National immunisation days and vitamin A distribution in Mali: has the vitamin A status of pre-school children improved?

OBJECTIVES: The impact on vitamin A status of the distribution of vitamin A during national immunisation days (NIDs) has not been well established despite strong promotion by international agencies and donors. Using a pre-post design, the change in prevalence of vitamin A deficiency was examined in pre-school children in Mali. DESIGN: Two cross-sectional surveys were conducted in Mopti region, the first in March 1997 before this strategy was adopted and the second in March 1999, four-and-a-half months after a mass distribution of vitamin A during NIDs. SUBJECTS AND SETTING: We compared the vitamin A status of children aged 12 to 66 months targeted in 1999 by NIDs with the status of children in the same age group in 1997. Infectious events of the previous two weeks were concurrently recorded. Within the 1999 sample, the status of recipient and non-recipient children was also compared. RESULTS: In 1997, the prevalence of xerophthalmia (defined by the presence of night blindness and/or Bitot spots) was 6.9% (95% confidence interval (CI) 5.1-9.2) and the modified retinol dose response (MRDR) test proved abnormal in 77.8% of 12-66-month-old children (95% CI 68.27-85.17). In 1999 this picture had improved significantly, both for xerophthalmia prevalence, 3.3% (95% CI 2.1-5.2), and abnormal MRDR test response, 63.1% (95% CI 54.25-71.23). The infectious morbidity rates between 1997 and 1999 tended to decrease. No significant improvement was found among children older than those targeted by NIDs. In 1999, children who received vitamin A had a lower risk for xerophthalmia (3.0% for recipients vs. 8.7% for non-recipients) and experienced fewer infectious events. CONCLUSIONS: The clinical and biological vitamin A status of pre-school children improved between 1997 and 1999. Mass distribution of vitamin A appears to reduce the occurrence of xerophthalmia and would seem to be associated with a decrease in other related illnesses. Vitamin A supplementation during NIDs should be given a high priority when vitamin A deficiency remains a public health problem.

[Strategies to control vitamin A deficiency]. / Stratégies de lutte contre les déficits en vitamine A.

Vitamin A deficiency is a major public health problem in the countries of the Sahel. It causes xerophthalmia and high rates of child mortality and it occurs mostly in underdeveloped regions. People of all ages may suffer from vitamin A deficiency but it is a particular problem in pre-school-age children. Each year, about 250,000 children throughout the world become blind due to vitamin A deficiency. Measles, pneumonia and diarrhea reduce the child's reserves of retinol and increase the dietary requirement for vitamin A. Improvement of social conditions is a radical approach to preventing vitamin A deficiency. Three strategies are currently in use: horticultural activities and health education; fortification of food products; distribution of high-dose vitamin A capsules.