The World Health Organization (WHO) has updated its fact sheet on HIV/AIDS recently.
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.
Acquired Immunodeficiency Syndrome (AIDS) is the most advanced stage of HIV infection, and can take from 2 to 15 years to develop depending on the individual.
HIV continues to be a major global public health issue, having claimed more than 35 million lives so far. In 2016, 1.0 million people died from HIV-related causes globally.
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.
54% of adults and 43% of children living with HIV are currently receiving lifelong antiretroviral therapy (ART).
Global ART coverage for pregnant and breastfeeding women living with HIV is high at 76% .
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.
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.
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.
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.
It is estimated that currently only 70% of people with HIV know their status. To reach the target of 90%, an additional 7.5 million people need to access HIV testing services. In mid-2017, 20.9 million people living with HIV were receiving antiretroviral therapy (ART) globally.
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 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.
Symptoms and signs
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.
As the infection progressively weakens the immune system, 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.
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 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.
Most individuals develop antibodies to HIV within 28 days of infection and therefore antibodies may not be detectable early, during the so-called window period. This early period of infection represents the time of greatest infectivity; however HIV transmission can occur during all stages of the infection.
It is best practice to also retest all people initially diagnosed as HIV-positive before they enrol in care and/or treatment to rule out any potential testing or reporting error. Notably, once a person diagnosed with HIV and has started treatment they should not be retested.
HIV testing services
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).
Major approaches for HIV prevention are:
- Male and female condom use: Male latex condoms have a protective effect of >=85% against HIV and other Sexually Transmitted Infections (STIs)
- Testing and counselling for HIV and STIs
- Testing and counselling, linkages to Tuberculosis care: TB is the leading cause of death among people with HIV (1 in 3 HIV deaths). All HIV patients should be offered TB testing, and vice versa.
- Voluntary Male Medical Circumcision: Medical male circumcision, reduces the risk of heterosexually acquired HIV infection in men by approximately 60%.
- Antiretroviral Therapy 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%. ART may also be used for Post-exposure Prophylaxis for HIV (PEP).
- Harm reduction for people who use and inject drugs
- Elimination of Mother-to-child transmission of HIV (EMTCT): MTCT can be nearly fully prevented if both the mother and the baby are provided with ARV drugs as early as possible in pregnancy and during the period of breastfeeding.
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.
Link to the updated fact sheet:
Link to WHO’s World AIDS Day 2017 page:
Link to Infographics on World AIDS Day 2017:
Link to Posters on World AIDS Day 2017:
Link to Consolidated guidelines on use of antiretroviral drugs for treating and preventing HIV infection:
Link to Global Health Sector Strategy on HIV, 2016-2021:
Link to WHO publications on HIV: