Quick answer: HIV is transmitted only when certain body fluids from a person with HIV who has a detectable viral load (blood, semen, pre-seminal fluid, vaginal fluids, rectal fluids or breast milk) get into another person's bloodstream. In practice, this happens mainly through condomless anal or vaginal sex, sharing needles, or from mother to baby. HIV is not spread through hugging, sharing food, toilets, saliva or mosquito bites.
Which body fluids can transmit HIV?
HIV can only be passed on through these body fluids from a person living with HIV:[1][2]
- Blood
- Semen (cum) and pre-seminal fluid (pre-cum)
- Vaginal fluids
- Rectal fluids
- Breast milk
For infection to happen, the virus in these fluids has to reach the bloodstream of an HIV-negative person. It does this through:
- Mucous membranes: the soft linings of the rectum, vagina, opening of the penis and, much less often, the mouth.
- Broken skin: open cuts, sores or damaged tissue.
- Direct injection: a used needle or syringe.
Healthy, unbroken skin is an effective barrier against HIV.
The main ways HIV is transmitted
1. Condomless anal or vaginal sex
Sex without a condom (or without PrEP) with a partner who has HIV and a detectable viral load is the most common route worldwide and in Malaysia. Anal sex carries the highest risk because the lining of the rectum is thin and tears easily. The receptive partner (the one being penetrated) faces a higher risk than the insertive partner, but both can acquire HIV. Having another sexually transmitted infection, such as syphilis or gonorrhoea, raises the risk further.
2. Sharing needles, syringes or other injecting equipment
Used needles can hold small amounts of blood containing HIV. This applies to injecting drugs, and also to sharing needles for hormones, steroids, silicone, tattoos or piercing with unsterilised equipment.
3. From mother to baby
HIV can pass from a mother living with HIV to her baby during pregnancy, childbirth or breastfeeding. With HIV testing in antenatal care and treatment during pregnancy, this risk can be reduced to very low levels, which is why HIV screening is part of routine antenatal care in Malaysia.
HIV risk by type of exposure
Not all exposures carry the same risk. The estimates below come from the US Centers for Disease Control and Prevention (CDC) and show the approximate number of infections per 10,000 exposures to a source with HIV, without condoms, PrEP or treatment.[3]
| Type of exposure | Estimated risk per 10,000 exposures |
|---|---|
| Blood transfusion from an HIV-positive donor | 9,250 |
| Receptive anal sex | 138 |
| Sharing needles to inject drugs | 63 |
| Needlestick injury | 23 |
| Insertive anal sex | 11 |
| Receptive vaginal sex | 8 |
| Insertive vaginal sex | 4 |
| Oral sex (giving or receiving) | Low |
A single exposure is usually low risk, but risk adds up over repeated exposures. Condoms, PrEP and effective treatment for the HIV-positive partner each lower these figures dramatically.
Very rare ways HIV can spread
- Oral sex: very low risk; higher if there is ejaculation in the mouth, mouth ulcers, bleeding gums, genital sores or other STIs.
- Blood transfusions and organ transplants: extremely rare today because donated blood and organs in Malaysia are screened. You cannot get HIV from donating blood.
- Needlestick injuries in healthcare: the risk is low, and PEP is available for health workers after an exposure.
- Bites: only a handful of cases, all involving severe injury, broken skin and blood. Spitting does not transmit HIV.
- Deep kissing: only when both partners have bleeding gums or open sores and blood is exchanged.
- Pre-chewed food: reported only in infants, where blood from a caregiver's mouth mixed with food.
How HIV is NOT transmitted
HIV does not survive long outside the body and cannot spread through everyday contact.[1] You cannot get HIV from:
- Hugging, shaking hands or touching
- Closed-mouth or social kissing
- Sharing plates, cups or cutlery
- Toilets, swimming pools or showers
- Mosquitoes or other insects
- Saliva, tears or sweat
- Air, water or coughing and sneezing
- Donating blood
Knowing these facts helps reduce stigma. People living with HIV can safely work, study, share meals and live alongside others.
Viral load and U=U
Viral load is the amount of HIV in a person's blood. The higher the viral load, the higher the chance of passing on HIV. Antiretroviral therapy (ART) lowers the viral load, and most people who take it as prescribed reach an undetectable level within about six months.[2]
People with HIV who keep an undetectable viral load do not transmit HIV to their sexual partners. This is the scientific consensus known as U=U (Undetectable = Untransmittable). To stay undetectable, treatment must be taken every day, with regular viral load tests. Condoms are still recommended to protect against other STIs.
HIV transmission in Malaysia
How HIV spreads in Malaysia has changed. It used to spread mainly through needle-sharing among people who use drugs; today almost all new infections come from sex. According to a parliamentary reply by the Health Minister in August 2025, Malaysia recorded 3,185 new HIV cases in 2024:[4]
- 96% were acquired through sexual transmission (64% homosexual or bisexual, 32% heterosexual).
- About 90% were men.
- Around three in four were aged 20 to 39.
Globally, WHO estimates 1.2 million people acquired HIV in 2025, and around 41 million people are living with HIV.[1]
How to protect yourself
- Use condoms correctly every time for anal and vaginal sex, with a water- or silicone-based lubricant.
- Ask about PrEP (pre-exposure prophylaxis) if you are at ongoing risk. PrEP is offered through Ministry of Health clinics and private clinics in Malaysia and is highly effective when taken as prescribed.[5]
- Use PEP after a possible exposure. Post-exposure prophylaxis must be started within 72 hours, so go to a clinic or emergency department immediately.
- Never share needles or injecting equipment, and use licensed tattoo and piercing services.
- Test regularly for HIV and other STIs, and encourage partners to test too. Treating STIs lowers HIV risk.
- If you are living with HIV, start and stay on treatment. An undetectable viral load protects your health and your partners.
Frequently asked questions
Can I get HIV from kissing?
Closed-mouth or social kissing does not transmit HIV, and saliva does not carry enough virus to infect someone. Transmission through deep kissing has only been reported in extremely rare cases where both partners had bleeding gums or open mouth sores.
Can HIV be transmitted through oral sex?
The risk is very low, much lower than vaginal or anal sex, but it is not zero. The risk may be higher if there is ejaculation in the mouth, or if either partner has mouth ulcers, bleeding gums, genital sores or another STI.
Can mosquitoes spread HIV?
No. Mosquitoes and other insects do not transmit HIV. The virus cannot survive or reproduce inside insects, and they do not inject blood from one person into another.
Can a person with an undetectable viral load pass on HIV through sex?
No. People living with HIV who take treatment as prescribed and keep an undetectable viral load do not transmit HIV to their sexual partners. This is known as Undetectable = Untransmittable (U=U).
What should I do if I think I was exposed to HIV?
Go to a clinic or hospital emergency department as soon as possible and ask about post-exposure prophylaxis (PEP). PEP must be started within 72 hours of exposure, and the sooner the better. Then follow up with HIV testing at the times your doctor advises.
How soon can an HIV test detect infection?
It depends on the test. Most rapid antibody tests, including self-test kits, are reliable from about 3 months (12 weeks) after exposure, while some lab tests can detect HIV earlier. A reactive self-test result must always be confirmed at a clinic.
Worried about a past exposure?
Testing is the only way to know your HIV status. The iCare HIV Test Kit lets you screen privately at home with discreet delivery. Any reactive result should be confirmed by a qualified healthcare service.
View iCare HIV Test Kit- World Health Organization. HIV and AIDS fact sheet, July 2026.
- US Centers for Disease Control and Prevention. How HIV Spreads, reviewed November 2024.
- US Centers for Disease Control and Prevention. HIV Risk Behaviors: estimated per-act probability.
- CodeBlue. Young men drive most new HIV cases, MOH says, August 2025 (Health Minister's parliamentary reply).
- Ministry of Health Malaysia. National Guideline on HIV PrEP Programme Implementation in Malaysia 2025.
