A 48-year-old white man (index case) with an abnormal chest radiograph
remained undiagnosed for tuberculosis for 4 years. Investigation by p
urified protein derivative (PPD) tuberculin test revealed positive tub
erculin reactions (greater than or equal to 10 mm induration) in seven
of eight (88%) initial close contacts, and in 12 of 46 (26%) coworker
s. On the suspicion that transmission had also occurred among members
of the index case's church congregation, a PPD tuberculin test survey
of 184 of 200 of the members revealed 77 (42%) positive reactors, Thir
ty percent of the members under the age of 35 years were infected, sug
gesting transmission of infection. Eight cases of active tuberculosis
(including the index case) were detected, yielding a high case rate (4
.3%) among the parishioners, Three of the cases were confirmed recent
PPD converters, Although bacteriologic findings were available in only
three of the eight cases, two cases had phage typing of organism iden
tical to the index case; the third had recrudescent tuberculous diseas
e. Of the remaining five cases without bacteriologic confirmation, two
had pleural tuberculosis, one child had progressive primary tuberculo
sis, and two persons had localized pulmonary nodules suggestive of pri
mary infection progressing to disease. Because transmission of tubercu
lous infection may occur in any closed environment, including a church
, physicians must be conversant with tuberculosis control measures and
preventive therapy guidelines to preclude unforeseen transmission of
disease,