- HIV continues to be a major global public health issue, having claimed more than 35 million lives so far. In 2017, 940 000 people died from HIV-related causes globally.
- There were approximately 36.9 million people living with HIV at the end of 2017 with 1.8 million people becoming newly infected in 2017 globally.
- 59% of adults and 52% of children living with HIV were receiving lifelong antiretroviral therapy (ART) in 2017.
- Global ART coverage for pregnant and breastfeeding women living with HIV is high at 80%.
- The WHO African Region is the most affected region, with 25.7 million people living with HIV in 2017. The African region also accounts for over 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 2017, an estimated 47% 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 75% of people with HIV know their status. In 2017, 21.7 million people living with HIV were receiving antiretroviral therapy (ART) globally.
- Between 2000 and 2017, new HIV infections fell by 36%, and HIV-related deaths fell by 38% with 11.4 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.
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.
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. The first few weeks after initial infection, individuals may experience no symptoms or an influenza-like illness including fever, headache, rash, or sore throat.
As the infection progressively weakens the immune system, an individual can develop other signs and symptoms, such as swollen lymph nodes, weight loss, fever, diarrhoea and cough. Without treatment, they could also develop severe illnesses such as tuberculosis, 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 blood, breast milk, semen and vaginal secretions. Individuals cannot become infected through ordinary day-to-day contact such as kissing, hugging, 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 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. HIV infection can be detected with great accuracy, using WHO prequalified tests within a validated approach.
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 enroll 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.
Testing and diagnosis of HIV-exposed infants has been a challenge. 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. However, new technologies are now becoming available to perform the test at the point of care and enable return of the result on the same day to accelerate appropriate linkage and treatment initiation.
HIV testing services
HIV testing should be voluntary and the right to decline testing should be recognized. Mandatory or coerced testing by a health care provider, authority, or by a partner or family member is not acceptable as it undermines good public health practice and infringes on human rights.
New technologies to help people test themselves are being introduced, with many countries implementing self-testing as an additional option to encourage HIV diagnosis. HIV self-testing is a process whereby a person who wants to know his or her HIV status collects a specimen, performs a test and interprets the test results in private or with someone they trust. HIV self-testing does not provide a definitive HIV-positive diagnosis – instead, it is an initial test which requires further testing by a health worker.
The sexual partners and drug injecting partners of people diagnosed with HIV infection have an increased probability of also being HIV-positive. WHO recommends assisted HIV partner notification services as a simple and effective way to reach these partners, many of whom are undiagnosed and unaware of their HIV exposure, and may welcome support and an opportunity to test for HIV.
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).
Individuals can reduce the risk of HIV infection by limiting exposure to risk factors. Key approaches for HIV prevention, which are often used in combination, are listed below.
Male and female condom use
Correct and consistent use of male and female condoms during vaginal or anal penetration can protect against the spread of sexually transmitted infections, including HIV. Evidence shows that male latex condoms have an 85% or greater protective effect against HIV and other sexually transmitted infections (STIs).
Testing and counselling for HIV and STIs
Testing for HIV and other STIs is strongly advised for all people exposed to any of the risk factors. This way people learn of their own infection status and access necessary prevention and treatment services without delay. WHO also recommends offering testing for partners or couples. Additionally, WHO is recommending assisted partner notification approaches so that people with HIV receive support to inform their partners either on their own, or with the help of health care providers.
Testing and counselling, linkages to tuberculosis care
Tuberculosis (TB) is the most common presenting illness and cause of death among people with HIV. It is fatal if undetected or untreated and is the leading cause of death among people with HIV, responsible for more than 1 of 3 HIV-associated deaths.
Early detection of TB and prompt linkage to TB treatment and ART can prevent these deaths. TB screening should be offered routinely at HIV care services and routine HIV testing should be offered to all patients with presumptive and diagnosed TB. Individuals who are diagnosed with HIV and active TB should urgently start effective TB treatment (including for multidrug resistant TB) and ART. TB preventive therapy should be offered to all people with HIV who do not have active TB.
Voluntary medical male circumcision (VMMC)
Medical male circumcision, reduces the risk of heterosexually acquired HIV infection in men by approximately 60%. This is a key prevention intervention supported in 15 countries in Eastern and Southern Africa (ESA) with high HIV prevalence and low male circumcision rates. VMMC is also regarded as a good approach to reach men and adolescent boys who do not often seek health care services. Since the 2007 WHO recommendation for VMMC as an additional prevention strategy, over 18 million adolescent boys and men in ESA were provided a package of services including HIV testing and education on safer sex and condom use.
Antiretroviral drug use for prevention
Prevention benefits of ART
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%. The WHO recommendation to initiate ART in all people living with HIV will contribute significantly to reducing HIV transmission.
Pre-exposure prophylaxis (PrEP) for HIV-negative partner
Oral PrEP of HIV is the daily use of ARV drugs by HIV-negative people to block the acquisition of HIV. More than 10 randomized controlled studies have demonstrated the effectiveness of PrEP in reducing HIV transmission among a range of populations including serodiscordant heterosexual couples (where one partner is infected and the other is not), men who have sex with men, transgender women, high-risk heterosexual couples, and people who inject drugs.
WHO recommends PrEP as a prevention choice for people at substantial risk of HIV infection as part of a combination of prevention approaches. WHO has also expanded these recommendations to HIV-negative women who are pregnant or breastfeeding.
Post-exposure prophylaxis for HIV (PEP)
Post-exposure prophylaxis (PEP) is the use of ARV drugs within 72 hours of exposure to HIV in order to prevent infection. PEP includes counselling, first aid care, HIV testing, and administration of a 28-day course of ARV drugs with follow-up care. WHO recommends PEP use for both occupational and non-occupational exposures and for adults and children.
Harm reduction for people who inject and use drugs
People who inject drugs can take precautions against becoming infected with HIV by using sterile injecting equipment, including needles and syringes, for each injection and not sharing drug using equipment and drug solutions. Treatment of dependence, and in particular opioid substitution therapy for people dependent on opioids, also helps reduce the risk of HIV transmission and supports adherence to HIV treatment. A comprehensive package of interventions for HIV prevention and treatment includes:
- needle and syringe programmes;
- opioid substitution therapy for people dependent on opioids and other evidence-based drug dependence treatment;
- HIV testing and counselling;
- HIV treatment and care;
- risk-reduction information and education and provision of naloxone;
- access to condoms; and
- management of STIs, tuberculosis and viral hepatitis.
Elimination of mother-to-child transmission of HIV (EMTCT)
The transmission of HIV from an HIV-positive mother to her child during pregnancy, labour, delivery or breastfeeding is called vertical or mother-to-child transmission (MTCT). In the absence of any interventions during these stages, rates of HIV transmission from mother-to-child can be between 15–45%. 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.
WHO recommends lifelong ART for all people living with HIV, regardless of their CD4 count clinical stage of disease, and this includes women who pregnant or breastfeeding. In 2017, 80% of the estimated 1.1 million pregnant women living with HIV globally received ARV treatments to prevent transmission to their children. A growing number of countries are achieving very low rates of MTCT and some (Armenia, Belarus, Cuba and Thailand) have been formally validated for elimination of MTCT of HIV as a public health problem. Several countries with a high burden of HIV infection are also progressing along the path to elimination.
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.
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. By mid-2018, 163 countries already have adopted this recommendation, which covers 98% of all PLHIV globally.
- Consolidated guidelines on the use of antiretroviral drugs for treating and preventing HIV infection
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.
Transition to dolutegravir has already started in 24 low- and middle-income countries and is expected to improve the durability of the treatment and the quality of care of people living with HIV. Despite improvements, limited options remain for infants and young children. For this reason, WHO and partners are coordinating efforts to enable a faster and more effective development and introduction of age-appropriate pediatric formulations of antiretrovirals.
In addition, 1 in 3 people living with HIV present to care with advanced disease, at low CD4 counts and at high risk of serious illness and death. To reduce this risk, WHO recommends that these patients receive a “package of care” that includes testing for and prevention of the most common serious infections that can cause death, such as tuberculosis and cryptococcal meningitis, in addition to ART.
Based on WHO’s new recommendations to treat all people living with HIV, the number of people eligible for ART has increased from 28 million to all 36.9 million people living with HIV.
In 2017, 21.7 million people living with HIV were receiving ART globally. In 2017, a global ART coverage of 59% of adults and children living with HIV was reached. However, more efforts are needed to scale up treatment, particularly for children and adolescents. Only 52% of them were receiving ARVs at the end of 2017 and WHO is supporting countries to accelerate their efforts to timely diagnose and treat these vulnerable populations.
Expanding access to treatment is at the heart of a set of targets for 2020 which aim to bring the world on track to end the AIDS epidemic by 2030.
The Sixty-ninth World Health Assembly endorsed a new Global Health Sector Strategy on HIV for 2016-2021. The strategy includes 5 strategic directions that guide priority actions by countries and by WHO over the next six years.
The strategic directions are:
- Information for focused action (know your epidemic and response).
- Interventions for impact (covering the range of services needed).
- Delivering for equity (covering the populations in need of services).
- Financing for sustainability (covering the costs of services).
- Innovation for acceleration (looking towards the future).
WHO is a cosponsor of the Joint United Nations Programme on AIDS (UNAIDS). Within UNAIDS, WHO leads activities on HIV treatment and care, HIV and tuberculosis co-infection, and jointly coordinates with UNICEF the work on the elimination of mother-to-child transmission of HIV.
HIV/AIDS By WORLD HEALTH ORGANIZATION (WHO)