What is HIV?

HIV infects cell
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HIV attaches to the CD4 cell and then enters the cell.

HIV stands for Human Immunodeficiency Virus. HIV is a virus that infects certain white blood cells of the immune sy​stem. These cells have several names: CD4 cells, CD4+ cells, T cells, helper cells or CD4 lymphocytes. CD4 cells fight off infections. HIV infects and destroys CD4 cells and makes the immune system weaker over time. This puts a person at risk of other serious infections.

People who are infected with HIV are called HIV-positive. People who are not infected with HIV are called HIV-negative.

HIV weakens the immune system and makes you sick

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HIV makes copies of itself inside CD4 cells. This destroys the CD4 cells.

When HIV enters the CD4 cell, it uses the cell machinery to make copies of itself. This is called viral replication. The process of viral replication destroys the cells.

Without medication the amount of viruses in the blood rises. The amount of viruses in the blood is called viral load. The higher the viral load, the more viruses there are in the blood.

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Without medication, the number of the CD4 cells becomes very low as the viral load goes up, and the immune system is weakened.

Without treatment, the number of CD4 cells decreases because they are destroyed by an increasing number of HIV. The number of CD4 cells in the blood is called CD4 cell count. When the CD4 cell count drops, it becomes harder for the immune system to fight off infections and the person becomes ill. These infections that are normally harmless for HIV-negative people are called opportunistic infections or opportunistic diseases.

Difference between HIV and AIDS

HIV infection means that the virus is in the person's body. Some people will remain healthy with their infection for some time, while others will get sick sooner. Once HIV is in your child's body, it never goes away.

AIDS stands for Acquired Immune Deficiency Syndrome. It is a late stage of HIV infection, which happens when the immune system is so damaged that opportunistic diseases have developed. This occurs when:

  • the CD4 count is very low
  • certain types of serious infections or cancers develop

How children g​et HIV

Children can get HIV in the following ways:

  • A woman infected with HIV can unknowingly pass it onto their baby during pregnancy, at birth or after pregnancy through breastfeeding. Some women do not know they have HIV until they are pregnant and get tested. Most children are infected this way. If you are HIV-positive and having a baby, please visit our page on HIV ​and pregnancy​. It explains how to lower the risk that your baby will get HIV and how to find out if your baby is infected.
  • Some children get HIV through blood or blood products that have HIV in them. This is very rare now as the blood supply in most countries is tested for HIV. Some children also get HIV through contaminated needles or surgical equipment. This usually happens in countries where the blood supply is not tested and surgical equipment and needles are not properly cleaned and sterilized.
  • Teenagers who have unprotected sex or children who have been abused can become infected with HIV.
  • Sharing needles that have been in contact with contaminated blood, such as in drug use, tattooing or body piercing.

Tests for HIV

The doctor cannot tell if your child has HIV just by looking at them. Most of the time, children with HIV look the same as HIV-negative children. If a child becomes sick with other infections, this could be related to HIV. It could also be an infection that the child would have had anyway.

Tests for HIV in babies

Your child's doctor needs to test your baby's blood soon after birth and two more times, usually when your baby is one month old and two months old. The test looks for HIV in your baby's blood. It takes about a month to get the test results back. If the tests do not find any virus, it means your baby is not infected with HIV.

Tests for HIV in children

For older children and adults, the regular HIV test is an antibody test. An​tibodies​ are what the immune system makes to help fight off infections. When someone has an infection or receives a vaccine, their body makes antibodies against the bug that made them sick or was used in the vaccine.

If someone has HIV antibodies in their blood, it usually means they have HIV. Unfortunately HIV antibodies do not protect against HIV.

The antibody test does not work for babies because when a woman is pregnant, she passes some of her own antibodies to her baby. This means that if a woman has HIV, the antibody test will always find HIV antibodies in her baby's blood, even if the baby does not have HIV infection.

HIV Antibodies Cross the Placenta
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The mother's antibodies against HIV can be passed to the baby during pregnancy. Therefore, antibody testing for newborn babies cannot accurately check for the presence of HIV.

Tests to mon​itor HIV infection

Every three to four months, blood work will be done to assess how your child is doing with the HIV infection. Two tests will be done:

  • The viral load will be checked to measure the amount of HIV in the blood. Viral load is measured in copies of virus per millilitre of blood (cpm).
  • The CD4 cell count will be checked to measure the number of CD4 cells present in the blood. This test tells the health care team how well the immune system is doing. The normal number of CD4 cells for a child depends on the age of the child.

Treatments for HIV

Two main types of treatment are given to children and teenagers with HIV:

  • medicines to treat the HIV
  • medicines to prevent other infections

Medicines to treat the HIV

Medicines that treat HIV prevent the virus from making more copies of itself or entering CD4 cells. These medicines are called anti-retrovirals (ARVs).

Most of the time HIV treatment consists of taking three or more types of medication. When given in combination, the treatment is often referred to as combination antiretroviral therapy or highly active antiretroviral therapy (HAART). Using HAART decreases the chance that resistance will develop to any one medication, making the treatment more effective in the long-term. The combination products lower the number of pills needed each day.

To work properly, these medicines must be taken as prescribed, without any missed doses. If your child follows their treatment properly, they can live a healthy, normal life.

For more information on specific medications, visit SickKids Positively Good 2 Go​ website.

Medicines to prevent ot​her infections

Other medicines are given to prevent other infections. These include medications such as trimethoprim-sulfamethoxazole (Septra), which is given to prevent a certain type of bad pneumonia. Not all children need these preventive medicines. They are given only when the child's immune system is too weak to prevent these kinds of infections.

Managing HIV medication

Your child (or te​enager) may need to take anti-HIV medicine. Some of the things that your health care team will consider when deciding to start a treatment include:

  • your child's medical history (time since diagnosis, symptoms, other infections)
  • your child's CD4 count
  • your child's viral load

The health care team will discuss your child's treatment options with you. There are many possible medicine combinations. You and your health-care team need to decide on a combination that will work for your child.

As you learn to manage your child's HIV medications, you will learn about:

  • Efficacy: How well they work to lower your child's viral load and increase their CD4 count.
  • Durability: How long they remain effective.
  • Tolerability: How easy it is for your child to take the medications, what side effects may occur and how serious they are.

How to take HI​V medication

Each medication has different dosing and frequency. Your health care team will tell you how and when your child should take the medication.

The medications will only work if your child takes them at the right time every day. Sticking to the schedule (adherence) can be difficult but is important for your child's long-term health.

The importa​nce of not forgetting your child's medicines

Missing doses of medicines can allow the virus to replicate more easily. This will lead to an increase in the amount of HIV in your child's blood (increased viral load). When this happens the virus can become resistant to the medication your child is taking. This also risks your child's immune system being further damaged. A few missed doses can be enough for this to happen. If the virus becomes resistant to the medications your child is taking, other antiretroviral medications that work in a similar way may also become ineffective.

Do NOT stop your child's medication without speaking to your doctor first.

Side effe​cts of anti-HIV medication

Most people do not have side effects from the anti-HIV medication. When side effects happen they can range from very mild to very severe. Every medication has its own unique side effects but there are some common ones listed below. They are examples listed from the most common to the most uncommon.

Digestive problem

Stomach or bowel problems are the most commonly noticed side effects by people taking anti-HIV medicines. They include nausea, vomiting, loss of appetite, diarrhea​ and excess gas. The health care team may call these gastrointestinal (GI) symptoms.

HIV disease can also cause digestive problems.

Here are some tips to help you with GI symptoms:

  • Eat small but frequent meals.
  • Eat salty snacks before taking medications.
  • Eat cool, bland and odourless foods.


Skin rash is another relatively common side effect of antiretroviral medications. In many cases the rash is mild and resolves over time without stopping the medication. In some cases rash can be a serious side effect. You should let your doctor know about a new rash, especially if it appears within one or two months of starting a new medicine.

Allergic rea​ctions

Before starting any anti-HIV medication, tell your doctor about any allergic reactions to other medications your child has had.

A rash caused by anti-HIV medications is usually mild or moderate and not dangerous. However, in rare cases, the reaction may become more severe and have more serious consequences. A more severe allergic reaction could be a rash that is accompanied by fever, nausea or vomiting, blisters, muscle or joint pain. For this reason, it is best that you bring your child to see a doctor if a rash appears.

Lipodystrophy Syndrome

Lipodystrophy syndrome can happen when taking certain kinds of anti-HIV medication. The body fat is relocated in other places. For example fat may decrease on the face and increase on the belly. Lipodystrophy syndrome may also increase sugar, insulin or fat levels in the blood which may have long-term effects on your health.

Liver toxicity

Very rarely, anti-HIV medications may cause damage to the liver. Symptoms may include:

  • nausea and vomiting
  • abdominal pain (belly ache)
  • dark coloured urine
  • yellowing of the eyes or skin

The damage can be reversed if the medication is stopped early enough. Your child will have regular blood tests to monitor the effect of the medications on their liver.

Managi​ng side effects

Always talk with your health-care team as soon as possible about any symptoms your child has. It may be a side effect of a medication. If the side effect is not too serious, waiting it out may be an option. Sometime side effects improve or go away on their own.

If the side effect is severe, or bothers your child too much, the medicine may need to be stopped.

Make sure your health-care team knows all the medications and supplements (such as vitamins and herbal medicine) your child is taking because sometimes side effects can be due to interactions between medications.

You should speak to your health-care team about possible side effects before your child starts any new treatments (including natural and herbal).

Medication interactions

Antiretroviral medications may interact with other medications. Other medications may lower or increase the effect of antiviral medications, or in some cases, the antiviral medication may lower or increase the effect of other medications.

Keep a list of all medications your child is taking, including other prescription medications, medications that you can buy in the pharmacy without a prescription, and vitamins or herbal supplements.


Disclosure means tell someone about your HIV status. You do not have to tell everyone that you and/or your child have HIV. This is private information.

However, it is in your child's and your best interest to disclose your HIV status to your doctors and other health-care professionals, such as your dentist. This way, you will get the best care possible.

Disclosing your status before having sex is also something you and/or your te​en need to consider and discuss. In Canada it is now the law that you must inform your partner of your status before having sex. You may face criminal charges if you knowingly keep your HIV status from a sexual partner. Disclosure is one way of protecting yourself and your partner. You or teen can adopt safer sex practices and protect everyone from sexually transmitted infections (STIs).

Key p​oints

  • HIV is a virus that takes over and destroys certain types of white blood cells that fight infections.
  • If left untreated, HIV weakens the immune system.
  • Children can get HIV from their mothers during pregnancy, at birth or through breastfeeding, through blood or blood products that are infected with HIV, or through infected needles or surgical equipment.
  • Many problems can be prevented if the HIV infection is caught early on.
  • Children with HIV can live healthy, normal lives if they go to their clinic regularly for health care and take their medicines as prescribed.

​Reviewed by
Debra Louch, RN
Ari Bitnun, MD, MSc, FRCPC
Stanley Read, MD, PhD, FRCPC, FAAP
Georgina MacDougall, RN
Miriam Kaufman​, BSN, MD, FRCPC