Table 1. Characteristics of the study population.

	n	Children included in the analysis [%]	n	Children not included in the analysis [%]a	P-value
Sociodemographic variables
Age (month)	836		282
< = 36		54.1		52.1	NS
>36		45.9		47.9
Age (year)	836		282
1		35.4		34.7	NS
2		18.4		17.4
3		17.7		15.6
4		15.4		14.2
5		13.0		18.1
Sex	836		317
male		50.4		51.1	NS
female		49.6		48.9
Village	836		317
a		10.0		7.3	0.01
b		11.7		12.0
c		23.3		15.8
d		8.8		10.4
e		12.9		11.7
f		12.4		18.6
g		9.0		8.5
h		11.7		15.8
Genotype distribution
No of copies of Hp2 allele	836		61
0		20.9		21.3	NS
1		58.0		59.0
2		21.1		19.7
-101C-G	836		162
CC		73.2		71.0	NS
CG		25.4		25.3
GG		1.4		3.7
-61A-C	836		161
AA		74.8		83.2	0.02
AC		25.2		16.8
CC		0.0		0.0
HbS	807		177
HbAA		82.0		86.4	NS
HbAS		18.0		13.7
Trachoma status
Active trachoma a	836		317
Yes		21.4		17.7	NS
No		78.6		82.3

^aOut of the 1155 children who had trachoma assessment, 836 children were included in the final analyses and 319 were not (because of missing data or because they were found to have sickle cell disease (HbSS), trachomatous scarring (TS) or protein-energy malnutrition as determined by weight-for-height z-score<−3 SD). In the 836 individuals included HWE p-values were <0.0001; 0.184, and <0.0001 for Hp1/2, -101C-G, and -61A-C, respectively.