The impact of a clinic for adults with HIV infection on the microbiology laboratory

The Infectious Diseases Clinic (IDC) discussed serves adults who are seropositive for human immunodeficiency virus. The authors reviewed the outpatient and inpatient microbiology tests of a three-month period during 1989 for a systematic sample of IDC patients. The 249 patients in the sample had 682 microbiology tests performed during the period (mean 2.7 tests per patient). Tests most frequently requested were mycobacterial culture, routine blood culture, and cryptococcal antigen determination. Patients with acquired immunodeficiency syndrome (43% of IDC patients) accounted for 63% of the requested IDC tests. IDC patients comprised about 2.4% of patients served but accounted for 3.9% of the requested microbiology tests and 6.6% of the microbiology work load for reported tests. Using Centers for Disease Control case projections, the authors estimated that services to IDC patients in 1993 would comprise 6.6% of all microbiology tests and 10.6% of the microbiology work load. The implications of these data for microbiology probably also apply to other laboratory testing and emphasize the need for more efficient ways to use and perform diagnostic studies required by patients with HIV infection.