The prevalence of trachoma was determined among displaced persons from
the north, west and south of The Sudan who had settled in Angola Vill
age, Omdurman County. Of 616 persons examined, 376 (61%) were found to
have clinical signs of active trachoma. Of the 448 children, aged 4 m
onths to 15 years, 55 (12%) had mild, 69 (15%) moderately severe, and
210 (47%) severe disease. The corresponding figures for those aged 16
and older (adults) were 5 (3%), 12 (7%) and 25 (15%), respectively. Th
e prevalence of active trachoma among the children in the village was
75%, being higher among those from southern (86%) Sudan than for those
from the northern (64%) and western (66%) regions. The corresponding
figures for the adults were 25%, 38%, 13% and 14%. Antibodies to Chlam
ydia trachomatis were found in the lachrymal fluid of 224 (67%) and in
the serum of 272 (81%) of the children tested. A higher (74%) prevale
nce rate of antibody-positive tears was found in children from the sou
th than from either northern (58%) or western (61%) Sudan. The corresp
onding percentages of antibody-positive sera were 90%, 72% and 73%. In
the adults, antibodies to C. trachomatis were found in tears of 28 (6
7%). As in the children, the proportion of adults with antibody-positi
ve tears was higher among those from the south (80%) than in those fro
m north or west Sudan (25% and 38%, respectively). This was also true
of the prevalence of serum antibodies, which was 93% versus 75% and 75
%, respectively. Trachoma is still common in The Sudan among persons o
f low socio-economic status. Our investigations also showed that the p
revalence can differ between ethnic groups originating from different
regions in spite of them having lived in the same place, often for yea
rs, and under the same primitive and trachoma-promoting conditions. Cl
ose family ties thus seem to be of greater importance in the prevalenc
e of trachoma than do environmental conditions.