Though the nation’s respiratory disease levels remain low overall, with COVID levels declining and little sign of a flu uptick, illnesses caused by Mycoplasma pneumoniae are increasing, especially in children, and respiratory syncytial virus (RSV) levels are also on the rise, the US Centers for Disease Control and Prevention (CDC) said today in it weekly respiratory virus update.

Pneumonia and acute bronchitis related to M pneumoniae bacteria have increased since late spring and have remained high, peaking in late August, the CDC said. The CDC said it using various surveillance tools to better understand the rise, which is especially affecting young children, a change from previous years when school-age children and adolescents were most affected.

“The increase in children ages 2–4 years is notable because M. pneumoniae historically hasn't been recognized as a leading cause of pneumonia in this age group,” the CDC said.

Also called “walking pneumonia,” the disease reemerged globally following low levels during the worst of the COVID-19 pandemic period.

Regarding RSV, the CDC said RSV activity is still low overall, but there are signs of increased activity in the southeastern United States, especially in young children.

COVID wastewater levels highest in northeast, flu activity still low

Emergency department visits for COVID-19 and test positivity continued to decline last week, the CDC said in data updates today. Test positivity is currently at 6.3% but is lower in the southern part of the country. Deaths from the virus were also down last week, with 327 reported last week, based on provisional data.

CDC wastewater tracking shows that viral levels remain low, with levels currently highest in the northeast. The latest data from WastewaterSCAN, a national wastewater monitoring system based at Stanford University in partnership with Emory University, show that detections are in the medium category nationally, with a downward trend over the last 3 weeks. It said the South and West are currently at the low level.

Regarding flu, the CDC said in its weekly FluView report that seasonal flu activity remains low nationally, with no new pediatric flu deaths reported, keeping the total at zero for the 2024-2025 flu season. However, it reported one more for the 2023-2024 flu season, putting that total at 202.

The results of multicenter, randomized clinical trial show that a 7-day course of antibiotics for patients hospitalized with bloodstream infections is non-inferior to a 14- day course, researchers reported at IDWeek 2024.

The trial, conducted at 74 hospitals in 7 countries, randomized 3,608 hospitalized patients with bloodstream infections to receive either 7 or 14 days of antibiotics, with antibiotic selection, dosing, and route of administration at the discretion of the treating team. The primary outcome was 90-day mortality, with a 4% absolute non-inferiority margin.

Similar outcomes in both groups

A total of 1,814 patients received a 7-day course of antibiotics, and 1,794 received a 14-day course. At enrollment, 55% of patients were in the intensive care unit (ICU) and 45% on hospital wards. Infections were community-onset (75.4%), hospital-acquired (13.4%), or ICU-acquired (11.2%). Bacteremia sources were most commonly the urinary tract (42.2%), abdomen (18.8%), lung (13.0%), vascular catheters (6.3%), and skin or soft tissue (5.2%).  

The primary outcome of 90-day mortality occurred in 14.5% of patients receiving 7 days of antibiotics and 16.1% of patients in the 14-day arm, for an absolute difference of –1.6% (95 % confidence interval [CI], –4.0% to 0.8%), demonstrating the non-inferiority of the 7-day treatment. The findings were generally consistent across secondary clinical outcomes and pre-specified patient, pathogen, and syndrome subgroups.

“These findings underscore the effectiveness of a shorter antibiotic regimen in patients with bloodstream infections, which is welcomed as we look to identify evidence-based prescribing guidelines for serious bacterial infections,” presenting author Nick Daneman, MD, clinician scientist in the Division of Infectious Diseases at Sunnybrook Health Sciences Centre and professor of Medicine at the University of Toronto, said in an IDWeek press release.

• Nigeria, the country with the world’s highest malaria burden, yesterday received its first malaria vaccine delivery, according to a statement from Gavi, the Vaccine Alliance. The first phase of the country’s campaign will begin in November, targeting Kebbi and Beyelsa states, where malaria activity is especially high. Newly added to the country’s routine immunization schedule, the vaccine will be administered in children younger than 1 year old. The vaccine requires 4 doses. Nigeria is using the R21/Matrix-M vaccine, developed by Oxford University and made by the Serum Institute of India.
• Federal health officials yesterday said they have wrapped up their investigation into a Salmonella Enteritidis outbreak linked to eggs from Milo’s Poultry Farms, which were the subject of a recall. Since the initial announcement in early September, the Centers for Disease Control and Prevention (CDC) reported 28 more illnesses and 3 more affected states, bringing the outbreak total to 93 infections across 12 states. The latest illness onset was September 13. Thirty-four people were hospitalized, and no deaths were reported. 
• Two countries reported new polio cases this week, according to the latest weekly update from the Global Polio Eradication Initiative (GPEI). Pakistan reported four more cases involving wild poliovirus type 1 (WPV1), lifting its total for the year to 32, a sharp rise compared with 2023. The patients are from Khyber Pakhtunkhwa and Sindh provinces and had paralysis onsets in August and September.  Elsewhere, Ethiopia reported two circulating vaccine-derived poliovirus type 2 (cVDPV2) cases, putting its total for the year at 13. The patients are from Gambella and Somali provinces and had paralysis onsets in July.