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.

A study of adults hospitalized with community-acquired pneumonia (CAP) in Georgia and Tennessee shows that a sizable fraction of infections were caused by Streptococcus pneumoniae, including serotypes covered by recently approved vaccines, researchers reported yesterday in JAMA Network Open.

The prospective active-surveillance study, led by researchers at Vanderbilt University Medical Center, analyzed data on patients with clinical and radiologic evidence of CAP at three hospitals in Georgia and Tennessee from 2018 through 2022. 

To determine whether CAP was caused by S pneumoniae and identify the specific serotypes, researchers used serotype-agnostic urinary antigen tests, serotype-specific urinary antigen detection assays covering 30 serotypes, and routine clinical tests. They were particularly interested in serotypes covered by the 21-valent (21-strain) pneumococcal conjugate vaccine (PVC), which wasn't commercially available during the study period.

"As new PCV programs are designed, approved, and implemented to incorporate expanded formulations, such as the recently approved adult-specific 21-valent pneumococcal conjugate vaccine (V116), it is important to monitor the burden of pneumococcal pneumonia and the distribution of pneumococcal serotypes causing pneumonia," the study authors wrote.

Improved vaccines could reduce burden of severe pneumonia

Among 2,016 patients (median age, 60) hospitalized for CAP, 279 (13.8%) had pneumococcal pneumonia, and 198 (9.8%) had evidence of pneumococcal CAP caused by serotypes in V116. The overall estimated annual incidence of hospitalizations for all-cause CAP was 340 per 100,000 adults. 

The incidence of hospitalizations for pneumococcal CAP and pneumococcal CAP due to serotypes included in V116 was 43 and 30 per 100,000 adults, respectively. The burden of all-cause and pneumococcal CAP was consistently highest among adults age 65 years or older.

The authors note that the annual incidence of 43 hospitalizations per 100,000 adults extrapolates to 114,800 US hospitalizations for pneumococcal CAP each year, based on current population estimates.

"Results of this study demonstrate that pneumococcal CAP remains an important cause of hospitalizations in the US," they wrote. "With vaccination as the primary preventive measure for pneumococcal pneumonia, improved pneumococcal vaccines with appropriate vaccination coverage could lessen the burden of severe pneumonia on the US population, especially among older adults."

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.