The virulent strain of adenovirus has already claimed the lives of 10 people and dozens more have been hospitalized say US health officials.
According to the Centers for Disease Control and Prevention (CDC) since May 2006 there have been growing numbers of adenovirus 14 (Ad14) cases across the country with cases appearing in New York, Oregon, Washington state and Texas.
The CDC says the virus can cause severe respiratory disease at any age and to date 140 people have been sickened by the virus and more than 50 hospitalized, including 24 admitted to intensive care units; two of the 10 who died were infants.
While adenoviruses often cause acute upper respiratory tract infections such as the common cold, they can also cause other illnesses like inflammation of the stomach and intestines, pink eye, bladder infections and rashes.
The CDC says colds caused by adenoviruses can be very severe in the very young and the very old as well as in those with compromised immune systems, but for most people they are a mild, temporary illness.
The CDC says this particular adenovirus is different in that it can make healthy young adults severely ill which is unusual and the CDC suspects others apart from the four states mentioned have been affected by the new strain of the virus.
The National Foundation for Infectious Diseases, says public health officials need to find out the extent of the problem in order to determine how widely distributed the virus is.
The first case reported was that of an infant girl in New York City who died in May 2006 and illnesses from the virus were reported at Lackland Air Force Base in Texas where a 19-year-old female recruit died from the virus.
Seven other people died in Oregon, including an infant and a patient with AIDS died in Washington state.
Experts say the emergence of a new and virulent adenovirus variant that has spread within the United States is a concern.
The CDC says controlling adenovirus outbreaks is a difficult task as the viruses can be shed in both respiratory secretions and faeces and can persist for weeks on environmental surfaces.
There are apparently 51 types of adenoviruses.
