The CD4 count tells you what infection this patient is vulnerable to, and therefore what to prophylax and what to monitor. The viral load tells you whether the regimen and the adherence are working. Move both dials and watch the plan rewrite itself, then screen an antiretroviral before its first dose and decide what a real exposure actually needs.
CD4 count (cells/mm3)
5620 cells/mm31200
501002005001200
Viral load (copies/mL)
Where is this patient in treatment?
Has an AIDS-defining illness ever occurred?
Therapy starts as soon as possible, at any CD4 countIdeally the same day as diagnosis. Regimens combine classes so the virus cannot mutate around a single pressure point, and most first-line regimens are one daily tablet built on an integrase strand transfer inhibitor. Adherence must exceed roughly 95 percent to prevent resistance.
Which agent are you about to give?
What else is on the medication list?
The situation in front of you
What these two numbers mean today
CD4 (cells/mm3)
Risk
Standard prophylaxis
Above 500
Near-normal immunity
None; routine vaccination and antiretroviral therapy
Azithromycin 1,200 mg weekly if therapy cannot be started promptly; dilated eye exams
The same principle outside HIV. Most secondary immunodeficiency on a medical–surgical floor is ordinary: corticosteroids, chemotherapy, malignancy, chronic kidney disease and dialysis, cirrhosis, poorly controlled diabetes, malnutrition, splenectomy and advanced age. In a neutropenic patient, a single temperature of 38.3 degrees C — or 38.0 degrees C sustained for one hour — with an absolute neutrophil count under 500 cells/mm3 is an emergency requiring blood cultures and antibiotics within one hour.