Vector Surveillance
YANG Ying-yu, WANG Ying-ying, CHEN Yun, FU Chao-wei
Objective To investigate the lag effects of meteorological factors on the density indices of Aedes mosquitoes in Baoshan district, Shanghai, China, and to provide a basis for early warning and prediction for local dengue fever epidemic. Methods A distributed lag non-linear model was used to analyze the lag effects of meteorological factors on Aedes density indices in Baoshan district from April to October, 2019, including daily average temperature, daily minimum temperature, daily maximum temperature, daily average air pressure, daily average wind speed, daily average relative humidity, and daily cumulative rainfall. Results For the net trap index, the lag effect peaked at shorter lags of 0 to 2 days when daily minimum temperature was high, and at longer lags of 20 to 30 days when the temperature was low. For the landing index, the lag effect peaked at shorter lags of 0 to 5 days when daily average temperature was high, and at longer lags of 25 to 30 days when the temperature was low. For the Breteau index, the lag effect peaked at the beginning when daily average temperature was high, and at lags of 5 to 10 days when the temperature was low. For the mosquito ovitrap index, the lag effect peaked at shorter lags of 0 to 3 days when daily average temperature was high, and at longer lags of 15 to 30 days when the temperature was low. Conclusion Meteorological factors, including daily average temperature, daily average relative humidity, and daily average wind speed, have lag effects on the density of Aedes mosquitoes in Baoshan district of Shanghai. High temperature and high humidity, with low or high wind speed, can accelerate the peak of the lag effect on Aedes density. Meteorological changes can be used to predict fluctuations in Aedes density.