Hospital patients not getting their teeth brushed, or not brushing their teeth themselves, is believed to be a leading cause of hundreds of thousands of cases of pneumonia a year in patients who have not been put on a ventilator. Pneumonia is among the most common infections that occur in health care facilities, and a majority of cases are non-ventilator hospital-acquired pneumonia, or NVHAP, which kills up to 30% of those infected, Giuliano and other experts said.

But unlike many infections that strike within hospitals, the federal government doesn’t require hospitals to report cases of NVHAP. As a result, few hospitals understand the origin of the illness, track its occurrence, or actively work to prevent it, the experts said.

Many cases of NVHAP could be avoided if hospital staffers more dutifully brushed the teeth of bedridden patients, according to a growing body of peer-reviewed research papers. Instead, many hospitals often skip teeth brushing to prioritize other tasks and provide only cheap, ineffective toothbrushes, often unaware of the consequences, said Dian Baker, a Sacramento State nursing professor who has spent more than a decade studying NVHAP.

“I’ll tell you that today the vast majority of the tens of thousands of nurses in hospitals have no idea that pneumonia comes from germs in the mouth,” Baker said.

Pneumonia occurs when germs trigger an infection in the lungs. Although NVHAP accounts for most of those cases, it historically has not received the same attention as pneumonia tied to ventilators, which is easier to identify and study because it occurs among a narrow subset of patients.

NVHAP, a risk for virtually all hospital patients, is often caused by bacteria from the mouth that gathers in the scummy biofilm on unbrushed teeth and is aspirated into the lungs. Patients face a higher risk if they lie flat or remain immobile for long periods, so NVHAP can also be prevented by elevating their heads and getting them out of bed more often.

According to the National Organization for NV-HAP Prevention, which was founded in 2020, this pneumonia infects about 1 in every 100 hospital patients and kills 15% to 30% of them. For those who survive, the illness often extends their hospital stay by up to 15 days and makes it much more likely they will be readmitted within a month or transferred to an intensive care unit.

John McCleary, 83, of Bangor, Maine, contracted a likely case of NVHAP in 2008 after he fractured his ankle in a fall and spent 12 days in rehabilitation at a hospital, said his daughter, Kathy Day, a retired nurse and advocate with the Patient Safety Action Network.

McCleary recovered from the fracture but not from pneumonia. Two days after he returned home, the infection in his lungs caused him to be rushed back to the hospital, where he went into sepsis and spent weeks in treatment before moving to an isolation unit in a nursing home.

He died weeks later, emaciated, largely deaf, unable to eat, and often “too weak to get water through a straw,” his daughter said. After contracting pneumonia, he never walked again.

“It was an astounding assault on his body, from him being here visiting me the week before his fall, to his death just a few months later,” Day said. “And the whole thing was avoidable.”

While experts describe NVHAP as a largely ignored threat, that appears to be changing.