Tuberculosis in rural Vietnam

Abstract

A tuberculosis survey was carried out in Quang Ngai province in South Vietnam in 1966; results obtained are compared with those of the W.H.O. survey in Saigon in 1962.The population of the province is approximately 700,000; the results of testing 20,798 people are presented in this paper. The standard W.H.O. Mantoux test was used, the test dose consisted of 0·l. containing 1 TU PPD RT23 with Tween 80, which is approximately equivalent to 3 TU international standard reference of PPD-S. The positivity limit was taken at 8 mm. induration or more. Bacteriological examination and x-ray of positive reactors was carried out.The proportion positive and presumed infected by tubercle bacilli rose from 5·4 of those under age 5 to 60·6 % of those aged 30–39. The greatest increase occurred between the age groups 10·14 (20·7%) and 15–19 (40·5%). In the Saigon survey the under-5 age group showed 11·0% and 15–19 79·6% infected.A total of 4,714 (83 % of the 5,672 positive reactors) had sputum specimens examined; all were over the age of 14 years. Thirty-three were found positive by direct microscopy. The estimated prevalence of `open' cases was 0–7 % as compared with the Saigon survey where 7,395 had sputum examined and 69 (0–9 %) were positive.A total of 4,321 (76 %) were examined by x-ray, 389 (9 %) of these were interpreted to have pulmonary tuberculosis. The estimated prevalence of x-ray evidence of tuberculosis in those with a positive tuberculin reaction in Quang Ngai was 9 %. In the Saigon survey 7,395 were examined by x-ray, and 767 (10-4 %) had abnormal shadows interpreted as tuberculous.In 1968, the estimated population over the age of 14 was 400,000; about 50% of these were positive reactors, of which 9 % showed evidence of tuberculosis on x-ray. The estimated prevalence was 45 per 1,000. Hence there were approximately 18,000 cases and suspect cases of pulmonary tuberculosis in the province and over 1,400 (0.7%) were spreading the infection.The prevalence of infection was almost three times greater in Saigon below the age of 14, and two times greater thereafter. The prevalence of sputum-positive cases was quite similar: 0·7% and 0·9% respectively. The tuberculin index showed a well marked difference between Saigon and Quang Ngai in children in the 0–4 age group, 11·0 and 5-4 % respectively.