The Epidemiology of Trachoma in Mozambique: Results of 96 Population-Based Prevalence Surveys

Figures & data

Table 1. Prevalence of trachomatous inflammation—follicular (TF) in children aged 1–9 years and trichiasis in adults aged 15 years and above, by evaluation unit, Mozambique, 2012–2015. The name given to each evaluation unit is a concatenation of the names of its constituent districts.

		1–9 years		≥15 years
Province	Evaluation unit	Examined (n)	Adjusted TF^a (%, 95%CI^b)	Examined (n)	Adjusted trichiasis^c prevalence (%, 95%CI^b)
Cabo Delgado	Ibo-Meluco-Macomia	727	6.6 (3.7–10.5)	1183	0.8 (0.2–1.2)
Cabo Delgado	Muidumbe-Mocimboa Praia	769	8.8 (5.3–13.4)	1254	0.7 (0.3–1.2)
Cabo Delgado	Pemba Metuge-Mecufi-Quissanga	753	8.4 (5–12.4)	1164	0.4 (0.1–0.7)
Cabo Delgado	Nangade-Palma	908	15.7 (10.6–19.8)	1480	1.2 (0.7–1.7)
Cabo Delgado	Ancuabe	845	11.6 (7.5–16.8)	1200	0.4 (0.1–0.6)
Cabo Delgado	Balama	1019	5.3 (3.7–7.3)	1275	0.8 (0.4–1.1)
Cabo Delgado	Chiure	798	13.9 (8.7–19.4)	1181	0.2 (0–0.6)
Cabo Delgado	Montepuez	820	7.8 (5–11.5)	1233	0.6 (0.4–1)
Cabo Delgado	Mueda	744	12.2 (8.6–16.8)	1313	0.7 (0.3–1.2)
Cabo Delgado	Namuno	835	4.8 (2.9–6.6)	1106	0.6 (0.2–1.1)
Gaza	Macia	1043	0.3 (0–0.6)	1112	0 (0–0.3)
Gaza	Chibuto	866	0.1 (0–0.2)	1088	0.1 (0–0.3)
Gaza	Guija-Chigubo-Mabalane	868	0.9 (0–2.4)	1055	0 (0–0.4)
Gaza	Chokwe	862	0.2 (0–0.6)	1086	0.2 (0–0.4)
Gaza	Manjacaze	935	0 (0–0)	1214	0.3 (0–0.6)
Gaza	Massingir-Massangena-Chicualacuala	1042	1.2 (0.3–2.5)	1026	0 (0–0.4)
Gaza	Xai-Xai	925	0.1 (0–0.3)	1114	0 (0–0.3)
Inhambane	Inhassoro-Govuro-Mabote	1095	1.4 (0.7–2.5)	1342	0.1 (0–0.4)
Inhambane	Funhalouro-Panda	879	0.4 (0–1)	1133	0 (0–0.3)
Inhambane	Homoine	857	0.1 (0–0.2)	1195	0.2 (0.1–0.4)
Inhambane	Inharrime	925	0 (0–0)	1236	0.1 (0.1–0.2)
Inhambane	Jangamo	936	0 (0–0)	1213	0.1 (0–0.3)
Inhambane	Massinga	819	0.4 (0–1)	1183	0.3 (0–0.5)
Inhambane	Morrumbene	894	0.3 (0–0.6)	1222	0.1 (0–0.2)
Inhambane	Vilankulo	904	0.9 (0.3–1.4)	1233	0.2 (0–0.4)
Inhambane	Zavala	963	0.7 (0.1–1.3)	1318	0.2 (0.1–0.5)
Manica	Macossa-Guro-Tambara	1693	10.7 (7.2–14.3)	1280	0.3 (0.1–0.5)
Manica	Barue	1344	1.6 (0.5–2.8)	1321	0 (0–0.3)
Manica	Macate-Gondola	1394	0.3 (0–0.7)	1240	0.1 (0–0.2)
Manica	Machaze	1273	2.6 (1.2–3.9)	1085	0.1 (0–0.3)
Manica	Vanduzi-Manica	1432	0.3 (0.1–0.6)	1219	0 (0–0.3)
Manica	Mossurize	1218	0.1 (0–0.4)	1110	0 (0–0.3)
Manica	Sussundenga	1293	0.4 (0.1–0.8)	1181	0.1 (0–0.3)
Maputo	Boane	760	0.6 (0.1–1.3)	1245	0.1 (0–0.3)
Maputo	Manhica	1294	1.1 (0.2–2.4)	1452	0 (0–0.3)
Maputo	Marracuene	1211	0.6 (0.2–1)	1582	0 (0–0.2)
Maputo	Moamba-Magude	768	1 (0.2–2)	1161	0 (0–0.3)
Maputo	Matutuine-Namaacha	1125	0.5 (0.1–1.1)	1447	0 (0–0.3)
Nampula	Ilha Mozambique-Mossuril	1192	14.5 (9.1–20)	1262	0.1 (0–0.1)
Nampula	Mecuburi-Lalaua	1137	3.7 (2.2–5.2)	1212	0.1 (0–0.3)
Nampula	Nacaroa-Muecate	1049	6.2 (3.6–9.2)	1211	0.3 (0–0.7)
Nampula	Angoche	1193	10.3 (6.1–14.9)	1291	0 (0–0.3)
Nampula	Meconta	1000	3.7 (1.7–6.4)	1239	0.1 (0–0.1)
Nampula	Mogincual-Liupo	1159	17.1 (11.6–22)	1249	0.1 (0–0.1)
Nampula	Mogovolas	1084	3.6 (1.8–5.3)	1273	0.1 (0–0.2)
Nampula	Moma-Larde	1209	8.3 (6.3–10.4)	1288	0.8 (0.2–1.9)
Nampula	Monapo	1114	7.6 (4.5–10.7)	1265	0 (0–3)
Nampula	Murrupula	1035	2.7 (1.3–4.4)	1222	0 (0–0.3)
Nampula	Nampula	984	2.9 (1.3–4.8)	1198	0 (0–0.3)
Nampula	Ribaue^e	1964	1.3 (0.7–1.7)	2335	0 (0–0.2)^d
Nampula	Malema^e	1680	1.1 (0.5–1.8)	2227	0 (0–0.2)^d
Nampula	Memba^e	1846	11.9 (9–16)	2300	0 (0–0.2)^d
Nampula	Erati^e	1581	8.4 (6.3–11.4)	2285	0 (0–0.2)^d
Nampula	Nacala-A-Velha^e	1858	9.4 (7.3–11.5)	2647	0 (0–0.1)^d
Niassa	Cuamba	1094	2.1 (0.9–3)	1119	0 (0–0.3)^d
Niassa	Lichinga	1016	1.2 (0.4–2)	978	0 (0–0.4)^d
Niassa	Mandimba	1395	1.4 (0.6–2.5)	1142	0 (0–0.3)^d
Niassa	Mecanelhas	1308	1.9 (1–2.6)	1194	0.1 (0–0.4)^d
Niassa	Sanga-Lago	1120	0.5 (0.2–0.9)	1106	0 (0–0.3)^d
Niassa	Magune-Marupa	985	2.4 (1.1–4.1)	1047	0.1 (0–0.2)^d
Niassa	N’gauma	1139	3.3 (1.7–5.3)	1086	0 (0–0.4)^d
Niassa	Maúa-Nipepe-Metarica	1245	1.4 (0.7–2.4)	1206	0 (0–0.3)^d
Niassa	Muembe -Mecula-Mavago	1172	0.7 (0.1–1.5)	1113	0 (0–0.3)^d
Sofala	Buzi	1063	0 (0–0)	1086	0 (0–0.4)
Sofala	Caia	1449	2.1 (1.3–3.3)	1224	0.2 (0–0.5)
Sofala	Machanga-Chibabava	979	0.8 (0.2–1.5)	1111	0 (0–0.3)
Sofala	Dondo	1128	0.4 (0.1–0.7)	998	0 (0–0.4)
Sofala	Gorongoza	1292	1.2 (0.4–2.4)	1173	0 (0–0.3)
Sofala	Cheringoma-Muanza-Marromeu	1510	4.1 (2.8–5.7)	1306	0.1 (0–0.3)
Sofala	Chemba-Maringue	1391	6.9 (4.8–9.5)	1139	0.2 (0–0.4)
Sofala	Nhamatanda	1197	1 (0.3–1.8)	1081	0.4 (0–1.1)
Tete	Angonia	834	3 (1.2–5.6)	1272	0.2 (0–0.5)
Tete	Chiuta-Cahora Bassa	892	5.7 (3.7–8.3)	1210	0.1 (0–0.1)
Tete	Changara	903	9.9 (6.9–12.9)	1163	0.2 (0–0.5)
Tete	Chifunde	1042	4.1 (2.5–6)	1228	0.1 (0–0.3)
Tete	Macanga	1063	3.6 (2.1–5.2)	1269	0 (0–0.3)
Tete	Magoe-Zumbu	845	5.2 (2.9–8.3)	1253	0.2 (0–0.4)
Tete	Maravia	879	1.9 (0.8–3.1)	1224	0 (0–0.3)
Tete	Moatize	1006	4.7 (2.8–6.8)	1200	0.2 (0–0.5)
Tete	Doa-Mutarara	1073	9.7 (7.2–13)	1248	0.1 (0–0.2)
Tete	Tsangano	836	1.7 (0.8–2.9)	1193	0 (0–3)
Zambezia	Chinde-Luabo-Inhassunge	1613	19.8 (15.6–24.1)	2200	0.2 (0–0.5)
Zambezia	Gile	935	2.3 (0.9–3.4)	1217	0 (0–3)
Zambezia	Gurue	797	3.3 (1.9–4.7)	1098	0 (0–0.4)
Zambezia	Ile-Mulevala	829	1.2 (0.3–2.3)	1150	0.3 (0–0.7)
Zambezia	Lugela	794	2 (0.6–3.3)	1231	0.1 (0–0.3)
Zambezia	Mocubela-Maganja da Costa	856	10.2 (6.5–13.3)	1188	0.2 (0–0.4)
Zambezia	Milange	872	3.7 (1.9–5.9)	1169	0 (0–0.3)
Zambezia	Mocuba	896	1.6 (0.8–2.7)	1214	0 (0–0.3)
Zambezia	Molocue	821	1.8 (0.9–2.5)	1170	0 (0–0.3)
Zambezia	Mopeia	853	6.9 (4.4–10.3)	1196	0 (0–0.3)
Zambezia	Morrumbala	865	7 (3.9–11.1)	1168	0.1 (0–0.3)
Zambezia	Namacurra	770	3.4 (1.6–5.7)	1263	0.2 (0–0.4)
Zambezia	Namaroi	774	2.7 (1–4.4)	1147	0 (0–0.3)
Zambezia	Nicoadala	1438	3.9 (2.2–6)	1713	0.1 (0–0.1)
Zambezia	Pebane	751	14.1 (9.9–19.7)	1210	0.3 (0–0.9)

^aPopulation-based trachomatous inflammation–follicular (TF) prevalence derived from cluster-level proportions adjusted for age in 1 year agebands using the latest available census data

^b95% Confidence intervals estimated by bootstrapping adjusted cluster-level proportions over 10,000 replicates. Zero-count estimate upper confidence interval limits estimated as a one-sided 97.5% exact binomial confidence interval.

^cPopulation-based trichiasis prevalence derived from cluster-level proportions adjusted for sex and age in 5 year agebands using the latest available census data

^dData on trachomatous scarring (TS) recorded for all subjects, or for eyes with trichiasis (see text), in these surveys, so the trichiasis prevalence estimates here may be accurately referred to as trachomatous trichiasis (TT) prevalence estimates.

^eFirst-phase, paper-based surveys.

Figure 1. Prevalence of trachomatous inflammation–follicular (TF) in those aged 1–9 years in 96 population-based prevalence surveys, Mozambique, 2012–2015.

Figure 2. Prevalence of trichiasis in those aged 15 years and above in 96 population-based prevalence surveys, Mozambique, 2012–2015. In 14 evaluation units (hatched), prevalence categories shown are for trachomatous trichiasis (TT), defined as trichiasis and (in the same eye) either (a) trachomatous conjunctival scarring (TS); or (b) the examiner’s inability to evert the eyelid to look for TS (with the difficulty in eversion presumed to be due to TS). In the other 82 evaluation units, prevalence categories shown are for all-trichiasis, regardless of the presence or absence of TS.

Table 2. Univariable mixed-effects logistic regression analysis of the outcome trachomatous inflammation–follicular (TF) in children aged 1–9 years against putative risk factors, using data from 91 population-based prevalence surveys, Global Trachoma Mapping Project, Mozambique, 2012–2015.

Variable	Examined (n)	TF cases (%)	Odds ratio (95% CI)^a	p-value^b
Age
1–4	42,919	2377 (5.5)	2.16 (2.01–2.33)	<0.0001
5–9	50,793	1386 (2.7)	1
Sex
Male	46,532	1859 (4.0)	1
Female	47,180	1904 (4.0)	1.03 (0.96–1.10)	0.43
Number of children aged 1–9 years in household
1–3	76,899	2900 (3.8)	1
≥4	16,813	863 (5.1)	1.44 (1.31–1.57)	<0.0001
Latrine type^c
Improved	16,040	382 (2.4)	1	<0.0001
Unimproved	36,684	1160 (3.2)	1.21 (1.07–1.37)
No facilities, bush or field	40,988	2221 (5.4)	1.46 (1.30–1.64)
Latrine access^d
Shared latrine	6681	172 (2.6)	1.05 (0.86–1.29)	<0.0001
Private latrine	42,920	1182 (2.8)	1
No structure, outside near the house, in the bush or field	44,111	2409 (5.5)	1.25 (1.13–1.38)
Time to source of water for face-washing^d
All face-washing done at source	307	6 (1.9)	1.51 (0.60–3.78)	0.2226
<30 mins round-trip	43,251	1486 (3.4)	1
≥30 mins round-trip	50,154	2271 (4.5)	1.09 (0.98–1.22)
Time to source of water for drinking^d
<30 mins round-trip	43,084	1485 (3.4)	1
≥30 mins round-trip	50,628	2278 (4.5)	1.08 (0.97–1.21)	0.1576
Source of water for drinking
Improved water source	53,561	1911 (3.6)	1	0.112
Unimproved water source	17,930	934 (5.2)	1.11 (0.95–1.30)
Surface water (river, lake, dam)	22,221	918 (4.1)	1.16 (0.99–1.36)
Source of water for face-washing
Improved water source	52,367	1872 (3.6)	1	0.0944
Unimproved water source	18,240	949 (5.2)	1.12 (0.96–1.31)
Surface water (river, lake, dam)	22,835	942 (4.1)	1.17 (1.00–1.35)

^aUnivariable odds ratio and 95% confidence interval against the outcome trachomatous inflammation—follicular in children aged 1–9 years. Analysis carried out at individual level.

^bWald’s test

^cDirect observation by recorders

^dSelf-reported estimates from household head.

Table 3. Multivariable mixed-effects logistic regression analysis of the outcome trachomatous inflammation–follicular (TF) in children aged 1–9 years against putative risk factors, using data from 91 population-based prevalence surveys, Global Trachoma Mapping Project, Mozambique, 2012–2015.

Variable	Odds ratio (95% CI)^a	p-value^b
Age
1–4	2.19 (2.03–2.36)	<0.0001
5–9	1
Number of children aged1–9 years in household
1–3	1
≥4	1.51 (1.38–1.65)	<0.0001
Latrine type^c
Improved	1	<0.0001
Unimproved	1.24 (1.03–1.49)
No facilities, bush or field	1.45 (1.22–1.73)

^aMultivariable odds ratio and 95% confidence interval against the outcome trachomatous inflammation–follicular in children aged 1–9 years. Analysis carried out at individual level.

^bLikelihood ratio test of inclusion/exclusion in the full multivariable model.

^cDirect observation by recorders.