East respiratory syndrome coronavirus) case involves a 63-year-old man from the city of Al Ju'ranah in Mecca province in the west. The man died of his infection, initially recorded on Jan 19, and the investigation didn't reveal any contact with camels. The source of the virus is listed as primary, meaning he likely didn't contract the virus from another known case-patient.

Also, the Saudi Ministry of Health (MOH) reported a second fatal case that was initially reported on Feb 2, involving a 48-year-old man from the city of Rabigh, located north of Jeddah in western Saudi Arabia on the Red Sea coast. His exposure is also listed as primary, and no history of contact with camels was found.

The other cases were reported on Feb 7 and Feb 9. The first patient is an 84-year-old man from Riyadh who had contact with camels, and the second is a 46-year-old man from Al Ahsa in eastern Saudi Arabia who also had contact with camels.

Earlier this month, the World Health Organization said in a snapshot of MERS activity in the last half of 2020 that, since 2012, 2,566 cases have been reported in humans, at least 882 of them fatal.
Saudi MOH epi week 3 report
Saudi MOH epi week 5 report
Saudi MOH epi week 6 report
Feb 1 CIDRAP News scan


Lower-dose intradermal flu vaccine possible alternatives to standard shots

A meta-analysis published yesterday in JAMA Network Open suggests reduced-dose intradermal flu vaccines could be a reasonable alternative to standard-dose intramuscular vaccines (the typical flu shot), and could be used as a dose-sparing strategy if needed for seasonal flu vaccination campaigns.

The study reviewed 30 completed studies that included a total of 177,780 participants. The authors found seroconversion rates of low doses of intradermal influenza vaccine compared with the standard intramuscular dose for each of the H1N1, H3N2, and B strains were not statistically significantly different.

"There was no statistically significant difference in seroconversion rates between the 3-µg, 6-µg, 7.5-µg, and 9-µg intradermal vaccine doses and the 15-µg intramuscular vaccine dose for each of the H1N1, H3N2, and B strains, but rates were significantly higher with the 15-µg intradermal dose compared with the 15-µg intramuscular dose for the H1N1 strain," the authors wrote.

The authors said their findings, which reflected vaccine immune response but not protection from contracting influenza, were important in light of the development of COVID-19 vaccines, and suggested intradermal needles could be a useful tool to improve vaccine acceptance.

"The development of novel intradermal vaccine delivery systems, such as self-administrable patches with coated microprojections or biodegradable needles, could potentially improve vaccine acceptance and uptake," the authors concluded.
Feb 9 JAMA Netw Open

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