Access to diagnostics in support of HIV/AIDS and tuberculosis treatment in developing countries.

Access to necessary diagnostic tests in support of HIV/AIDS and tuberculosis treatment, such as CD4 cell counts, viral load, tuberculosis culture, and susceptibility testing, has significantly lagged the provision of drug therapy in developing countries. This is an outcome of the fundamental limitations in overall access to basic health services in the developing world, particularly in sub-Saharan Africa. Among health services, laboratory capacity and access are particularly deficient, and often non-existent in rural settings. As such, treatment is commonly administered in the absence of diagnostic testing, potentially accelerating the incidence of drug-related toxicity and the onset of drug resistance if therapy results in incomplete viral suppression. Factors constraining the expansion of necessary diagnostic testing include a severe shortage of qualified laboratory personnel, limited access to training for specific diagnostic tests, and a lack of national standards and systems for laboratory accreditation, proficiency testing, quality control and logistics. Additional factors include insufficient funding for improvements in laboratory services, limited availability of technical support, and the cost of diagnostic instrumentation and consumables. As a result, laboratory tests that are routine and expected in the industrialized world are often not performed in developing countries, despite the massive scale-up in treatment access for HIV/AIDS. This results in unintended consequences such as higher levels of mortality among patients who have not been properly diagnosed, additional costs for providing ART to patients who may not yet require drug therapy, and earlier onset of resistance to first-line therapies among patients predisposed to drug resistance.