Church pastor tied to COVID-19 super-spreader events in Arkansas
Church events held between Mar 6 and 11 at an Arkansas church—where the pastor and his wife were positive for COVID-19 and showing symptoms—led to 35 confirmed COVID-19 cases among 92 people (38%) who attended events. The super-spreading event is described today in Morbidity and Mortality Weekly Report (MMWR).
The high attack rate also led to three fatalities among church members. Case contact with the 35 confirmed cases led to 26 additional cases, and 1 additional death. The age-specific attack rates among persons age 18 years and under, 19–64 years, and over 65 years were 6.3%, 59.4%, and 50.0%, respectively, the authors said.
Several church events were held over the 2-day period when people were exposed, including two children's events and bible study. No severe illnesses occurred in children.
The pastor closed the church indefinitely on Mar 11, after he became aware of several church members with non-specific respiratory ailments.
"Faith-based organizations that are operating or planning to resume in-person operations, including regular services, funerals, or other events, should be aware of the potential for high rates of transmission of SARS-CoV-2," the authors concluded.
May 19 MMWR study
Study: 4.5% SARS-CoV-2 seroprevalence for LA County residents
A community seroprevalence study in Los Angeles County found that 4.65% had antibodies to SARS-CoV-2, the virus that causes COVID-19, suggesting that the number of people infected is greater than the number of confirmed cases. Researchers from the Los Angeles area reported their findings yesterday in a research letter in JAMA.
They invited a random sample of residents to be tested, with quotas for key subgroups such as age, sex, and ethnicity. Participants were tested in mid-April at six study sites or in their homes with Premier Biotech's antibody test. Of 865 adults tested, results were inconclusive for 2, so researchers based their analysis on results from 863 participants, 60% of them women and 58% white. Between 6% and 13% had symptoms consistent with COVID-19.
Weighted prevalence of antibodies, after adjusting for test sensitivity, was 4.65% (bootstrap confidence interval, 2.52% to 7.07%). The team estimated that 367,000 adults in Los Angeles County had SARS-CoV-2 antibodies, substantially higher than the 8,430 confirmed infections. They said deaths from the virus may also be higher than reported, and contact tracing to limit the spread of the virus will likely be challenging.
They cautioned that the study was likely influenced by selection bias and that symptomatic people were probably more likely than others to seek testing.
Public health officials have warned that few people have antibodies showing that they were infected, suggesting that many people would be vulnerable to the virus in a second wave of infections.
May 18 JAMA research letter
Coughs may propel virus-laden saliva droplets farther than 6 feet, study finds
The 6 feet recommended by public health officials for social distancing in the COVID-19 pandemic may not be far enough to prevent exposure if there is any wind, according to a study published today in Physics of Fluid.
Using a computational fluid dynamics simulation that monitors the movement and state of every saliva droplet in the air in front of someone coughing, researchers in Cyprus found that saliva can travel as far as 18 feet in 5 seconds—even with only a light breeze of 4 kph (2.5 mph).
Sneezes and coughs expel large saliva droplets and small mucous droplets from the lungs and vocal cords that travel together in a warm, moist, dynamic gas cloud that gradually disperses, cools, and evaporates with distance.
It takes about 15 seconds for droplets to fall below the human waist, which is considered a safe vertical distance for adults, but not necessarily children or shorter adults. Large droplets fall to the ground first.
"At a lower wind speed, the total mass reduction occurs more slowly compared to a higher speed, which may prolong the exposure of a human to the droplets if the subject is located within the droplets envelope," the authors wrote.
They called for further research to quantify the influence of other factors such as relative humidity and temperature on droplet behavior and droplet dispersion in indoor settings.
"The violent cough of patients with respiratory diseases will affect droplet generation, secretions of fluids on airway surfaces and heighten coughing frequency," the researchers said. "These factors need to be further quantified."
May 19 Phys Fluids study
Childhood vaccinations drop in Michigan during COVID-19 pandemic
A study yesterday in MMWR shows less than 50% of Michigan children under the age of 2 are up to date on routine vaccinations, as well-child visits to the pediatricians have dropped significantly during the COVID-19 pandemic.
The study was based on data collected from the Michigan Care Improvement Registry (the state’s immunization information system), and assessed the vaccination status of children at ages 1, 3, 5, 7, 16, 19, and 24 months, with each cohort including an average sample size of 9,269 children for the study period years 2016–2019, and 9,539 for 2020.
The authors found reductions in all routine vaccinations except hepatitis B, which is administered to newborns at birth. Among children aged 5 months, up-to-date status for all recommended vaccines declined from approximately 67% of children during 2016–2019 to fewer than half (49.7%) in May 2020. For the 16-month age cohort, coverage with all recommended vaccines declined, with measles-containing vaccination coverage decreasing from 76.1% in May 2019 to 70.9% in May 2020, the authors said.
Michigan implemented a stay-at-home order on Mar 23 that is currently still in place. The authors said practitioners should use electronic health records to identify children who have missed routine immunizations and schedule in-person visits, even during the pandemic.
"The observed declines in vaccination coverage might leave young children and communities vulnerable to vaccine-preventable diseases such as measles. If measles vaccination coverage of 90%–95% (the level needed to establish herd immunity) is not achieved, measles outbreaks can occur. Concerted efforts are needed to ensure rapid catch-up for children who are not up-to-date with measles-containing vaccines," they concluded.
May 18 MMWR study
Study finds higher antibiotic appropriateness with ID consults
Even in a hospital with a high level of antibiotic appropriateness, patients who received infectious disease consultation (IDC) were more likely to receive appropriate antibiotics than those who didn't receive it, researchers reported yesterday in Antimicrobial Agents and Chemotherapy.
In a cross-sectional study conducted at a large academic medical center with an established antibiotic stewardship program, researchers with the University of Maryland compared the appropriateness of antibiotic orders in patients with and without IDC, using propensity score matching and multivariable logistics regression. The analyses were stratified by primary care services caring for the patients.
The researchers reviewed 10,508 antimicrobial orders from 6,165 unique patient encounters at the hospital from October 2017 through March 2019. The overall appropriateness was 92%, with higher appropriateness among patients with IDC vs. without IDC (94% vs 84%, P < 0.0001).
After propensity-score matching and adjustment for certain antibiotics, organisms, syndromes, and locations, IDC was associated with a greater antimicrobial appropriateness odds ratio (OR) of 2.4 (95% confidence interval [CI], 1.9 to 3.0). The increased appropriateness was seen across most services, with stratification by primary service showing an OR of 2.9 (95% CI, 2.1 to 3.8) for surgical specialties and an OR of 1.6 (95% CI, 1.1 to 2.2) for medical specialties.
"Our results suggest that Infectious Diseases expertise is needed at the bedside and can be synergistic with AS [antibiotic stewardship] efforts," the authors wrote.
May 18 Antimicrob Agents Chemother abstract