What is the Risk for Exposure to Vector-Borne Pathogens in United States National Parks?
ABSTRACT United States national parks attract > 275 million visitors annually and collectively present risk of exposure for staff and visitors to a wide range of arthropod vector species (most notably fleas, mosquitoes, and ticks) and their associated bacterial, protozoan, or viral pathogens. We assessed the current state of knowledge for risk of exposure to vector-borne pathogens in national parks through a review of relevant literature, including internal National Park Service documents and organismal databases. We conclude that, because of lack of systematic surveillance for vector-borne pathogens in national parks, the risk of pathogen exposure for staff and visitors is unclear. Existing data for vectors within national parks were not based on systematic collections and rarely include evaluation for pathogen infection. Extrapolation of human-based surveillance data from neighboring communities likely provides inaccurate estimates for national parks because landscape differences impact transmission of vector-borne pathogens and human-vector contact rates likely differ inside versus outside the parks because of differences in activities or behaviors. Vector-based pathogen surveillance holds promise to define when and where within national parks the risk of exposure to infected vectors is elevated. A pilot effort, including 5-10 strategic national parks, would greatly improve our understanding of the scope and magnitude of vector-borne pathogen transmission in these high-use public settings. Such efforts also will support messaging to promote personal protection measures and inform park visitors and staff of their responsibility for personal protection, which the National Park Service preservation mission dictates as the core strategy to reduce exposure to vector-borne pathogens in national parks.
SourceAvailable from: Matteo Marcantonio[Show abstract] [Hide abstract]
ABSTRACT: West Nile Virus (WNV) is a globally important mosquito borne virus, with significant implications for human and animal health. The emergence and spread of new lineages, and increased pathogenicity, is the cause of escalating public health concern. Pinpointing the environmental conditions that favour WNV circulation and transmission to humans is challenging, due both to the complexity of its biological cycle, and the under-diagnosis and reporting of epidemiological data. Here, we used remote sensing and GIS to enable collation of multiple types of environmental data over a continental spatial scale, in order to model annual West Nile Fever (WNF) incidence across Europe and neighbouring countries. Multi-model selection and inference were used to gain a consensus from multiple linear mixed models. Climate and landscape were key predictors of WNF outbreaks (specifically, high precipitation in late winter/early spring, high summer temperatures, summer drought, occurrence of irrigated croplands and highly fragmented forests). Identification of the environmental conditions associated with WNF outbreaks is key to enabling public health bodies to properly focus surveillance and mitigation of West Nile virus impact, but more work needs to be done to enable accurate predictions of WNF risk.PLoS ONE 01/2015; 10(3-3):e0121158. DOI:10.1371/journal.pone.0121158 · 3.53 Impact Factor
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ABSTRACT: Abstract Since 1998, Lyme disease cases have increased in south-central Pennsylvania, which includes Gettysburg National Military Park (NMP). Limited information is available about tick populations or pathogens in this area, and no data regarding frequency of tick bites or prevention measures among Gettysburg NMP employees are available. To address these gaps, ticks were collected, classified, and replaced (to minimize disruptions to tick populations) at two sites within Gettysburg NMP during April-September, 2009, among eight nonremoval samplings. On two additional occasions during May and June, 2009, ticks were collected and removed from the two original sites plus 10 additional sites and tested for tick-borne pathogens by using PCR. A self-administered anonymous survey of Gettysburg NMP employees was conducted to determine knowledge, attitudes, and practices regarding tick-borne diseases. Peak Ixodes scapularis nymph populations were observed during May-July. Of 115 I. scapularis ticks tested, 21% were infected with Borrelia burgdorferi, including 18% of 74 nymphs and 27% of 41 adults; no other pathogen was identified. The entomologic risk index was calculated at 1.3 infected nymphs/hour. An adult and nymph Amblyomma americanum were also found, representing the first confirmed field collection of this tick in Pennsylvania, but no pathogens were detected. The survey revealed that most park employees believed Lyme disease was a problem at Gettysburg NMP and that they frequently found ticks on their skin and clothing. However, use of personal preventive measures was inconsistent, and 6% of respondents reported contracting Lyme disease while employed at Gettysburg NMP. These findings indicate a need to improve surveillance for tick bites among employees and enhance prevention programs for park staff and visitors.Vector borne and zoonotic diseases (Larchmont, N.Y.) 04/2014; DOI:10.1089/vbz.2013.1363 · 2.53 Impact Factor
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ABSTRACT: In the context of public health, risk governance (or risk analysis) is a framework for the assessment and subsequent management and/or control of the danger posed by an identified disease threat. Generic frameworks in which to carry out risk assessment have been developed by various agencies. These include monitoring, data collection, statistical analysis and dissemination. Due to the inherent complexity of disease systems, however, the generic approach must be modified for individual, disease-specific risk assessment frameworks.Study designThe analysis was based on the review of the current risk assessments of vector-borne diseases adopted by the main Public Health organisations (OIE, WHO, ECDC, FAO, CDC etc…).Methods Literature, legislation and statistical assessment of the risk analysis frameworks.ResultsThis review outlines the need for the development of a general public health risk assessment method for vector-borne diseases, in order to guarantee that sufficient information is gathered to apply robust models of risk assessment. Stochastic (especially spatial) methods, often in Bayesian frameworks are now gaining prominence in standard risk assessment procedures because of their ability to assess accurately model uncertainties.Conclusions Risk assessment needs to be addressed quantitatively wherever possible, and submitted with its quality assessment in order to enable successful public health measures to be adopted. In terms of current practice, often a series of different models and analyses are applied to the same problem, with results and outcomes that are difficult to compare because of the unknown model and data uncertainties. Therefore, the risk assessment areas in need of further research are identified in this article.Public Health 11/2014; 128(12). DOI:10.1016/j.puhe.2014.08.018 · 1.48 Impact Factor