West Nile virus transmission in resident birds, Dominican Republic

Centers for Disease Control and Prevention http://www.cdc.gov/ncidod/EID/vol9no10/03-0222.htmWe report West Nile virus (WNV) activity in the Dominican Republic for the first time. Specific anti-WNV antibodies were detected in 5 (15%) of 33 resident birds sampled at one location in November 2002. One seropositive bird was <4 months old, indicating a recent infection

West Nile virus transmission in resident birds, Dominican Republic

Centers for Disease Control and Prevention http://www.cdc.gov/ncidod/EID/vol9no10/03-0222.htmWe report West Nile virus (WNV) activity in the Dominican Republic for the first time. Specific anti-WNV antibodies were detected in 5 (15%) of 33 resident birds sampled at one location in November 2002. One seropositive bird was <4 months old, indicating a recent infection

West Nile Virus Isolated from a Virginia Opossum (Didelphis virginiana) in Northwestern Missouri, USA, 2012

We describe the isolation of West Nile virus (WNV; Flaviviridae, Flavivirus) from blood of a Virginia opossum (Didelphis virginiana) collected in northwestern Missouri, USA in August 2012. Sequencing determined that the virus was related to lineage 1a WNV02 strains. We discuss the role of wildlife in WNV disease epidemiology

Rapid West Nile Virus Antigen Detection

We compared the VecTest WNV antigen assay with standard methods of West Nile virus (WNV) detection in swabs from American Crows (Corvus brachyrhynchos) and House Sparrows (Passer domesticus). The VecTest detected WNV more frequently than the plaque assay and was comparable to a TaqMan reverse transcription–polymerase chain reaction

\u3ci\u3eWest Nile virus\u3c/i\u3e detection in nonvascular feathers from avian carcasses

West Nile virus (WNV) is a public health threat and has caused the death of thousands of North American birds. As such, surveillance for WNV has been ongoing, utilizing numerous biological specimens and testing methods. Nonvascular (i.e., fully grown) feathers would provide a simple method of collection from either dead or live birds of all ages and molt cycles, with presumably less biosafety risk compared with other specimen types, including feather pulp. The current study evaluates WNV detection in nonvascular feathers removed from naturally infected avian carcasses of several species groups. Feathers of corvid passeriforms had the highest sensitivity of detection (64%), followed by noncorvid passeriforms (43%), columbiforms (33%), and falconiforms (31%). Storing feathers for 1 year at 220uC or at ambient room temperature resulted in detection rates of infectious WNV of 16% and zero, respectively, but had no effect on detection rates of WNV RNA in a subset of matched feather pairs (47% for both storage temperatures). The efficacy of WNV detection in nonvascular feathers is greatly enhanced by testing multiple feathers. The advantages of using nonvascular feathers over other tissues may outweigh the relatively low detectability of WNV RNA in certain situations such as remote areas lacking resources for acquiring other types of samples or maintaining the cold chain

Vector Competence of the Stable Fly (Diptera: Muscidae) for West Nile Virus

In 2006-2007, stable flies, Stomoxys calcitrans (L.) (Diptera: Muscidae), were suspected of being enzootic vectors of West Nile virus (family Flaviviridae, genus Flavivirus, WNV) during a die-off of American white pelicans (Pelecanus erythrorhynchos Gmelin) (Pelecanidae) in Montana, USA. WNV-positive stable flies were observed feeding en masse on incapacitated, WNV-positive pelicans, arousing suspicions that the flies could have been involved in WNV transmission among pelicans, and perhaps to livestock and humans. We assessed biological transmission by infecting stable flies intrathoracically with WNV and testing them at 2-d intervals over 20 d. Infectious WNV was detected in fly bodies in decreasing amounts over time for only the first 6 d post infection, an indication that WNV did not replicate within fly tissues and that stable flies cannot biologically transmit WNV. We assessed mechanical transmission using a novel technique. Specifically, we fed WNV-infected blood to individual flies by using a cotton swab (i.e., artificial donor), and at intervals of 1 min-24 h, we allowed flies to refeed on a different swab saturated with WNV-negative blood (i.e., artificial recipient). Flies mechanically transmitted viable WNV from donor to recipient swabs for up to 6 h post infection, with the majority of the transmission events occurring within the first hour. Flies mechanically transmitted WNV RNA to recipient swabs for up to 24 h, mostly within the first 6 h. Given its predilection to feed multiple times when disturbed, these findings support the possibility that the stable fly could mechanically transmit WNV

Zika Virus MB16-23 in Mosquitoes, Miami-Dade County, Florida, USA, 2016

We isolated a strain of Zika virus, MB16-23, from Aedes aegypti mosquitoes collected in Miami Beach, Florida, USA, on September 2, 2016. Phylogenetic analysis suggests that MB16-23 most likely originated from the Caribbean region

Bourbon Virus in Field-Collected Ticks, Missouri, USA

Bourbon virus (BRBV) was first isolated in 2014 from a resident of Bourbon County, Kansas, USA, who died of the infection. In 2015, an ill Payne County, Oklahoma, resident tested positive for antibodies to BRBV, before fully recovering. We retrospectively tested for BRBV in 39,096 ticks from northwestern Missouri, located 240 km from Bourbon County, Kansas. We detected BRBV in 3 pools of Amblyomma americanum (L.) ticks: 1 pool of male adults and 2 pools of nymphs. Detection of BRBV in A. americanum, a species that is aggressive, feeds on humans, and is abundant in Kansas and Oklahoma, supports the premise that A. americanum is a vector of BRBV to humans. BRBV has not been detected in nonhuman vertebrates, and its natural history remains largely unknown