Counting CD4 cells cheaply: diagnostic accuracy study
HIV infection is prevalent in sub-Saharan Africa, but resources for testing and treatment are limited. According to guidelines from the World Health Organization, if CD4 counting is available adults and children over 5 years old should start antiretroviral treatment as soon as their CD4 count drops below 200 cells/micro l, regardless of their clinical stage. Flow cytometric CD4 counting is the best technique for measuring cell counts. However, despite efforts to bring the cost of consumables down for developing countries, the technique is still too expensive for most African communities to consider it.
In Africa a programme to deliver free antiretrovirals has been started, but because the cost of CD4 testing often precludes its use, many patients are allocated to treatment on the basis of clinical criteria rather than CD4 counts. Clinical staging of HIV disease does not fully predict immunological status, so a CD4 cell count is the most