World AIDs day: what you didn't know about the spread of HIV/Aids

It's world Aids day today, which aims both to raise global awareness, and to challenge outdated stereotypes about the disease and the HIV virus which causes it HIV globally affects about 34m people. 

Even if you think you understand the scale of the problem, new research is constantly revealing surprising facts about the nature and spread of HIV and Aids. Here are four stories you might not have heard about. 

European epidemic

The number of new cases of HIV in Europe reached its highest level ever last year, according to the World Health Organisation (WHO). Over 142,000 people were diagnosed with the virus in Europe in 2014, and since 2004, the rates of new diagnoses have more than doubled in some EU and EEA countries. The WHO also warned against stigmatising migrants and refugees, who thanks to social exclusion and other issues are at particular risk from the disease. The number of migrants diagnosed with HIV in Europe has fallen, but a significant proportion of those who do have the virus contracted it after arriving in Europe, with the WHO cautioning that migrants can be forced to engage in "risky behaviour" when they aren't properly welcomed in receiving countries.

Dating apps

A UN report has drawn a link between mobile dating apps and a rise in HIV cases in Asia, the Guardian reports. The number of 10-19 year olds living with HIV in Asia and the Pacific has swelled to 220,000, with fewer than half of them receiving treatment. The trend is particularly worrying among men who have sex with men, with the report raising fears that stigma in some countries may lead these men not to seek proper advice about their sexual practices. The report says that the rise of mobile dating apps has exacerbated the problem by providing opportunities for casual sex which did not exist before, including in some fairly conservative societies.

False cure

In 2013, many believed we might have found a cure for HIV. Hannah Gay, an HIV specialist from the University of Mississippi, treated a baby born with the virus with an unusual three-drug combination in 2010. About two years later, all traces of the virus had disappeared from the patient, despite a period without any treatment when mother and child vanished from the hospital they were attending. Gay was named in TIME's list of 2013's most influential people. The scientific community rejoiced and began to wonder how they could replicate the treatment. But in 2014, after more than two years without treatment, the virus returned to the child. Sarah Boseley writes for Prospect that many scientists now accept that a permanent cure for HIV may never arrive.

Stopping the spread

New South Wales in Australia is to begin a landmark trial of HIV prevention methods, according to an announcement timed to coincide with World AIDs day. Some 3,700 people deemed to be at risk of contracting the virus, mostly gay and bisexual men, are to be given a daily dose of the antiretroviral medication known as PrEP, or pre-exposure prophylaxis. Researchers hope that rapid identification and committed prevention treatment can stop the disease in its tracks.