Every year, on December 1, the world observes World AIDS Day. People around the world unite to show support for people living with HIV and to remember those who have died from AIDS-related illnesses. Founded in 1988, World AIDS Day was the first ever international day for global health. Every year, United Nations agencies, governments and civil society join hands to campaign around specific themes related to HIV. Awareness-raising activities take place around the globe. People living with HIV make their voice heard on issues important in their lives.

HIV/AIDS is a global pandemic. More than 40 million people worldwide currently have HIV. Women make up slightly more than half of the infected population; 2.1 million of the patients are children. Sub-Saharan Africa is the most affected region. An estimated 20.6 million live in eastern and southern Africa. South and South East Asia are the second most affected region, with an estimated 4 million cases; approximately 2.4 million of these cases are in India. Since the time when AIDS was first identified (early 1980s) and 2018, the disease has caused an estimated 32 million deaths worldwide.

HIV/AIDS is a spectrum of conditions caused by infection with the immunodeficiency virus, HIV. There are three main stages of HIV infection: acute infection, clinical latency and AIDS.

The initial period is called acute HIV or primary HIV. Many individuals develop flu like symptoms 2–4 weeks after exposure while others have no significant symptoms. Symptoms occur in 40–90 percent of cases and most commonly include fever, large tender lymph nodes, sore throat, headache, sores of the mouth and genitals, a rash in 20–50 percent of cases on the trunk. Some people also develop opportunistic infections at this stage.

Gastrointestinal symptoms like vomiting or diarrhea may occur. Neurological symptoms of peripheral neuropathy also occur. The duration of the symptoms varies, but is usually one or two weeks. Owing to their nonspecific character, these symptoms are not often recognised as signs of HIV infection.

The second stage is called clinical latency, asymptomatic HIV, or chronic HIV. Without treatment, this stage can last from about three years to over 20 years, an average of eight years. Near the end of this stage many people experience fever, weight loss, gastrointestinal problems and muscle pains. Between 50 percent and 70 percent of people also develop persistent generalised lymphadenopathy, characterised by unexplained, non-painful enlarged lymph nodes (other than in the groin) for over three to six months.

In the absence of specific treatment, around half of people infected with HIV develop AIDS within ten years. The most common initial conditions are pneumonia (40 percent), extreme weight loss and muscle wasting (20 percent), and esophageal candidiasis. Other common signs include recurrent respiratory tract infections. Opportunistic infections may be caused by bacteria, viruses, fungi and parasites that are normally controlled by the immune system. These infections can affect nearly every organ system.

Additionally, people with AIDS frequently have systemic symptoms such as prolonged fevers, sweats (particularly at night), swollen lymph nodes, chills and weakness. Diarrhea is present in about 90 percent of people with AIDS. They can also be affected by diverse psychiatric and neurological symptoms.

Globally, the most common mode of HIV transmission is via sexual contact between people of opposite sex; however, most HIV transmission in the United States are among men who had sex with men.

Due to unprotected heterosexual contacts, estimates of the risk of HIV transmission per sexual act appear to be four to ten times higher in low-income countries. The risk of transmission from anal intercourse is especially high, but relatively low from oral sex. Genital ulcers appear to increase the risk approximately five-fold.

The viral load of an infected person is an important risk factor in both sexual and mother-to-child transmissions. During the first 2.5 months of an HIV infection a person’s infectiousness is twelve times higher due to the high viral load associated with acute HIV. If the person is in the late stages of infection, rates of transmission are approximately eight times greater.

The second-most frequent mode of HIV transmission is via blood and blood products. Blood-borne transmission can be through needle-sharing during intravenous drug use, needle-stick injury, transfusion of contaminated blood or blood product, or medical injections with unsterilised equipment.

Risks are also associated with invasive procedures, assisted delivery, and dental care. Tattoos, piercings and mosquitoes or other insects do not transmit HIV.

HIV can be transmitted from mother to child during pregnancy, during delivery or through breast milk.

After the virus enters the body there is a period of rapid viral replication leading to an abundance of virus in the peripheral blood. During primary infection, the level of HIV may reach several million virus particles per milliliter of blood.

Globally, the most common mode of HIV transmission is via sexual contact between people of opposite sex; however, most HIV transmission in the United States has been among men who had sex with men. 

HIV/AIDS is diagnosed via laboratory testing and then staged based on the presence of certain signs and symptoms. Most people infected with HIV develop specific antibodies within twelve weeks after the initial infection.

Methods of prevention include safe sex, needle exchange programmes, treating those who are infected and prophylaxis.

Consistent condom use reduces the risk of HIV transmission by approximately 80 percent. When condoms are used consistently by a couple in which one person is infected, the rate of HIV infection is less than 1 percent per year, female condoms may provide an equivalent level of protection. Circumcision reduces the risk of HIV for heterosexual men.

Programmes to prevent the transmission of HIV from mothers to children can reduce rates of transmission by 99 percent. This primarily involves the use of a combination of antiviral medications during pregnancy and after birth in the infant, and includes bottle feeding instead of breast feeding.

Blood and blood products transfusion should be done after careful screening.

There is currently no cure, no licensed and effective vaccine for HIV or AIDS. However, antiretroviral treatment can slow the course of the disease and may lead to a near-normal life expectancy. The treatment regime includes preventive and active treatment of opportunistic infections. As of March 2020, two persons have been successfully cleared of HIV. Rapid initiation of anti-retroviral therapy within a week of diagnosis appears to improve treatment outcomes in low and medium-income settings.

Benefits of treatment include a decreased risk of progression to AIDS and a decreased risk of death. Treatment also improves physical and mental health. With treatment, there is a 70 percent reduced risk of acquiring tuberculosis. Additional benefits include a decreased risk of transmission of the disease to sexual partners and a decrease in mother-to-child transmission.

Vaccination against hepatitis A and B is advised for all people at risk of HIV. Influenza vaccination and pneumococcal polysaccharide vaccine are often recommended in people with HIV/AIDS with some evidence of benefit.

A generally healthy diet is promoted. Dietary intake of micronutrients by HIV-infected adults is recommended by the WHO; but higher intake of vitamin A, zinc and iron can produce adverse effects in HIV-positive adults, and is not recommended unless there is documented deficiency. Dietary supplementation may strengthen their immune systems or help them recover from infections.

For pregnant and lactating women with HIV, multivitamin supplement improves outcomes for both mothers and children. There is some evidence that vitamin A supplementation in children with an HIV infection reduces mortality and improves growth.

Prognosis varies between people. Without treatment, average survival time after infection with HIV is estimated to be 9 to 11 years. After the diagnosis of AIDS, without treatment survival ranges between 6 and 19 months. Antiviral treatment and appropriate prevention of opportunistic infections reduce the death rate by 80 percent, and raise the life expectancy for a newly diagnosed young adult to 20–50 years. If treatment is started late, prognosis is not as good. Half of infants born with HIV die before two years of age without treatment.

The primary causes of death from HIV/AIDS are opportunistic infection (like TB, hepatitis C) and Cancer, both of which are frequently the result of the progressive failure of the immune system.

HIV is believed to have originated in non-human primates and was transferred to humans in the early 20th century.

AIDS stigma exists around the world in a variety of ways, including exclusion, rejection, discrimination and avoidance of HIV-infected people; violence against HIV-infected individuals; and the quarantine of HIV-infected individuals. Stigma-related fear of violence prevents many people from seeking HIV testing, or treatment, possibly turning what could be a manageable chronic illness into death and perpetuating the spread of HIV.

The writer is a physician of long standing