AIDS

Quick overview

What is AIDS?

AIDS (Acquired Immune Deficiency Syndrome) results from an infection by the HIV, a retrovirus which attacks the immune system. AIDS itself is the final stage of the infection.

The virus has existed in the United States, Haiti and Africa since at least 1977-1978. In 1979, rare types of pneumonia, cancer and other illnesses were being reported by doctors in Los Angeles and New York. AIDS was first recognized in 1981.

By the end of 2008, the UN estimated that 33.4 million people around the world were HIV-positive, and that the disease had caused 2 million deaths during the year. In 2008, there were 2.1 millions children living with HIV.

Although the outbreak is a cause for concern all over the globe, it is particularly virulent in Sub-Saharan Africa, South-East Asia, Latin America and Russia.

For travellers, the risk of infection depends more on drug use and sexual behavior rather than destination.

Immunity

Immunity mechanisms remain widely unknown for the time being. As of today, there is no known immunisation against AIDS.

Risks for Travellers

Transmission

HIV is transmitted through the contact with infected blood (injection or transfusion of infected blood, sharing of unsterilised equipment, e.g. needles, etc.), through unprotected sexual intercourse with an HIV-positive partner, and between mother and child during pregnancy, at birth or via breastfeeding.

Mosquitoes are not vectors of the virus, neither are saliva, sweat, tears or urine. The skin serves as a barrier to the virus. The use of public transportation (e.g., airplanes, automobiles, boats, buses, trains) by persons with AIDS or HIV does not pose a risk of infection for the crew members or other travellers.

High-risks population

Certain high-risk behaviours (drug abuse, sharing of needles, unprotected sexual intercourse, multiple partners, use of commercial sex workers - both male and female- etc.) favor the transmission of HIV; health professionals may also have more exposure to the virus.

What are the consequences of AIDS?

Incubation period

The incubation period varies from three weeks to six months on average. Symptoms often appear much later, several years or even decades after the initial infection.

Symptoms

There are three main phases in the progression of the virus.

The primary infection, or sero-conversion phase, occurs four to eight weeks after the contamination and is generally asymptomatic. 30 to 60% of those infected develop a flu-like syndrome (sore throat, headache, mild fever, muscle and joint pain...). Symptoms usually last one to four weeks.

The asymptomatic latent phase, or "silent phase", may last several years. In that phase, infected persons usually display no symptoms and may not be aware that they are carrying the virus. The silent phase is characterised by a progressive deterioration of immune defenses, which may lead to occasional fever, shingles, swelling of the lymph nodes, infections and moderate weight loss.

The final phase, or AIDS phase, usually occurs after a decade and is characterized by the appearance of opportunistic diseases which may affect the nervous system (memory loss, confusion, toxoplasmosis...), the respiratory tract (pneumonia, tuberculosis...), the digestive system (Candida, diarrhea, nausea), etc. The patient usually suffers from significant weight loss, feels persistently tired and his lymph nodes are severely swollen. Skin lesions, notably Kaposi's sarcomas, are frequent.

Tuberculosis remains a leading cause of death among people living with HIV, who are twice as likely to acquire multidrug-resistant tuberculosis as people who are HIV-negative.

Prevention and Treatment

Prevention

The best prevention method is consistent use of condoms during sex and the refusal of any transfusion or injection made in non-sterile conditions. When travelling, it is also recommended to avoid any practice involving sharp instruments, such as tattoos and piercings. Travellers should avoid sexual contact with people infected with HIV or whose HIV infection status is unknown. Travellers should also be aware that many persons may be infected and unaware of their status.

Travellers with insulin-dependent diabetes, hemophilia, or other conditions that necessitate frequent injections are advised to carry a supply of syringes, needles, and disinfectant swabs (e.g., alcohol wipes) to last their entire stay abroad.

There is no immunisation against HIV. Immediately after a possible contamination (unprotected intercourse, condom breakage, wound due to a bloody object...), it is possible to take antiretroviral post-exposure prophylaxis to reduce the risk of infection. This treatment can be obtained in hospitals or testing sites, within 48 hours after the posible infection. However, it is not effective in 100% of the cases and may not be available in developing countries.

Treatment

The use of antiretroviral therapy slows down the progression of the virus but does not guarantee a complete recovery. This treatment involves a number of side effects and constraints that may prove difficult to manage on a daily basis. However, it is still necessary and somewhat effective.