HIV stands for human immunodeficiency virus. HIV is a retrovirus that infects cells of the human immune system (mainly CD4-positive T-cells and macrophages—key components of the cellular immune system) and destroys or impairs their function. Infection with this virus results in the progressive depletion of the immune system, leading to immunodeficiency.
The immune system is considered deficient when it can no longer fulfil its role of fighting off infection and diseases. People with immunodeficiency are much more vulnerable to a wide range of infections and cancers, most of which are rare among people without immunodeficiency. Diseases associated with severe immunodeficiency are known as opportunistic infections because they take advantage of a weakened immune system.
AIDS stands for acquired immunodeficiency syndrome and describes the collection of symptoms and infections associated with acquired deficiency of the immune system. Infection with HIV has been established as the underlying cause of AIDS. The level of immunodeficiency or the appearance of certain infections are used as indicators that HIV infection has progressed to AIDS.
Most people infected with HIV do not know that they have become infected. Immediately after the infection, some people have a glandular fever-like illness (with fever, rash, joint pains and enlarged lymph nodes), which can occur at the time of seroconversion. Seroconversion refers to the development of antibodies to HIV and usually takes place between one and two months after an infection has occurred.By: UNAIDS
The term AIDS applies to the most advanced stages of HIV infection.
The majority of people infected with HIV, if not treated, develop signs of AIDS within eight to 10 years.
AIDS is identified on the basis of certain infections. Stage 1 HIV disease is asymptomatic and not categorized as AIDS. Stage II (includes minor mucocutaneous manifestations and recurrent upper respiratory tract infections), III (includes unexplained chronic diarrhoea for longer than a month, severe bacterial infections and pulmonary tuberculosis) or IV (includes toxoplasmosis of the brain, candidiasis of the oesophagus, trachea, bronchi or lungs and Kaposi’s sarcoma) HIV disease are used as indicators of AIDS. Most of these conditions are opportunistic infections that can be treated easily in healthy people.
In addition, the United States Centers for Disease Control and Prevention defines AIDS on the basis of a CD4-positive T-cell count of less than 200 per mm3 of blood (see: http://www.cdc.gov/epo/dphsi/print/aids1993.htm). CD4-positive T-cells are critical in mounting an effective immune response to infections.
The length of time can vary widely between individuals. The time between infection with HIV and becoming ill with AIDS can be 10–15 years, sometimes longer, but sometimes shorter. Antiretroviral therapy can prevent progression to AIDS by decreasing viral load in an infected body.
UNAIDS: HIV can be found in body fluids, such as blood, semen, vaginal fluids and breast milk.
HIV is transmitted through penetrative (anal or vaginal) sex, blood transfusion, the sharing of contaminated needles in health-care settings and drug injection and between mother and infant during pregnancy, childbirth and breastfeeding.
HIV can be transmitted through penetrative sex. HIV is not transmitted very efficiently so the risk of infection through a single act of vaginal sex is low. Transmission through anal sex has been reported to be 10 times higher than by vaginal sex. A person with an untreated sexually transmitted infection, particularly involving ulcers or discharge, is, on average, six to 10 times more likely to pass on or acquire HIV during se
Oral sex is regarded as a low-risk sexual activity in terms of HIV transmission.
When a person living with HIV is taking effective antiretroviral therapy and has a suppressed viral load they are no longer infectious.
Transmission through sharing of needles and syringes
Re-using or sharing needles or syringes represents a highly efficient way of transmitting HIV. The risk of transmission can be lowered substantially among people who inject medicines by always using new needles and syringes that are disposable or by properly sterilizing reusable needles/syringes before reuse. Transmission in a health-care setting can be lowered by health-care workers adhering to universal precautions.
HIV can be transmitted to an infant during pregnancy, labour, delivery and breastfeeding. Generally, there is a 15–30% risk of transmission from mother to child before and during delivery. A number of factors influence the risk of infection, particularly the viral load of the mother at birth (the higher the load, the higher the risk). Transmission from mother to child after birth can also occur through breastfeeding (see question 21). The chances of transmission of HIV to a child is very low if the mother is on antiretroviral therapy during pregnancy and when breastfeeding.
Transmission through blood transfusion
There is a high risk (greater than 90%) of acquiring HIV through transfusion of infected blood and blood products. However, the implementation of blood safety standards ensures the provision of safe, adequate and good-quality blood and blood products for all patients requiring transfusion. Blood safety includes screening of all donated blood for HIV and other blood-borne pathogens, as well as appropriate donor selection.
Transmission through kissing on the mouth carries no risk, and no evidence has been found that the virus is spread through saliva by kissing
Sexual transmission of HIV can be prevented by:
Additional ways of avoiding infection:
Safer sex involves taking precautions that decrease the potential of transmitting or acquiring sexually transmitted infections, including HIV, while having sex. Using condoms correctly and consistently during sex is considered safer sex, as is oral sex and non-penetrative sex or taking pre exposure prophylaxis if you are at risk of HIV infection or having undetectable viral load if you are living with HIV.
Quality-assured condoms are the only products currently available to protect against sexual infection by HIV and other sexually transmitted infections. When used properly, condoms are a proven and effective means of preventing HIV infection among women and men.
In order to achieve the protective effect of condoms, they must be used correctly and consistently. Incorrect use can lead to condom slippage or breakage, thus diminishing their protective effect.
After sex, the condom needs to be removed the right way.
If you are going to have sex again, use a new condom and repeat the whole process.
An HIV test is a test that reveals whether a person has been infected with HIV. Commonly used HIV tests detect the antibodies produced by the immune system in response to HIV, as they are much easier (and cheaper) to detect than the virus itself. Antibodies are produced by the immune system in response to an infection.
For most people, it takes a month for these antibodies to develop. Antibodies can be found in blood or oral fluid.
Generally, it is recommended that you wait three months after possible exposure before being tested for HIV. Although HIV antibody tests are very sensitive, there is a window period of up to two months, depending on the specific test being used, which is the period between infection with HIV and the appearance of detectable antibodies to the virus. In the case of the most sensitive anti-HIV tests currently recommended, the window period is about three weeks. This period may be longer if less-sensitive tests are used.
During the window period, people infected with HIV have no antibodies in their blood that can be detected by an HIV test. However, the person may already have high levels of HIV in their body fluids, such as blood, semen, vaginal fluids and breast milk. HIV can be passed on to another person during the window period even though an HIV test may not show that they are infected with HIV.
Knowing your HIV status has two vital benefits. Firstly, if you are HIV-infected, you can start treatment promptly, thereby potentially prolonging your life for many years (see question 36). Secondly, if you know you are infected, you can take all the necessary precautions to prevent the spread of HIV to others (see question 13). If you are not infected with HIV, you can learn how to protect yourself from HIV in the future.
There are many places where you can be tested for HIV: in the offices of a private doctor, a local health department, hospitals, family planning clinics and sites specifically set up for HIV testing. Always try to find testing at a place where counselling is provided about HIV. You can also take an HIV test in privacy by using an HIV self-test kit. However you should go and see your health-care provider in the event of a positive test result for confirmation and seeking appropriate treatment
HIV is not spread by mosquitoes or other biting insects. Even if the virus enters a mosquito or another sucking or biting insect, it cannot reproduce in the insect. Since the insect cannot be infected with HIV, it cannot transmit HIV to the next human it feeds on or bites.
HIV is not transmitted by day-to-day contact in social settings, schools or the workplace. You cannot be infected by shaking someone’s hand, by hugging someone, by using the same toilet or drinking from the same glass as someone living with HIV or by being exposed to coughing or sneezing by an infected person.
No. Anyone who has condom-less sex, shares injecting equipment or has a transfusion with contaminated blood can become infected with HIV. Infants can be infected with HIV from their mothers during pregnancy, during labour or after delivery through breastfeeding.
COVID-19 is a serious disease and all people living with HIV should take all recommended preventive measures to minimize exposure to, and prevent infection by, the virus that causes COVID-19.
As in the general population, older people living with HIV or people living with HIV with heart or lung problems may be at a higher risk of becoming infected with the virus and of suffering more serious symptoms.
We will actively learn more about how HIV and COVID-19 together impact on people living with HIV from countries and communities responding to both epidemics. Lessons in rolling out innovations or adapting service delivery to minimize the impact on people living with HIV will be shared and replicated as they become available. Until more is known, people living with HIV—especially those with advanced or poorly controlled HIV disease—should be cautious and pay attention to the prevention measures and recommendations.
People living with HIV should protect themselves and others from the virus that causes COVID-19 in the same way that all people are advised to reduce exposure:
However, that in many countries, owing to weaker health-care systems, informal settlements, overcrowded cities and public transportation and a lack of clean water and sanitation, the current approaches to self-protection, social distancing and containment may not be viable.
Key populations, including people who use medicines, sex workers, gay men and other men who have sex with men, transgender people and prisoners, should continue to ensure that they have essential means to prevent HIV infection, such as sterile needles and syringes and/or opioid substitution therapy, condoms and pre-exposure prophylaxis (PrEP).
If you are experiencing violence, it may be helpful to reach out to family, friends and neighbours, to seek support from a hotline or, if safe, from an online service for survivors of violence. Find out if local services (e.g. shelters, counselling) are open and reach out to them if available. Make a safety plan in case the violence against you or your children escalates. This includes: