The World Health Organization (WHO) this week released new guidance to spur development of rapid diagnostic tests for serious bacterial infections in newborns and infants.

The WHO target product profile aims to guide manufacturers, regulators, and other stakeholders in developing affordable in vitro diagnostic tests that can quickly and accurately identify serious bacterial infections, including sepsis, in infants aged o to 59 months. 

Of the estimated 2.3 million newborns who die each year, 15% die from neonatal sepsis. Evidence suggests that 84% of newborn deaths caused by infection could be prevented through early diagnosis and appropriate clinical management, the WHO said.

"Timely and accurate diagnosis tests for serious bacterial infection is critical to reducing newborn mortality," Yvan J-F. Hutin, MD, PhD, director of the WHO's Department of Antimicrobial Resistance, said in a WHO press release.

Current tests inadequate

Current in vitro diagnostic tests for bacterial infections in newborns and infants are either inadequate or unavailable in healthcare settings in the low-and middle-income countries (LMICs) where newborn mortality is highest. 

Blood cultures have low sensitivity, long turnaround times, and require an amount of blood that's difficult to obtain infants, while blood-culture systems and molecular diagnostic tests are unaffordable. As a result, healthcare workers in LMICs often rely on clinical assessments to determine whether to initiate antibiotics or sepsis management.

The target product profile defines the essential and desirable features needed for in vitro diagnostic tests in hospitals and non-hospital (primary care) settings. Essential features include a turnaround time of less than 30 minutes, high sensitivity (90% or higher), and the ability to perform the test with less than 100 microliters (μL) of blood.

"This new target product profile outlines the essential features needed in diagnostic tools to improve clinical decision-making, reduce unnecessary antibiotic use and prevent antimicrobial resistance, especially in low-resource settings where the burden of neonatal sepsis remains critical," said Silvia Bertagnolio, MD, head of the WHO's Antimicrobial Resistance Surveillance, Evidence and Laboratory Strengthening Unit.

NYC Health said the Legionnaires' disease outbreak in Central Harlem is now up to 73 cases, including 3 deaths, an increase of 15 cases and one fatality since Monday.

Anyone in Central Harlem experiencing flu-like symptoms should seek medical care, NYC Health said, although the risk to most people is low.

Most people who are exposed to the bacteria do not develop Legionnaires’ disease, and it is not contagious—you cannot get it from someone else.

“Most people who are exposed to the bacteria do not develop Legionnaires’ disease, and it is not contagious—you cannot get it from someone else. You cannot get Legionnaires’ disease by drinking the water,” NYC Health said, adding that plumbing systems in Harlem are not the problem, and residents should continue to drink water, bathe, shower, cook, and use air conditioners.

Cooling towers, showers, and hot tubs

Earlier this week, NYC Health said remediation had been completed on 11 cooling towers that initially screened positive for Legionella pneumophila, a type of bacteria that causes Legionnaires’ disease.

“People who inhale mist that contains Legionella bacteria can get sick. Sources of water with Legionella contamination may include cooling towers, showers and hot tubs,” NYC Health said. 

Cost-effectiveness of the two respiratory syncytial virus (RSV)-prevention interventions for newborns—maternal vaccination and use of the long-acting monoclonal antibody nirsevimab (Beyfortus) in infants—may depend on timing of administration, University of Utah researchers report in JAMA Network Open.

The team modeled the cost-effectiveness, efficacy, and clinical outcomes of maternal vaccination, nirsevimab administration, and no intervention from a societal perspective, applying a willingness-to-pay threshold of $150,000 per quality-adjusted life-year (QALY). Data were collected from October 2023 to June 2024 on 299,277 US infants born during the virus season.

The maternal vaccine can be administered at a gestational age of 32 to 36 weeks from September through January, and if the pregnant mother wasn't vaccinated, nirsevimab can be given to the infant.

Differences in uptake, costs, and efficacy between these agents may affect cost-effectiveness depending on the timing of administration.

"The Advisory Committee on Immunization Practices and the Centers for Disease Control and Prevention recommend seasonal administration of maternal vaccine (MV) or nirsevimab to protect infants in the first year of life from respiratory syncytial virus (RSV) infections," the study authors wrote. "Differences in uptake, costs, and efficacy between these agents may affect cost-effectiveness depending on the timing of administration."

Limiting use to certain months

For RSV hospitalization, initial effectiveness was 67.9% for maternal vaccination and 76.8% for nirsevimab. For RSV outpatient infection, the initial effectiveness was 48.2% for maternal vaccination and 78.0% for nirsevimab.

For infants born in the combined cohort (October-February), maternal vaccination was cost-effective, at $19,562/QALY. Compared with maternal vaccination, nirsevimab was cost-effective only in October ($67,178/QALY) and November ($88,531/QALY). 

Maternal vaccination was projected to avert 45,558 outpatient visits, 7,154 hospital admissions, and 12 deaths during the RSV season, while nirsevimab was predicted to prevent 92,265 outpatient visits, 11,893 hospitalizations, and 19 deaths. The odds of cost-effectiveness were 19.8% for no intervention, 62.2% for maternal vaccination, and 18.0% for nirsevimab.

"Intervention use may be optimized by restricting administration to select months," the researchers wrote. "Further study is needed to assess transmission dynamics to refine cost-effectiveness outcomes."

• Public Health Scotland today announced new findings that show infants younger than 3 months old whose mothers were vaccinated against respiratory syncytial virus (RSV) during pregnancy were 80% less likely to be hospitalized for RSV than babies of mothers who weren’t vaccinated. In a statement, the group said the country launched its RSV vaccination program in August 2024 and that initial reports suggest about half of all eligible pregnant woman had received the vaccine. Officials estimated that 228 fewer babies younger than 3 months older were hospitalized for serious RSV infection during the peak of the season, a number they hope will increase as more women are vaccinated. The new vaccine is offered starting in the 28th week of pregnancy and is designed to provide antibodies that pass from mother to baby that shield newborns from RSV during the first 6 months of life.
• Israel’s health ministry has reported polio detections in wastewater samples collected from Bnei Brak, Ramle, Lod, and the Shafdan treatment facility, The Jerusalem Post reported today, noting that that the findings follow an earlier detection in Jerusalem-area wastewater. Health officials urged people to check their polio vaccination status and asked healthcare providers to monitor patients for signs of acute flaccid paralysis. In a related development, the Global Polio Eradication Initiative said today that Israel has reported six environmental samples of circulating vaccine-derived poliovirus type 1 (cVDPV1), five from Jerusalem and one from Center. Also, Germany reported eight positive environmental samples of circulating vaccine-derived poliovirus type 2 (cVDPV2), including one from Baden, three from Bayern, one from Rhineland, and three from Sachsen. The detections bring Germany’s number of positive samples for 2025 to 11.
• Centers for Disease Control and Prevention Director Susan Monarez, PhD, has accepted a June recommendation from the Advisory Committee on Immunization Practices (ACIP) that all babies younger than 8 months of age born during or entering their first RSV season and who aren’t protected by maternal RSV vaccination receive one dose of clesrovimab. The CDC’s ACIP recommendation page reflects that the director accepted the recommendation on August 4. Clesrovimab is the second RSV monoclonal antibody preventive for babies on the US market, available alongside nirsevimab.