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Background: West Nile virus (WNV) is a mosquito-borne flavivirus, first detected in the Western Hemisphere in 1999 and spread across North America over the next decade. Though endemic in the most populous areas of North America, few studies have estimated the healthcare costs associated with WNV. The objective of this study was to determine direct healthcare costs attributable to WNV illness in Ontario, Canada., Methods: We conducted a cost-of-illness study on incident laboratory confirmed and probable WNV infected subjects identified from the provincial laboratory database from Jan 1, 2002 through Dec 31, 2012. Infected subjects were linked to health administrative data and matched to uninfected subjects. We used phase-of-care methods to calculate costs for 3 phases of illness: acute infection, continuing care, and final care prior to death. Mean 10-day attributable costs were reported in 2014 Canadian dollars, per capita. Sensitivity analysis was conducted to test the impact of WNV neurologic syndromes on healthcare costs., Results: One thousand five hundred fifty-one laboratory confirmed and probable WNV infected subjects were ascertained; 1540 (99.3%) were matched to uninfected subjects. Mean age of WNV infected subjects was 49.1 ± 18.4 years, 50.5% were female. Mean costs attributable to WNV were $1177 (95% CI: $1001, $1352) for acute infection, $180 (95% CI: $122, $238) for continuing care, $11,614 (95% CI: $5916, $17,313) for final care - acute death, and $3199 (95% CI: $1770, $4627) for final care - late death. Expected 1-year costs were $13,648, adjusted for survival. Three hundred seventeen infected subjects were diagnosed with at least one neurologic syndrome and greatest healthcare costs in acute infection were associated with encephalitis ($4710, 95% CI: $3770, $5650)., Conclusions: WNV is associated with increased healthcare resource utilization across all phases of care. High-quality studies are needed to understand the health system impact of vector-borne diseases and evaluate the cost effectiveness of novel WNV interventions.

Rapid detection of West Nile virus (WNV) in mosquito pools is essential for predicting epizootics and epidemics. We compare the efficiency and sensitivity of the Rapid Analyte Measurement Platform (RAMP) to reverse transcriptase polymerase chain reaction (RT-PCR) from 2005 to 2008 from field mosquito populations in Mercer County, NJ. Overall, 316 pools tested negative and 115 pools tested positive for WNV. Eighty-nine pools tested positive using RAMP and all were confirmed by RT-PCR; 26 pools were WNV-negative using RAMP but positive using RT-PCR. False-positives from RAMP were not detected in our four-year study, indicating that RAMP is a reliable tool when used to augment existing RT-PCR-based WNV surveillance programs. Local mosquito control programs using RAMP will benefit from its ease of use, quick results, and lack of false positives but should understand the sensitivity of this test when compared to RT-PCR. Used with standard methods, RAMP will enhance existing mosquito control and WNV surveillance by providing rapid results and improved mosquito management decisions.

The Asian tiger mosquito Aedes albopictus (Skuse) was first detected in New Jersey in 1995 during mosquito surveillance operations in Monmouth County. We tracked statewide changes in populations of the Asian tiger mosquito and its association with West Nile virus from 2003 to 2007. Ae. albopictus population abundance has increased in New Jersey since 2003, primarily along the urban corridor between New York City and Philadelphia, and they are now expanding their range further into suburban and rural areas of the state. Ae. albopictus has invaded all counties of New Jersey except for two northwest rural counties (Sussex and Warren). West Nile virus was detected in Ae. albopictus throughout several foci in New Jersey during the study, underscoring the public health significance of this mosquito.

Standard surveillance traps in North America for adult Aedes albopictus (Skuse) (Diptera: Culicidae), an invasive mosquito with public health implications, are currently ineffective. We compared the efficacy of the BG-Sentinel trap (BGS) with and without lures (BG-lure, octenol, and CO2), the Centers for Disease Control and Prevention light trap (CDC) with and without lures, and the gravid trap (GT) for Ae. albopictus collection in two urban sites in New Jersey. The BGS with or without lures collected more Ae. albopictus compared with other trap configurations and was more specific for Ae. albopictus. In Camden County, the BGS with lures collected three times more Ae. albopictus than the CDC (with CO2 only) and five times more than the GT. In Mercer County, BGS with lures collected the most mosquitoes, with 3 times more Ae. albopictus than the CDC with all lures and 50 times more than the GT. The BGS collected more male Ae. albopictus than other traps in both counties, providing further population monitoring. The GT and BGS provided a relative measure of the enzootic activity of West Nile virus in Culex spp. and the potential epidemic activity of WNV in Ae. albopictus. The BGS provides effective chemical and visual cues for host-seeking Ae. albopictus and should be used as a part of existing surveillance programs and new initiatives targeting this mosquito.

Background: Aedes japonicus was first documented in Ontario, Canada, in 2001. The objective of this study was to determine the effect of Ae. japonicus establishment on the abundance of other mosquitoes in the Greater Golden Horseshoe (GGH) region of Ontario. Methods: Adult mosquito data from the Ontario West Nile virus surveillance program were used. Descriptive analyses, linear trends and distribution maps of average trap count per month for six mosquito species of interest were produced. Multivariable negative binomial regression models were constructed to 1) test whether the invasion of Ae. japonicus affected the abundance of other mosquitoes by comparing the time period before Ae. japonicus was identified in an area (pre-detection), to after it was first identified (detection), and subsequently (establishment), and 2) identify the variables that explain the abundance of the various mosquito species. Results: The monthly seasonal average (May–October) of Ae. japonicus per trap night increased from 2002 to 2016, peaking in September, when the average of most other mosquitoes decrease. There were increased numbers of Ae. triseriatus/hendersoni (Odds Ratio (OR): 1.40, 95% Confidence Interval (CI): 1.02–1.94) and decreased numbers of Coquillettidia perturbans (OR: 0.43, 95% CI: 0.26–0.73) in the detection period, compared to the pre-detection period. Additionally, there was a decrease in Cx. pipiens/restuans (OR: 0.87, 95% CI: 0.76–0.99) and Cq. perturbans (OR: 0.68, 95% CI: 0.49–0.94) in the establishment period, compared to the pre-detection period. None of the most parsimonious explanatory models included the period of the establishment of Ae. japonicus. Conclusions: There is no evidence that the introduction of Ae. japonicus significantly reduced populations of Ae. triseriatus/hendersoni, Cx. pipiens/restuans or An. punctipennis in the GGH. While further research is needed to understand the impact of the Ae. japonicus invasion on other mosquito species, our work indicates that, on a regional scale, little impact has been noted. [ABSTRACT FROM AUTHOR]