The Centers for Disease Control and Prevention (CDC) is urging US clinicians and public health authorities to be aware of an increase in pediatric invasive group A streptococcal infections (iGAS).

In a Health Alert Network (HAN) notice issued last week, the CDC said it was notified in November about a possible increase in iGAS infections at a hospital in Colorado, and that potential increases in other states were subsequently noted by contributors to the Emerging Infections Network and the CDC's Active Bacterial Core Surveillance System. While the overall number of cases is low, the CDC says it's currently investigating these reports.

Group A Streptococcus bacteria causes a range of infections, including acute pharyngitis (strep throat), scarlet fever, and other, more serious and life-threatening invasive infections. The CDC says strep throat and iGAS infections tend to have a pronounced seasonal pattern in the United States, with a peak occurring from December through April, and notes that this year's increase in pediatric iGAS cases in some jurisdictions is occurring amid increased circulation of influenza, respiratory syncytial virus, and SARS-CoV-2.

The United States isn't the only country seeing an uptick in group A streptococcal activity. The HAN notice comes on the heels of a disease outbreak update from the World Health Organization that reported an increase in iGAS infections and scarlet fever cases in at least five European countries.

The CDC says people with concurrent or preceding infections (like flu or chicken pox), people age 65 and over, residents of long-term care facilities, American Indian and Alaska Native populations, and people with medical conditions are among those at risk for iGAS infections.

The agency is recommending that clinicians be aware of iGAS as a possible cause of severe illness in children and adults with concomitant viral respiratory infections and calling on state and territorial health departments to investigate unusually aggressive or severe iGAS infections in children under 18 and clusters of infections in any age group.

An analysis of more than 14,000 Escherichia coli bloodstream infections in Canada found that antimicrobial resistance (AMR) was associated with increased mortality, but some of that mortality is explained by patient characteristics, researchers reported yesterday in eClinicalMedicine.

The retrospective cohort study of all people hospitalized with E coli bacteremia in Ontario, Canada, from 2017 through 2020 examined the odds of mortality associated with resistant versus susceptible isolates before and after accounting for clinically relevant patient characteristics, including prior healthcare exposure. Researchers assessed resistance to eight individual classes of antibiotic agents and examined a special category of difficult-to-treat-resistance (DTTR), defined as resistance to multiple classes of antibiotics. The primary outcome of interest was 90-day mortality.

Among 14,548 eligible episodes of E. coli bloodstream infection in 13,706 patients (median age 74, 55.7% women), resistance was most common to aminopenicillins (46.8%), followed by first generation cephalosporins (38.8%), fluoroquinolones (26.5%), sulfonamides (24.1%), third generation cephalosporins (13.8%), aminoglycosides (11.7%), beta-lactam/beta-lactamase-inhibitors (9.1%) and carbapenems (0.2%). Only 18 (0.1%) episodes exhibited DTTR. Overall, 2,585 episodes (17.8%) were associated with death within 90 days.

For each antibiotic class, the unadjusted odds of mortality were much higher among resistant isolates, particularly those antibiotics most commonly used for empiric treatment. After accounting for patient characteristics, the adjusted odds ratio (aOR) of mortality were greatly attenuated but remained statistically significant: aminopenicillins (aOR, 1.09; 95% CI, 0.99 to 1.20), first generation cephalosporins (aOR, 1.07; 95% CI, 0.97 to 1.18), third generation cephalosporins (aOR, 1.29; 95% CI, 1.15 to 1.46), beta-lactam/beta-lactamase-inhibitors (aOR, 1.28; 95% CI, 1.13 to 1.45), carbapenems (aOR, 2.06; 95% CI, 0.91 to 4.66), sulfonamides (aOR, 1.06; 95% CI, 0.95 to 1.18), fluoroquinolones (aOR, 1.16; 95% CI, 1.05 to 1.29), aminoglycosides (aOR, 1.27; 95% CI, 1.11 to 1.46), and DTTR (aOR, 2.58; 95% CI, 0.87 to 7.66).

"Surveillance for AMR-associated mortality should incorporate adjustment for patient characteristics and prior healthcare utilization," the authors wrote.

Sudan and Yemen reported more vaccine-derived polio cases, according to the latest weekly update from the Global Polio Eradication Initiative (GPEI).

Sudan reported a circulating vaccine-derived poliovirus type 2 (cVDPV2) case in a child from West Darfur whose acute flaccid paralysis began on Oct 31, marking its first case of the year. The GPEI said the strain is most closely related to a strain that circulated in Borno, Nigeria, in 2020. It is not related to the cVDPV2 strain that circulated in Sudan in 2020 and was confirmed as successfully ended earlier this year. A risk assessment and field investigation are underway.

Elsewhere, Yemen reported one cVDPV2 case involving a patient from Sanaa, bringing the country's 2022 total to 159.