Analysis of Mycobacterium tuberculosis transmission patterns in a homeless shelter outbreak.
METHODS
From July 1997 through May 1998, ten tuberculosis (TB) cases were reported among men in a Syracuse New York homeless shelter for men.


OBJECTIVE
Investigation to determine extent of, and prevent further, transmission of Mycobacterium tuberculosis.


RESULTS
Epidemiologic and laboratory evidence suggests that eight of the ten cases were related. Seven cases had isolates with matching six-band IS6110 DNA fingerprints; the isolate from another case had a closely related fingerprint pattern and this case was considered to be caused by a variant of the same strain. Isolates from eight cases had identical spoligotypes. The source case had extensive cavitary disease and stayed at the shelter nightly, while symptomatic, for almost 8 months before diagnosis. A contact investigation was conducted among 257 shelter users and staff, 70% of whom had a positive tuberculin skin test, including 21 with documented skin test conversions.


CONCLUSIONS
An outbreak of related TB cases in a high-risk setting was confirmed through the use of IS6110 DNA fingerprinting in conjunction with spoligotyping and epidemiologic evidence. Because of the high rate of infection in the homeless population, routine screening for TB and preventive therapy for eligible persons should be considered in shelters.
Curtis
A B
AB
Division of Tuberculosis Elimination, National Center for STD, HIV, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. ajc8@cdc.gov
Ridzon
R
R
Novick
L F
LF
Driscoll
J
J
Blair
D
D
Oxtoby
M
M
McGarry
M
M
Hiscox
B
B
Faulkner
C
C
Taber
H
H
Valway
S
S
Onorato
I M
IM
D000328:Adult; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics*; D004196:Disease Outbreaks / Q000517:prevention & control / Q000706:statistics & numerical data*; D015658:HIV Infections / Q000150:complications; D006703:Ill-Housed Persons / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000235:genetics*; D009518:New York / Q000453:epidemiology; D012307:Risk Factors; D012621:Seasons; D013997:Time Factors; D014374:Tuberculin Test; D014397:Tuberculosis, Pulmonary / Q000150:complications / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission*
D004269:DNA, Bacterial