Table 4 Characteristics of studies on the association between climatic variables and JE transmission
From: Climate change and mosquito-borne diseases in China: a review
Study & Language | Study area & period | Data Collection | Statistical Methods | Main findings | Comments | |
|---|---|---|---|---|---|---|
| Â | Â | Risk factors | Disease/vector | Â | Â | Â |
Lin et al. (2010) English [62] | Linyi city, Shangdong Province 1956-2004 | Monthly average temperature, relative humidity, total rainfall. Vaccination | Monthly incidence | -Cross-correlation | -Monthly average temperature and relative humidity with no lag were positively associated with the JE incidence after adjusting for the effect of vaccination. | -Vaccination effect was adjusted, but only treated as a simple binary variable. |
-ARIMA model | ||||||
Bi et al. (2007) English [63] | Jinan city, Shangdong Province 1959-1979 | Monthly mean maximum temperature, minimum temperature, relative humidity, rainfall and air pressure. | Case counts | -Spearman correlation | -The JE incidence was positively associated with two temperature variables, rainfall and relative humidity, and negatively correlated with air pressure. Lag times were from one to two months | -A potential threshold of the effect of temperature was detected. |
-Poisson regression | ||||||
-The effect of the vaccination was very limited during the study period of this study. | ||||||
-The Hockey Stick model | ||||||
-Thresholds of 25.2°C for maximum temperature and 21.0°C were indentified. | ||||||
-Non-climatic factors were neglected | ||||||
HSU et al. (2008) English [64] | Taiwan 1991-2005 | Monthly temperature and precipitation Pig density Vaccination | Case counts | -Poisson regression | -The monthly temperature and precipitation with two months lags and the pig density were significantly associated with JE cases. | -Adjustment for vaccination, pig density and seasonal factors. |
-No significant relationship between vaccination rate and counts of JE cases was found. | ||||||
Bi et al. (2003) English [65] | Jieshou County, Anhui Province 1980-1996 | Monthly mean maximum temperature, minimum temperature and rainfall | Monthly incidence | -Spearman correlation | -The monthly minimum temperature and precipitation had a significant relationship with JE incidence, with a one-month lag | -Vaccination and other non-climatic factors were neglected |
-Multiple linear regression | ||||||
Huo et al. (2011) Chinese [66] | Hebei Province Tianjin City Beijing City Inner Mongolia Shanxi Province 1994-2000 | Annual mean temperature, maximum temperature, relative humidity, minimum humidity, rainfall and duration of sunshine | Annual incidence | --Poisson regression | -The annual incidence of JE was found to be positively correlated with annual mean relative humidity and negatively associated with duration of sunshine | -Yearly variables were use |
-Non-climatic factors were neglected | ||||||
Xu et al. (2009) Chinese [67] | Tongren area, Guizhou Province 1983-2003 | Monthly mean temperature, air pressure, relative humidity, rainfall, wind velocity, duration of sunshine | Case counts | -Multiple regression analysis. | -Among various climatic variables, the transmission of JE was only correlated with duration of sunshine. | -Non-climatic factors such as vaccination were not adjusted |
-Only one area were analyzed | ||||||
Gao et al. (2009) Chinese [68] | Guiyang City, Guizhou Province 1956-2005 | Annual mean temperature and precipitation Monthly mean temperature and precipitation of June, July and August. | Annual incidence | -Descriptive analysis | -Temperature and precipitation were correlated with the incidence of JE, especially in July. | -Fifty years long-term data were collected |
-Non-climatic factors such as vaccination were ignored. | ||||||
Liu et al. (2008) Chinese [69] | Kaijiang County, Sichuan Province 1975-1993 | Mean temperature, relative humidity, rainfall, duration of sunshine during November and December, July and August, January and June respectively. | Annual incidence | -Correlation analysis | -Duration of sunshine and temperature were most closely associated with JE incidence. | -Only one county was analyzed -Annual indicators were used |
-Grey correlation analysis | ||||||
-Non-climatic factors such as vaccination were ignored. | ||||||
Qu et al. (2006) Chinese [70] | Chaoyang City, Liaoning Province 1981-1994 | Annual mean air pressure, precipitation, air temperature, ground temperature, maximum air temperature, minimum ground temperature, evaporation and extreme maximum and minimum temperature | Annual incidence | -Correlation analysis | -The JE incidence was negatively correlated with air pressure, and positively correlated with evaporation, maximum temperature and extreme maximum temperature. | -Various meteorological factors were applied |
-Back propagation artificial neural network | -The predictive ability of the BP neural network model is not very strong. | |||||
Zhang et al. (2004) Chinese [71] | Dali, Yunnan Province 1992-2001 | Mean temperature in May, rainfall in September, annual mean temperature, rainfall estimated vaccination coverage, paddy field areas | Annual incidence | -Correlation analysis | -The annual JE incidence was found to be correlated with temperature and rainfall. No relationships between the JE incidence and estimated vaccination, as well as paddy field areas were found. | -Use of approximate estimated vaccination data |
-Multiple regression | -Data of paddy field areas were collected. | |||||
Liu et al. (2003) Chinese [72] | Chaoyang City, Liaoning Province 1983-2002 | Mean temperature and rainfall during June and August, annual mean rainfall | Annual incidence | -Correlation analysis | -The annual JE incidence was just correlated to the rainfall in July among climatic factors selected. | -Non-climatic factors such as vaccination were ignored. |
-Multiple regression | ||||||
-Annual incidence was used | ||||||
Shen et al. (2002) Chinese [73] | Shanghai 1952-1997 | Monthly temperature of June, July and August respectively, total rainfall of June and July Areas of rice field, pig rising, mosquito density, vaccination rate | Annual incidence | -Descriptive analysis | -No obvious relationships between JE incidence and climatic factors and areas of rice field as well as pig rising were observed, implying that the decrease of JE incidence during study period may be due to massive vaccination conducted in Shanghai. | -Both climatic and non-climatic data were collected |
-Climatic variables only in three months were analysis | ||||||
Zhang et al. (1997) Chinese [74] | Henan Province Not specific | Temperature, rainfall Elevation | Case count JE incidence | -Correlation analysis | -The JE incidence was positively correlated with temperature and rainfall, but decreased with increased elevation. | -The impact of vaccination was ignored |
-Data collection was not described clearly | ||||||
Feng et al. (1996) Chinese [75] | Fengyi of Eyuan County, Dali, Yunnan Province 1991 | Monthly mean temperature and rainfall | Monthly incidence | -Descriptive analysis | -The monthly incidence was found to be related to monthly temperature and rainfall | -Only one year data was analysed |