U.S. researchers have discovered a new virus they believe it is linked to a rare but extremely lethal type of skin cancer, a study released Thursday said.

Merkel cell carcinoma (MCC) is a highly aggressive disease, which afflicts the elderly and people with weaker immune systems, including AIDS and transplant patients.

The disease develops in the nerve cells that respond to touch. It spreads easily to other tissue and organs, killing two thirds of its victims within five years.

MCC strikes about 1,500 people in the U.S. each year. When found in advanced stages, it kills about half its victims within nine months. By comparison, about 60,000 cases of melanoma are diagnosed every year and about 14 percent of those people die.

Professor Patrick Moore, from the University Of Pittsburgh School Of Medicine, who led the study, said he and his team found a strong link between the rare cancer and a new virus they called Merkel Cell Polyomarivus (MCV).

“This is the first polyomavirus to be strongly associated with a particular type of human tumor. Although polyomavirus have been studied in relation to cancer development for years, the weight of scientific evidence had been leaning toward the view that these viruses do not cause human cancers,” Moore and his colleagues said in the online issue of the journal Science.

The researchers found that 16 percent of people carry the Merkel cell polyomavirus, but this does not mean those people will get cancer. The discovery indicates that most people’s immune systems fight the virus, keeping it from infecting cells and causing cancer.

“It’s integrated in such a way that it looks like it was present before the tumor actually started growing. That at least gives us some evidence that the virus may play a role in this tumor,” Moore said.

If the new virus is proved to cause MCC it should give new leads for treating skin cancer. Experts suspect the virus is deadly because it produces a cancer-causing protein or knocks out a gene that suppresses tumor growth.

“Information that we gain could possibly lead to a blood test or vaccine that improves disease management and aids in prevention,” Moore said.

Moore added that more study was needed to prove that this agent would lead to developing MCC, but “the fact that the virus is so strongly associated with the tumor is at least a very good bet that it is playing an important role.”

MCV shares some of the characteristics of human papilloma virus (HPV) which is responsible for cervical cancer. Like HPV, it is likely that few people infected with the virus develop cancer, Moore said.