Vector Surveillance
NIU Yan-fen, ZHANG Yi-hui, KANG Dong-mei, CHEN Yong-ming, LIU Guang, LIU He-zhi, SHI Xian-ming, DU Guo-yi
Objective To investigate the relationship between the population densities of Meriones unguiculatus and its nest fleas and meteorological factors in M.unguiculatus plague foci in Hebei province,China.Methods The monitoring data of M.unguiculatus and its nest fleas in M.unguiculatus plague foci in Hebei province from 2001 to 2013,as well as meteorological data such as precipitation,temperature and humidity during the same period were collected.The Kruskal-Wallis H test was used to compare the flea infestation rate and flea index of nest fleas among groups by the density of M.unguiculatus (≥ 1.00 rodents/hm2 as high-risk group,0.21-0.99 rodents/hm2 as warning group,≤ 0.20 rodents/hm2 as standard group).Nest flea index were also compared among groups by total precipitation,average temperature,and average relative humidity (four groups each according to their interquartile ranges).Multiple correspondence analysis was performed to analyze the relationship between the density of M.unguiculatus,nest flea index,and meteorological factors.Results The flea infestation rate distribution was statistically different between different groups by total precipitation (H=10.220,P=0.017),and when the precipitation was ≥ 426.00 mm,the flea infestation rate was highest.The nest flea index distribution statistically differed between those groups by total precipitation,average relative humidity,and M.unguiculatus density (H=27.807,12.685,7.130,all P<0.05).When the precipitation was ≥ 426.00 mm,average relative humidity was ≥ 58.71%,and M.unguiculatus density was ≥ 1.00 rodents/hm2,the nest flea index values were all highest,with statistical differences from those of the lowest groups (t=4.722,2.999,2.504,all P<0.05).The multiple correspondence analysis showed strong associations of the flea index P75-100 with the total precipitation P50-75,the average relative humidity P25-50,and M.unguiculatus density in the high-risk group,and strong associations of the flea index P50-75 with the total precipitation P75-100 and average relative humidity P75-100.Conclusion Precipitation and M.unguiculatus density are important factors affecting the rodent nest flea index in M.unguiculatus plague foci in Hebei province.When determining the site,extent,and time of flea control,host density and meteorological conditions should be considered for precise flea control to prevent plague among rodents.