Assessment of vitamin A deficiency in a rural area in Mali. Estimation of sample size for the impression cytology test.
The prevalence of vitamin A deficiency among two to ten years old children in a rural area of Mali was assessed by ophthalmic examination, determination of plasma retinol levels and impression cytology with transfer tests. A Public Health problem of vitamin A deficiency was identified in this rural area by: the prevalence of nightblindness significantly (p < 0.001) above the cut-off (1%) defined by the World Health Organization (WHO); the prevalence of corneal scarring significantly (p < 0.001) above the WHO's cut-off (0.05%); the percentage of subjects with plasma retinol levels below 0.35 mumol/l (10 micrograms/dl) significantly (p < 0.001) higher than the WHO's threshold (5%); and 52.8 +/- 8.2% children with "Abnormal" impression cytology as determined by the impression cytology test (IC). This preliminary survey confirmed widespread vitamin A deficiency in Mali. The minimum sample size required for a study using the impression cytology test to determinate a Public Health problem in a population was calculated for different situations. Ophthalmic examination indicated a very high rate of active trachoma (29.6 +/- 7.0%), and a relationship between active trachoma and impression cytology results was identified.
Bonnet
S
S
INSERM U 56, Hôpital de Bicêtre, Le Kremlin-Bicêtre, France.
Resnikoff
S
S
Castan
R
R
Konate
S
S
Periquet
B
B
Coste
J
J
Amédée-Manesme
O
O
D002648:Child; D002675:Child, Preschool; D003228:Conjunctiva / Q000166:cytology*; D003581:Cytodiagnosis; D004812:Epidemiologic Methods; D005123:Eye; D006801:Humans; D008302:Mali / Q000453:epidemiology; D008403:Mass Screening / Q000379:methods*; D010808:Physical Examination / Q000379:methods; D015995:Prevalence; D012423:Rural Health; D014141:Trachoma / Q000453:epidemiology* / Q000209:etiology; D014801:Vitamin A / Q000097:blood; D014802:Vitamin A Deficiency / Q000150:complications / Q000453:epidemiology*; D014985:Xerophthalmia / Q000175:diagnosis / Q000453:epidemiology*
D014801:Vitamin A