[Xerophthalmia. Identification of populations at intermediate risk]

In developing countries, vitamin A deficiency (VAD) is a major contributor to child blindness and is associated with increased mortality. We assessed the vitamin A status of a Sahelien population and evaluated the correlation between the various criteria used to score xerophthalmia. The survey was carried out between June 1992 (the end of the dry season) using a representative sample of 906 children between the ages of 3 and 7 years in the district of Douentza. The population sample was selected by a two stage cluster sampling method (villages and then households). Vitamin A status was evaluated using clinical, histological and nutritional criteria. Clinical examination included testing for night blindness (XN), Bitot's spots (X1B) and corneal scars (XS). The Impression Cytology with Transfer (ICT) test described by Amedee-Manesme was used for histological analysis. Cases of follicular trachoma were recorded because of the possible influence of active trachoma on the findings of the ICT test. Nutritional status was determined by measuring the height for weight ratio according to the National Center for Health Statistics criteria. The prevalence of XN was 2.7% (1.6-3.7), significantly higher than the WHO threshold for a public health problem. The prevalence of X1B was 0.5% (0.1-1.2), and no corneal scars were detected. 31.7% of the children were suffering from malnutrition, but malnutrition did not correlate with any of the ophthalmological indicators of a public health problem. Among the 842 readable ICT tests, 265 were abnormal (31.4% of the total, 28.2-34.5). This incidence of abnormal results was unexpectedly low, in the light of the clinical results, and well below the threshold value of 50% suggested by Carlier.(ABSTRACT TRUNCATED AT 250 WORDS)