Monitoring HIV in children and babies

Monitoring HIV in children and babies

Your child will need regular medical monitoring to see how HIV is affecting his or her health. This will involve a number of tests and examinations. Two of the most important tests measure CD4 cell count and viral load.

CD4 cells are the immune system cells that HIV attacks. The number of CD4 cells in a sample of blood, or CD4 cell count, gives a rough idea of the health of the immune system.

Before the age of five or six years children have higher CD4 cell counts than adults. This means that babies and children can become ill with HIV when they have CD4 cell counts that would seem high in an adult. Very young children can become ill when their CD4 cell count is between 1000 and 2000.

Because of this doctors use another test to look at the strength of the immune system of babies and young children. This measures the number of CD4 cells as a proportion of all immune system cells. A CD4 cell percentage below 25% shows that there has been some damage to the immune system. A CD4 cell percentage below 15% shows that there’s been a lot of damage and a risk of severe, even life-threatening illness.

Another key test used to monitor HIV is viral load – the amount of HIV in a sample of blood. Babies have very high viral loads – about 200,000 – but this falls gradually over the next five years.