Undiagnosed TB spurs hospital outbreak

Centers for Disease Control and Prevention. Tuberculosis outbreak in a community hospital — District of Columbia, 2002. MMWR 2004; 53:214-216.

One health care worker developed tuberculosis and 56 others converted TB skin tests after a patient with unrecognized TB spent three weeks in a community hospital in Washington, DC, the Centers for Disease Control and Prevention (CDC) reports. The patient’s coinfection with HIV possibly masked the TB, resulting in a failure to implement respiratory isolation measures. Although the incidence of TB continues to decline, heightened awareness and vigilance is required by hospital staff to identify and treat people with suspected TB promptly, the CDC advised.

Patients with suspected TB should be placed in respiratory isolation until infectious TB is ruled out. When the patient is transported for medical procedures that cannot be performed in the isolation room, the patient should wear a surgical mask. Hospital infection-control programs are encouraged to develop protocols and implement administrative procedures for HIV-infected patients with pulmonary symptoms suggestive of TB.

Five secondary TB cases were identified, including four patients who had been hospitalized in different rooms on the same medical ward as the index patient. All four had at least one condition associated with increased risk for progression to TB disease (one had HIV infection and diabetes, one had diabetes, and two had end-stage renal disease). The fifth secondary case was a phlebotomist who worked on the same medical ward as the index patient. All five secondary patients received diagnoses three to six months after exposure to the index patient. M. tuberculosis isolates from all six patients had matching genotypes. All TB strains were susceptible to isoniazid and rifampin. In addition to the phlebotomist, 495 (63%) of 784 hospital staff members were evaluated with TB skin tests. Of those, 56 staff members tested positive, of whom 21 (38%) were direct-care providers, six (11%) were ward-based staff, and 29 (52%) were other staff.

Mupirocin strategy fails in nonsurgical patients

Wertheim HFL, Vos MC, Ott A, et al. Mupirocin Prophylaxis against nosocomial Staphylococcus aureus infections in nonsurgical patients. Ann Intern Med 2004; 140:419-425.

Routine patient culture for Staphylococcus aureus nasal carriage at admission and subsequent mupirocin application did not provide effective prophylaxis against nosocomial S. aureus infections in nonsurgical patients, the authors of this study reported. Staphylococcus aureus nasal carriage is a major risk factor for nosocomial S. aureus infection. Studies show intranasal mupirocin can prevent nosocomial surgical-site infections.

To assess the efficacy of mupirocin prophylaxis in preventing nosocomial S. aureus infections in nonsurgical patients, researchers conducted a randomized, double-blind, placebo-controlled trial at three tertiary care academic hospitals and one nonacademic hospital.

The patients included 1,602 culture-proven S. aureus carriers hospitalized in nonsurgical departments. Therapy with mupirocin 2% nasal ointment was applied to 793 patients, while a group of 809 received a placebo ointment. The regimen was mupirocin twice daily for five days, started one to three days after admission.

The mupirocin and placebo groups did not statistically differ in the rates of nosocomial S. aureus infections (mupirocin, 2.6%; placebo, 2.8%); mortality (mupirocin, 3.0%; placebo, 2.8%), or duration of hospitalization (median for both, eight days). A total of 77% of S. aureus nosocomial infections were endogenous.