tailieunhanh - Báo cáo y học: "Mosquitoes infected with dengue viruses in Brazil"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Mosquitoes infected with dengue viruses in Brazil | de Figueiredo et al. Virology Journal 2010 7 152 http content 7 1 152 VIROLOGY JOURNAL RESEARCH Open Access Mosquitoes infected with dengue viruses in Brazil Mario LG de Figueiredo1 Almério de C Gomes2 Alberto A Amarilla3 André de S Leandro4 Agnaldo de S Orrico5 Renato F de Araujo5 Jesuína do SM Castro5 Edison L Durigon1 Victor H Aquino6 and LuizTM Figueiredo 3 Abstract Dengue epidemics have been reported in Brazil since 1985. The scenery has worsened in the last decade because several serotypes are circulating and producing a hyper-endemic situation with an increase of DHF DSS cases as well as the number of fatalities. Herein we report dengue virus surveillance in mosquitoes using a Flavivirus genus-specific RT-Hemi-Nested-PCR assay. The mosquitoes Culicidae n 1700 collected in the Northeast Southeast and South of Brazil between 1999 and 2005 were grouped into 154 pools. Putative genomes of DENV-1 -2 and -3 were detected in 6 mosquito pools . One amplicon of putative DENV-1 was detected in a pool of Haemagogus leucocelaenus suggesting that this virus could be involved in a sylvatic cycle. DENV-3 was found infecting 3 pools of larvae of Aedes albopictus and the nucleotide sequence of one of these viruses was identified as DENV-3 of genotype III phylogenetically related to other DENV-3 isolated in Brazil. This is the first report of a nucleotide sequence of DENV-3 from larvae of Aedes albopictus. Findings Dengue viruses family Flaviviridae genus Flavivirus serotypes 1 to 4 DENV-1 -2 -3 and -4 are responsible for large urban outbreaks. Infection with any of the four dengue virus serotypes can lead to acute febrile illness and to the severe sometimes fatal dengue hemorrhagic fever dengue shock syndrome DHF DSS 1 . DENV are transmitted to humans mainly by Aedes aegypti mosquitoes which acquired the infection through blood-feeding on infected individuals or by transovarial transmission 2 . Besides in Africa and Asia DENV have been reported in .