What is it?

– The HIV-AIDS pandemic, which erupted in the early 1980s, is one of the most devastating events in modern-day global health. An estimated 35 million people have already died from AIDS; the current annual death toll, while slowly declining,  is estimated at around one million.

– Most of the burden is in sub-Saharan Africa, where some 25 million people were living with HIV in 2015, and where some two thirds of all new infections are happening.

– AIDS is short for Acquired Immunodeficiency Syndrome, which is the gradual destruction of the immune system by the Human Immunodeficiency Virus (HIV). AIDS is nearly universally fatal, but with proper treatment, HIV-infected people don’t progress to AIDS; many live long and healthy lives.

– There are persistent rumors, stories, and theories that HIV does not cause AIDS. These are false and are a threat to public health.

HIV budding (colored green) from a white blood cell. Credit: C. Goldsmith, P. Feorino, E. L. Palmer, W. R. McManus, CDC


What are the symptoms?

– The first stage of an HIV infection, called the acute infection, typically occurs within a few weeks after the virus first enters the body. Common symptoms include fever, swollen lymph nodes, a rash, a soar throat, and sores in the mouth or genital area. Some people also have nausea, vomiting or diarrhea.

– Symptoms usually pass within a few weeks. The virus has now integrated itself into the DNA of the host and a ‘latent phase’ starts, with few or no symptoms. This can last from just a few years to more than two decades. Eventually, however, HIV-infected people may begin experiencing fever, weight loss, and other problems.

– If untreated, most patients will eventually progress to the third phase: AIDS. The virus infects and destroys more and more CD4+ cells, a type of white blood cells involved in fighting infections. This makes the patient vulnerable to infections by dozens of other viruses, bacteria, fungi, and parasites. Which infections occur depends in part on the environment and behavior of the patient, but almost one third of deaths from HIV are caused by tuberculosis (TB).

– Patients are also vulnerable for cancers caused by viruses, including Kaposi sarcoma (a type of skin cancer) and lymphoma. Other symptoms include long-lasting fevers, weight loss, night sweats, weakness, and diarrhea.



How does it spread?

– The most important route of HIV transmission is through unprotected sexual contact. Most transmissions worldwide occur during heterosexual contact, but in many western countries, the majority of new infections are among men who have sex with men. People who have other sexually transmitted infections or genital ulcers are at higher risk of contracting HIV. The risk also depends strongly on the amount of virus circulating in the body of the sex partner.

– HIV also spreads via blood and blood products-for instance when people share needles for intravenous drug use, during transfusions, and in medical interventions using unsterilized needles or other tools.

– HIV can also be transmitted from mother to child during pregnancy and delivery, or after birth through breast milk.

– You can’t become infected with HIV through kissing, hugging, shaking hands, or sharing personal objects, food or drinks. HIV is not spread by mosquitoes.


How is it treated?

– So far, there is no cure for HIV infection. But progression to AIDS can be stopped by so-called Highly Active Antiretroviral Therapy, or HAART, which consists of a cocktail of at least three different drugs that suppress the virus. HAART is so effective that HIV often becomes undetectable using standard tests. The treatment greatly reduces the risk of death.

– Treatment with HAART should begin as soon as a person is diagnosed with HIV. But many people don’t know that they have the virus. That’s why testing of people at risk is very important.


How can it be prevented?

– Although several HIV vaccines have been tested in humans, none has been shown to work so far. There is a large number of other measures that can be taken to prevent the spread of HIV, however. The use of male condoms during anal sex & male or female condoms during vaginal sex is the most important way.

– People at risk should undergo periodic tests for HIV, and if they test positive, receive counselling on how to prevent others from becoming infected. Infected people should also go on treatment: Because HIV drugs can suppress the virus almost completely, infected people on drugs are far less likely to pass it on. (Treatment, in other words, is a form of prevention.)

– Voluntary circumcision of men at risk reduces the risk of transmission.

– Partners of HIV-infected people can take anti-retroviral drugs to avoid becoming infected, which is called pre-exposure prophylaxis (PrEP). People who have been exposed to the virus – for instance though unsafe sex or contact with contaminated blood – can take antiretroviral drugs for four weeks, along with counseling and testing, to avoid becoming infected. This is called post-exposure prophylaxis, or PEP.

– The risk from blood can be strongly curtailed as well, for instance by providing injecting drugs users with clean needles, testing blood and blood products for transfusion, and making sure medical equipment is properly sterilized.

– Mother-to-child transmission can be almost completely prevented if the mother takes HIV drugs during pregnancy and delivery, and the baby gets them for 4 to 6 weeks after birth.


The number of people taking antiretroviral treatment has sharply increased the past decade. (Numbers for 2020 and 2030 are targets.). Credit: WHO/UNAIDS



What’s the outlook?

– The availability of very effective drugs has made HIV a chronic disease in rich countries – one that you can live a long and healthy life with.  Globally, however, roughly half of the more than 35 million people living with HIV still don’t have access to drugs. Raising drug coverage is a key priority for the global health community. To achieve that, more people also need to have access to testing.

– In 2014, UNAIDS adopted the 90-90-90 strategy, as part of its Fast Track plan to end AIDS: “By 2020, 90% of all people living with HIV will know their HIV status. By 2020, 90% of all people with diagnosed HIV infection will receive sustained antiretroviral therapy. By 2020, 90% of all people receiving antiretroviral therapy will have viral suppression.” (Those numbers would all go up to 95% by 2030.) Those are ambitious targets however, that will require many billions in extra investments.

– An effective vaccine, which could make a huge difference, has so far proven elusive. But scientists are still trying new approaches and have not given up hope.

Contact an HIV-Aids expert. 


WHO information about HIV/AIDS

UNAIDS’s Fast Track plan to end the AIDS epidemic by 2030.