ARE HTLV-II-SEROPOSITIVE INJECTION-DRUG USERS AT INCREASED RISK OF BACTERIAL PNEUMONIA, ABSCESS, AND LYMPHADENOPATHY

Disease associations of HTLV-II are poorly defined, despite a high ser oprevalence among injection drug users (IDU). One hundred twenty-four HTLV-II-seropositive emergency room and clinic patients were matched b y age, sex, and clinic to 120 HTLV-I/II-seronegative patients. Medical records were reviewed blinded to HTLV-II status, and International Cl assification of Disease 9th Clinical Modification (ICD-9CM)-coded diag noses were compared between seropositive patients and controls. After adjustment for relevant confounding variables such as human immunodefi ciency virus infection, HTLV-II-seropositive IDU had an increased risk of bacterial pneumonia (odds ratio [OR], 3.45; 95% confidence interva l [CI], 1.58, 7.56), abscess (OR, 8.30; 95% CI, 4.02, 17.11), and lymp hadenopathy (OR, 3.91; 95% CI, 1.24, 12.32) compared with HTLV-II-nega tive non-IDU patients. In contrast, HTLV-II-negative IDU were at only marginally increased risk of the same conditions, with OR of 1.76 (95% CI, 0.42, 7.40), 3.00 (95% CI, 0.94, 9.59), and 1.31 (95% CI, 0.15, 1 1.66), respectively. These results indicate that HTLV-II seropositivit y may define a subgroup of IDU who are at particularly high risk of ba cterial pneumonia, skin and soft tissue abscess, and lymphadenopathy. Whether HTLV-II has an etiologic role in pre- disposing IDU to bacteri al infections and lymphadenopathy will require further investigation.