Despite major advances, HIV/Aids remains one of the world’s most significant public health challenges, particularly in low- and middle-income countries, with new diagnoses every year and young women in sub-Saharan Africa seen as being particularly at risk.

World Aids Day, marked today, is used to unite people in the fight against HIV, the human immunodeficiency virus first identified in 1984, to show their support for people living with HIV and commemorate those who have died.

Globally, there are about 36.9 million people living with HIV including 2.6 million children.

According to the Global Aids Response Report 2013, there were an estimated 300 persons living with diagnosed HIV in Malta by the end of that year.

UNAIDS, the international agency tasked with quelling Aids globally, has set a goal to reduce the number of new HIV infections and Aids-related deaths by 90 per cent by 2030.

By 2020 the agency wants 90 per cent of people to know their HIV status, 90 per cent of those HIV-positive to be on treatment, and 90 per cent of those on treatment to be “virally suppressed”, meaning they are unlikely to pass on the virus.

Pepfar – the US President’s Emergency Plan for Aids Relief and a major funder of anti-Aids initiatives in Africa, which has the biggest HIV epidemic in the world – is also seeking a specific 40 per cent reduction in HIV incidence in adolescent girls and young women by the end of 2017 in some of the hardest hit regions of Africa.

In South Africa, despite major advances in fighting Aids – from stronger political support for treatment to cheaper drugs and the discovery that male circumcision can cut transmission rates – those goals may be hard to meet, experts say.

Violence against women, and poverty that lures young women to trade sex for cash or gifts are also problems in this part of the world.

Brian Brink, the former chief medical officer for mining group Anglo American and one of the earliest advocates for Aids treatment in South Africa, said drop-out rates from HIV treatment remain a particular worry.

These are estimated at around 25 per cent as those who take the drugs begin to feel better or as drugs are not delivered on time to rural clinics. Brink said this could spur resistance to cheap front line treatment drugs.

Volkswagen Beetle cars during a World Aids Day rally organised by Sri Lanka's UNAIDS in Colombo. Photo:Dinuka Liyanawatte

Free government drug treatment is not yet available to all those HIVpositive in South Africa, but this may be needed to meet the global goals, not least because those on treatment are much less likely to pass on the virus, Brink said. In a country where 40 per cent of the population is under the age of 20, keeping young people – particularly young women – free of HIV will be the marker of success, he said.

World Aids Day is also a good time to promote education as people still seem not to know the facts about how to protect themselves and others, even in developed countries, and stigma and discrimination remain a reality for many people living with the condition.

For example, Britain’s National Aids Trust’s campaign for this year is Think Positive: Rethink Aids, challenging people to rethink outdated stereotypes, challenge myths and be positive about HIV. One of the main messages it wants to convey is that there are only three ways to get HIV: unprotected sex, sharing needles and mother-to-child transmission.

Is the end of Aids in sight?

Here are some facts about Aids in 2015 with data from the World Health Organisation, the United Nations children’s agency Unicef, and UNAIDS:

1. Globally about 36.9 million people are living with HIV including 2.6 million children.

2. An estimated two million were infected in 2014.

3. An estimated 34 million people have died from HIV or Aids, including 1.2 million in 2014.

4. The number of adolescent deaths from Aids has tripled over the last 15 years.

5. Aids is the number-one cause of death among adolescents in Africa and the second among adolescents globally.

6. In sub-Saharan Africa, the region with the highest prevalence, girls account for seven in 10 new infections among those aged 15-19.

7. At start of 2015, 15 million people were receiving antiretroviral therapy compared to one million in 2001.

8. Despite widespread availability of HIV testing, only an estimated 51 per cent of people with HIV know their status.

9. The global response to HIV has averted 30 million new HIV infections and nearly eight million deaths since 2000.

10. In 2015, Cuba was the first country declared to have eliminated mother-to-child transmission of HIV.