HIV and AIDS: Prevention and risks

Preventing HIV

There are several treatments that prevent the transmission of the human immunodeficiency virus (HIV).

While treatment can prevent HIV transmission, you should still protect yourself against other sexually transmitted infections (STIs), such as:

Other methods of protection, such as condoms, can help prevent STIs.

Treatment as prevention

HIV treatment improves the health of people living with HIV and is a highly effective strategy to prevent HIV transmission.

HIV treatment can reduce the amount of virus (viral load) in the blood and other bodily fluids (like semen, and vaginal and rectal fluids) to undetectable levels.

People living with HIV who are on treatment, engaged in care and have an ongoing undetectable viral load have effectively no risk of:

transmitting HIV to their sexual partners
transmitting HIV to their baby during pregnancy and delivery

To reach an undetectable viral load and keep it, people living with HIV need to take their treatment as prescribed. In addition to taking HIV medications, regular medical visits are important to:

monitor viral load to make sure it stays undetectable
receive other medical support

This means Undetectable = Untransmittable (U = U).

Pre-exposure prophylaxis (medication)

People who are HIV-negative can take medication called pre-exposure prophylaxis (PrEP) to help prevent them from getting HIV. Taking PrEP also involves:

seeing a doctor or nurse every 3 months for HIV testing
screening for other STIs
- medication should be taken in combination with safer sex practices to lower the transmission risk
monitoring for possible side effects
ongoing support

When PrEP is used consistently and correctly, it's rare for HIV to be transmitted through sex.

PrEP can be less effective when pills are missed because drug levels in your body may be too low to prevent HIV infection.

This medication does not prevent pregnancy.

If you want to take PrEP, talk to your health care provider. Any doctor can prescribe PrEP and some nurses are also licensed to prescribe it.

Post-exposure prophylaxis (medication)

Medication called post-exposure prophylaxis (PEP) reduces the risk of contracting HIV. It involves taking HIV medications as soon as possible after a potential exposure to HIV. PEP means taking daily pills for 4 weeks.

PEP is very effective but won't prevent 100% of HIV infections. It must be started as soon as possible after an exposure to HIV, ideally within 72 hours.

If you think you may have been exposed to HIV, immediately contact your health care provider, a hospital emergency room or sexual health clinic to see if they offer PEP.

Condoms

Because the most common way to transmit HIV is through sexual activity, using condoms can reduce your risk of contracting or transmitting the virus.

You're at risk if you:

have condomless vaginal or anal sex with someone who is HIV-positive and isn't on treatment and virally suppressed
- virally suppressed means the amount of virus in the person's system is too low to be measured on a standard blood test
perform oral sex without a condom
- this is considered low risk unless you have open sores or cuts in your mouth

Reducing your risks

Injecting drugs

If you inject drugs, you can reduce the risk of contracting or transmitting HIV by following safe injection practices.

Avoid sharing drug injection equipment, such as:

water
filters
spoons
cookers
needles
syringes

Use new equipment every time you inject.

You may get help by signing up for a treatment program on substance use, such as:

methadone therapy
opioids substitution therapy

Such programs can help you reduce your:

substance dependence
frequency of injection and other risky behaviours, such as sex without a condom with someone whose HIV status is unknown

Pregnancy and childbirth

If you're pregnant or plan to become pregnant, you and your partner should be tested for sexually transmitted and blood-borne infections (STBBIs), including HIV. Even if you have HIV, you have effectively no risk of transmitting the virus to your baby if you:

take antiretroviral drugs and maintain an undetectable viral load during pregnancy
avoid breastfeeding after you give birth

Tattooing, body piercings, acupuncture and other procedures

If you're getting a tattoo, body piercing, electrolysis or acupuncture, you can avoid contracting or transmitting HIV by asking if:

procedures are carried out by professionals who follow proper infection control practices (PDF), like those used in hospitals
all needles used, as required by law, are:
- used only once
- disposed of safely after use

Medical tourism

If you're travelling to another country for medical care, ask if the:

facility follows proper practices to control infection (PDF)
blood and blood products used in the facility are screened for HIV and other STBBIs

Workplace exposure

If your job exposes you to blood or other bodily fluids, you may be at risk for HIV infection.

You can reduce your risk by following routine practices for controlling infection in your workplace.

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