Am. J. Respir. Crit. Care Med.,
Volume 158, Number 2, August 1998, 484-488
Long-term Trends in Tuberculosis
Comparison of Age-cohort Data between Hong Kong and England and Wales
KAREN
TOCQUE,
MARK A.
BELLIS,
CHEUK M.
TAM,
SHIU L.
CHAN,
QUTUB
SYED,
TRACEY
REMMINGTON,
and
PETER D. O.
DAVIES
Communicable Disease Surveillance Center (North West), Public Health Laboratory, Fazakerley Hospital; Department of Public Health,
John Moores University; Tuberculosis Research Unit, Cardiothoracic Centre, Liverpool, United Kingdom; Department of Health
Chest Service, Wanchai Polyclinic, Hong Kong, Republic of China
The caseload of tuberculosis in developing countries is increasingly associated with the elderly. This is
possibly due to increased longevity today and a change in the lifetime risk of tuberculosis within birth
cohorts. Published data for tuberculosis notifications for Hong Kong and England and Wales have
been used to calculate age-specific rates of disease by different age groups for different birth cohorts. In Hong Kong, each birth cohort showed a similar pattern of disease by age, with rates peaking
in the 25 to 39-yr age groups and gradually declining thereafter. After 1978, regardless of age at that
time, all age cohorts showed an increase in tuberculosis rates with increasing age. This trend was
more marked in males than females. A similar pattern was seen for birth cohorts in England and
Wales except that the peak occurred earlier in life (before 25 yr of age) and the decline with age ceased in 1984. Thereafter, rates increased in males born before 1930 but showed only a leveling off
in females. If these data represent a true increase in tuberculosis rates, rather than resulting from a
change in reporting accuracy and completeness, the burden of tuberculosis in the elderly is likely to
continue to increase substantially.
