Status of tuberculosis control in Thailand.

The national tuberculosis control program (NTP) was implemented in Thailand as integrated with the provincial general health services since 1967, with BCG vaccination successfully introduced from the beginning, but progress in expansion of case-finding and chemotherapy had only been achieved following the establishment of hospitals at the district level since the late seventies. At present, case-detection and treatment have operated in more than 95% of the 600 district hospitals and 87 hospitals at provincial and regional levels, with patient follow-up by health centers, logistically supported and technically supervised by 12 zonal TB centers. The trend of the disease has shown noticeable decline as indicated by the three national surveys in 1962, 1977 and 1991, that is, morbidity rate as suspected by x-ray of 2.1%, 1.4% and 1.01%; infectious case rate of 0.5%, 0.31% and 0.24% respectively, a reduction of about 2-3% per year. The infection rate of children 0-14 years of age was found to be 15.2% in 1977; 8.9% in 1983; and 5.18% in 1987, giving the annual risk of infection (ARI) of 4.9%, 2.3% and 2.0% respectively. Currently the program detects and treats about 31,000 smear-positive TB cases plus an equal number of smear-negative cases per year. Short-course chemotherapy was introduced since 1985 and expanded to cover all the former by 1991, resulting in improvement of the treatment success rate from less than 50% when using the old standard 18-24 months regimen to 70-80%. As the coverage of case detection and treatment is still only about 60% of the incidence or 30% of the prevalence, trials of primary health care approach have yielded substantially increased case detection coverage as well as improved cure rates. BCG vaccination as part of the Expanded Program on Immunization has reached 90-100% coverage of infants.