HTLV-1: A virus continues to spread unnoticed
Millions of people worldwide are already infected with HTLV-1, a human virus that is transmitted primarily during sex and causes a special form of leukemia (blood cancer). The virus is also associated with various other diseases. But hardly anyone knows HTLV-1 (human T-lymphotropic virus 1) and the dangers that it poses. Although the virus was discovered decades ago, research has only recently started to focus on this topic again. Vaccination or cure has not yet been possible.
In a letter to the World Health Organization (WHO), scientists have now called for increased awareness of HTLV-1 infections. More than ten million people around the world are already infected with the virus and most are unaware of the infection, according to the research team led by Charles Bangham from Imperial College London. The British experts had looked into the effects of HTLV-1 on the human genome in a recent study, with worrying results. The study was published in the specialist magazine "eLife".
90 percent of those affected do not know about their infection
The fact that millions of people are unsuspectingly infected with a virus, which in the worst case can cause fatal diseases and is transmitted during sexual intercourse, is strongly reminiscent of the initial situation with HIV. "Humans have been carrying the virus without symptoms for decades, and 90 percent of those affected don't know that they have it," the scientists at Imperial College London report. The virus can also be transmitted through blood transfusions and breast milk, but the infection usually results from unprotected sexual intercourse. An estimated five to ten percent of those infected develop an aggressive form of leukemia or progressive paralytic disease as a result of the infection.
Research on HTLV-1 neglected for years
The discovery of HTLV-1 in 1980 by a working group led by Robert Gallo at the NIH was a sensation at the time. For decades, researchers had been looking for retroviruses in humans, and now it had finally been proven that they exist. However, the AIDS virus HIV was discovered shortly afterwards and in view of the enormous health threat posed by HIV, research in the coming decades focused primarily on this type of retrovirus. HTLV-1 has been neglected. A mistake, according to medical experts today.
Significant interventions in the genome
The British scientists at Imperial College London have shown in their current study what far-reaching consequences the viruses can have on the genome of those infected. The researchers explain that viruses such as HTLV-1 have the potential to destroy tens of thousands of genes due to the large number of so-called CTCF sites in the human genome. The new findings are also a possible explanation for the connection with leukemia and other diseases.
Connection with lung diseases
The diseases that HTLV-1 can cause include bronchiectasis (bronchial sac), according to an Australian study from March this year. The study was conducted on native Australians who had previously found relatively high infection rates with HTLV-1. The scientists examined possible connections between the viruses and lung disease such as bronchiectasis, bronchitis and bronchiolitis. The influence of the viruses on the risk of death was also determined.
Risk underestimated so far?
According to the study authors, the viruses are associated with respiratory infections and with premature death due to complications from bronchiectasis. "Our results suggest that the mortality associated with HTLV-1c infection could be higher than previously thought," warned the researchers. Further studies on the risks of HTLV-1 infections are now required. (Fp)