Effect of different temperature on the susceptibility of Aedes albopictus for transmission of dengue 2 virus

Abstract

Objective To investigate the effect of different temperature on the susceptibility of Aedes albopictus for transmission of dengue 2 virus.Methods Mosquitoes were orally infected with dengue virus type 2 suspension,then fully blood-engorged mosquitoes were separated and transferred to new cartons and sustained at 18,21,26,31,33℃ and 36℃ with 10％ sucrose.Immunofluorescence assays were used to detect antigen of dengue virus type 2 in the head,salivary gland and thorax-abdomen,and calculated the disseminated infection rate of mosquitoes.Results For mosquitoes held at 18℃,the infection rate of thoraxabdomen was 8％,infection in head and salivary gland were not detected until 25d.Maximum infection rate of thorax-abdomen was attained at 31℃,the highest infection rate of head and salivary gland existed at 33℃,however,the infection rate of mosquitoes at 36℃ was significantly decreased compared with that at 33℃.The lowest disseminated infection rate was zero at 18℃,while the highest disseminated infection rate was 100％ at 36 ℃.Conclusion As the temperature went up,the infection rate showed a tendency of ascending first and descending later.Dengue virus might not be transmitted by Aedes albopictus when temperature was below 18℃.The disseminated infection rate increased gradually with the increase of temperature. Key words: Aedes; Dengue virus; Temperature