Cases of influenza-like illness (ILI) among students in a Wisconsin school district dropped by nearly half after winter and spring breaks, with the largest dips occurring when the breaks coincided with spikes in local flu activity, University of Wisconsin researchers report.

Published yesterday in Influenza and Other Respiratory Viruses, the observational study compared school absenteeism for ILI (a-ILI) among about 4,100 K-12 students in the 2 weeks before and after winter and spring breaks from September 2014 to June 2019. The investigators inserted a 9-day "pseudobreak" 5 weeks before spring break when school was in session as the control.

"School-aged children and school reopening dates have important roles in community influenza transmission," the authors wrote. "Children frequently have larger social networks, experience prolonged viral shedding, have lower coverage rates for influenza vaccine, and may lack sufficient preexisting immunity for herd effects.^"

More flu among younger students

The average numbers of flu cases during the 2 weeks before winter and spring breaks were 130.4 (range, 51 to 262) and 151.4 (range, 69 to 275), respectively. The average case counts for the periods after winter and spring breaks were 82 (range, 33 to 152) and 49.6 (range, 33 to 74), respectively. Greater flu activity was reported among younger students than among those in middle and high schools.

The 2 weeks after breaks were tied to a statistically significant decline in the likelihood of flu, as well as after winter (estimated odds ratio [OR], 0.68) and spring (OR, 0.33) breaks.

These findings suggest that brief breaks of in-person schooling, such as planned breaks lasting 9–16 calendar days, can effectively reduce influenza in schools and community spread.

The 2 weeks before and after pseudobreaks saw average flu tallies of 106 (range, 43 to 200) and 100.8 (range, 71 to 131), respectively. No significant differences were seen in the 2 weeks before and after pseudobreaks.

"These findings suggest that brief breaks of in-person schooling, such as planned breaks lasting 9–16 calendar days, can effectively reduce influenza in schools and community spread," the researchers wrote. "Additional analyses investigating the impact of well-timed shorter breaks on a-ILI may determine an optimal duration for brief school closures to effectively suppress community transmission of influenza."

A new preprint study published on the preprint server medRxiv estimates how many lives were directly saved by vaccinating adults against COVID-19 in Europe from December 2020 through March 2023. Overall, the authors said the vaccines reduced deaths by 57% and saved an estimated 1.4 million lives in Europe.

As of March 2023, the 34 countries and territories in the World Health Organization’s European region had reported 2.2 million cases. The authors of the study estimated the impact of COVID-19 vaccination in adults by age-group, vaccine dose, and period of circulation of variants of concern.

Among adults over 25 years, 1.5 million lives (range, 0.7 to 2.6 million) were saved because of vaccines during the first 2.5 years of use. Overall, the first booster dose of vaccine delivered before the Omicron variant became dominant saved the most lives, 721,122 of 1,408,967 (57%) of all lives saved. The first booster dose became available in Europe in July 2021.

67% of lives saved during Omicron period

Most lives (67%) were saved during the Omicron period (942,571), and lives saved were almost all among adults ages 60 and older (96%, or 1,349,617).

Booster doses in older age-groups played an important role in saving lives.

The researchers previously estimated that vaccination directly saved 469,186 lives among people 60 years and older in 33 European countries during first year of the vaccination program.

"Booster doses in older age-groups played an important role in saving lives: early introduction of the first booster dose, which was recommended because of concerns about waning protection against severe disease," the authors said. "The first booster dose was responsible for the majority of lives saved, highlighting the importance of up-to-date vaccination in this high-risk age group."

A study of six US cities found a high prevalence of bacterial sexually transmitted infections (STIs) in transgender women (TGW), particularly those with HIV, researchers reported today in the Journal of Infectious Diseases.

Using baseline data from the Leading Innovation for Transgender Women's Health and Empowerment study, which examined HIV incidence and other health outcomes in TGW in six southeastern and eastern US cities (Atlanta, Baltimore, Boston, Miami, New York, and Washington, DC), a team led by researchers from Johns Hopkins Bloomberg School of Public Health analyzed bacterial STI test results from 1,018 participants. The primary outcome was the prevalence of at least one bacterial STI (gonorrhea, chlamydia, or syphilis) at any anatomic site.

Prevalence higher in those with HIV

The median age of participants was 29 years, 29% were Black, 27% were Hispanic, and 27% had HIV. The overall prevalence of any bacterial STI was 16% but was threefold higher in TGW with HIV (32% vs 11% among those without HIV). After adjustments for age, race and ethnicity, and region, HIV infection remained significantly associated with any bacterial STI (adjusted prevalence ratio, 1.9; 95% confidence interval, 1.39 to 2.62).

Among TGW without HIV, bacterial STI prevalence differed by geographic region, race and ethnicity, and gender identity, and was positively associated with reporting more than 1 sexual partner, hazardous alcohol use, homelessness, having safety concerns regarding transit to healthcare, and no prior receipt of gender-affirming health services. Among TGW with HIV, older age was inversely associated with bacterial STI.

...the variation in bacterial STI prevalence and correlates seen between TGW with and without HIV highlights the differential burden and needs of these two populations

The study authors say the findings underscore the need to develop interventions that are tailored to the unique needs and risks of each population.

"Although participants with and without HIV had a high prevalence of bacterial STIs, the variation in bacterial STI prevalence and correlates seen between TGW with and without HIV highlights the differential burden and needs of these two populations," they wrote. "Elucidating the ways in which situated vulnerabilities are associated with STI risk may help inform more tailored intervention strategies for each population."

A new large study published in CMAJ (Canadian Medical Association Journal) shows that even though the first 2 years of the pandemic resulted in significant disruptions to regular healthcare, preventable diseases and deaths didn't increase among Canadian children.

The study was based on emergency visits, hospital admissions, and deaths for children ages 0 to 17 years recorded in Ontario from January 2017 to February 2020 (the prepandemic period), with trends seen from March 2020 to August 2022.

All acute care and emergency visits dropped at the start of the pandemic, with the lowest number seen in April 2020. Compared to the prepandemic period, the adjusted relative rate (RR) for emergency visits was 0.28 (95% confidence interval [CI], 0.28 to 0.29), and hospital admissions was 0.43 (95% CI, 0.40 to 0.44). These decreases were sustained until September 2021 and May 2022, respectively, the authors said.

The only acute condition with significant delays in diagnosis in the first year of the pandemic was diabetes. Diabetes diagnoses dropped sharply in March, April, and May 2020, but rebounded in 2021 and 2022 (peak adjusted RR, 1.49; 95% CI, 1.28 to 1.74). Children diagnosed as having diabetes in 2021 and 2022 were more likely to present with diabetic ketoacidosis.

"While ongoing pandemic-related challenges, such as surgical wait times, for pediatric care persist, our analyses suggest that most urgent medical care needs of children were met despite the disruptions to the health care system," senior author Astrid Guttmann, MD, at the Hospital for Sick Children in Toronto, said in a press release.

Mpox cases continue to be reported at a low level in the European region, with 138 cases from 11 countries and areas reported over the last month, according to a joint update from the European Centre for Disease Prevention and Control (ECDC) and the World Health Organization (WHO) European regional office.

The groups are now posting the updates quarterly rather than monthly, noting that since their last report in October, the region has reported 472 cases from 19 cases and areas.

Countries reporting the most cases are still Spain, Portugal, the United Kingdom, and Germany.

Of mpox samples that were sequenced, all belonged to clade 2, known as the West African clade. Clade 2 is fueling the global outbreak in countries outside of Africa, which mainly involves men who have sex with men. Meanwhile, clade 1—known to be more virulent and deadly—is still spreading in Africa, where the virus was recently linked to a large outbreak in the Democratic Republic of Congo (DRC), the country's first involving sexual transmission of the virus.