Dan Higgins, James Archer / CDC

A new study by Chinese researchers suggests a highly resistant, healthcare-associated bacterial pathogen could be transmitted through the air.

In the study, published yesterday in the American Journal of Infection Control, researchers from Sichuan University investigated the extent of air contamination with carbapenem-resistant Acinetobacter baumannii (CRAB) in an intensive care unit (ICU) at West China Hospital. CRAB is a multidrug-resistant pathogen that tends to infect severely ill hospital patients, and is known to spread in ICUs through contact with contaminated high-touch surfaces and shared medical devices. 

The study authors note that while CRAB air contamination has been detected in previous studies or infected or colonized patients, airborne transmission has not been documented.

A challenge for infection prevention and control

On February 26, 2025, the researchers collected air samples from five rooms in the ICU that had at least one patient who had CRAB recovered from a clinical specimen or screening swab, along with nasal or rectal swabs. Whole-genome sequencing (WGS) was used to analyze CRAB colonies recovered from 13 of 88 (10%) of air samples and nine swab samples. All the CRAB colonies from air samples were collected from multipatient rooms

WGS revealed two sequence types (STs) of CRAB among air and patient samples: ST2, a well-known high-risk lineage, and ST164, an emerging high-risk lineage. Further analysis showed four of nine ST2 isolates were associated with transmission within rooms or between rooms, while all of the ST164 isolates belonged to a common clone and were found in two rooms.

The researchers suggest that daily activities conducted for ICU patients—including mechanical ventilation, endotracheal suctioning, diaper changing, and bed making—could facilitate the air dispersal of CRAB. While multicenter studies are needed to demonstrate that air transmission is a common problem, they say air contamination poses serious challenges for infection prevention and control.

"The route through the air may represent a yet-to-be-recognized, important mode of CRAB spread in ICUs. Without addressing such a route, infection control of CRAB transmission in healthcare settings could be compromised in effectiveness and even fail," they wrote.

Novartis's Bexsero vaccine, which includes the outbreak serogroup B strain, was approved by the FDA for use in the Princeton outbreak., Courtesy of Novartis; all rights reserved

Today, the Vaccine Integrity Project (VIP), based at the University of Minnesota’s Center for Infectious Disease Research and Policy (CIDRAP), announced it will examine existing scientific evidence on meningococcal and pneumococcal vaccines for children and young adults for its next independent review. CIDRAP publishes CIDRAP News.

 The federal vaccine review and recommendation process is not functioning as it historically has

“Parents and clinicians need to trust that vaccine recommendations are grounded in a comprehensive and transparent review of the best available science,” said VIP Executive Director Michael Osterholm, PhD, MPH. “That need is especially important today, when the federal vaccine review and recommendation process is not functioning as it historically has.”

This is the latest in a series of independent evidence reviews, including reviews of influenza, COVID-19, and respiratory syncytial virus (RSV) immunizations, the hepatitis B birth dose, human papillomavirus (HPV) vaccination, and tetanus, diphtheria, and pertussis (Tdap) vaccination during pregnancy. 

All licensed meningococcal and pneumococcal vaccines in the United States, including those protecting against serogroups A, C, W, and Y (MenACWY); serogroup B (MenB); and newer pentavalent vaccines protecting against five vaccine-preventable serogroups (MenABCWY), will be analyzed. 

Meningococcal vaccine guidance changed under Kennedy 

Cases of meningococcal disease, a bacterial infection caused by Neisseria meningitidis, are rare in the United States, but there has been an uptick in infections since 2021, driven largely by serogroup Y, which is vaccine-preventable.

Ten percent to 15% of meningococcal infections are fatal, and 10% to 20% of survivors have permanent aftereffects, including brain injury, limb amputation, or hearing loss, according to the Centers for Disease Control and Prevention. 

Under new federal vaccine guidelines ushered in this year by Health and Human Services Secretary Robert F. Kennedy Jr., the pneumococcal vaccine is recommended for all children, but the MenB and MenACWY vaccines have been reclassified as recommended only for certain high-risk groups or populations, and other meningococcal vaccines have been relegated to immunization based on “shared clinical decision-making.”

The American Academy of Pediatrics, however, still recommends the vaccines for all children and adolescents.