Cuban health authorities have detected patients infected with a new strain of the human immunodeficiency virus, HIV, which leads to a quicker progress to acquired immune deficiency syndrome, Aids, according to Cuban state television.

A study conducted by the Pedro Kouri Institute of Tropical Medicine in Havana showed that in some cases HIV took between eight and ten years to advance to Aids, while in others the same happened in less than three years, the channel reported Tuesday.

Institute spokeswoman Vivian Kouri said that researchers studied three groups of patients and for the first time found a variant of the HIV strain, known as CRF 19, which advances more rapidly to Aids, circulating in Cuba.

The new variant is believed to have originated in Africa; however its prevalence in Cuba is quite significant as it accounts for about 17 to 19 percent of patients, according to Kouri.

She also said that none of the HIV strains in Cuba was found to have a higher resistance to antiretroviral drugs and that all of them had a similar possibility for effective treatment.

However, the television report warned that the rapid spread of HIV infections from the new strain would increase the risk of patients getting gravely affected by the virus without them even realizing that they are infected.

In Cuba, almost 22,000 cases of HIV has been registered since the beginning of the epidemic in 1986, and more than 18,000 of those infected are still alive, according to official data.