Reported rates of nephrotoxicity associated with the systemic use of polymyxins have varied widely. The emergence of infections due to multiresistant gram-negative bacteria has necessitated the use of systemic polymyxin B once again for the treatment of such infections. We retrospectively investigated the rate of nephrotoxicity in patients receiving polymyxin B parenterally for the treatment of infections caused by multiresistant gram-negative bacteria from October 1999 to September 2000. Demographic and clinical information was obtained for 60 patients. Outcome measures of interest were renal toxicity and clinical and microbiologic efficacy. Renal failure developed in 14% of the patients, all of whom had normal baseline renal function. Development of renal failure was independent of the daily and cumulative doses of polymyxin B and the length of treatment but was significantly associated with older age (76 versus 59 years, P ‫؍‬ 0.02). The overall mortality was 20%, but it increased to 57% in those who developed renal failure. The organism was cleared in 88% of the patients from whom repeat specimens were obtained. The use of polymyxin B to treat multiresistant gram-negative infections was highly effective and associated with a lower rate of nephrotoxicity than previously described.

Rates of invasive disease caused by penicillin-resistant pneumococci are rising. Previous reports have found no association between resistant pneumococci and increased mortality. To evaluate the impact of penicillin resistance and other variables on mortality, we retrospectively studied all cases of pneumococcal bacteremia identified by our microbiology laboratory from 1 January 1992 through 31 December 1996. There were 462 cases of pneumococcal bacteremia in 432 patients. The mean age was 35 years; 55% of the cases occurred in male patients, 58% were in black patients, and 40% were in Hispanic patients. One-half of the cases occurred in patients with documented human immunodeficiency virus (HIV) infection. Penicillin resistance was first noted in 1994 and increased yearly, accounting for 17% of 1996 isolates. Of all resistant isolates, 65% were resistant to penicillin at a high level. The overall mortality was 17%. On multivariate analysis, high-level penicillin resistance, older age, severe disease, multilobar infiltrates and/or effusion(s) on chest roentgenogram, and Hispanic ethnicity were independent predictors of mortality in pneumococcal bacteremia. In HIV-infected patients, a CD4 cell count below the median just missed statistical significance. This is the first report demonstrating penicillin resistance as an independent predictor of mortality among patients with pneumococcal bacteremia.

We conducted a retrospective study of patients with culture-confirmed multidrug-resistant tuberculosis (MDR-TB) at Bronx-Lebanon Hospital Center (South Bronx, NY) to determine what factors affected clinical and microbiological responses and survival. For the 38 patients with MDR-TB, reporting of first-line drug susceptibilities was relatively rapid (median time, 30 days). Thirty-four patients (89%) were infected with human immunodeficiency virus (HIV), and initial and overall response rates were 59% and 50%, respectively; the median survival was 315 days; and 50% of these patients died of tuberculosis. Bivariate analysis revealed that the following factors had a positive impact on response and survival: receiving > or = 2 consecutive weeks of appropriate therapy with at least two drugs to which the isolate was susceptible in vitro; starting appropriate therapy within 4 weeks of the diagnosis; and having tuberculosis that was limited to the lungs. Multivariate analysis revealed that the only variable associated with response was receipt of appropriate therapy for > or = 2 consecutive weeks. In contrast to findings in the published literature, our results indicate the outcome of MDR-TB can be improved, particularly for severely immunosuppressed HIV-infected patients. Rapid reporting of susceptibilities and prompt initiation and continuation of appropriate antituberculous therapy improved response and survival.

This parent BCG strain was distributed widely, and the distributed and may have become further attenuated in the process [6].All BCG substrains share a 10-kb deletion (RD1), which may Although there is much to be learned by comparing substrains, a crucial question is whether any BCG substrain should be used in populations with high rates of both HIV infection and tuberculo- Factors Influencing Time to Sputum Conversion Among sis. We demonstrated a high mortality among patients with AIDS Patients with Smear-Positive Pulmonary Tuberculosisand disseminated BCG disease, but we could not determine the rate of this complication. In contrast, in some countries up to half of patients with AIDS develop tuberculosis. If BCG vaccination SIR-The editorial by Iseman [1] raises important issues about the duration of respiratory isolation for patients hospitalized with is even moderately efficacious in preventing tuberculosis in patients with AIDS, then the benefits will outweigh the risks. One tuberculosis. However, his response to our article had little to do with the data we presented and much more to do with his objections population-based study showed that the risk of disseminated BCG disease is low for adults with AIDS who were vaccinated as chilto the 1994 Centers for Disease Control and Prevention (CDC) guidelines for the prevention of nosocomial transmission of tuberdren and that childhood BCG vaccination is associated with protection against Mycobacterium tuberculosis bacteremia [9]. We are culosis [2]. The point of our paper was to quantify the time to sputum conversion, which the title clearly indicates, and, by implicurrently participating in an international study to further address this question.cation, quantify the number of hospital days required to meet CDC guidelines [3]. This paper was not intended, explicitly or implicitly, M. tuberculosis still causes the deaths of more adults than any other infectious agent. BCG is our only tuberculosis vaccine, but to be a public policy paper, and we never suggested that the guidelines be adopted by other physicians in different clinical settings. it has limited efficacy and causes important complications. The development of an improved tuberculosis vaccine is a pressing Although there is much in Iseman's editorial that we agree with, given the greatly improved situation in 1997 in New York public health priority.City with respect to tuberculosis control, the situation several years ago was very different.