Table 1.

Sample sizes for the trachoma impact survey and the serological and infection sub-studies among four districts in Amhara, Ethiopia, 2017

			Full survey		Sub-studies
Zone	District	Years of surgery, antibiotics, facial cleanliness, and environmental improvement	Clusters, N	Total N, aged 1–9 years	Serological clusters, N	Serological N, aged 1–9 years	Infection clusters, N	Infection N, aged 1–5 years
North Gondar	Alefa	8	30	1,106	22	712	8	120
South Gondar	Woreta town	5	20	532	12	275	8	98
South Gondar	Dera	11	30	967	22	628	8	118
South Gondar	Andabet	11	30	824	22	580	8	106