Table 1.
Baseline demographic characteristics of study participants, and community prevalence of malaria by microscopy/mRDT and PCR in Zanzibar, 2005–2013.
| Asymptomatic subjects |
Symptomatic subjects | ||||
|---|---|---|---|---|---|
| Year | 2005 | 2009 | 2011a | 2013 | 2013 |
|
| |||||
| Sample material | Filter paper | Filter paper | Filter paper | Filter paper | mRDT |
| Number screened by PCR | 534 | 2423 | 2977 | 3038 | 102 |
| North A (%) | 327 (61.2) | 1013 (41.8) | 1599 (53.7) | 1463 (48.2) | 36 (35.3) |
| Micheweni (%) | 207 (38.8) | 1410 (58.2) | 1378 (46.3) | 1575 (51.8) | 66 (64.7) |
| Age group (years) | |||||
| <5 (%) | 129 (24.2) | 567 (23.4) | 456 (15.3) | 646 (21.3) | 2 (2.0) |
| 5–15 (%) | 152 (28.5) | 546 (22.5) | 583 (19.6) | 872 (28.7) | 8 (7.8) |
| 15–25 (%) | 85 (15.9) | 369 (15.2) | 370 (12.4) | 459 (15.1) | 11 (10.8) |
| >25 (%) | 168 (31.5) | 842 (34.8) | 696 (23.4) | 1046 (34.4) | 15 (14.7) |
| Unknown (%) | 0 | 99 (4.1) | 872 (29.3) | 15 (0.5) | 66 (64.7) |
| Sex | |||||
| Male (%) | 222 (41.6) | 928 (38.3) | 891 (29.9) | 1257 (41.4) | – |
| Female (%) | 312 (58.4) | 1422 (58.7) | 1257 (42.2) | 1766 (58.1) | – |
| Unknown (%) | 0 | 73 (3.0) | 829 (27.9) | 15 (0.5) | 102 (100) |
| Parasite prevalence | |||||
| By microscopy/mRDT % (95% CI) | 7.5 (6.4–8.6) | 0.0 (0–0.2) | 0.4 (0.2–0.7) | 0.3 (0.1–0.7) | – |
| By PCR % (95% CI) | 21.1b (17.4–24.9) | 3.3 (2.6–4.1) | 2.2 (1.6–2.8) | 2.3 (1.7–2.9) | – |
a
A labelling issue occurred in the field in 2011, resulting in a large number of samples with unknown age and sex data.
b
Prevalence adjusted to account for the sample selection.