Long-term surveillance defines spatial and temporal patterns implicating Culex tarsalis as the primary vector of West Nile virus.

West Nile virus (WNV) has become the most epidemiologically important mosquito-borne disease in the United States, causing ~50,000 cases since its introduction in 1999. Transmitted primarily by Culex species, WNV transmission requires the complex interplay between bird reservoirs and mosquito vectors, with human cases the result of epizootic spillover. To better understand the intrinsic factors that drive these interactions, we have compiled infection data from sentinel chickens, mosquito vectors, and human cases in Iowa over a 15 year period (2002-2016) to better understand the spatial and temporal components that drive WNV transmission.

A taxonomic checklist of the mosquitoes of Iowa.

The last published report of the mosquito species composition present in the state of Iowa was published in 1969 and included 43 species in 8 genera. Since that time, reassessment of specimens in the Iowa State Insect Collection and annual mosquito surveillance efforts have yielded 12 new species records, bringing the total to 55 species in 8 genera. In addition to providing an updated taxonomic checklist for the state of Iowa, abundance information is provided for each species using specimen counts from New Jersey light trapping events that span 45 years.

Antibodies to West Nile virus in raccoons and other wild peridomestic mammals in Iowa.

Surveillance for evidence of West Nile virus (WNV) infection in small- and medium-sized wild mammals was conducted in Iowa, USA, from May 2005 to June 2007. Sera were collected from 325 mammals belonging to nine species and tested for antibodies to WNV and other flaviviruses by epitope-blocking enzyme-linked immunosorbent assay (ELISA). All sera that had antibodies to flaviviruses by blocking ELISA were further examined by plaque reduction neutralization test (PRNT).

Susceptibility of fox squirrels (Sciurus niger) to West Nile virus by oral exposure.

Fox squirrels (Sciurus niger) (five of eight) were infected with West Nile virus (WNV) when challenged by the oral route with 10(2.3) or 10(3.4) plaque forming units (PFU).

Fox squirrels (Sciurus niger) develop West Nile virus viremias sufficient for infecting select mosquito species.

The West Nile virus (WNV) viremia and shedding profiles of 11 adult fox squirrels (Sciurus niger) infected by needle inoculation or mosquito bite were characterized. Daily mean titers (95% confidence intervals) for all squirrels on days 1 through 6 postexposure (p.e.

West Nile virus viremia in eastern chipmunks (Tamias striatus) sufficient for infecting different mosquitoes.

In eastern chipmunks (Tamias striatus) inoculated intramuscularly with 101.5 to 105.7 PFU of West Nile virus (WNV), serum titers developed sufficient to infect Aedes triseriatus (Say), Ae.

Eastern cottontail rabbits (Sylvilagus floridanus) develop West Nile virus viremias sufficient for infecting select mosquito species.

The potential of the eastern cottontail rabbit (CTR; Sylvilagus floridanus) to contribute to an enzootic West Nile virus (WNV) cycle was demonstrated by characterizing the WNV viremia profile of 15 CTRs and demonstrating that mosquitoes could become infected by feeding on these CTRs. Eight CTRs were infected with a titer of 10(5.0) cell-infectious dose 50% endpoints (CID50s) of WNV (NY99-Crow) by needle and seven CTRs by bite of one or more WNV-infected mosquitoes.

A comparision of West Nile Virus transmission by Ochlerotatus trivittatus (COQ.), Culex pipiens (L.), and Aedes albopictus (Skuse).

Transmission of West Nile virus (WNV) by Ochlerotatus trivittatus, Culex pipiens, and Aedes albopictus were compared 14 days after taking blood meals from viremic chickens with titers ranging from 10(2.5) to 10(9.5) cell infective dose (50)s (CID50s)/mL serum.

Susceptibility of Ochlerotatus trivittatus (Coq.), Aedes albopictus (Skuse), and Culex pipiens (L.) to West Nile virus infection.

The susceptibility of Ochlerotatus trivittatus (Coq.) to West Nile virus (WNV) was assessed by comparing it to the susceptibility of Aedes albopictus (Skuse), a likely bridge vector, and Culex pipiens (L.), a primary WNV amplifying species.