Sustainability of a nutrition education programme to prevent night-blindness in Bangladesh.

Cross-sectional surveys were conducted to assess prevalence of night-blindness and dietary habits prior to intervention (in 1986), after 3 years of intervention (in 1989) and 3 years after the termination of active intervention (in 1992), in the northern part of Bangladesh. The prevalence of night-blindness per thousand children decreased from 1986 to 1989 (during intervention) and rose from 1989 to 1992, but remained significantly lower in 1992 than the 1986 prevalence. Household income declined from 1989 to 1992, and lower consumption of beta-carotene rich food, protein items and vitamin A capsules was registered in 1992 despite almost the same level of awareness relating to the prevention of night-blindness in the community during the period 1989-1992. The results indicate that the long-term impact of a health education programme to prevent night-blindness is uncertain. Improvement in socioeconomic conditions, in addition to relevant knowledge, is probably a precondition for maintaining a sustainable impact of health education.