Background
Methods
Malaria in Tanzania
Geography and population
Climate and seasonality
Education system and schools
School malaria parasitaemia survey (SMPS)
Survey design, procedures and study tools
Survey staff and training
Ethical considerations
Data entry
Data analysis
Variable definitions and sources
Multilevel mixed-effects logistic regression analysis
Model I | Model II | |
---|---|---|
Regions | All | Excluding phase I data: Kigoma, Mtwara, Lindi, Ruvuma, Dar es Salaam |
Number of observations | 47,157 (96%) | 30,715 (62.5%) |
Variables | ||
Included | Gender, age, bed net use or RDT result, type of council, altitude, geographic zone, TSI | Gender, age, reported parental education, bed net use or RDT result, type of council, altitude, eco-zone, geographic zone, TSI |
Excluded | Reported parental education, eco-zone | |
Random effects | Council, school | Council, school |
Results
Councils | Schools | Children | Total pop. (2010) *, % | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
N | Children per council | N | Children per school | N | % | ||||||
Mean | Min | Max | % | Mean | Min | Max | |||||
Transmission zone* | |||||||||||
Low stable | 30 | 253.5 | 111 | 546 | 88 | 86.4 | 44 | 166 | 7606 | 15.5 | 25.4 |
Hypo-endemic 1 | 40 | 296.1 | 64 | 501 | 130 | 91.1 | 42 | 157 | 11,845 | 24.1 | 20.4 |
Hypo-endemic 2 | 27 | 303.3 | 97 | 653 | 91 | 90 | 44 | 199 | 8188 | 16.7 | 13.3 |
Meso-endemic | 67 | 316.5 | 89 | 1109 | 224 | 94.7 | 44 | 165 | 21,208 | 43.2 | 38.4 |
Hyper-holo-endemic | 1 | 146 | 146 | 146 | 2 | 73 | 73 | 73 | 146 | 0.3 | 2.3 |
Missing** | 1 | 120 | 120 | 120 | 2 | 60 | 60 | 60 | 120 | 0.2 | – |
Total | 166 | 295.9 | 64 | 1109 | 537 | 91.5 | 42 | 199 | 49,113 | 100 | 100 |
Characteristics of sample
Total children | Malaria (N = 49,102) | Bed net use (N = 47,800) | ||||||
---|---|---|---|---|---|---|---|---|
Children tested positive | Children sleeping under bed net | |||||||
N | % | n | % | 95% CI | n | % | 95% CI | |
Total | 49,113 | 100 | 10,627 | 22 | (19.6–23.9) | 33,284 | 70 | (67.6–71.6) |
Gender | ||||||||
Male | 24,205 | 49.3 | 5606 | 23.2 | (21.0–25.5) | 16,077 | 68.3 | (66.1–70.3) |
Female | 24,681 | 50.3 | 4940 | 20.0 | (18.0–22.2) | 17,078 | 71.0 | (68.9–73) |
Missing | 227 | 0.5 | 81 | 35.7 | – | 129 | 63.9 | – |
Age | ||||||||
< 9 | 9075 | 18.5 | 1651 | 18.2 | (16.1–20.5) | 5974 | 68.8 | (66.3–71.2) |
9–12 | 18,892 | 38.5 | 4045 | 21.4 | (19.2–23.8) | 13,106 | 71.2 | (69.2–73.3) |
> 12 | 20,730 | 42.2 | 4847 | 23.4 | (21.2–25.7) | 13,957 | 68.6 | (66.3–70.8) |
Missing | 416 | 0.9 | 84 | 20.2 | – | 247 | 62.7 | – |
Parental education | ||||||||
No school | 3736 | 7.6 | 1074 | 28.8 | (24.4–33.5) | 1930 | 54.7 | (50.2–59.1) |
Primary | 23,445 | 47.7 | 5163 | 22.0 | (19.4–24.8) | 14,968 | 65.8 | (63.1–68.3) |
Secondary | 4547 | 9.3 | 808 | 17.8 | (15.1–20.9) | 3430 | 77.5 | (74.8–80) |
Diploma or higher | 525 | 1.1 | 52 | 9.9 | (7.0–13.9) | 415 | 80.7 | (76.1–84.7) |
Missing | 5424 | 11.0 | 970 | 17.9 | – | 3617 | 69.7 | – |
Not interviewed* | 11,436 | 23.3 | 2560 | 22.4 | – | 8924 | 78.4 | – |
Bed net use | ||||||||
No | 14,516 | 29.6 | 2943 | 20.3 | (17.8–23.0) | – | – | – |
Yes | 33,284 | 67.8 | 7270 | 21.9 | (19.6–24.2) | – | – | – |
Missing | 1313 | 2.7 | 414 | 31.5 | – | – | – | – |
Zone | ||||||||
Eastern | 6967 | 14.2 | 1269 | 18.2 | (13.3–24.4) | 5819 | 86.6 | (83.4–89.3) |
Western | 4805 | 9.8 | 1449 | 30.2 | (25.5–35.2) | 3221 | 68.8 | (64–73.2) |
Southern | 4002 | 8.1 | 1344 | 33.6 | (27.2–40.8) | 3255 | 81.6 | (76.8–85.6) |
Southern highlands | 4116 | 8.4 | 495 | 12.0 | (7.2–19.4) | 2350 | 58.7 | (52.4–64.7) |
Southwest highlands | 4867 | 9.9 | 846 | 17.4 | (11.6–25.2) | 2946 | 61.6 | (55.3–67.5) |
Central | 5653 | 11.5 | 156 | 2.8 | (1.6–4.6) | 3077 | 55.1 | (49.6–60.5) |
Northern | 6191 | 12.6 | 317 | 5.1 | (3.1–8.4) | 3360 | 55.6 | (49.4–61.7) |
Lake | 12,512 | 25.5 | 4751 | 38.0 | (33.6–42.5) | 9256 | 77.2 | (73.1–80.8) |
Missing | 0 | 0.0 | 0 | 0.0 | – | 0 | 0.0 | – |
Area | ||||||||
Urban | 9708 | 19.8 | 588 | 6.1 | (4.0–9.1) | 7866 | 82.2 | (78.7–85.2) |
Rural | 39,405 | 80.2 | 10,039 | 25.5 | (23.1–28.0) | 25,418 | 66.5 | (64.1–68.8) |
Missing | 0 | 0.0 | 0 | 0.0 | – | 0 | 0.0 | – |
Eco-zone (tropical) * | ||||||||
Dry forest | 7124 | 19.0 | 2247 | 31.5 | (25.9–37.8) | 5417 | 79.4 | (74.7–83.4) |
Moist decid. forest | 5819 | 15.5 | 1816 | 31.2 | (25.1–38) | 3786 | 67.8 | (62–73.1) |
Mountain system | 6053 | 16.1 | 723 | 11.9 | (7.9–17.6) | 3329 | 57.0 | (50.3–63.5) |
Rainforest | 3331 | 8.9 | 1272 | 38.2 | (28.6–48.7) | 2664 | 82.8 | (76.3–87.8) |
Scrubland | 15,216 | 40.5 | 2009 | 13.2 | (10.3–16.7) | 9078 | 61.2 | (57.4–64.9) |
Missing | 11,570 | 23.6 | 2560 | 22.2 | – | 9010 | 77.9 | – |
Altitude (m) | ||||||||
< 750 | 13,228 | 26.9 | 3248 | 24.6 | (20.7–28.9) | 10,697 | 82.7 | (80.1–85) |
750–1250 | 18,901 | 38.5 | 5040 | 26.7 | (23.3–30.4) | 13,284 | 72.0 | (68.8–75) |
1250–1750 | 14,581 | 29.7 | 2335 | 16.0 | (12.6–20.1) | 8434 | 59.8 | (56–63.4) |
> 1750 | 2403 | 4.9 | 4 | 0.2 | (0.1–0.5) | 869 | 37.8 | (30.5–45.7) |
Missing | 0 | 0.0 | 0 | 0.0 | – | 0 | 0.0 | – |
Malaria infections
Malaria infection, bed net use and associated risk factors
Outcome/covariates | Univariable | Model I (N = 47,157) | Model II (N = 30,715) | |||||
---|---|---|---|---|---|---|---|---|
Malaria | Malaria | Malaria | Bed net use | |||||
OR (95% CI) | p- value | OR (95% CI) | p-value | OR (95% CI) | p-value | OR (95% CI) | p-value | |
Gender | ||||||||
Male vs female | 0.75 (0.71–0.79) | < 0.01 | 0.77 (0.72–0.81) | < 0.01 | 0.74 (0.69–0.79) | < 0.01 | 1.21 (1.14–1.28) | < 0.01 |
Age (years) | ||||||||
< 9 vs 10–12 | 1.06 (0.98–1.15) | 0.11 | 1.05 (0.96–1.14) | 0.36 | 1.03 (0.92–1.15) | 0.55 | 1.1 (1.01–1.20) | 0.02 |
< 9 vs > 12 | 1.09 (1.01–1.18) | 1.06 (0.98–1.15) | 1.05 (0.95–1.17) | 1.12 (1.03–1.22) | ||||
Parental education | ||||||||
Primary vs no school | 1.18 (1.06–1.31) | < 0.01 | – | 1.18 (1.06–1.32) | < 0.01 | 0.69 (0.63–0.76) | < 0.01 | |
Primary vs secondary or higher | 0.74 (0.67–0.82) | – | 0.75 (0.67–0.83) | 1.48 (1.35–1.61) | ||||
Bed net use | ||||||||
No vs yes | 0.76 (0.71–0.81) | < 0.01 | 0.76 (0.71–0.82) | < 0.01 | 0.81 (0.74–0.88) | < 0.01 | – | |
Malaria | ||||||||
Negative vs positive | – | – | – | 0.81 (0.74–0.88) | < 0.01 | |||
Area | ||||||||
Rural vs urban | 0.14 (0.05–0.38) | < 0.01 | 0.12 (0.066–0.21) | < 0.01 | 0.15 (0.072–0.29) | < 0.01 | 1.92 (1.25–2.94) | < 0.01 |
Altitude (m) | ||||||||
< 750 vs 750–1250 | 0.25 (0.12–0.48) | < 0.01 | 0.18 (0.081–0.39) | < 0.01 | 0.26 (0.11–0.62) | 0.02 | 0.43 (0.25–0.74) | 0.01 |
< 750 vs 1250–1750 | 0.07 (0.04–0.15) | 0.12 (0.045–0.31) | 0.25 (0.088–0.72) | 0.27 (0.14–0.53) | ||||
< 750 vs > 1750 | 0.002 (0.00–0.02) | 0.02 (0.003–0.14) | 0.07 (0.0093–0.47) | 0.12 (0.049–0.31) | ||||
Temperature suitability index | ||||||||
TSI (2er intervals) | 3.51 (2.80–4.39) | < 0.01 | – | < 0.01 | 2.2 (1.56–3.09) | < 0.01 | 1 (0.81–1.24) | 0.98 |
Zone | ||||||||
Central vs eastern | 28.15 (7.68–103.20) | < 0.01 | 1.86 (0.60–5.72) | < 0.01 | 2.11 (0.63–7.01) | < 0.01 | 2.13 (0.96–4.71) | < 0.01 |
Central vs western | 59.21 (15.40–228.10) | 31.13 (11.6–83.4) | 11.21 (3.23–39.0) | 2.18 (0.91–5.19) | ||||
Central vs southern | 72.58 (17.70–296.90) | 2.79 (0.83–9.33) | ||||||
Central vs southern highlands | 2.13 (0.53–8.53) | 2.64 (0.91–7.67) | 0.41 (0.092–1.85) | 0.71 (0.33–1.52) | ||||
Central vs southwest highlands | 10.33 (2.82–37.80) | 6.7 (2.52–17.9) | 3.19 (1.06–9.60) | 1.57 (0.78–3.15) | ||||
Central vs northern | 1.05 (0.29–3.77) | 0.47 (0.17–1.31) | 0.43 (0.15–1.19) | 0.72 (0.40–1.30) | ||||
Central vs lake | 69.76 (23.0–211.9) | 40.97 (18.0–93.4) | 24.43 (10.4–57.1) | 3.54 (2.03–6.18) | ||||
Eco-zone (tropical) | ||||||||
Scrubland vs dry forest | 4.92 (2.44–9.94) | < 0.01 | – | 2.06 (1.14–3.72) | 0.22 | 0.93 (0.61–1.41) | 0.81 | |
Scrubland vs moist deci. forest | 4.98 (2.31–10.73) | – | 2.36 (1.21–4.60) | 0.89 (0.57–1.38) | ||||
Scrubland vs mountain system | 0.56 (0.23–1.34) | – | 1.51 (0.68–3.38) | 1.01 (0.64–1.60) | ||||
Scrubland vs rainforest | 7.63 (2.90–20.08) | – | 3.01 (1.41–6.40) | 1.33 (0.76–2.31) |