HIV Transmission
எச்.ஐ.வி பரவும் முறைகள்
HIV is not a contagion of proximity; it is a pathogen of fluid exchange. Do not confuse transmission vectors with casual contact. Biology demands you distinguish between a virus and a social stigma.
The idea
HIV transmission occurs exclusively through the exchange of infected body fluids. Primary routes include unprotected sexual contact, transfusion of contaminated blood, and the use of infected needles or syringes. Vertical transmission from an infected mother to the fetus occurs via the placenta. Casual physical contact, such as touching or sharing space, does not transmit the virus.
Why it matters
The virus requires a direct route into the bloodstream or mucosal surfaces to infect target immune cells, as it cannot survive or penetrate intact skin.
NEET lens
NEET focuses on the specific modes of transmission; distinguish clearly between 'blood-borne' and 'casual contact'. Questions often trap students by listing non-transmissible activities like sharing food or mosquito bites. Memorize that HIV is a retrovirus that requires specific fluid-to-blood or fluid-to-mucosa contact. Expect at least one statement-based question on this in every alternate paper.
Clinical significance
HIV targets CD4+ T-helper cells, effectively dismantling the adaptive immune system. This leads to profound immunosuppression, leaving the host vulnerable to opportunistic infections like Mycobacterium tuberculosis. Without intervention, the body loses its ability to mount a defense against even common pathogens.
Introduction
HIV is transmitted through body fluids. Knowing the routes is the key to preventing AIDS, which has no cure.
Core concept
Routes (NCERT): (a) sexual contact with an infected person; (b) transfusion of contaminated blood and blood products; (c) sharing infected needles, as in intravenous drug abusers; (d) from an infected mother to her child through the placenta. High-risk groups include individuals with multiple sexual partners, drug addicts who take drugs intravenously, individuals who require repeated blood transfusions, and children born to an HIV-infected mother. HIV/AIDS is not spread by mere touch or physical contact; it spreads only through body fluids. Prevention: safe blood from blood banks, use of disposable needles and syringes, free distribution of condoms, controlling drug abuse, advocating safe sex and regular check-ups; NACO (National AIDS Control Organisation) and NGOs educate people.
Go deeper
Because there is no cure, prevention is the best option. Anti-retroviral therapy prolongs life but cannot prevent death from AIDS.
From Class 10
HIV does not spread through hugging, shaking hands or sharing food. It spreads through blood, sexual fluids and from mother to baby.