Human Health & Disease
AIDS
AIDS isn't a disease you catch directly — it's the slow collapse of your immune defence after the virus HIV disables it over years.
HIV is a retrovirus: it copies its RNA into DNA and inserts that into your immune cells (mainly helper T-cells), then hides. Over years it destroys these cells, so your defence weakens quietly, often with no obvious illness.
Once the immune system is crippled, ordinary microbes a healthy body shrugs off start causing serious infections. That stage — immune failure plus these infections — is AIDS. It spreads only through blood, semen, vaginal fluids and breast milk (including mother to child), and is detected by the ELISA test.
Where students slip up
Two things trip students up. HIV does NOT spread by touch, sharing food, or mosquitoes — it needs body-fluid contact. And HIV (the virus) is not the same as AIDS (the late stage it causes).
Why it helps in the exam: ELISA for diagnosis, the retrovirus mechanism, and the exact transmission routes recur.
Where this connects
HIV runs the genetic flow backwards, copying its RNA into DNA, which is how it hides inside your own cells for years. Its target is the very defence system your body would use to fight it.
The defence it dismantles →Quick check
Which technique is used to confirm HIV infection?
- AWidal test
- BMRI scan
- CBiopsy
- DELISA