There are differences in disease progression and diagnosis of HIV infection between adults and children. The main differences in disease progression and diagnosis are listed below:

• Young children have immature immune systems and thus are more susceptible to common childhood infections, as well as opportunistic infections.
• Early diagnosis of HIV infection in children is essential, as the infection in infants and children progresses faster than that of adults Although HIV-infected infants are generally symptom-free at birth, in the absence of any intervention, most of them develop severe symptoms in the first two years of life, and die. Therefore, early diagnosis and management of HIV-exposed and HIV-infected children is key to ensure maximum benefit from ART, and to reduce AIDS-related morbidity (the presence of an illness or disease) and death in children.
• In HIV-exposed infants, maternally acquired antibodies make the diagnosis of HIV challenging. The antibodies present in the blood of an HIV-exposed infant may originate from the mother and not the infant itself. Therefore, a positive rapid HIV test is not definitive for the diagnosis of HIV infection in children below the age of 18 months. However, a rapid test, done six or more weeks after the complete cessation of breastfeeding, which gives a negative result, is more useful, because it excludes HIV infection in HIV-exposed infants.