NOSOCOMIAL TRANSMISSION OF A DRUG-SENSITIVE W-VARIANT MYCOBACTERIUM-TUBERCULOSIS STRAIN AMONG PATIENTS WITH ACQUIRED-IMMUNODEFICIENCY-SYNDROME IN TENNESSEE
Dw. Haas et al., NOSOCOMIAL TRANSMISSION OF A DRUG-SENSITIVE W-VARIANT MYCOBACTERIUM-TUBERCULOSIS STRAIN AMONG PATIENTS WITH ACQUIRED-IMMUNODEFICIENCY-SYNDROME IN TENNESSEE, Infection control and hospital epidemiology, 19(9), 1998, pp. 635-639
OBJECTIVE: To use DNA fingerprinting to characterize nosocomial spread
of,Mycobacterium tuberculosis following hospitalization of a patient
with acquired immunodeficiency syndrome and active pulmonary tuberculo
sis, for whom respiratory isolation was not initiated promptly. DESIGN
: Epidemiological investigation. SETTING: A tertiary-care medical cent
er in Tennessee. PARTICIPANTS: Patients and healthcare workers potenti
ally exposed to the infectious patient in 1992. RESULTS: Of 172 health
care workers exposed, 35 (20%) were judged to have acquired tuberculou
s infection. Risk of acquisition was greatest for nurses and medical r
eceptionists. Active tuberculosis later developed in one healthcare wo
rker and one, hospitalized patient. Nosocomial transmission was suppor
ted by epidemiological evidence and DNA fingerprinting. The outbreak s
train of Mycobacterium tuberculosis differed from other isolates at th
is hospital, but its DNA hybridization pattern was highly similar to t
hat of the multidrug-resistant outbreak strain W that has been prevale
nt in New York City, suggesting a common strain ancestry. However, the
Tennessee isolates were susceptible to all first-line antituberculous
agents. CONCLUSIONS: This report suggests the possibility that a mole
cular characteristic(s) shared by these successful outbreak strains is
associated with increased transmissibility or pathogenicity and empha
sizes the need for continued vigilance for tuberculosis in the nosocom
ial setting (Infect Control Hosp Epidemiol 1998:19:635-639).