Mapping xerophthalmia in Mali: results of a national survey on regional distribution and related risk factors.

BACKGROUND

Vitamin A deficiency is recognized to be a severe public health problem in most of the sahelian countries. In Mali, several surveys had been performed at the district or regional level. Unfortunately, they did not cover the entire territory. In the aim of getting a general picture, we collected information on the frequency and presentation of xerophthalmia among the children under 10 years old population recruited in the setting of a national survey planned in 1996 and 1997 to evaluate the prevalence and determinants of trachoma in Mali.

METHODS

In each of the seven regions (with the exception of Bamako district), a random sample of thirty villages was taken from the general population. In a subsample of those villages, children under 10 years of age were examined by an ophthalmologist and their related mothers interviewed. Diagnosis of night blindness and Bitot spot occurrence was used for data gathering. Information was collected on village's infrastructures and familial socioeconomic condition. Multiple logistic regression analyses were performed to purpose the best model to describe the relationship between each outcome variable and the various risk factors assessed.

RESULTS

The prevalence of night blindness was estimated to be 1.95% (95% Confidence Interval [CI]: 1.58-2.39) and Bitot spots frequency to be 1.10% (95% CI: 0.83-1.45) among children between 2 and 6 years of age. Xerophthalmia prevalence was 2.51% (95% CI: 2.09-3.00) and nearly similar according to gender (2.68% among boys and 2.32% among girls). By region of the country and for the same age group, the prevalence ranged from 0.26% in the Kayes region to 7.02% in the Timbuktu region. In Mali, in four regions out of seven, the WHO thresholds defining a serious public health problem have been exceeded. The higher prevalence rates were found in Timbuktu, Mopti and Segou. After adjustment to season, the main risk factors were latitude, village size and poor sanitary coverage. The main protective determinants were education and rice culture.

CONCLUSIONS

This presentation illustrates a public health problem concerning vitamin A deficiency among young children in the general population and allows considering the effectiveness of substitutive intervention with vitamin A capsule distribution along with the improvement of vitamin A rich food production and consumption.