Although HIV infection and asplenia are relatively infrequent in adults with invasive group B streptococcal infection [1, 2], we agree that they probably predisposed this patient to streptococcal infection. The rarity of asplenia in our study populations has prevented an accurate assessment of the risk associated with this condition. However, invasive group B streptococcal disease has been documented to occur more frequently in HIV-infection patients than in age-matched HIV-negative populations [2]. In our case–control study [1], 5% of 219 patients with invasive streptococcal infection identified through population-based surveillance were known to be infected with HIV. Farley and colleagues [2] used population-based surveillance to estimate the annual incidence of invasive group B streptococcal infection in HIV-infected persons 30 to 49 years of age and determined the rate to be 54 per 100 000 persons—a risk approximately 30 times greater than that of HIV-negative persons [2].

In response to the report by Waite and associates, we reviewed abstracted medical information from our previous population-based studies for cases of invasive streptococcal disease that occurred among persons known to be infected with HIV [1, 2]. Sixteen patients (13 men, 3 women) were identified in the two studies. Patients ranged in age from 31 to 70 years (median, 42 years). Information on risk factors for HIV infection was available for 11 patients: Infection drug use was reported in 7, homosexuality or bisexuality in 3, and blood transfusion in 1. For 9 patients, CD4 counts were available: CD4 values ranged from 8 to 717 cells/mm³ (median, 241 cells/mm³).

Only 1 of the 16 HIV-infected patients in our series presented with meningitis, confirmed by isolation of group B streptococci from cerebrospinal fluid. The proportion of HIV-infected patients with meningitis (6%) was similar to that identified in all patients with invasive streptococcal disease (4%).

Group B streptococcal infections were polymicrobial in 8 of 16 cases. Concomitant blood cultures identified Staphylococcus aureus in five cases, coagulase-negative staphylococci in two cases, and Acinetobacter species in one case. In three polymicrobial infections, intravenous catheters were considered a focus of infection.

Concomitant medical conditions unrelated to HIV infection were frequent in patients with streptococcal infection. Two patients were asplenic, 5 had chronic liver disease, 3 had congestive heart failure, and 1 had insulin-dependent diabetes mellitus. Only 3 of 16 HIV-infected patients with invasive group B streptococcal infection had no chronic medical condition (other than those related to HIV infection). Thus, the contribution of HIV infection, independent of other chronic medical conditions, to the risk for invasive group B streptococcal disease remains unclear.