| West Nile Virus Antibodies in Bats from New Jersey and New York | Pilipski, Jacob D. | 2004 |
KeywordsAntibodies, bats, New Jersey, survey, West Nile virus, WNV AbstractEighty-three serum samples were obtained from big brown (Eptesicus fuscus), little brown (Myotis lucifugus), and northern long-eared (Myotis septentrionalis) bats (Chiroptera: Vespertilionidae), from New Jersey and New York (USA) between July and October 2002. Samples were analyzed for neutralizing antibodies to West Nile virus (WNV) and St. Louis encephalitis (SLE) virus. One little brown bat and one northern long-eared bat tested positive for WNV neutralizing antibodies. No bats had antibodies to SLE virus. This was the first large-scale investigation of WNV infection in bats in New Jersey. Additional work is needed to determine the effects of WNV on bat populations. AuthorsPilipski, Jacob D., Pilipski, Lucas M. and Risley, Lance S. Year Published2004 PublicationJournal of Wildlife Diseases Locations- Atlantic (39.5ºN, 74.3ºW), Morris (40.7ºN, 74.4ºW), and Passaic (41.1ºN, 74.2ºW) counties in New Jersey and Orange County (41.3ºN, 74.6ºW) in New York. (41.3, -74.6)
- Atlantic (39.5ºN, 74.3ºW), Morris (40.7ºN, 74.4ºW), and Passaic (41.1ºN, 74.2ºW) counties in New Jersey and Orange County (41.3ºN, 74.6ºW) in New York. (41.1, -74.2)
- Atlantic (39.5ºN, 74.3ºW), Morris (40.7ºN, 74.4ºW), and Passaic (41.1ºN, 74.2ºW) counties in New Jersey and Orange County (41.3ºN, 74.6ºW) in New York. (40.7, -74.4)
- Atlantic (39.5ºN, 74.3ºW), Morris (40.7ºN, 74.4ºW), and Passaic (41.1ºN, 74.2ºW) counties in New Jersey and Orange County (41.3ºN, 74.6ºW) in New York. (39.5, -74.3)
DOI10.7589/0090-3558-40.2.335 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/15362837 |
| West Nile Virus in California | Reisen, William | 2004 |
KeywordsWNV AbstractWest Nile virus (WNV) was first detected in California during July 2003 by isolation from a pool of Culex tarsalis collected near El Centro, Imperial County. WNV then amplified and dispersed in Imperial and Coachella Valleys, where it was tracked by isolation from pools of Cx. tarsalis, seroconversions in sentinel chickens, and seroprevalence in free-ranging birds. WNV then dispersed to the city of Riverside, Riverside County, and to the Whittier Dam area of Los Angeles County, where it was detected in dead birds and pools of Cx. pipiens quinquefasciatus. By October, WNV was detected in dead birds collected from riparian corridors in Los Angeles, west to Long Beach, and through inland valleys south from Riverside and to San Diego County. WNV was reported concurrently from Arizona in mid-August but not from Baja, Mexico, until mid-November. Possible mechanisms for virus introduction, amplification, and dispersal are discussed. AuthorsReisen, William, Lothrop, Hugh, Chiles, Robert, Madon, Minoo, Cossen, Cynthia, Woods, Leslie, Husted, Stan, Kramer, Vicki and Edman, John Year Published2004 PublicationEmerging Infectious Diseases LocationsDOI10.3201/eid1008.040077 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/15496236 |
| Assessment of arbovirus vector infection rates using variable size pooling | Gu, W. | 2004 |
KeywordsCulex pipiens;Cx. restuans;arbovirus vector;maximum likelihood estimation;minimum infection rate;pool testing;variable size pooling;West Nile virus;Chicago;U.S.A, WNV AbstractPool testing of vector samples for arboviruses is widely used in surveillance programmes. The proportion of infected mosquitoes (Diptera: Culicidae) is often estimated from the minimum infection rate (MIR), based on the assumption of only one infected mosquito per positive pool. This assumption becomes problematic when pool size is large and/or infection rate is high. By relaxing this constraint, maximum likelihood estimation (MLE) is more useful for a wide range of infection levels that may be encountered in the field. We demonstrate the difference between these two estimation approaches using West Nile virus (WNV) surveillance data from vectors collected by gravid traps in Chicago during 2002. MLE of infection rates of Culex mosquitoes was as high as 60 per 1000 at the peak of transmission in August, whereas MIR was less than 30 per 1000. More importantly, we demonstrate roles of various pooling strategies for better estimation of infection rates based on simulation studies with hypothetical mosquito samples of 18 pools. Variable size pooling (with a serial pool sizes of 5, 10, 20, 30, 40 and 50 individuals) performed consistently better than a constant size pooling of 50 individuals. We conclude that variable pool size coupled with MLE is critical for accurate estimates of mosquito infection rates in WNV epidemic seasons. AuthorsGu, W., Lampman, R. and Novak, R. J. Year Published2004 PublicationMedical and Veterinary Entomology LocationsDOI10.1111/j.0269-283X.2004.00482.x Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/15189246 |
| Epidemiology of West Nile Virus in Connecticut: A Five-Year Analysis of Mosquito Data 1999–2003 | Andreadis, Theodore G. | 2004 |
KeywordsWNV AbstractTwo hundred and ten isolations of West Nile virus (WNV) were obtained from 17 mosquito species in six genera in statewide surveillance conducted in Connecticut from June through October, 1999–2003. Culex pipiens (86), Culex salinarius (32), Culex restuans (26), Culiseta melanura (32), and Aedes vexans (12) were implicated as the most likely vectors of WNV in the region based on virus isolation data. Culex pipiens was abundant from July through September and is likely involved in early season enzootic transmission and late season epizootic amplification of the virus in wild bird populations. Epidemic transmission of WNV to humans in urban locales is probable. The abundance of Cx. restuans in June and July and isolations of WNV in early July suggest that this species may play an important role as an enzootic vector involved in early amplification of WNV virus among wild birds. Its involvement as a bridge vector to humans is unlikely. Culex salinarius was the most frequently captured Culex species and was abundant in August and September when virus activity was at its height. Frequent isolations of WNV from this species in September when the majority of human cases were reported in union with its abundance at this time of the year, demonstrated vector competence, and broad feeding habits, make Cx. salinarius a likely bridge vector to humans, horses and other mammals. Multiple isolations WNV from Cs. melanura collected in more rural locales in late August and September, provide supportive evidence to suggest that this predominant avian feeder may play a significant role in epizootic amplification of the virus among wild bird populations in these environs. Aedes vexans was the only species of Aedes or Ochlerotatus from which multiple isolations of WNV were made in more than one year and was among the most frequently trapped and abundant species throughout the season. Since Ae. vexans predominately feeds on mammals it is unlikely to play a significant role in epizootic amplification of WNV, however, because of its abundance and aggressive mammalian and human biting behavior it must receive strong consideration as a bridge vector to humans and horses. The occasional virus isolations obtained from Aedes cinereus (4), Uranotaenia sapphirina (3), Ochlerotatus canadensis (2), Ochlerotatus trivittatus (2), Ochlerotatus sollicitans (2), Ochlerotatus sticticus (2), Psorophora ferox (2), Anopheles punctipennis, Anopheles walkeri, Ochlerotatus cantator, Ochlerotatus taeniorhynchus, and Ochlerotatus triseriatus in conjunction with their inefficient vector competency and host feeding preferences indicate that these species likely play a very minor role in either the enzootic maintenance or epizootic transmission of WNV in this region. The principal foci of WNV activity in Connecticut were identified as densely populated (>3,000 people/mi2) residential communities in coastal Fairfield and New Haven Counties, and in the case of 2002, similar locales in proximity of the city of Hartford in central Hartford County. In almost all instances we observed a correlation both temporally and spatially between the isolation of WNV from field-collected mosquitoes and subsequent human cases in these locales. In most years the incidence of human cases closely paralleled the number of virus isolations made from mosquitoes with both peaks falling in early September. We conclude that the isolation of WNV from fieldcollected mosquitoes is a sensitive indicator of virus activity that is associated with the risk of human infection that habitually extends from early August through the end of October in Connecticut.Vector-Borne Zoonotic Dis. 4, 360–378. AuthorsAndreadis, Theodore G., Anderson, John F., Vossbrinck, Charles R. and Main, Andrew J. Year Published2004 PublicationVector-Borne and Zoonotic Diseases LocationsDOI10.1089/vbz.2004.4.360 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/15682518 |
| Year-round West Nile Virus Activity, Gulf Coast Region, Texas and Louisiana | Tesh, Robert B. | 2004 |
KeywordsWNV AbstractWest Nile virus (WNV) was detected in 11 dead birds and two mosquito pools collected in east Texas and southern Louisiana during surveillance studies in the winter of 2003 to 2004. These findings suggest that WNV is active throughout the year in this region of the United States. AuthorsTesh, Robert B., Parsons, Ray, Siirin, Marina, Randle, Yvonne, Sargent, Chris, Guzman, Hilda, Wuithiranyagool, Taweesak, Higgs, Stephen, Vanlandingham, Dana L., Bala, Adil A., Haas, Keith and Zerinque, Brian Year Published2004 PublicationEmerging Infectious Diseases LocationsDOI10.3201/eid1009.040203 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/15498169 |
| Antibody Prevalence of West Nile Virus in Birds, Illinois, 2002 | Ringia, Adam M. | 2004 |
KeywordsWNV AbstractAntibodies to West Nile virus were detected in 94 of 1,784 Illinois birds during 2002. Captive and urban birds had higher seropositivity than did birds from natural areas, and northern and central Illinois birds’ seropositivity was greater than that from birds from the southern sites. Adult and hatch-year exposure rates did not differ significantly. AuthorsRingia, Adam M., Blitvich, Bradley J., Koo, Hyun-Young, Van de Wyngaerde, Marshall, Brawn, Jeff D. and Novak, Robert J. Year Published2004 PublicationEmerging Infectious Diseases LocationsDOI10.3201/eid1006.030644 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/15207067 |
| Investigation of an outbreak of encephalomyelitis caused by West Nile virus in 136 horses | Ward, Michael P. | 2004 |
KeywordsWNV AbstractNo abstract available AuthorsWard, Michael P., Levy, Michel, Thacker, H. Leon, Ash, Marianne, Norman, Sandra K. L., Moore, George E. and Webb, Paul W. Year Published2004 PublicationJournal of the American Veterinary Medical Association LocationsDOI10.2460/javma.2004.225.84 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/15239478 |
| Mosquito and Arbovirus Activity During 1997–2002 in a Wetland in Northeastern Mississippi | Cupp, E. W. | 2004 |
KeywordsSaint Louis encephalitis, eastern equine encephalomyelitis virus, Culex erraticus, Culiseta melanura, blood meal identification, WNV AbstractThe species composition and population dynamics of adult mosquitoes in a wetland near Iuka, MS, were analyzed over a 6-yr period (1997–2002) and reverse transcription-polymerase chain reaction (PCR) detection rates of arboviruses determined during five of those years. Blood meals of three likely vector species were identified using a PCR-based method that allows identification of the host to species. Culex erraticus (Dyar & Knab) composed 51.9% of the population during the 6-yr period with 295 females collected per trap night. Eastern equine encephalomyelitis (EEE) virus was detected in six genera of mosquitoes [Coquillettidia perturbans (Walker), Culex restuans Theobald, Culex salinarius Coquillett, Culex erraticus (Dyar & Knab), Anopheles crucians Wiedemann, Anopheles quadrimaculatus Say, Aedes vexans (Meigen), Ochlerotatus triseriatus Say, and Psorophora ferox Humboldt) with positive pools occurring in 1998, 1999, and 2002. Culiseta melanura Coquillett occurred at a low level (<1%) and was not infected. Saint Louis encephalitis virus was detected once in a single pool of Cx. erraticus in 1998. Neither West Nile virus nor LaCrosse virus was found. Minimum infection rates per 1000 females tested of competent vectors of EEE virus were variable and ranged from 0.14 for Cx. erraticus to 40.0 for Oc. triseriatus. Thirty-nine species of birds were identified in the focus with blood-engorged mosquitoes found to contain meals (n = 29) from eight avian species. The majority of meals was from the great blue heron, Ardea herodias L. (n = 55%), but when bird abundance data were adjusted for avian mass, the brown-headed cowbird, Molothrus ater (Boddaert); blue jay, Cyanocitta cristata (L.); and northern mockingbird, Mimus polyglottos (L.), were overrepresented as hosts. AuthorsCupp, E. W., Tennessen, K. J., Oldland, W. K., Hassan, H. K., Hill, G. E., Katholi, C. R. and Unnasch, T. R. Year Published2004 PublicationJournal of Medical Entomology LocationsDOI10.1603/0022-2585-41.3.495 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/15185956 |
| Pesticide Spraying for West Nile Virus Control and Emergency Department Asthma Visits in New York City, 2000 | Karpati, Adam M. | 2004 |
KeywordsWNV AbstractNo abstract available AuthorsKarpati, Adam M., Perrin, Mary C., Matte, Tom, Leighton, Jessica, Schwartz, Joel and Barr, R. Graham Year Published2004 PublicationEnvironmental Health Perspectives LocationsDOI10.1289/ehp.6946 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/15289164 |
| West Nile Virus Surveillance: A Simple Method for Verifying the Integrity of RNA in Mosquito (Diptera: Culicidae) Pools | Hoffmann, Peter R. | 2004 |
KeywordsWest Nile virus, reverse transcriptase-polymerase chain reaction, mosquito, arbovirus, 18S rRNA, WNV AbstractIn a West Nile virus (WNV)-free ecosystem, it is essential to verify the integrity of RNA before concluding that RNA extracted from mosquito specimens is negative for WNV gene sequences. The primary objective of our study was to develop a rapid molecular assay to rapidly screen mosquitoes for the presence of 18S RNA and WNV gene sequences. Mosquitoes, collected from multiple sites on the island of O‘ahu, were pooled into groups of 1–50 mosquitoes according to capture site, date, and species. Using primer design software and the GenBank database, generic oligonucleotide primer pairs were designed to amplify mosquito18S rRNA gene sequences from different species. RNA was extracted from mosquito pools, and reverse transcriptase-polymerase chain reaction (RT-PCR) was performed for the presence of mosquito18S rRNA and WNV gene sequences. Three of the seven primer pairs successfully detected 18S rRNA sequences for both Aedes and Culex by RT-PCR, and one primer pair successfully amplified 18S rRNA sequences for 15 different mosquito species. All 64 mosquito pools from 10 different sites on the island of Oahu, Hawaii, were negative for WNV nonstructural protein-5 gene sequences. This simple, one-step RT-PCR method for screening mosquito pools for arboviruses will become an increasingly valuable tool as WNV becomes endemic throughout the Americas. AuthorsHoffmann, Peter R., Woodrow, Robert J., Calimlim, Precilia S., Sciulli, Rebecca, Effler, Paul V., Miyamoto, Vernon, Imrie, Allison, Yanagihara, Richard and Nerurkar, Vivek R. Year Published2004 PublicationJournal of Medical Entomology LocationsDOI10.1603/0022-2585-41.4.731 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/15311468 |
