6 min readConcept sheetPart I MCQ and Part II (2 marks) on spread or prevention; Part III (4 marks) on AIDS

AIDS: cause, spread and prevention

AIDS is caused by HIV, a virus that destroys helper T-cells and weakens immunity. It spreads through blood, unsafe sexual contact and mother to child, and is preventable.

AIDSAcquired Immuno Deficiency Syndrome

HIVHuman Immunodeficiency Virus, a retrovirus (an RNA virus)

TestELISA (enzyme-linked immunosorbent assay) blood test, confirmed by further tests

World AIDS Day1 December

What happens in AIDS?

HIV enters the body and attacks helper T-cells, a kind of white blood cell that guides the immune system. The virus multiplies inside them and slowly destroys them. Over several years the immune system becomes weak. The person then gets infections that a healthy body would fight off easily. Examples are tuberculosis, pneumonia, fungal infections and long-lasting diarrhoea. These are called opportunistic infections. This late stage is AIDS. AIDS was first reported in 1981 in the USA. In India, HIV infection was first detected in Chennai in 1986.

How HIV spreads, and how it does not

HIV spreads throughUnprotected sexual contact with an infected person. Transfusion of infected blood. Sharing needles and syringes. An infected mother to her baby during pregnancy, birth or breastfeeding.

HIV does not spread throughTouching, hugging or shaking hands. Sharing food, plates, toilets or clothes. Coughing, sneezing or mosquito bites. So people living with HIV must never be shunned.

Treating people living with HIV with kindness and fairness is part of controlling the disease.

Signs, diagnosis and treatment

Signs: fever for a long time, weight loss, diarrhoea for over a month, swollen lymph nodes and frequent infections.
Diagnosis: the ELISA blood test, confirmed by further blood tests.
There is no cure yet. Antiretroviral therapy (ART) drugs control the virus and help people live long, healthy lives.
ART is given free at government ART centres in India.

Prevention of AIDS

Use only screened (tested) blood for transfusion.
Use disposable needles and syringes, and never share them. Tools for tattoos, ear-piercing and shaving must be new or sterilised.
Avoid unsafe sexual contact.
Pregnant women should be tested. ART for an HIV-positive mother greatly lowers the chance of passing HIV to the baby.
Awareness programmes in schools and the media, such as those of the National AIDS Control Organisation (NACO).

In real life

Insist on a new disposable syringe for every injection and a new blade at the barber's. These small habits block the spread of HIV and hepatitis B.

Exam angle

2 marks: “Expand AIDS and HIV. Name the test used to detect HIV.” AIDS: Acquired Immuno Deficiency Syndrome. HIV: Human Immunodeficiency Virus. Test: ELISA.

2 marks: “Mention any two ways in which HIV does not spread.” Touching or hugging; sharing food, plates or toilets; coughing or sneezing; mosquito bites.

4 marks: “How does HIV spread? How can AIDS be prevented?” Spread: unprotected sexual contact, infected blood, shared needles, mother to baby. Prevention: screened blood, disposable syringes, safe behaviour, testing and ART for pregnant women, awareness.

Remember it

HIV travels by B-S-N-M: Blood, Sexual contact, Needles, Mother to baby. Never by hugs, food or mosquitoes.