Detection of dengue viruses in field caught male Aedes aegypti and Aedes albopictus (Diptera: Culicidae) in Singapore by type-specific PCR.
Field male Aedes aegypti (L.) and Aedes albopictus (Skuse) adults caught from fixed monitoring stations weekly for 1 yr were screened for dengue viruses (DEN-1, DEN-2, DEN-3, and DEN-4). The assay was carried out using a single-step reverse transcription (or transcriptase)-polymerase chain reaction (PCR) (RT-PCR) followed by a semi-nested PCR using an upstream consensus primer and four type-specific primers within the nonstructural protein three gene (NS3) of dengue viruses. The diagnostic fragments for DEN-1, DEN-2, DEN-3, and DEN-4 serotypes were of sizes 169, 362, 265, and 426 bp, respectively. Results showed that in Singapore 1.33% and 2.15% of Aedes aegypti and Aedes albopictus adult male mosquitoes, respectively, were positive for dengue viruses. The serotypes detected in male Ae. aegypti was DEN-1 (44%), followed by DEN-2 (22.2%) and DEN-3 (22.2%), and DEN-4 (11.1%). For Aedes albopictus males, the serotype was DEN-4 (38.9%), followed by DEN-2 (33.3%), DEN-3 (16.7%), and DEN-1 (11.1%).
Kow
C Y
CY
Vector Control and Research Department, Ministry of the Environment, Singapore.
Koon
L L
LL
Yin
P F
PF
D000330:Aedes / Q000821:virology*; D000818:Animals; D001483:Base Sequence; D004279:DNA, Viral / Q000032:analysis; D003716:Dengue Virus / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012846:Singapore
D004279:DNA, Viral