ABSTRACT
<p><b>OBJECTIVE</b>To study the prevalence of skin positivity to purified protein derivative (PPD) in human immunodeficiency virus (HIV)-infected patients in Hong Kong.</p><p><b>METHODS</b>Consecutive clients of an HIV clinic were administered the PPD test and 2 units of PPD-RT23 were used. The area of induration was then measured in 48 to 72 h. Results were related to patient characteristics and HIV-related parameters.</p><p><b>RESULTS</b>Eight (17.0%) out of 47 clients tested positive to the administration of 2 units of PPD-RT23. If the cutoff were raised to 10 mm according to current practice, only two (4.3%) would test positive.</p><p><b>CONCLUSION</b>The prevalence of PPD positivity in HIV-infected patients in Hong Kong is 17%, when a cutoff of 5 mm is used. This figure may form the basis for further studies on the utility of isoniazid preventive therapy in this group of patients.</p>