Table 1 Characteristics of participants in the cross-sectional survey
|  | 1350–1449 m | 1450–1499 m | 1500–1549 m | 1550–1650 m | Total |
|---|---|---|---|---|---|
Number of participants (number of compounds) | 5424 (1108) | 6363 (1235) | 4579 (816) | 839 (140) | 17,503 (3213) |
Age, Â % (n/N) (years) | |||||
 <5 | 26.4 (1429/5424) | 27.0 (1791/6636) | 27.1 (1239/4579) | 27.7 (232/839) | 26.9 (4701/17,503) |
 6–10 | 18.9 (1024/5424) | 18.1 (1202/6636) | 18.0 (822/4579) | 19.4 (163/839) | 18.4 (3215/17,503) |
 11–15 | 15.2 (823/5424) | 13.9 (923/6636) | 15.0 (685/4579) | 14.3 (120/839) | 14.6 (2552/17,503) |
 16–25 | 13.7 (744/5424) | 15.3 (1018/6636) | 14.8 (677/4579) | 16.5 (138/839) | 14.7 (2579/17,503) |
 >26 | 25.9 (1404/5424) | 25.7 (1702/6636) | 25.3 (1156/4579) | 22.2 (186/839) | 25.5 (4456/17,503) |
Fever,  % temperature > 37.5 °C,  % (n/N) | 4.0 (216/5423) | 3.1 (204/6631) | 2.5 (116/4575) | 1.3 (11/839) | 3.1 (547/17,468) |
Clinical malaria, Â % (n/N)a | 2.3 (126/5423) | 1.8 (120/6631) | 1.1 (48/4575) | 0.12 (1/839) | 1.7 (295/17,468) |
Parasite prevalence, Â % PCR positive (n/N) | 27.2 (1111/4083) | 19.6 (900/4599) | 16.7 (592/3548) | 8.1 (54/664) | 20.6 (2663/12,912) |
Antibody prevalence, Â % positive (n/N)b | 62.6 (3108/4967) | 58.0 (3623/6252) | 48.3 (2104/4361) | 31.7 (246/777) | 55.5 (9092/16,381) |
Anaemia, Â % (n/N) | |||||
 Severe (<6 g/dL) | 0.6 (30/5282) | 0.7 (46/6391) | 0.4 (19/4366) | 0.2 (2/818) | 0.6 (97/16,878) |
 Moderate (<8 g/dL) | 3.1 (163/5282) | 3.4 (214/6391) | 2.6 (112/4336) | 2.0 (16/818) | 3.0 (505/16,878) |
 Mild (<11 g/dL) | 26.0 (1374/5282) | 23.0 (1472/6391) | 21.5 (938/4336) | 20.2 (165/818) | 23.4 (3954/16,878) |