Intestinal helminths and xerophthalmia in Nepal. A case-control study.

The study reports on 25 cases of xerophthalmia among children 6-120 months of age and single controls for which faecal egg counts were available as proxy for hookworm and Ascaris lumbricoides infection. The selection of cases and controls was performed by ophthalmic assistants. Controls were healthy children matched for sex, age, and neighbourhood of residence. Faecal analyses were performed by Kato thick-smear technique, recording the number of eggs of hookworm and A. lumbricoides. The xerophthalmia cases had a significantly higher prevalence (P < 0.05) and intensity (P < 0.01) of infection, as expressed by the presence and number of A. lumbricoides eggs per gram of faeces, respectively, compared with the control group. Hookworm eggs were not detected in the faecal specimens of any of the cases or controls. This study demonstrates the importance of A. lumbricoides as a risk factor for ocular signs of vitamin A deficiency. Reduction of prevalence and intensity of A. lumbricoides infection may reduce the incidence of xerophthalmia in the community with its potential sequels of blindness, morbidity, and mortality.