[another case of west nile fever in the netherlands: a man with encephalitis following a trip to canada].shortly after his return to the netherlands from a trip to ontario, a part of canada where infection with west-nile virus has been reported, a 69-year-old man became increasingly confused and generally unwell, accompanied by fever. the clinical picture was compatible with viral encephalitis and this was supported by eeg findings and the results of the cerebrospinal-fluid examination. mri of the brain did not contribute to the diagnosis. the patient was treated with aciclovir because herpes simpl ...200312784533
rapid antigen-capture assay to detect west nile virus in dead corvids.the utility of the vectest antigen-capture assay to detect west nile virus (wnv) in field-collected dead corvids was evaluated in manitoba and ontario, canada, in 2001 and 2002. swabs were taken from the oropharynx, cloaca, or both of 109 american crows, 31 blue jays, 6 common ravens, and 4 black-billed magpies from manitoba, and 255 american crows and 28 blue jays from ontario. the sensitivity and specificity of the antigen-capture assay were greatest for samples from american crows; oropharyng ...200314718083
west nile virus outbreak in north american owls, ontario, 2002.from july to september 2002, an outbreak of west nile virus (wnv) caused a high number of deaths in captive owls at the owl foundation, vineland, ontario, canada. peak death rates occurred in mid-august, and the epidemiologic curve resembled that of corvids in the surrounding niagara region. the outbreak occurred in the midst of a louse fly (icosta americana, family hippoboscidae) infestation. of the flies tested, 16 (88.9 %) of 18 contained wnv rna. species with northern native breeding range a ...200415663850
accumulated organic debris in catch basins improves the efficacy of s-methoprene against mosquitoes in toronto, ontario, control west nile virus in the greater toronto area of ontario, canada, s-methoprene (altosid xrbriquets 2.1% ai) is applied each year to storm water catch basins. because the efficacy of the xrbriquets to reduce adult mosquito populations had not been evaluated locally and was influenced by organic debris in a pilot study, we compared the efficacy of the briquets in 17 sediment and debris-filled catch basins versus 20 catch basins that were vacuumed free of debris. emergence rates approached ...201020649127
the impact of weather conditions on culex pipiens and culex restuans (diptera: culicidae) abundance: a case study in peel region.mosquito populations are sensitive to long-term variations in climate and short-term variations in weather. mosquito abundance is a key determinant of outbreaks of mosquito-borne diseases, such as west nile virus (wnv). in this work, the short-term impact of weather conditions (temperature and precipitation) on culex pipiens l.-culex restuans theobald mosquito abundance in peel region, ontario, canada, was investigated using the 2002-2009 mosquito data collected from the wnv surveillance program ...201121485391
west nile virus in ontario, canada: a twelve-year analysis of human case prevalence, mosquito surveillance, and climate data.west nile virus (wnv) first arrived in ontario, canada in 2001 and has since spread throughout most of the province, causing disease in humans. the provincial government established a province-wide surveillance program to monitor wnv transmission throughout the 36 regional health units. here we have acquired records of wnv human and mosquito surveillance from 2002 to 2013 to describe seasonal and geographic trends in wnv activity in southern ontario. additionally, we obtained climate data from s ...201728829827
outbreaks of west nile virus in captive waterfowl in ontario, canada.the detrimental effects of west nile virus (wnv) have been well characterized in several taxonomic groups of north american birds, such as corvids and raptors. relatively less is known about the virus' effects in waterfowl species, many of which are abundant in north america and occupy habitats, for example wetlands and marshes, likely to harbour dense mosquito populations. in two successive years, outbreaks of wnv-associated disease were observed in waterfowl at a rehabilitation centre. in the ...201525636141
establishment of culex (melanoconion) erraticus (diptera: culicidae) in southern ontario, canada.culex (melanoconion) erraticus (dyar and knab) is now established in southern ontario, canada. this species was first discovered in 2002 during a province-wide adult mosquito surveillance program for west nile virus. using co2-baited cdc miniature light traps, a few cx. erraticus were collected from 2002 to 2011, but the total number increased during the 2012 and 2013 seasons. the number of ontario public health units with records for cx. erraticus has also increased since 2002, demonstrating th ...201526334828
a comparison of west nile virus surveillance using survival analyses of dead corvid and mosquito pool data in ontario, 2002-2008.the aim of this study was to improve understanding of the relative performance of the use of dead wild corvids and mosquito pools infected with west nile virus (wnv) in surveillance for wnv activity in the environment. to this end, all records on dead corvid submissions and mosquito pools tested in public health units (phus) in ontario, from 2002 to 2008, were explored. survival analyses were employed using the first-wnv-positive cases detected each year for each phu, and censored observations f ...201526520177
evaluation of the control of west nile virus in ontario: did risk patterns change from 2005 to 2012?the goal of this study was to evaluate and compare the risk distribution of human cases of west nile virus (wnv) disease in ontario in 2005 to 2012. the objectives were to: map the risk distribution of wnv in 2005 and 2012, identify clusters of human wnv disease and determine whether the clusters are significantly different between the years 2005 and 2012. west nile virus surveillance data were used to calculate empirical bayesian smoothed estimates of disease incidence in southern ontario for 2 ...201727362952
a geographic study of west nile virus in humans, dead corvids and mosquitoes in ontario using spatial scan statistics with a survival time application.surveillance of west nile virus (wnv) in ontario has included passive reporting of human cases and testing of trapped mosquitoes and dead birds found by the public. the dead bird surveillance programme was limited to testing within a public health unit (phu) until a small number of birds test positive. these dead corvid and mosquito surveillance programmes have not been compared for their ability to provide early warning in geographic areas where human cases occur each year. spatial scan statist ...201728220657
heeding the message? determinants of risk behaviours for west nile virus.west nile virus (wnv) emerged in north america in 1999, with the first incursion causing an outbreak of meningoencephalitis in the new york city area which resulted in seven deaths. in the face of wnv, public health professionals recommend various personal protective behaviours (ppbs) that either reduce the risk of mosquito bites (e.g., wearing protective clothing and/or insect repellent when outside at dusk or dawn) or eliminate mosquito breeding sites (e.g., preventing opportunities for standi ...200818457290
establishment of ochlerotatus japonicus (diptera: culicidae) in ontario, canada.ochlerotatus (finlaya) japonicus (theobold) is newly established in ontario, canada. it was first discovered in 2001 during the province-wide west nile virus mosquito surveillance program implemented by the ontario ministry of health and long term care. although the numbers of adults trapped in cdc light traps were low in 2001 and 2002, they increased during the 2003 and 2004 surveillance seasons. oc. japonicus larvae also have been collected in large numbers in the niagara peninsula in a variet ...200616619591
protective behavior and west nile virus risk.we conducted a cross-sectional, household survey in oakville, ontario, where an outbreak of west nile virus (wnv) in 2002 led to an unprecedented number of cases of meningitis and encephalitis. practicing > or =2 personal protective behavior traits reduced the risk for wnv infection by half.200516229774
west nile virus infection rates in pooled and individual mosquito samples.the detection of west nile virus (wnv) in mosquitoes by real-time rt-pcr provides valuable information on the epidemiology of the virus and identifies mosquito species that are potential vectors. testing sets of pooled mosquitoes of the same species is logistically the easiest and most cost-effective approach for wnv testing; however, little information is available on how the results of small pooled sets relate to those of testing individual mosquitoes. during the 2002 outbreak, we compared poo ...200415631063
neurological manifestations of west nile virus infection.over the past four years, west nile virus (wnv) has become a significant health issue in north america. in 2002, wnv infection made its first appearance in the human population in canada.200415198442
community-acquired west nile virus infection in solid-organ transplant recipients.west nile virus (wnv) is rapidly spreading through north america. in the general population, the majority of wnv infections are asymptomatic. during 2002, an outbreak of wnv occurred in toronto, canada. we observed four cases of severe symptomatic community-acquired wnv infection in our organ-transplant population.200414966414
ontario's 2003 west nile virus public education campaign: was anybody listening? 200314650095
atypical west nile virus infection in a child. 200314515836
west nile virus encephalomyelitis in horses in ontario: 28 cases.west nile virus encephalomyelitis was diagnosed in 28 horses presented to the ontario veterinary college veterinary teaching hospital between august 20 and october 15, 2002. the age range of affected horses was 5 months to 20 years (mean 6.9 years, median 6 years). clinical signs were highly variable. duration of hospitalization ranged from < 1 to 12 days (mean 5 days, median 5.4 days). overall, 16 of the 28 (57%) horses were discharged and, of the 14 from which follow-up information was availab ...200312839240
pesticide use for west nile virus. 200312771072
west nile virus infection in 2002: morbidity and mortality among patients admitted to hospital in southcentral august and september 2002 an outbreak of west nile virus (wnv) infection occurred in southern ontario. we encountered a number of seriously ill patients at our hospitals. in this article we document the clinical characteristics of these cases.200312771068
human surveillance for west nile virus infection in ontario in 2000.the first reports of west nile virus (wnv) infection in the united states in 1999 prompted ontario to establish a surveillance protocol to monitor for the possible spread of the virus into the province. surveillance components included evaluation of dead birds, sentinel chickens, mosquito pools and human disease. we report the results of human surveillance in 2000.200211800244
on the effect of diagnostic misclassification bias on the observed spatial pattern in regional count data--a case study using west nile virus mortality data from ontario, 2005.geographic epidemiology is concerned with the investigation of spatially referenced data to discover spatial patterns in the health status of populations. in this context it is generally assumed that a perfect diagnostic test is used to classify individuals as being positive or negative, meaning the health status is measured without error. in this work the effect of an imperfect diagnostic test on spatial patterns of disease in regional count data is investigated in a case study. specifically th ...201022749468
development of three additional culex species-specific polymerase chain reaction primers and their application in west nile virus surveillance in 2002, more than 17,000 mosquito pools collected in canada (quebec, ontario, and manitoba) were tested at the national microbiology laboratory in winnipeg, manitoba, for infection with west nile virus (wnv). using real-time reverse-transcriptase polymerase chain reaction (rt-pcr), 558 mosquito pools (86% culex species and 14% other species) had evidence of infection with wnv. only 30% of the culex specimens, however, were identified to the species level. in this study, culex species-specific p ...201020402349
self-reported protective behaviour against west nile virus among pregnant women in toronto.west nile virus (wnv) is an emerging infection that can lead to substantial morbidity and mortality. although data are limited with respect to the risk to the fetus and neonate, this risk is not inconsequential. methods to reduce the risk of mosquito bites and wnv transmission are simple, economical, and effective in the non-pregnant population. the objective of this descriptive cross-sectional study was to assess adherence to protective behaviours against wnv in pregnant women and to determine ...200819175961
a neural network-based method for risk factor analysis of west nile virus.there is a lack of knowledge about which risk factors are more important in west nile virus (wnv) transmission and risk magnitude. a better understanding of the risk factors is of great help in developing effective new technologies and appropriate prevention strategies for wnv infection. a contribution analysis of all risk factors in wnv infection would identify those major risk factors. based on the identified major risk factors, measures to control wnv proliferation could be directed toward th ...200818419664
west nile virus: the buzz on ottawa residents' awareness, attitudes and 2002, the city of ottawa was interested in the public perception of west nile virus (wnv) and mosquito control. their objectives were to assess: awareness of wnv, practices to reduce mosquito sources, personal protective measures, and attitudes towards community-based insecticide programs.200515850029
real-time syndrome surveillance in ontario, canada: the potential use of emergency departments and telehealth.the purpose of this paper is to review new bioterrorist and emerging infectious threats to public health in ontario, canada, and to propose a means of integrating a telephone-based health information service and emergency department triage with a first-line real-time, 24-h a day syndrome surveillance system. this automated system could be beneficial in detecting a bioterrorist threat as well as in detecting and monitoring disease outbreaks such as influenza, norwalk, west nile virus, escherichia ...200415167186
monitoring the fate of methoprene larvicide for west nile virus management.since the outbreak of vector-borne west nile virus in new york city in 1999, the disease has spread across united states and canada, resulting in the use of larvicides such as methoprene at catch basins for widespread urban mosquito control. although the manufacturer has recommended a methoprene dosage for catch basin application, the effect of rainfall on this dosage is not known. a field study on the fate of methoprene pellets and ingots was conducted during the summer of 2004 at three catch b ...200617302344
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