Table 2.
P. falciparum | P. vivax | |||||||
---|---|---|---|---|---|---|---|---|
IR | IRR | CI95 | p | IR | IRR | CI95 | p | |
Areas of residence | ||||||||
Ilahita 1–4, 6,7 | 1.09 | Reference group | 0.65 | Reference group | ||||
Balanga and Balif | 1.25 | 1.22 | 0.70–2.12 | 0.485 | 0.94 | 1.46 | 0.81–2.64 | 0.213 |
Kamanokor and Ilahita 5 | 1.82 | 1.61 | 0.92–2.80 | 0.096 | 4.83 | 6.66 | 4.24–10.5 | < 0.001 |
Sunuhu 1 and 2 | 3.57 | 3.10 | 2.08–4.63 | < 0.001 | 5.37 | 8.16 | 5.38–12.4 | < 0.001 |
p < 0.0001a | p < 0.0001a | |||||||
Age | 1.26 | 1.13–1.40 | < 0.001 | |||||
ADI visit interval | ||||||||
Enrolment–week 4 | 1.23 | Reference group | 3.20 | Reference group | ||||
Week 4–week 8 | 0.85 | 0.58 | 0.27–1.23 | 0.153 | 2.62 | 0.71 | 0.52–0.98 | 0.035 |
Week 8–week 12 | 0.22 | 0.15 | 0.06–0.38 | < 0.001 | 1.60 | 0.44 | 0.30–0.63 | < 0.001 |
Week 12–week 16 | 0.77 | 0.50 | 0.23–1.09 | 0.081 | 2.30 | 0.59 | 0.43–0.82 | < 0.001 |
Week 16–week 20 | 1.23 | 3.20 | 0.87 | 0.60–1.25 | 0.446 | |||
Week 20–week 24 | 2.58 | 1.99 | 1.00–3.96 | 0.049 | 3.60 | |||
Week 24–week 28 | 1.17 | 0.83 | 0.43–1.61 | 0.583 | 2.20 | 0.57 | 0.41–0.79 | < 0.001 |
Week 28–week 32 | 1.13 | 0.84 | 0.43–1.64 | 0.602 | 1.98 | 0.48 | 0.34–0.69 | < 0.001 |
Week 32–week 36 | 1.28 | 0.89 | 0.49–1.64 | 0.719 | 2.46 | 0.58 | 0.42–0.80 | < 0.001 |
Week 36–week 40 | 7.19 | 5.55 | 3.33–9.25 | < 0.001 | 2.26 | 0.56 | 0.39–0.79 | < 0.001 |
p < 0.0001a | p < 0.0001a | |||||||
Recent antimalarial useb | 8.50 | 10.4 | 5.92–18.2 | < 0.001 | 2.79 | |||
Febrile illness | 2.05 | 3.02 | ||||||
2 weeks history of febrile illnessc | 2.11 | 2.31 | ||||||
Haemoglobin | ||||||||
≥ 10 g/dL | 1.60 | 2.15 | ||||||
9–9.9 g/dL | 1.88 | 2.48 | ||||||
≤ 9 g/dL | 2.06 | 2.87 |
Estimates from a multivariate negative binomial regression with GEE model predicting risk of acquiring new species-specific clones for P. falciparum and P. vivax in a 4-week interval when the child was considered at risk. A backward selection approach was used with the best fitting model consisting of the significant associations. IR incidence rate, IRR incidence rate ratio, CI95 95% confidence interval, p p value, g/dL grams/decilitre, ADI active detection of infections. aOverall significance level for the variable estimated using Wald chi-square test. bAntimalarial treatment within 28 days before the start of the interval. cExcluding febrile illness at the time of visit