title: Dissemination of western equine encephalomyelitis virus in the potential vector, Culex pipiens pallens.
abstract: Two western equine encephalomyelitis virus (WEEV) strains have been isolated in China. Our previous studies have verified that the mosquito Culex pipiens pallens Coquillett (Diptera: Culicidae) infected with WEEV was capable of transmitting this arbovirus, but it was not clear how the sequential multiplication and spread of virus occurred within the mosquito. In this study, we observed the distribution of WEEV antigen in orally-infected Cx. p. pallens by immunohistochemistry in order to better understand the initial infection, dissemination, and transmission of WEEV in the potential vector. Orally-infected WEEV dissemination varied within the different tissues of Cx. p. pallens, with virus antigen consistently observed in the salivary glands, foregut, midgut epithelial cells, Malpighian tubules, hindgut, and ovarian follicles of some individuals after various days of extrinsic incubation. We suggest that Cx. p. pallens, the potential vector of WEEV, has the ability to harbor the virus through the alimentary system, and the midgut epithelial cell may be the initial site of WEEV replication after ingestion of a viremic blood meal.
authors.affiliation: State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, PR China.
authors.forename: Zhongming
authors.initials: Z
authors.lastname: Wang
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Zhang
authors.forename: Chunxiao
authors.initials: C
authors.lastname: Li
authors.forename: Yingmei
authors.initials: Y
authors.lastname: Zhang
authors.forename: Dan
authors.initials: D
authors.lastname: Xin
authors.forename: Tongyan
authors.initials: T
authors.lastname: Zhao
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000378:metabolism; D003465:Culex / Q000821:virology*; D004064:Digestive System / Q000821:virology*; D004667:Encephalitis Virus, Western Equine / Q000378:metabolism / Q000502:physiology*; D005260:Female; D007150:Immunohistochemistry; D007303:Insect Vectors / Q000821:virology*
chemical_list: D000956:Antigens, Viral