Prevalence of tuberculous infection and active tuberculosis in old age homes in Hong Kong.
OBJECTIVE
To assess the prevalence of tuberculous infection and active tuberculosis (TB) in old age homes in Hong Kong and to determine whether there is institutional transmission in these homes.


METHODS
Cross-sectional.


METHODS
Old age homes.


METHODS
Total of 2,243 residents, representing 84.6% of all residents in 15 old age homes; 1,698 were women, and 545 were men, with an average age of 82.


METHODS
All residents had a questionnaire-based interview, medical record review, two-stage tuberculin testing using two units purified protein derivative-RT23, and a chest x-ray. Those with radiological abnormalities had sputum examined for acid-fast bacilli.


RESULTS
The estimated prevalence rate of active TB in this population was 669 per 100,000, significantly higher in men than in women (1,101 per 100,000 vs 530 per 100,000). The proportion with positive tuberculin reactivity (> or =10 mm induration) after two-stage testing was 68.6%, significantly higher in men than in women. There was no evidence of active transmission of disease in these old age homes, with restriction fragment length polymorphism (RFLP) analysis performed on five cases of active pulmonary TB in the home with the highest rate of TB showing unique RFLP patterns.


CONCLUSIONS
The rate of active TB and TB infection in old age homes in Hong Kong is still high. Because treatment for latent TB carries a high risk for liver dysfunction in this population, clinicians and other healthcare workers need a high index of suspicion and to diagnose and treat this disease as early as possible to prevent transmission.
Chan-Yeung
Moira
M
Respiratory Division, Department of Medicine, University of Hong Kong, Hong Kong, China. mmwchan@hkucc.hku.hk
Chan
Felix H W
FH
Cheung
Amy H K
AH
Dai
David L K
DL
Chu
Leung-Wing
LW
Lam
Wah-Kit
WK
Leung
Chi-Chiu
CC
Kam
Kai-Man
KM
Tam
Cheuk-Ming
CM
D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D005191:Family Characteristics; D005260:Female; D006304:Health Status; D006707:Homes for the Aged; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D015995:Prevalence; D014374:Tuberculin Test; D014376:Tuberculosis / Q000175:diagnosis / Q000453:epidemiology*