Matu notes that many health care workers don't know how to deal with HIV in children: "They go around in circles without informing the parent or guardian that the child is HIV-infected until it is too late to save the child's life."
Some parents and health workers believe that the survival of HIV-positive children is so poor that their early death must be accepted, Matu adds.
The UNICEF report lists several barriers to paediatric ART. Among them are limited availability of fixed-dose ARV combinations, poor palatability of recommended drug formulations for infants, lack of technology to test HIV infection among children under 18 months and fewer ART options for children than for adults.
Of the 22 ARVs approved by the United States Food and Drug Administration, five are not approved for use in children and another six are not available in paediatric formulations, according to UNAIDS.
Mary Naliaka, a health worker in paediatric AIDS with the Ministry of Health, explains that effective ART for kids requires a complex treatment formula.
"Changing dosage as a child grows is a major challenge," she says. "One needs complex calculations to guide the adjustment."
In a country where 35 percent of children suffer from malnutrition, "measuring the right dosage against the weight of the child can be daunting," Naliaka told IPS.
For children in boarding schools, the lack of disclosure hurts treatment effectiveness. "If the school nurse is unaware of the child's HIV status, they are unable to support them," says Naliaka.
Matu says that parents, especially mothers struggling to accept their own HIV-positive diagnosis, find it difficult to take their children for HIV testing and feel guilty of passing on the virus.
The government estimates that 1.1 million children have lost one or both parents to AIDS; Many live with their elderly, illiterate and poor grandparents.
Although the Ministry of Health plans to reach 40 percent of caregivers of orphans through local community health workers who will teach them HIV care and provide food parcels, this help is yet to reach Sabina and Melvis.
Despite his hard life, Melvis has a sunny disposition and is energetic. He hawks pan-fried nuts in Kibera after school while Sabina sells deep fried potatoes near her shanty: "This is how we survive."
*Not his real name. Family name omitted to protect privacy.