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Results: 12

1.
Int J Environ Res Public Health. 2013 Nov 27;10(12):6366-79. doi: 10.3390/ijerph10126366.

Vector contact rates on Eastern bluebird nestlings do not indicate West Nile virus transmission in Henrico County, Virginia, USA.

Author information

  • 1St. Tammany Parish Mosquito Abatement District, 62512 Airport Rd. Bldg. 23, Slidell, LA 70460, USA. caillouet@stpmad.org.

Abstract

Sensitive indicators of spatial and temporal variation in vector-host contact rates are critical to understanding the transmission and eventual prevention of arboviruses such as West Nile virus (WNV). Monitoring vector contact rates on particularly susceptible and perhaps more exposed avian nestlings may provide an advanced indication of local WNV amplification. To test this hypothesis we monitored WNV infection and vector contact rates among nestlings occupying nest boxes (primarily Eastern bluebirds; Sialia sialis, Turdidae) across Henrico County, Virginia, USA, from May to August 2012. Observed host-seeking rates were temporally variable and associated with absolute vector and host abundances. Despite substantial effort to monitor WNV among nestlings and mosquitoes, we did not detect the presence of WNV in these populations. Generally low vector-nestling host contact rates combined with the negative WNV infection data suggest that monitoring transmission parameters among nestling Eastern bluebirds in Henrico County, Virginia, USA may not be a sensitive indicator of WNV activity.

PMID:
24287858
[PubMed - in process]
PMCID:
PMC3881119
Free PMC Article
Icon for Multidisciplinary Digital Publishing Institute (MDPI) Icon for PubMed Central
2.
J Med Entomol. 2013 Mar;50(2):462-6.

Nesting bird "host funnel" increases mosquito-bird contact rate.

Author information

  • 1Department of Biology, Virginia Commonwealth University, 1000 W. Cary St., Richmond, VA 23284-2012, USA. kacaillouet@vcu.edu

Abstract

Increases in vector-host contact rates can enhance arbovirus transmission intensity. We investigated weekly fluctuations in contact rates between mosquitoes and nesting birds using the recently described Nest Mosquito Trap (NMT). The number of mosquitoes per nestling increased from < 1 mosquito per trap night to 36.2 in the final 2 wk of the nesting season. Our evidence suggests the coincidence of the end of the avian nesting season and increasing mosquito abundances may have caused a "host funnel," concentrating host-seeking mosquitoes to the few remaining nestlings. The relative abundance of mosquitoes collected by the NMT suggests that significantly more Aedes albopictus (Skuse) and Culex pipiens (L.) /restuans (Theobald) sought nesting bird bloodmeals than were predicted by their relative abundances in CO2-baited Centers for Disease Control and Prevention light and gravid traps. Culex salinarius (Coquillett) and Culex erraticus Dyar and Knab were collected in NMTs in proportion to their relative abundances in the generic traps. Temporal host funnels and nesting bird host specificity may enhance arbovirus amplification and explain observed West Nile virus and St. Louis encephalitis virus amplification periods.

PMID:
23540137
[PubMed - indexed for MEDLINE]
3.
Am J Disaster Med. 2012 Fall;7(4):253-71. doi: 10.5055/ajdm.2012.0099.

Eye of the storm: analysis of shelter treatment records of evacuees to Acadiana from Hurricanes Katrina and Rita.

Author information

  • 1Louisiana Center Health Informatics, University of Louisiana at Lafayette, USA.

Abstract

OBJECTIVE:

The objective of this study is to gain insight into the medical needs of disaster evacuees, through a review of experiential data collected in evacuation shelters in the days and weeks following Hurricanes Katrina and Rita in 2005, to better prepare for similar events in the future. Armed with the information and insights provided herein, it is hoped that meaningful precautions and decisive actions can be taken by individuals, families, institutions, communities, and officials should the Louisiana Gulf Coast-or any other area with well-known vulnerabilities-be faced with a future emergency.

DESIGN:

Demographic and clinical data that were recorded on paper documents during triage and treatment in evacuation shelters were later transcribed into a computerized database management system, with cooperation of the Department of Health Information Management at The University of Louisiana at Lafayette. Analysis of those contemporaneously collected data was undertaken later by the Louisiana Center for Health Informatics.

SETTING:

Evacuation shelters, Parish Health Units, and other locations including churches and community centers were the venue for ad hoc clinics in the Acadiana region of Louisiana.

PATIENTS, PARTICIPANTS:

The evacuee-patients-3,329 of them-whose information is reflected in the subject dataset were among two geographically distinct but similarly distressed groups: 1) evacuees from Hurricane Katrina that devastated New Orleans and other locales near Louisiana and neighboring states in late August 2005 and 2) evacuees from Hurricane Rita that devastated Southwest Louisiana and neighboring areas of Texas in September 2005. Patient data were collected by physicians, nurses, and other volunteers associated with the Operation Minnesota Lifeline (OML) deployment during the weeks following the events.

INTERVENTIONS:

Volunteer clinicians from OML provided triage and treatment services and documented those services as paper medical records. As the focus of the OML "mission of mercy" was entirely on direct individually specific evaluation and care, no population-based experimental hypothesis was framed nor was the effectiveness of any specific intervention researched at the time.

MAIN OUTCOME MEASURE(S):

This study reports experiential data collected without a particular preconceived hypothesis, because no specific outcome measures had been designed in advance.

RESULTS:

Data analysis revealed much about the origins and demographics of the evacuees, their hurricane-related risks and injuries, and the loss of continuity in their prior and ongoing healthcare.

CONCLUSIONS:

The authors believe that much can be learned from studying data collected in evacuee triage clinics, and that such insights may influence personal and official preparedness for future events. In the Katrina-Rita evacuations, only paper-based data collection mechanisms were used-and those with great inconsistency-and there was no predeployed mechanism for close-to-real-time collation of evacuee data. Deployment of simple electronic health record systems might well have allowed for a better real-time understanding of the unfolding of events, upon arrival of evacuees in shelters. Information and communication technologies have advanced since 2005, but predisaster staging and training on such technologies is still lacking.

PMID:
23264274
[PubMed - indexed for MEDLINE]
4.
Malar J. 2012 Jun 10;11:193. doi: 10.1186/1475-2875-11-193.

PCR detection of malaria parasites in desiccated Anopheles mosquitoes is uninhibited by storage time and temperature.

Author information

  • 1Department of Tropical Medicine, Tulane University, New Orleans, LA 70112, USA. mrider@tulane.edu

Abstract

BACKGROUND:

Reliable methods to preserve mosquito vectors for malaria studies are necessary for detecting Plasmodium parasites. In field settings, however, maintaining a cold chain of storage from the time of collection until laboratory processing, or accessing other reliable means of sample preservation is often logistically impractical or cost prohibitive. As the Plasmodium infection rate of Anopheles mosquitoes is a central component of the entomological inoculation rate and other indicators of transmission intensity, storage conditions that affect pathogen detection may bias malaria surveillance indicators. This study investigated the effect of storage time and temperature on the ability to detect Plasmodium parasites in desiccated Anopheles mosquitoes by real-time polymerase chain reaction (PCR).

METHODS:

Laboratory-infected Anopheles stephensi mosquitoes were chloroform-killed and stored over desiccant for 0, 1, 3, and 6 months while being held at four different temperatures: 28, 37, -20 and -80°C. The detection of Plasmodium DNA was evaluated by real-time PCR amplification of a 111 base pair region of block 4 of the merozoite surface protein.

RESULTS:

Varying the storage time and temperature of desiccated mosquitoes did not impact the sensitivity of parasite detection. A two-way factorial analysis of variance suggested that storage time and temperature were not associated with a loss in the ability to detect parasites. Storage of samples at 28°C resulted in a significant increase in the ability to detect parasite DNA, though no other positive associations were observed between the experimental storage treatments and PCR amplification.

CONCLUSIONS:

Cold chain maintenance of desiccated mosquito samples is not necessary for real-time PCR detection of parasite DNA. Though field-collected mosquitoes may be subjected to variable conditions prior to molecular processing, the storage of samples over an inexpensive and logistically accessible desiccant will likely ensure accurate assessment of malaria parasite presence without diminishing PCR-detection of parasites in mosquitoes stored for at least six months.

PMID:
22682161
[PubMed - indexed for MEDLINE]
PMCID:
PMC3405449
Free PMC Article
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5.
J Vector Ecol. 2012 Jun;37(1):210-5. doi: 10.1111/j.1948-7134.2012.00218.x.

Nest Mosquito Trap quantifies contact rates between nesting birds and mosquitoes.

Author information

  • 1Department of Biostatistics, Virginia Commonwealth University, Richmond, VA 23298-0032, USA. kacaillouet@vcu.edu

Abstract

Accurate estimates of host-vector contact rates are required for precise determination of arbovirus transmission intensity. We designed and tested a novel mosquito collection device, the Nest Mosquito Trap (NMT), to collect mosquitoes as they attempt to feed on unrestrained nesting birds in artificial nest boxes. In the laboratory, the NMT collected nearly one-third of the mosquitoes introduced to the nest boxes. We then used these laboratory data to estimate our capture efficiency of field-collected bird-seeking mosquitoes collected over 66 trap nights. We estimated that 7.5 mosquitoes per trap night attempted to feed on nesting birds in artificial nest boxes. Presence of the NMT did not have a negative effect on avian nest success when compared to occupied nest boxes that were not sampled with the trap. Future studies using the NMT may elucidate the role of nestlings in arbovirus transmission and further refine estimates of nesting bird and vector contact rates.

© 2012 The Society for Vector Ecology.

PMID:
22548555
[PubMed - indexed for MEDLINE]
6.
J Med Entomol. 2011 Nov;48(6):1210-3.

Disproportionate mosquito feeding on aggregated hosts.

Author information

  • 1Department of Epidemiology, Tulane University, School of Public Health and Tropical Medicine, 1400 Canal Street, New Orleans, LA 70112, USA. ivo.foppa@gmail.com

Abstract

Despite the importance of per-capita feeding rates for mosquito-borne transmission dynamics, the relationship between host aggregation and per-capita feeding rates remains poorly characterized. We conducted indoor experiments to investigate how Culex quinquefasciatus (Say) mosquitoes distribute their blood feeding on variably aggregated domestic chickens (Callus gallus domesticus L.) (one chicken vs. a flock of seven to nine birds). Mosquitoes were always more likely to feed on the larger chicken group; yet, the single chicken tended to be fed on at a higher per-capita rate. When 10 chickens were available the feeding intensity was 4.5 times higher for the single chicken compared with the flock. We conclude that more highly aggregated hosts may experience lower exposure to mosquito bites than less aggregated hosts.

PMID:
22238881
[PubMed - indexed for MEDLINE]
7.
J Med Entomol. 2011 Sep;48(5):1091-4.

High Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae) prevalence in Triatoma sanguisuga (Hemiptera: Redviidae) in southeastern Louisiana.

Author information

  • 1Department of Tropical Medicine, Tulane University, New Orleans, LA 70112, USA.

Abstract

From May through November 2007, intensive weekly surveys at the site of a previously reported autochthonous human case of Chagas parasite infection resulted in the collection of 298 Triatoma sanguisuga (Leconte) specimens, of which 60.4% (180) were polymerase chain reaction positive for Trypanosoma cruzi Chagas. All were adults, in a ratio of approximately 1:1 female to male, indicating that the domicile was not colonized, but was a destination for these host-seeking adults. We report on seasonal activity pattern, T. cruzi prevalence in T. sanguisuga, and attempts at insect exclusion and control at the case residence.

PMID:
21936329
[PubMed - indexed for MEDLINE]
PMCID:
PMC3544525
Free PMC Article
Icon for PubMed Central
8.
J Vector Ecol. 2008 Jun;33(1):191-7.

Characterization of aquatic mosquito habitat, natural enemies, and immature mosquitoes in the Artibonite Valley, Haiti.

Author information

  • 1Department of Tropical Medicine, Tulane University, New Orleans, LA 70112, USA.

Abstract

This paper characterizes water body types harboring immature mosquitoes in a low-lying area of Haiti and investigates the relationship between immature Anopheles albimanus abundance and aquatic predator presence. Larval An. albimanus were found in permanent and semi-permanent groundwater habitats including (in order of greatest abundance) hoof/footprints, ditches, rice fields, and ground pools. High levels of species co-occurrence were observed in habitats. Among water bodies positive for immature Anopheles, 42.9% also contained immature Culex species. Significant association between An. albimanus abundance and the absence of fish predators was detected. Results from the multivariate negative binomial regression suggest that the interactive effect of increasing distance from the Artibonite River and elevation are positively associated with the abundance of immature An. albimanus. The presence of fish predators was not associated with the abundance of An. albimanus larvae in habitats while controlling for habitat distance and elevation. The results of this study provide baseline entomological information to inform vector control programs in the country.

PMID:
18697323
[PubMed - indexed for MEDLINE]
9.
J Vector Ecol. 2008 Jun;33(1):166-72.

Colonization of abandoned swimming pools by larval mosquitoes and their predators following Hurricane Katrina.

Author information

  • 1Department of Tropical Medicine, Tulane University, New Orleans, LA 70112, USA.

Abstract

Thousands of flooded swimming pools were abandoned in New Orleans following Hurricane Katrina and provided a natural experiment to examine colonization of a novel aquatic habitat by mosquito larvae and their aquatic predators. We conducted a randomized survey of flooded swimming pools in two neighborhoods in January 2006 and found that 64% contained mosquito larvae, 92% contained predatory invertebrates, and 47% contained fishes. We collected 12,379 immature mosquitoes representing five species, primarily Culiseta inornata, and secondarily, the arboviral vector Culex quinquefasciatus. Dragonfly nymphs in the families Aeshnidae and Libellulidae were the most common predatory invertebrates collected among a total of 32 non-mosquito invertebrate species. Eleven species of fishes were collected, with Gambusia affinis accounting for 76% of the catch. Diversity of fishes in swimming pools was positively correlated with proximity to a levee breach and the fish assemblage found in swimming pools was similar to that found along shorelines of Lake Pontchartrain and drainage canals that flooded the study area. Mosquito larvae were rare or absent from pools containing fishes; however, path analysis indicated that the presence of top predators or abundant competitors may somewhat mitigate the effect of Gambusia affinis on mosquito presence.

PMID:
18697320
[PubMed - indexed for MEDLINE]
10.
Emerg Infect Dis. 2008 May;14(5):804-7. doi: 10.3201/eid1405.071066.

Increase in West Nile neuroinvasive disease after Hurricane Katrina.

Author information

  • 1Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, 1430 Tulane Ave, SL-17, New Orleans, LA 70112, USA. kcaillou@tulane.edu

Abstract

After Hurricane Katrina, the number of reported cases of West Nile neuroinvasive disease (WNND) sharply increased in the hurricane-affected regions of Louisiana and Mississippi. In 2006, a >2-fold increase in WNND incidence was observed in the hurricane-affected areas than in previous years.

PMID:
18439367
[PubMed - indexed for MEDLINE]
PMCID:
PMC2600257
Free PMC Article
Icon for CDC-NCEZID Icon for PubMed Central
11.
J Am Mosq Control Assoc. 2005 Mar;21(1):33-8.

Impact of West Nile virus outbreak upon St. Tammany Parish Mosquito Abatement District.

Author information

  • 1St. Tammany Parish Mosquito Abatement District, 2800A Terrace Avenue, Slidell, LA 70458, USA.

Abstract

St. Tammany Parish, Louisiana, experienced an outbreak of West Nile virus (WNV) in 2002, with 40 human cases and 4 deaths, most occurring from June to August. Culex pipiens quinquefasciatus was believed to be the primary vector of WNV during the outbreak, although circumstantial evidence suggests that Aedes albopictus also may have been involved in transmission. Dead bird reports were the 1st indication of the outbreak and were an excellent indicator of WNV activity; however, sentinel chickens were the most effective in tracking viral activity. Although sentinel chickens tested positive 2-3 wk after the 1st dead bird, they peaked at about the same time as human cases, and continued testing positive when viral activity was no longer detected in birds and mosquito pools. Lag time between the 1st positive sentinel chicken and the peak in human cases was 6 wk. If this trend continues in the future, sentinel chickens could be used to predict the peak in number of human cases. The 2002 WNV outbreak had a strong impact on operational budget of the St. Tammany Parish Mosquito Abatement District (88% increase above the 3-year average). Vector control activities accounted for most of the operational increase and consisted of targeted population reduction of known WNV-competent mosquito species. The goal of these activities was to prevent new human WNV cases. The 3- to 10-fold reduction in vector mosquito populations from May to August, together with a dramatic drop in number of new human cases by the end of August, indicated that our strategy was effective.

PMID:
15825759
[PubMed - indexed for MEDLINE]
12.
Emerg Infect Dis. 2003 Nov;9(11):1388-94.

West Nile virus infection in nonhuman primate breeding colony, concurrent with human epidemic, southern Louisiana.

Author information

  • 1Tulane National Primate Research Center, Covington, Louisiana, USA.

Abstract

During the summer of 2002, an epidemic of West Nile meningoencephalitis occurred in southern Louisiana. Following the outbreak, blood samples were collected from 1,692 captive rhesus monkeys (Macaca mulatta), pigtail macaques (M. nemestrina), and baboons (Papio spp.) that were permanently housed outdoors at a nonhuman primate breeding facility in St. Tammany Parish, Louisiana. The serum samples were examined for antibodies to West Nile virus (WNV). Overall, 36% of the captive nonhuman primates had WNV antibodies; comparison of these samples with banked serum samples from previous blood collections indicated that the animals were infected subclinically from February to August 2002. WNV activity was demonstrated in surveillance at the nonhuman primate-breeding colony and in the neighboring community during this same period. The high infection rate in this captive nonhuman primate population illustrates the intensity of WNV transmission that can occur silently in nature among other susceptible vertebrates during epidemic periods.

PMID:
14718080
[PubMed - indexed for MEDLINE]
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