Camp outbreak shows COVID-19 transmission from children to adults
Children and teens spread COVID-19 to household adults after returning home from a sleep-away camp in June 2020, according to correspondence published in the New England Journal of Medicine yesterday.
The camp outbreak led to 224 index patients ages 7 to 19 with COVID-19 in the retrospective cohort, with 88% symptomatic. After the campers returned, 377 (72%) of 526 household contacts were tested for COVID-19, and 46 (12%) had positive results; 2 more were also considered infected because they met the criteria for clinical and epidemiologic COVID-19.
For 141 of 198 symptomatic index patients (71%), symptom onset occurred after they came back from camp, and 38 (79%) of the secondary cases were their household contacts. The median days from index to secondary patient symptom onset was 5.0. Overall, transmission occurred in 35 of 194 households (18%), with a secondary attack rate of 45% (95% confidence interval [CI], 36% to 54%). Four of 41 (10%) of adult household members were hospitalized for their infections.
The researchers also looked at mitigation methods used post-camp. About two-thirds of index patients (146) reported physical distancing, and about one-third (73) said they always wore masks during their infectious period at home, with older campers more likely to follow mitigation tactics.
For those who did physical distancing, the adjusted odds ratio (OR) for secondary case infection was 0.4 (95% CI, 0.1 to 0.9), whereas household members with close or direct contact with the index patient had an adjusted OR of 5.2 to 5.8.
“This retrospective study showed that the efficient transmission of SARS-CoV-2 from school-age children and adolescents to household members led to the hospitalization of adults with secondary cases of Covid-19. In households in which transmission occurred, half the household contacts were infected,” the researchers write.
“When feasible,” they continued, children and adolescents with a known exposure to SARS-CoV-2 or a diagnosis of Covid-19 should remain at home and maintain physical distance from household members.”
Jul 21 N Engl J Med study
Historic low for non-COVID respiratory viruses during pandemic
Likely because of COVID-related disruptions (eg, reduced travel, physical distancing, masking), non–COVID-19 respiratory viruses such as the flu and respiratory syncytial virus (RSV) saw low prevalence from 2020 to 2021, according to a Morbidity and Mortality Weekly Report (MMWR) study today.
The researchers looked at flu activity from Oct 3, 2020, to May 22, 2021, and other virus activity from Jan 4, 2020, to May 22, 2021.
Flu activity during the 2020-21 season was at its lowest since at least 1997, the earliest year with data available. Out of 1.1 million clinical specimens tested, 0.2% were positive for influenza A (37.5%) and influenza B (62.5%). Public health laboratories, however, had more influenza A than B (60.0% vs 40.0%) in 0.05% of positive samples from 502,782 specimens. Cumulative incidence of flu-associated hospitalizations was 0.8 per 100,000 people, lower than the 62.0 to 102.9 during the previous four seasons.
RSV had similarly low levels. From Jan 4 to Apr 4, 2020, it fell from 15.3% of weekly samples to 1.4% and then remained at less than 1.0% per week for the next year. Cumulative incidence of RSV-associated hospitalization was 0.3 per 100,000 people from October 2020 to April 2021, compared with 27.1 and 33.4 during the previous two seasons. More than 76% of 226 related hospitalizations from Oct 1, 2020, to May 22, 2021, were in April and May, the researchers add.
Respiratory adenovirus (RAdV), and rhinovirus and enterovirus (RV/EV) circulation decreased starting in spring 2020 but is now nearing pre-pandemic levels. Parainfluenza viruses and common human coronaviruses saw a delay in their increases, possibly because their high prevalence in children was cut by remote schooling, but they have also begun to rise. Human metapneumovirus, which affects the same age-group, was still lower than usual as of May 22.
“In the United States, the circulation of respiratory viruses was disrupted during the COVID-19 pandemic, but the magnitude, timing, and duration of this effect varied among viruses,” the researchers write. “Clinicians should be aware of increases in some respiratory virus activity and remain vigilant for off-season increases.”
Jul 23 MMWR study
Funds for new solutions for infectious diseases, antimicrobial resistance
The London School and Hygiene & Tropical Medicine (LSHTM) announced yesterday that a knowledge exchange program led by the Royal Veterinary College, known as Bloomsbury SET, has received a total of £1.9 million ($2.6 million) from Research England for a 1-year project. The effort will engage businesses to deliver vaccines, diagnostics, and treatments to battle infectious diseases and antimicrobial resistance in animals and people.
One of the goals of the program—called the Impact Connector—is to build support for commercializing research across partner groups and collaborate across geographic regions. Components will include product development workshops, skills programs to commercialize research, and activities to support connections between groups.
The program will also provide small grants to encourage new collaborations.
Hannah Whiteman, BSc Msc, PhD, head of strategic research at LSHTM, said, “The programme will empower our innovators across career stages with training, funding, and opportunities to forge new external industrial networks and advance their technologies closer to delivering societal and economic impact.”
Jul 21 LSHTM press release