The World Health Organization (WHO) has updated its fact sheet on HIV/AIDS.
The Human Immunodeficiency Virus (HIV) targets the immune system and weakens people’s defence systems against infections and some types of cancer. As the virus destroys and impairs the function of immune cells, infected individuals gradually become immunodeficient. Immune function is typically measured by CD4 cell count.
Immunodeficiency results in increased susceptibility to a wide range of infections, cancers and other diseases that people with healthy immune systems can fight off.
The most advanced stage of HIV infection is Acquired Immunodeficiency Syndrome (AIDS), which can take from 2 to 15 years to develop depending on the individual. AIDS is defined by the development of certain cancers, infections, or other severe clinical manifestations.
HIV continues to be a major global public health issue, having claimed more than 35 million lives so far.
There were approximately 36.7 million people living with HIV at the end of 2016 with 1.8 million people becoming newly infected in 2016 globally.
The WHO African Region is the most affected region, with 25.6 million people living with HIV in 2016. The African region also accounts for almost two thirds of the global total of new HIV infections.
Between 2000 and 2016, new HIV infections fell by 39%, and HIV-related deaths fell by one third with 13.1 million lives saved due to Antiretroviral Therapy (ART) in the same period. This achievement was the result of great efforts by national HIV programmes supported by civil society and a range of development partners.
In 2016, 1.0 million people died from HIV-related causes globally.
Signs and Symptoms
The symptoms of HIV vary depending on the stage of infection. Though people living with HIV tend to be most infectious in the first few months, many are unaware of their status until later stages.
Initially, there may be no symptoms, or an influenza-like illness including fever, headache, rash, or sore throat.
Later, an individual can develop other signs and symptoms, such as
- swollen lymph nodes,
- weight loss,
- diarrhoea and
Without treatment, they could also develop severe illnesses such as
- cryptococcal meningitis,
- severe bacterial infections and
- cancers such as lymphomas and Kaposi’s sarcoma, among others.
HIV can be transmitted via the exchange of a variety of body fluids from infected individuals, such as
- breast milk,
- semen and
- vaginal secretions.
Individuals cannot become infected through ordinary day-to-day contact such as
- shaking hands, or
- sharing personal objects, food or water.
Behaviours and conditions that put individuals at greater risk of contracting HIV include:
- having unprotected anal or vaginal sex;
- having another sexually transmitted infection such as syphilis, herpes, chlamydia, gonorrhoea, and bacterial vaginosis;
- sharing contaminated needles, syringes and other injecting equipment and drug solutions when injecting drugs;
- receiving unsafe injections, blood transfusions, tissue transplantation, medical procedures that involve unsterile cutting or piercing; and
- experiencing accidental needle stick injuries, including among health workers.
Key populations are groups who are at increased risk of HIV irrespective of epidemic type or local context. They include:
- men who have sex with men,
- people who inject drugs,
- people in prisons and other closed settings,
- sex workers and their clients, and
- transgender people.
Key populations often have legal and social issues related to their behaviours that increase vulnerability to HIV and reduce access to testing and treatment programmes.
In 2015, an estimated 44% of new infections occurred among key populations and their partners.
HIV infection is often diagnosed through rapid diagnostic tests (RDTs), which detect the presence or absence of HIV antibodies. Most often these tests provide same-day test results, which are essential for same day diagnosis and early treatment and care.
Serological tests, such as RDTs or enzyme immunoassays (EIAs), detect the presence or absence of antibodies to HIV-1/2 and/or HIV p24 antigen.
No single HIV test can provide an HIV-positive diagnosis. It is important that these tests are used in combination and in a specific order that has been validated and is based on HIV prevalence of the population being tested.
It is important to note that serological tests detect antibodies produced by an individual as part of their immune system to fight off foreign pathogens, rather than direct detection of HIV itself.
It is estimated that currently only 70% of people with HIV know their status. The remaining 30% – or 7.5 million people – need to access HIV testing services.
Notably, once a person diagnosed with HIV and has started treatment they should not be retested.
For infants and children less than 18 months of age, serological testing is not sufficient to identify HIV infection – virological testing must be provided (at 6 weeks of age, or as early as birth) to detect the presence of the virus in infants born to mothers living with HIV.
The sexual partners and drug injecting partners of people diagnosed with HIV infection have an increased probability of also being HIV-positive.
All HIV testing services must follow the 5 Cs principles recommended by WHO:
- informed Consent
- Correct test results
- Connection (linkage to care, treatment and other services).
- Male and female condom use
- Testing and counselling for HIV and STIs
- Testing and counselling, linkages to Tuberculosis care
- Voluntary Male Medical Circumcision (VMMC)
- Antiretroviral Drug use for prevention
A 2011 trial has confirmed that if an HIV-positive person adheres to an effective ART regimen, the risk of transmitting the virus to their uninfected sexual partner can be reduced by 96%.
- Pre-exposure Prophylaxis (PrEP) for HIV-negative partner
- Post-exposure Prophylaxis (PEP) for HIV
- Harm reduction for people who inject and use drugs
- Elimination of Mother-to-child transmission of HIV (EMTCT)
There is no cure for HIV infection. However, effective antiretroviral (ARV) drugs can control the virus and help prevent transmission so that people with HIV, and those at substantial risk, can enjoy healthy, long and productive lives.
HIV can be suppressed by combination ART consisting of 3 or more ARV drugs. ART does not cure HIV infection but suppresses viral replication within a person’s body and allows an individual’s immune system to strengthen and regain the capacity to fight off infections.
54% of adults and 43% of children living with HIV are currently receiving lifelong antiretroviral therapy (ART).
In 2016, 19.5 million people living with HIV were receiving ART globally.
Global ART coverage for pregnant and breastfeeding women living with HIV is high at 76%.
In 2016, WHO released the second edition of the Consolidated guidelines on the use of antiretroviral drugs for treating and preventing HIV infection. These guidelines recommend to provide lifelong ART to all people living with HIV, including children, adolescents and adults, pregnant and breastfeeding women, regardless of clinical status or CD4 cell count.
The 2016 guidelines include new alternative ARV options with better tolerability, higher efficacy, and lower rates of treatment discontinuation when compared with medicines being used currently:
- dolutegravir and low-dose efavirenz for first-line therapy, and
- raltegravir and darunavir/ritonavir for second-line therapy.
Link to the updated fact sheet:
Link to Policy Brief of the Consolidated Guidelines on use of ARV drugs for treating and preventing HIV infection (English) [PDF]:
Links to fact sheets based on the Consolidated Guidelines on use of ARV drugs for treating and preventing HIV infection:
Fact sheet ‘What’s new in HIV treatment’ (English) [PDF]:
Fact sheet ‘What’s new in Monitoring’ (English) [PDF]:
Fact sheet ‘What’s new in Service Delivery’ (English) [PDF]:
Fact sheet ‘What’s new in Infant Diagnosis’ (English) [PDF]:
Fact sheet ‘What’s new in Adolescent treatment and care’ (English) [PDF]: