The effects of weather conditions on measles incidence in Guangzhou, Southern China

Figures & data

Table 1. Monthly/daily weather conditions and the monthly/daily incidence of measles in Guangzhou, southern China

Variable	Minimum	P25	Median	P75	Maximum	Mean	Std. deviation
	Monthly meteorological variables and monthly measles cases (2000–2012)
Maximum temperature (°C)	14.0	22.1	28.1	32.0	34.9	27.1	5.5
Mean temperature (°C)	9.5	17.9	23.8	27.9	30.8	22.6	5.6
Minimum temperature (°C)	6.5	14.6	20.7	24.9	27.5	19.4	5.6
Relative humidity (%)	48.0	70.0	74.0	79.0	87.0	73.4	7.5
Duration of sunshine (h)	0.6	3.0	4.4	5.6	8.0	4.3	1.7
Air pressure (hPa)	994.3	1002.7	1008.0	1013.2	1018.9	1007.8	6.1
Number of measles cases	0	7	29	106	686	100	153.9
	Daily meteorological variables and daily measles cases (2005–2008)
Maximum temperature (°C)	6.2	23.2	28.5	32.4	39.0	27.3	6.4
Mean temperature (°C)	5.4	18.5	24.7	27.9	34.2	22.9	6.3
Minimum temperature (°C)	2.1	15.2	21.6	25.1	30.4	19.9	6.3
Relative humidity (%)	20.0	63.5	73.0	81.0	95.0	71.1	13.4
Duration of sunshine (h)	0.0	0.0	3.4	7.3	11.4	3.9	3.5
Air pressure (hPa)	988.7	1003.2	1008.2	1014.1	1027.2	1008.6	6.9
Number of measles cases	0	3	6	12	40	8	6.8

Figure 1. The estimated overall effects of the monthly/daily weather variables on the monthly/daily incidence of measles. For monthly cases, the lags of mean temperature, relative humidity, and sunshine hours are 2 mo. For daily cases, the lags of mean temperature, relative humidity, and sunshine hours are 30, 5, 10 d, respectively. The red lines represent mean relative risks, and gray regions represent 95%CIs.

Table 2. Relative risk of measles incidence associated with the wet and dry effects by gender and age

Variable	RR (95%CI)
	Wet effect	Dry effect
Gender
Male	0.35 (0.20, 0.62)	1.08 (0.50, 2.35)
Female	0.50 (0.26, 0.96)	2.74 (1.15, 6.66)
Age
<1	0.21 (0.11, 0.43)	0.95 (0.33, 2.69)
1~14	0.31 (0.15, 0.63)	3.17 (1.28, 7.88)
>15	1.59 (0.71, 3.55)	1.05 (0.35, 3.17)

The wet effect was the relative risk of measles by comparing the 99th to the median of daily relative humidity. The dry effect was the relative risk of measles incidence by comparing the 1st to the median of daily relative humidity. The bold font means statistically significant.