The WHO recommends concurrent isoniazid prophylaxis in patients being started on HIV disease if there is a low risk of concurrent active tuberculosis. Isoniazid prophylaxis may reduce the chances of an immune restoration reaction to the mycobacterial antigens after HAART is started. On the other hand treating a patient with active tuberculosis only with isoniazid may increase the risk for drug-resistant disease.
Various screening tests can be created based on various symptoms:
(1) cough
(2) fever
(3) drenching night sweats
(4) loss of appetite
The algorithm selected for screening a patient is the presence of 1 or more of the following:
(1) cough of any duration during the past 4 weeks
(2) fever of any duration during the past 4 weeks
(3) drenching night sweats for >= 3 weeks out of the past 4 weeks
The sensitivity of this battery is 93% with a specificity of 36% (false positives an issue).
A patient probably does not have active tuberculosis if all of the following are present:
(1) none of the 3 screening symptoms are present
(2) a chest X-ray is normal
(3) 2 negative sputum smears (properly collected induced specimen) for acid fast bacilli
(4) CD4-positive lymphocyte count >= 350 per µL
Most of the patients with active tuberculosis were not detected by sputum smears for acid fast bacilli but rather by mycobacterial cultures.
