Antiretroviral therapy: the importance of turnaround time for CD4 counts

Human immunodeficiency virus (HIV) infection may lead to the development of immunological responses that make laboratory support critical in all areas of diagnosis and management. Diagnosis of HIV infection cannot be established by means other than serological testing, and CD4 lymphocyte count is a prerequisite for the initiation of antiretroviral therapy (ART) and for monitoring treatment outcomes.
 The role of the laboratory in HIV infection prevention and intervention strategies is increasingly being recognised especially in the implementation and monitoring of ART in resource-poor countries. The capacity of laboratory services will therefore need to be strengthened to cope with the scaling up of HIV intervention programmes and provide support for the response to HIV/acquired immune deficiency syndrome (AIDS).

Zambia in sub-Saharan Africa has a high HIV/AIDS disease burden with high morbidity and mortality due to the disease. Thus, the ART intervention programme has become a priority in the management of HIV/AIDS using antiretroviral drugs. Since 2004, Zambia has been rolling out and scaling up access to ART in accordance with World Health Organization (WHO) guidelines. Currently, there are 246 ART centres in the public sector across the country, but only 57 (23%) centres have laboratory services that provide full diagnosis and monitoring for HIV/AIDS patients on ART. Furthermore, the distance between some laboratories and ART centres is not in accordance with WHO guidelines.  

Consequently, in many situations clinicians have had to stage and manage patients according to WHO staging guidelines, without laboratory support or evidence. In addition, the ART is often given to patients without performing monitoring tests for response and toxicity to therapy. This poses a risk to some HIV/AIDS patients on ART to develop pathophysiological damage and drug resistance.