As discussed in Chapter 1, in 1998 ZL began administering ART in Haiti based on patients’ clincal status alone. Since CD4 testing has become available in central Haiti, initiation of treatment has been guided by CD4 count as well as by the clinical status of the patient. The WHO has also used both clinical staging and total lymphocyte count as surrogate markers for immune suppression. Under the WHO guidelines, the total lymphocyte count is calculated by multiplying WBC count per high-powered field by the patient’s percentage of lymphocytes. Protocol 3.1* provides an overview of both the laboratory and syndromic approaches to initiating ART; for a discussion of when to initiate ART in HIV-positive pregnant women, also see Sections 2.5.2 through 2.5.5 and Protocol 2.3.
Based on evidence from clinical trials, the U.S. Department of Health and Human Services (DHHS) and the European Guidelines agree that all HIV-positive adults with a CD4 count below 200 cells/mm3 should be started on ART. Thus, when a CD4 count is in fact available, 200 cells/mm3 should be the minimum standard for initiating ART.
Other studies suggest that patients with a CD4 count below 350 cells/mm3 also benefit from ART. In Haiti and Rwanda, as in many HIV-endemic countries, more aggressive pathogens such as TB and salmonella are associated with high morbidity and mortality among HIV-positive patients. Therefore, in PIH projects, the decision to initiate ART is based on this more conservative guideline of 350 cells/mm3. See Section 2.4.3 for a discussion of ART initiation in co-infected patients.
Lastly, a small subset of persons with a CD4 count above 350 cells/mm3 may merit ART based on symptoms that indicate either that the patient is failing to thrive or that the patient is suffering from recurrent OIs.
* All protocols for Chapter 3 are grouped at the end of the chapter, immediately before the References.
In settings where CD4 count technology is not yet available, the patient’s total lymphocyte count may be used as a proxy for CD4 count as discussed above. However, measuring total lymphocyte count is a labor-intensive process and requires either expertise in microscopy or a cell counter; therefore, the most practical alternative to CD4 testing is clinical staging. The WHO recommends ART for all patients with Adult Clinical Stage III or IV disease, irrespective of total lymphocyte count, and for patients with Stage II disease when the total lymphocyte count is less than 1,200 cells/mm3.1