Mutant cold virus kills 10 since May 2006

Los Angeles: A virulent new form of a common cold virus has killed 10 people and hospitalised at least 53 since May 2006, the national Centers for Disease Control and Prevention has reported.

The adenovirus serotype 14 virus has sickened more than 360 people in Texas, Oregon, Washington and New York, the report said. One of the largest outbreaks occurred at Lackland Air Force Base in San Antonio, where 106 soldiers were infected and one died.

"Adenoviruses have been known to cause severe disease in the very young and the very old and people with medical problems," said co-author Dr John Su, a CDC infectious diseases investigator.

"What brought this to our attention is that it can cause severe respiratory diseases in otherwise healthy adults."

Researchers did not know what caused the virus to mutate or what sparked the outbreaks.

Contaminated air

Adenoviruses come in 51 types, causing illnesses that include pink eye, bronchitis and gastrointestinal problems. There is no drug specifically designed for adenovirus infections, but many infections resolve on their own.

Adenovirus 14 tends to cause colds or respiratory illnesses and can be spread by contaminated surfaces and through air in a cough or sneeze, Su said.

It caused respiratory disease among military recruits in the Netherlands in 1955 but has been detected only sporadically since. The strain of adenovirus 14 involved in the recent outbreaks is genetically distinct from the 1955 strain, Su said.

The largest outbreaks occurred at four air force bases in Texas. In addition to the cases reported at Lackland, three other bases in Texas reported 220 adenovirus 14 infections between March and September. The outbreaks at the bases "may potentially have to do with crowding", Su said.

Oregon identified 31 cases. Those who fell ill had a median age of 54, which is younger than the typical age for patients with severe disease, Su said. Seven people, with a median age of 64 years, died from severe pneumonia.