A newly discovered fast-progressing strain of HIV discovered in Cuba has been found to lead to AIDS as much as three times faster than the most common strains of the virus, a study by the University of Leuven in Belgium has shown.

To investigate the potentially increased proportion of Cuban patients with rapid progression to AIDS over the past decade - mostly white males from Havana in their early 30s - the research team set up an exploratory study evaluating the association of rapid progression with epidemiological, clinical, viral and immunological parameters, comparing three groups of patients.

The first two groups were newly diagnosed patients who had had an HIV negative test less than three years earlier. They either had been already diagnosed with AIDS (AIDS-RP) or were still AIDS-free (non-AIDS). The third group were chronically infected HIV-1 patients with AIDS.

All of the patients infected with CRF19, a recombinant of subtype D, subtype A and subtype G, with a subtype D protease, were found to have higher loads of the virus in their bodies. They were also more likely to have developed AIDS within three years, the study published in the journal EBioMedicine noted.

The findings led the researchers to conclude that an evolutionary very fit CRF19 together with co-infections is behind the increase of rapid progression to AIDS.