An ancient virus that has been called a cousin of HIV is "off the charts" prevalent in Australia, affecting more than 40% of adults in remote regions, experts tell CNN. Human T-cell leukemia virus type 1, or HTLV-1, is considered a sexually transmitted infection since it can be spread through unprotected sex; it can also spread via blood contact and breastfeeding. It weakens the immune system and can lead to a number of serious health conditions; in up to 10% of cases, a "rapidly fatal" form of leukemia develops, the Guardian reports. Yet the chair of the Global Virus Network's HTLV-1 Task Force, whose lab first detected the virus in 1979, says almost nothing has been done to attempt to screen for, treat, or vaccinate against the disease. "The virus is neglected, and the diseases that it causes are neglected," says another expert.
HTLV-1, whose DNA can be found in Andean mummies from 1,500 years ago, is present around the world, but is highly endemic in several areas including the central Australia cluster. Indigenous communities are being hit the hardest in Australia, with a rate of prevalence that is "probably the highest-ever reported ... in any population," says an expert, who notes that people in the area—including young people—are dying from the lung condition, bronchiectasis, it can cause. "A 45% infection rate in communities is shocking to me," he tells the Guardian. It's not clear what is behind this particular outbreak, but experts say it's a wake-up call and a public health response is needed. The disease is sometimes carried for 30 years before chronic complications appear, and Australia's ABC reports that many in Australia who have it have no idea they are infected. (In the US, there's something else to worry about.)