Bone marrow transplant patients are especially susceptible to a wide range of infections, and researchers say rhinovirus is an overlooked infection that can lead to pneumonia, according to an article first published by Rachel Tompa of

The study, published last month in the journal Haematologica has found that like more “serious” viruses, rhinovirus can cause pneumonia, and when it does, it can be deadly to those recovering from transplantation.

The results not only point to the importance of strong infection prevention measures for transplant patients and better care for those with rhinovirus-related pneumonia but lend a rationale for drug companies and researchers to prioritize developing effective antiviral drugs for this most common of common cold-causing viruses, said Dr. Michael Boeckh, a Fred Hutchinson Cancer Research Center infectious disease specialist.

Their study was not the first to show that transplant patients get rhinovirus but the first to definitively link the virus to pneumonia in these patients. That new discovery is thanks to modern virus detection methods — rhinovirus was difficult to pinpoint using older technologies, Boeckh said. Over the past decade, with the advent of better viral detection, he and other clinicians started to see evidence of rhinovirus in the lungs in transplant patients with pneumonia. But they didn’t know if the virus was causing the complication or if it was just along for the ride.

In their recent study, the researchers took a retrospective look at 697 patients who’d received transplants at Seattle Cancer Care Alliance, Fred Hutch’s clinical care partner, between 1993 and 2015 and who had also tested positive for rhinovirus. They compared the 128 patients with rhinovirus in the lower respiratory tract to those infected with viruses already known to cause pneumonia — and sometimes death — in transplant patients, namely, influenza; parainfluenza virus, or PIV; and respiratory syncytial virus, or RSV.

In contrast to what researchers believed in the past, their study showed that rhinovirus is linked to pneumonia and death even without any other co-existing infections, strongly suggesting that the so-called mild virus can be dangerous all on its own.

Boeckh and his colleagues found that rhinovirus infection led to pneumonia less often than the other viruses. About 15 percent of patients with an upper respiratory tract infection — the type of infection we typically think of as a “common cold” — went on to develop pneumonia, or an infection of the lower respiratory tract. Progression from cold-like symptoms to pneumonia for patients infected with RSV, for example, happened about twice as often.

But once patients developed pneumonia, rhinovirus turned out to be just as deadly as the other viruses, the researchers found. About 40 percent of patients in their study who developed pneumonia from any viral infection died.

Even though rhinovirus is less likely on a case-by-case basis to lead to pneumonia, it’s actually the most common cause of pneumonia caused by respiratory viruses in transplant patients, Boeckh said. That’s because the virus is so common and because it’s present year-round, unlike the other, more seasonal viruses.

Overall, their results point to the need for better preventions and treatments for the virus, Boeckh said.