Table 2. Active Trachoma and Chlamydia trachomatis (Ct) infection after the introduction of mass antibiotic treatment.
| Country, Year | Study design | Time Point post 1st MDA | Participants | Active Trachoma % | Ct % | Ct+/TF+ | Ct+/TF- | Comments |
|---|---|---|---|---|---|---|---|---|
| Tanzania, 1993, [20, 66] | Cross-section survey of randomly selected children one month after the completion of a one month tetracycline treatment course, given as MDA to the entire community. | 1 month | 1–7 years: 227 | 1–7 years: ● TF/TI 41.9% (95/227) ● TI 2.6% (6/227) |
1–7 years: 23.8% (54/227) | Data not available | Data not available | ● Hyperendemic setting ● Clinical grading: simplified WHO system ● Chlamydia test: in-house PCR-EIA for OMP1. |
| Egypt, 2003, [10, 31] | Cross-section population-based survey 14 months after azithromycin MDA. | 14 months | 1–10 years: 354 | 1–10 years: ● TF/TI 26.0% (92/354) |
1–10 years: 5.1% (18/354) | 1–10 years: 9.8% (9/92) | 1–10 years: 3.4% (9/262) | ● Hyperendemic setting ● Clinical grading: detailed WHO-FPC system ● Chlamydia test: LCR, Abbott Laboratories. ● Only the azithromycin arm is included. |
| Gambia, 1999, [31] | Cross-section population-based survey 12 months after azithromycin MDA. | 12 months | All ages: ● 675 (exam) ● 540 (tested) |
All ages: ● TF/TI 8.6% (58*/675) ● TI 2.2% (15*/675) |
All ages: 8.3% (45/540) | Data not available | Data not available | ● Hyperendemic setting, pre treatment ● Clinical grading: detailed WHO-FPC system ● Chlamydia test: LCR, Abbott Laboratories. ● Only the azithromycin arm is included. |
| Tanzania, 1999, [31] | Cross-section population-based survey 12 months after azithromycin MDA. | 12 months | All ages: ● 1308 (exam) ● 1162 (tested) |
All ages: ● TF/TI 24.6% (322*/1308) ● TI 6.3% (83*/1308) |
All ages: 7.0% (82/1162) | Data not available | Data not available | ● Hyperendemic setting ● Clinical grading: detailed WHO-FPC system ● Chlamydia test: LCR, Abbott Laboratories. ● Only the azithromycin arm is included. |
| Nepal, 2001, [23] | Cross-section survey of randomly selected normal children and a purposive sample of children with Active Trachoma, 6 months after azithromycin MDA. | 6 months | 1–7 years: ● 5262 (exam) ● 394 (tested) |
1–7 years: ● TF/TI 16% (841*/5262) |
Data not available | 1–7 years: 11.8% (31/263) | 1–7 years: 5.1% (6/118) | ● Mesoendemic setting ● Clinical grading: simplified WHO system ● Chlamydia test: LCR, Abbott Laboratories. |
| Tanzania, 2004, [34, 35] | Cross-sectional survey of all residents of a sub-village, 24 months after MDA | 24 months | All ages: 842 | All ages: ● TF/TI 5.8% (49/842) |
All ages: 0.1% (1/842) | All ages: 2.0% (1/49) | All ages: 0.0% (0/793) | ● Hyperendemic setting, pre-treatment ● Clinical grading: simplified WHO system ● Chlamydia test: Amplicor PCR, Roche |
| Gambia, 2005, [7, 27, 32, 33] | Cross-sectional survey of all residents of 14 small villages, 12 months after MDA | 12 months | ● All ages: 1210 ● 1–9 years: 440 |
All ages: ● TF/TI 3.9% (47/1210)1–9 years: ● TF 6.8% 30/440) ● TI 0.9% (4/440) |
All ages: 2.3% (28/1210)1–9 years: 5.4% (24/440) | All ages: 29.8% (14/47)1–9 years: 36.7% (11/30) | All ages: 1.2% (14/1163)1–9 years: 3.2% (13/410) | ● Mesoendemic setting, pre-treatment ● Clinical grading: detailed WHO-FPC system ● Chlamydia test: Amplicor PCR, Roche. |
| Tanzania, 2005, [27, 36–39] | Cross-sectional survey of residents of a village, 12 months after MDA | 12 months | 0–7 years: 287 | 0–7 years: ● TF/TI 46.8% (134*/287) |
0–7 years: 12.8% (37*/287) | Data not available | Data not available | ● Hyperendemic ● Clinical grading: simplified WHO system ● Chlamydia test: Amplicor PCR, Roche |
| Tanzania, 2007, [39] | Cross-sectional of population-based survey 5 years after baseline MDA and 3.5 years after a second MDA. | 5 years | 0–10 years: 464 | 0–10 years: ● TF 30.2% (140/464) ● TI 10.6% (49/464) |
0–10 years: 25.9% (120/464) | Data not available | Data not available | ● Hyperendemic setting ● Clinical grading: simplified WHO system ● Chlamydia test: Amplicor PCR, Roche |
| Ethiopia, 2008, [67] | Cross-sectional population based sample of children from 32 communities. These had received between 1 and 3 rounds of MDA, with the most recent does less than 6 months in about half the communities. | Variable | 3–9 years: 1459 | 3–9 years: ● TF 23.6% (345/1459) |
3–9 years: 3.0% (44/1459) | 3–9 years: 6.1% (21/345) | 3–9 years: 6.1% (23/1114) | ● Hyperendemic setting ● Heterogeneous treatment history ● Clinical grading: simplified WHO system ● Chlamydia test: Amplicor PCR, Roche |
| Ethiopia, 2009, [47] | Cross-sectional population-based sample of 8 randomly selected children (1–5 years) per village from eight villages. The villages had received MDA biannually for 2 years, with the last dose 18 months prior to the survey. | 42 months | 0–5 years: 120 | 0–5 years: ● TF/TI 47.5%: (57/120) ● TI 30.0% (36/120) |
0–5 years: 15% (18/120) | Data not available | Data not available | ● Hyperendemic setting ● Clinical grading: simplified WHO system ● Chlamydia test: Amplicor PCR, Roche |
| Ethiopia, 2010, [18, 48] | Cross-sectional population-based sample of children (1–5 years) living in 24 villages. Communities had received 4 biannual MDA, the most recent 6 months before survey | 24 months | 1–5 years: 1234 | 1–5 years: ● TF/TI 39.2% (mean village prevalence) |
1–5 years: 2.0% (mean village prevalence) | Data not available | Data not available | ● Hyperendemic setting ● Clinical grading: simplified WHO system ● Chlamydia test: Amplicor PCR, Roche ● NB: The data are reported a mean of the prevalence across all 24 villages. |
| Tanzania, 2011, [15] | Cross-sectional population-based sample of children from 71 communities. All communities had received 3 to 7 rounds of MDA. | Variable | 0–5 years: 7817 | 0–5 years: ● TF 10.0% (784/7817) ● TI 3.2% (252/7817) |
0–5 years: 5.5%% (429/7817) | 0–5 years: 23.5% (184/784) | 0–5 years: 3.5% (245/7033) | ● Mesoendemic setting ● Clinical grading: simplified WHO system ● Chlamydia test: Amplicor PCR, Roche Heterogeneous MDA history. Wide range of community level prevalence of infection and disease. Summary data here pools these communities |
| Ethiopia, 2011, [57] | Cross-sectional population-based survey in 24 communities. Both arms of a cluster RCT of latrine provision received a single round of MDA at baseline. | 24 months | 0–9 years: 1211 | 0–9 years: ● TF/TI 47.0% (567/1207) |
0–9 years: 14.6% (177/1211) | Data not available | Data not available | ● Hyperendemic setting ● Clinical grading: simplified WHO system ● Chlamydia test: Amplicor PCR, Roche ● Data from both arms combined. |
| Ethiopia, 2012, [19, 58, 59, 68, 69] | Cross-sectional survey of 50 children per village under 10 years in 12 villages. Three annual rounds of MDA were given. The final survey was months after the last MDA. | 36 months | 0–9 years: 577 | 0–9 years: ● TF 43.5% (251/577) |
0–9 years: 4.3% (25/577) | Data not available | Data not available | ● Hyperendemic setting ● Clinical grading: simplified WHO system ● Chlamydia test: Amplicor PCR, Roche |
| Gambia, 2013, [25, 70] | Cross-sectional population-based sample of children from 48 communities enrolled in an cluster RCT from four districts. 24 communities had 3 annual MDA and 24 communities had a single round of MDA at baseline. Survey was 3 years after the first round of MDA. | 36 months | 0–5 years: ● District 1: 1128 ● District 2: 1199 ● District 3: 1243 ● District 4: 1246 |
0–5 years: ● TF 0.2% (2/1128) ● TF 0.3% (3/1199) ● TF 3.8% (47/1243) ● TF 6.4% (80/1246) |
0–5 years: ● 0.5% (6/1128) ● 0.1% (1/1198) ● 1.1% (13/1241) ● 0.3% (4/1235) |
0–5 years: ● 0.0% (0/2) ● 0.0% (0/3) ● 6.4% (3/47) ● 0.0% (0/80) |
0–5 years: ● 0.5% (6/1126) ● 0.1% (1/1196) ● 0.8% (10/1196) ● 0.3% (4/1166) |
● Hypoendemic setting ● Clinical grading: simplified WHO system ● Chlamydia test: Amplicor PCR, Roche. ● Data from both trial arms were combined, and presented separately for each district. |
| Tanzania, 2014, [51, 71] | Cross-sectional survey of all children under 10 years in four villages. Four annual rounds of MDA were given. The final survey was 6 months after the last MDA. | 42 months | 0–9 years: 2234 | 0–9 years: ● TF/TI 7.9% (176/2234) |
0–9 years: 5.1% (114/2234) | Data not available | Data not available | ● Hyperendemic setting, pre-treatment ● Clinical grading: simplified WHO system ● Chlamydia test: Amplicor PCR, Roche |
| Tanzania, 2014, [71, 72] | Cross-sectional population-based sample of children aged 0–5 years in 32 villages, 100 children per village. Survey was done 12 months after the third MDA. | 36 months | 0–5 years: 3136 | 0–5 years: ● TF 7.6% (237/3136) |
0–5 years: 4.5% (142*/3136) | 0–5 years: 29.5% (70/237) | 0–5 years: 2.5% (72*/2899) | ● Hyperendemic setting, pre-treatment ● Clinical grading: simplified WHO system ● Chlamydia test: Amplicor PCR, Roche |
| Tanzania,: 2015,[73] | Cross-sectional population-based of residents of a village, which had received 2 rounds of MDA 12 and 10 years previously. | 12 years | ● All ages: 571 ● 1–9 years: 200 |
All ages: ● TF 2.5% (14/571)1–9 years: ● TF 6.5% (13/200) ● TI 1.5% (3/200) |
All ages: 0% (0/571)1–9 years: 0% (0/200) | Data not available | Data not available | ● Hyperendemic setting, pre-treatment ● Clinical grading: simplified WHO system ● Chlamydia test: Amplicor PCR, Roche |
| Nepal, 2016,[74] | Cross-section survey of 1–9 year olds in 24 randomly selected communities. Four rounds of MDA. The survey was conducted 5 years after the first round. | 5 years | 1–9 years: 1124 | 1–9 years: ● TF/TI 0.3% (3/1124) |
1–9 years: 0% (0/1124) | Data not available | Data not available | ● Hypoendemic setting ● Clinical grading: simplified WHO system ● Chlamydia test: Amplicor PCR, Roche |
| Tanzania, 2016, [75] | Random sample of children aged 1–9 years, from 30 hamlets. 50 children were sampled per hamlet. Communities had received variable rounds of MDA, between 4 and seven years previously. | 7 years | 1–9 years: 1474 | 1–9 years: ● TF 0.4% (6*/1474) |
1–9 years: 1.1% (16/1474) | Data not available | Data not available | ● Hypoendemic setting ● Clinical grading: simplified WHO system ● Chlamydia test: Aptima Combo2, Hologic |
* Estimated value inferred from available data in publication.
a Additional data sub-divided by district were provided by the authors of this study.