A University of Calgary–led research team finds that only 7% of children infected with Shiga toxin–producing Escherichia coli (STEC) developed hemolytic uremic syndrome (HUS) during a 395-case outbreak at 11 daycare centers in Alberta, Canada, perhaps partly due to daily lab monitoring for kidney injury.

The researchers investigated the outbreak among children and adults related to contaminated food served at the centers in August 2023, publishing the findings yesterday in JAMA Network Open.

An estimated 15% to 20% of children infected with STEC develop HUS, more than half of whom require dialysis. “Alberta, Canada, has one of the highest STEC infection rates in North America,” the authors wrote. “Accordingly, the province has developed expertise in diagnostics, public health responses, and care pathways.” 

Substantial use of health care resources

In total, 326 primary and 33 secondary infections occurred among 288 children and 71 adults. Of the 359 infections, 18.4% caused no symptoms. There were 508 and 395 emergency department and STEC clinic visits, respectively, among the 285 children with outcome data. 

Only 7% of children infected with STEC developed HUS, which is lower than reported in most prior outbreaks and sporadic case series.

HUS was documented in 7.4% of children, while no adults developed the condition. Forty children were hospitalized, nine needed dialysis, and three required intensive care. Daily lab monitoring for thrombotic microangiopathy (TMA) identified all future HUS cases. TMA is a life-threatening syndrome characterized by small blood-vessel injury, blood clots, and end-organ damage.

The most common symptoms in both children and adults were diarrhea, abdominal pain, and bloody diarrhea. TMA testing had 100% sensitivity, 95.7% specificity, and 96.1% diagnostic accuracy for HUS.

The study identified significant use of health care resources, the researchers said. “Only 7% of children infected with STEC developed HUS, which is lower than reported in most prior outbreaks and sporadic case series,” they wrote. “These findings highlight the importance of a coordinated public health response integrated with clinical care and suggest that proactive screening for TMA has the potential to mitigate adverse outcomes.”

The World Health Organization (WHO) is warning that the war in Iran is worsening public health conditions across the Middle East region. 

After 10 days of bombings and conflict in Iran, national health authorities in Iran report more than 1,300 deaths and 9,000 injuries, and Lebanon reports at least 570 deaths and more than 1,400 injuries. In Israel, authorities have documented 15 deaths and 2,142 injuries. The WHO said eight health care workers have died in Iran.

Moreover, hundreds of thousands of Iranians and Lebanese have moved into collective shelters, which increase the risk of respiratory infections and diarrheal diseases.

In Iran, petroleum fires and smoke from damaged infrastructure exposed nearby communities to toxic pollutants that potentially cause breathing problems, eye and skin irritation, and contaminated water and food sources.

“Environmental hazards are also a raising concern. In Iran, petroleum fires and smoke from damaged infrastructure exposed nearby communities to toxic pollutants that potentially cause breathing problems, eye and skin irritation, and contaminated water and food sources,” the WHO said.

Airspace restrictions limiting aid

The WHO said temporary airspace restrictions have disrupted the movement of medical supplies from WHO’s global logistics hub in Dubai, resulting in significant backlogs to emergency supply requests.

The Middle East region is the most dependent on assistance and humanitarian need in the world, representing almost half of all people in need globally.

“WHO calls on all parties to protect civilians and health care, ensure unimpeded and sustained humanitarian access, and pursue de-escalation of the conflict so communities can begin to recover and move towards peace,” the organization said.

From June 2023 to September 2025, only 16% to 38% of non-hospitalized US COVID-19 patients aged 65 years and older were given an antiviral prescription, while those aged 75 to 84 and older were more likely to receive such a prescription than younger patients, according to a report from Centers for Disease Control and Prevention (CDC) researchers.

For the study, published in Morbidity and Mortality Weekly Report, the team used electronic health records to evaluate factors tied to receipt of an antiviral prescription among non-hospitalized COVID-19 aged 65 years and older. 

“Adults aged ≥65 years have the highest rates of COVID-19–related hospitalization,” the authors wrote. “Despite the proven benefit of COVID-19 antivirals in preventing severe outcomes, data suggest that their use is low among older adults.”

Prescription rates vary by age, race, season, vaccination status

The odds of receiving an antiviral prescription were greatest among those aged 75 to 84 years and 85 and older (adjusted odds ratio [aOR], 1.09 and 1.11, respectively), those of Asian (aOR, 1.42) or Hispanic (aOR, 1.24) race, and recipients of at least one COVID-19 vaccine dose (aOR, 1.73).

Encouraging annual COVID-19 vaccination and increased prescribing of antivirals among adults aged ≥65 years with COVID-19 could reduce the risk for severe illness and hospitalization in this population.

The proportion of COVID-19 outpatients aged 65 and older given an antiviral prescription was lower in spring 2024 (21%), fall and winter 2024-25 (23%), spring 2025 (16%), and summer 2025 (19%) than during other seasons (range, 37% to 38%). The odds of antiviral prescription were highest in summer 2024 (aOR, 1.05). 

Among prescription recipients, 99% received it within 7 days of COVID-19 diagnosis, and 80% were prescribed nirmatrelvir-ritonavir (Paxlovid). Patients with at least one underlying condition and rural residents had lower odds of receiving an antiviral prescription. The chances of prescribing were lower when COVID-19 incidence was lower. 

“Antivirals might be underprescribed among adults aged ≥65 years, and prescribing rates vary temporally,” the researchers concluded. “Encouraging annual COVID-19 vaccination and increased prescribing of antivirals among adults aged ≥65 years with COVID-19 could reduce the risk for severe illness and hospitalization in this population.”