Table 1.
Dengue serotype distribution in Singapore from 2001 to 2009.
Figure 1.
Scatter plot of AH v.s. Tc and RH ((Eq. 1)).
Figure 2.
Time-lagged cross-correlation of dengue incidence and each weather variable (0 to 20-weeks lag).
Significant correlation coefficients with p-value<0.05 are in solid circles.
Figure 3.
Residual analysis for DLNM-AH model.
A: Residual histogram; B: Residual v.s. Number of dengue cases per week; C: Residual autocorrelation function; D: Residual partial autocorrelation function.
Table 2.
QAIC based on best lag number for each weather predictor considering DLNM.
Figure 4.
Effect of AH and MeanT on relative risk (RR) of dengue incidence.
A: RR curve shows overall cumulative effect of AH (with the maximum lag number up to 16 weeks) on dengue incidence with reference value of AH being 22.4 g/m3 and 95% CI of fitted RR shown in the grey region; B: RR curve shows overall cumulative effect of MeanT (with the maximum lag number up to 9 weeks) on dengue incidence with reference value of MeanT being 27.8°C and 95% CI of fitted RR shown in the grey region.
Figure 5.
Weekly counts of dengue cases from 2001–2009.
A: Observed dengue cases and number of fitted dengue cases estimated by the AH term in the DLNM model; B: observed dengue cases and number of fitted dengue cases estimated by the MeanT term.
Figure 6.
Residual analysis for DLNM-MeanT model.
A: Residual histogram; B: Residual v.s. Number of dengue cases per week; C: Residual autocorrelation function; D: Residual partial autocorrelation function.
Figure 7.
Effect of AH and MeanT on RR of dengue incidence obtained from the distributed lag model for each sub-period.
A1–A3: Effect of 0–16 weeks lag of AH; B1–B3: Effect of 0–9 weeks lag of MeanT. The grey region indicates 95% CI of fitted RR. Reference AH = 22.4 g/m3 and MeanT = 27.8°C.