Despite testing program, children with HIV remain undiagnosed

A two-year clinic-based HIV testing program in Zimbabwe failed to diagnose many cases of HIV in children in the surrounding area, Dr. Victoria Simms from the London School of Hygiene & Tropical Medicine, UK, and colleagues, report in PLOS Medicine.

Worldwide, an estimated 1.8 million children under the age of 15 are living with HIV, most in sub-Saharan Africa, and they often go without treatment due to under-diagnosis. In the new study, researchers at the Biomedical Research and Training Institute launched a provider-initiated testing and counseling (PITC) program in Harare, Zimbabwe, offering an HIV test to every child aged 6-15 who came into any of 7 local clinics during a two-year timespan. After the two years, the researchers did a house-to-house survey in the same area, testing children aged 8-17 for HIV using an oral test.

2.6% (95% CI 2.2-3.1%) of children tested in the house-to-house survey were HIV positive, and over a third of those (37.7%; 95% CI 29.8-46.2%) were undiagnosed. Based on the survey results, the researchers estimated that the two year PITC program had identified between 18% and 42% of previously undiagnosed children in the community. This extrapolation is limited by the lack of a baseline survey. In addition, under-reporting of known HIV infection is an inherent problem when using self-report.

"In order to diagnose all children with HIV it is not enough to test every child who comes to a clinic, because some HIV positive children either do not visit a clinic often or do not go with a guardian able to give consent for them to take an HIV test," the authors say. "Other methods, such as community-based testing or targeted tracing, must be tried to reach the children who cannot be tested in the clinic."

In an accompanying Perspective, Marguerite Lightfoot of the University of California San Francisco and colleagues discuss the limitations and challenges of PITC to diagnose HIV in children and adolescents. "PITC can play an important role in increasing uptake of testing among older children and adolescents, but needs to better address barriers to testing in this population, and is likely not sufficient on its own," they write.