Surveillance for Early Detection of High-Consequence Pests and Pathogens

Surveillance for Early Detection of High-Consequence Pests and Pathogens

John H. Bowers (USDA APHIS, USA), Jerry R. Malayer (Oklahoma State University, USA), Beatriz Martínez-López (University of California, Davis, USA), Joseph LaForest (University of Georgia, USA), Charles T. Bargeron (University of Georgia, USA), Alison D. Neeley (USDA APHIS, USA), Leonard B. Coop (Oregon State University, USA), Brittany S. Barker (Oregon State University, USA), Alexander J. Mastin (University of Salford, UK), Stephen R. Parnell (University of Salford, UK), Allard A. Cossé (USDA APHIS, USA), Brian J. McCluskey (Trace First Inc., USA), Scott A. Isard (The Pennsylvania State University, USA), and Joseph M. Russo (Independent Researcher, USA)
Copyright: © 2022 |Pages: 58
DOI: 10.4018/978-1-7998-7935-0.ch005
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Surveillance is one of the core activities of national organizations responsible for human, animal, or plant health, with the goal of demonstrating the absence of infection or infestation, determining the presence or distribution of infection or infestation, and/or detecting as early as possible exotic or emerging pests and pathogens that may be harmful to agriculture and the environment. Surveillance is a tool to establish absence of the pest or pathogen, monitor trends, facilitate the mitigation and control of infection or infestation, provide data for use in risk analysis, substantiate the rationale for sanitary measures, and provide assurances to trading partners, producers, and the public. The type of surveillance applied depends on the objectives of the surveillance, the available data sources, resources, and the outputs needed to support decision-making.
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Introduced pests and pathogens require strategies for detection, identification, and prevention of spread. These strategies can be applied across regions, states, or international borders. Threats include known, high-consequence pests and pathogens, as well as emerging, unknown threats. Ideally, an integrated, strategic approach to intervention and mitigation is in place prior to introduction of the threat, however there are manifold threats and myriad pathways by which foreign or exotic pests and pathogens may enter a new area or region. This may occur through human-assisted transport of animals and plants, products made from animal or plant materials, contaminated food, migratory wild animals or insects, and even through shipping containers and airport luggage. However, natural spread of pests and pathogens also can occur. Given that weather patterns, especially hurricanes and typhoons, can move birds and insects, or dust and debris, across international borders, movement of pests and pathogens become almost inevitable.

With awareness of potential threats and routes of introduction, what strategies and tactical elements can be applied to detect an introduced pathogen or pest early and rapidly contain the invader? Critically, we need sound surveillance strategies, including guidelines for when to look, where to look, how to look, and for timely data analysis and sharing. These strategies include interoperable tactical sciences to look for, and identify, something unusual that could be indicative of some new organism that may pose an agricultural or environmental threat. A global surveillance system for crop diseases has been proposed that would allow sharing of information to facilitate detection of new threats to enable countries and regions to quickly respond to emerging disease outbreaks (Carvajal-Yepes et al., 2019). Global systems also exist to facilitate information sharing and threat detection for animal pathogens through a network of national and international organizations. The Office International des Epizooties (World Organization for Animal Health [OIE], 2021) coordinates efforts among more than 75 national and regional organizations.

The common analogy for the detection of foreign or exotic pathogens and pests in the United States (U.S.) is the ‘needle in a haystack’ reference. It is much more complex. The premise is that we only ‘know what we know,’ but we also must acknowledge that what we ‘do not know is much more than what we do know.’ Essentially, in many instances, the unknown universe of potential pest and pathogens is far greater than the relatively limited knowledge of those we know cause disease and/or economic damage to agricultural crops, livestock, landscape plants, forest and urban trees, and other aspects of the food and environmental landscape in which we live. What we do know, however, are the characteristics of the populations we are trying to protect. We know location, density, prevailing conditions of climate, operational norms, and opportunities for movement in and out of the area. This knowledge helps determine our strategies.

Design and implementation of an effective surveillance system is critical to early detection, identification, and containment. The goal of early detection is to find and identify pathogens and pests before they become established and cause widespread damage and economic harm to the agricultural, landscape, and environmental sectors (Reaser et al., 2020). The U.S. National Invasive Species Council’s National Management Plan (2018) champions the concept that early detection, rapid assessment, and rapid response is a critical second line of defense and provides the greatest opportunity for eradication and cost-effective management. An effective early detection and rapid response program increases the likelihood that invasive species will be found, contained, and eradicated before they become widely established.

Key Terms in this Chapter

Pustule: A small, blister-like elevation of epidermis formed as spores emerge.

SARS: See Severe Acute Respiratory Syndrome.

Olfactometer: Devices used to present odor stimuli in a standardized laboratory setting; a device used to study insect behavior in presence of an olfactory stimulus.

Pheromone: A chemical substance produced and released into the environment by an animal, especially a mammal or an insect, affecting the behavior or physiology of others of its species; a secreted or excreted chemical factor that triggers a social response in members of the same species.

Blotch: Dead areas of tissue on the foliage, irregular in shape, and larger than leaf spots.

Vesicular Stomatitis: A virulent disease of livestock in New World caused by any of several arboviruses assigned to Rhabdoviridae. Transmission to humans by phlebotomine sand flies ( Lutzomyia spp.) implicated during epizootics.

Kairomone: A chemical substance emitted by an organism and detected by another of a different species which gains advantage from this, e.g., a pest seeking a host.

Urediniospore: The asexual, dikaryotic, often rust-colored spore of a rust fungus, produced in a structure called a uredinium; the “repeating stage” of a heteroecious rust fungus, i.e., capable of infecting the host species on which it is produced.

Surveillance, Passive: There is no active search for cases. It involves passive notification by surveillance sites and reports are generated and sent by local staff or the public; Information and data is gathered from all sources.

Poikilothermic: An organism with variable body temperature that fluctuates with and is similar to the temperature of its environment: a cold-blooded organism.

Lesion: A localized diseased area or wound.

Oviposition: The deposit or laying of eggs.

Canker: A plant disease characterized (in woody plants) by the death of cambium tissue and loss and/or malformation of bark, or (in non-woody plants) by the formation of sharply delineated, dry, necrotic, localized lesions on the stem.

Gall: An abnormal swelling or localized outgrowth produced by a plant as a result of attack by a fungus, bacterium, nematode, insect, or other organism.

Prevalence: The proportion of the population with a given symptom or quality.

Uredinium (pl. uredinia): The fruiting body (sorus) of a rust fungus that produces urediniospores.

Objective Prioritization of Exotic Pests (OPEP): Developed by USDA, APHIS to prioritize exotic pests according to the impacts they are likely to have if introduced into the United States. Separate models were developed and validated for arthropods and plant pathogens (including nematodes). Risk criteria consist of questions focused on biology and natural history, pest damage, research, and management elsewhere in the world. Control measures and production practices in place in the United States are also considered when predicting the potential impacts. Questions require objective, documented evidence from primary scientific literature and are statistically weighted based on their ability to predict impact. Each model predicts the likelihood each organism will cause high, moderate, or low impact (as defined by APHIS) in the United States. The results of each assessment are used to develop a prioritized list to help focus resources on those pests that are most likely to cause significant impacts.

Ambrosia Beetles: Beetles of the weevil subfamilies Scolytinae and Platypodinae (Coleoptera, Curculionidae), which live in nutritional symbiosis with fungi. The beetles excavate tunnels in dead or stressed trees in which they cultivate fungal gardens, their sole source of nutrition.

Ebola: Ebola virus disease (EVD), formerly known as Ebola haemorrhagic fever, is a rare but severe, often fatal illness in humans. The virus is transmitted to people from wild animals and spreads in the human population through human-to-human transmission.

Select Agent: Biological agents and toxins that have been determined to have the potential to pose a severe threat to public health and safety, to animal and plant health, or to animal or plant products; regulated through the Federal Select Agents Program.

Defoliation: The loss of leaves from a plant, whether normal or premature.

Blight: A sudden, severe, and extensive spotting, discoloration, wilting, or destruction of leaves, flowers, stems, or entire plants.

Incidence: The frequency at which individuals within a specific population develop a given symptom or quality.

Fecundity: The ability to produce an abundance of offspring or new growth.

Delimiting Survey: Surveillance conducted to determine the boundaries over an area where a pest has been detected or considered to be established or invasive.

Symptom, Plant: An indication of disease by reaction of the host, e.g., canker, leaf spot, wilt (contrasts with sign).

Standard: Document established by consensus and approved by a recognized body that provides for common and repeated use, rules, guidelines, or characteristics for activities or their results, aimed at the achievement of the optimum degree of order in a given context.

Monitoring: An ongoing process to verify an event; an official ongoing process to verify phytosanitary situations, e.g., monitoring survey.

Stunting: The reduction in height of a vertical axis resulting from a progressive reduction in the length of successive internodes or a decrease in their number; abnormally small plant growth.

Shot Hole: Small fragments of leaves falling off and leaving small holes in the leaf tissue.

Office International des Epizooties (OIE): See World Organization for Animal Health.

Sign, Plant: An indication of disease from direct observation of a pathogen or its parts (contrasts with symptom).

Surveillance, General: A process whereby information on pests of concern in an area is gathered from various sources. Sources may include national or local government bodies, research institutions, universities, museums, scientific societies (including those of independent specialists), producers, consultants, the general public, scientific and trade journals, unpublished data, and the websites of other National Plant Protection organizations (NPPOs) or international organizations (ISPM 6, ).

Vector: An organism or object that transports or transmits a pest, parasite, or pathogen from one area or host to another place or host.

Sentinel Plot/Population: A survey methodology that consists of plots of land with a specific crop or plant species or defined populations of animals that are routinely or consistently monitored for the presence of a pest or pathogen.

Epizootics: Widespread, rapid occurrence of a disease affecting many individuals or a large proportion of an animal population at same time.

Dieback: The progressive death of shoots, leaves, or roots, beginning at the tips.

Mycelium: A mass of hyphae constituting the body (thallus) of a fungus.

Ringspot: A disease symptom characterized by yellowish or necrotic rings enclosing green tissue.

Intertropical Convergence Zone: A narrow zone near the equator where northern and southern air masses converge, typically producing low atmospheric pressure.

Sclerotium (pl. Sclerotia): A vegetative resting body of a fungus, composed of a compact mass of hyphae with or without host tissue, usually with a darkened rind.

Vesicular: Pertaining to or consisting of vesicles or small sacs or bladders.

Mildew: A thin coating of mycelial growth and spores on the surfaces of infected plant parts.

Diapause: A physiological condition or state of restrained development and reduced metabolic activity which cannot be directly attributed to unfavorable environmental conditions. Visual consequences of diapause in postembryonic stages includes lowed or suspended growth, differentiation, metamorphosis, or reproduction.

Sensillum (pl. sensilla): An arthropod sensory organ protruding from the cuticle of exoskeleton, or sometimes lying within or beneath it.

Phenology: The study of the timing of recurring biological events and the causes of their timing with regard to weather and climate.

Voltinism: Pertaining to organisms with many generations in a year or season. Term often applied to Lepidoptera, Diptera and other insects of economic importance.

Survey: An official procedure conducted over a defined period to determine the presence or absence of pests, or the boundaries or characteristics of a pest population, in an area, place of production, or production site (ISPM 5, ).

Spore: A reproductive structure of fungi and some other organisms, containing one or more cells; a bacterial cell modified to survive an adverse environment.

Wilt: The drooping of leaves and stems from lack of water (i.e., inadequate water supply or excessive transpiration); a vascular disease that interrupts normal water uptake.

Chlorosis: The yellowing or whitening of green plant parts as a result of chlorophyll breakdown or production failure.

Semiochemical: A chemical substance or mixture released by an organism that affects the behaviors of other individuals; a pheromone or other chemical that conveys a signal from one organism to another to modify the behavior of the recipient organism.

Zika: Zika virus is a mosquito-borne flavivirus that was first identified in Uganda in 1947 in monkeys. It was later identified in humans in 1952 in Uganda and the United Republic of Tanzania.

World Organization for Animal Health (OIE): The need to fight animal diseases at global level led to the creation of the Office International des Epizooties through the international Agreement signed on January 25, 1924. In May 2003, the Office became the World Organization for Animal Health but kept its historical acronym OIE. The OIE is the intergovernmental organization responsible for improving animal health worldwide. It is recognized as a reference organization by the World Trade Organization (WTO), and in 2018 has a total of 182 Member Countries. The OIE maintains permanent relations with nearly 75 international and regional organizations AU264: Anchored Object 1 and has Regional and sub-regional Offices on every continent. The organization is placed under the authority and control of a World Assembly of Delegates consisting of Delegates designated by the Governments of all Member Countries. AU265: URL Validation failed because the page does not exist (HTTP error 404).

Surveillance, Specific: A process whereby information on pests of concern in an area is obtained over a defined period. Organizations actively gather specific pest-related data. Specific surveillance includes surveys that are conducted to determine the characteristics of a pest population or to determine which species are present or absent in an area (ISPM 6, ).

Gas Chromatography-Mass Spectrometry?(GC-MS): An analytical method that combines the features of gas-chromatography and mass spectrometry to identify different substances within a test sample; separates chemical mixtures (the GC component) and identifies the components at a molecular level (the MS component).

Stochasticity: By random chance or probability.

Ecthyma: A skin infection characterized by crusted sores beneath which ulcers form.

Electroretinogram: A diagnostic test that measures the electrical activity of the retina in response to a light stimulus; used to measure photoreceptor responses in insect retinas to different wavelengths of visual stimuli so they can identify the most attractive colors, patterns, and intensities.

Hypha (pl. hyphae): A single, tubular filament of a fungal thallus or mycelium; the basic structural unit of a fungus.

Mosaic: A disease symptom characterized by nonuniform coloration, with intermingled normal, light green and yellowish patches, usually caused by a virus.

Climate Normals: A 30-year average of a weather variable for a given time of year.

Fruiting Body: Various shaped structures that contain the spores of a fungus.

Detection Survey: Surveillance conducted in an area over a specified period of time to determine if a pest is present or absent.

Flagging: An isolated, wilted, or necrotic branch with dead leaves attached.

Surveillance: An official process which collects and records data on pest presence or absence by survey, monitoring, or other methods.

Mortality: Mortality is related to the number of deaths caused by the health event under investigation. It can be communicated as a rate or as an absolute number ( Hernandez & Kim, 2020 ).

Terrestrial and Aquatic Animal Health Code: Provides standards for the improvement of animal health and welfare and veterinary public health worldwide, including through standards for safe international trade in terrestrial animals (mammals, reptiles, birds, and bees) and their products. The health measures in the Terrestrial Code should be used by the Veterinary Authorities of importing and exporting countries to provide for early detection, reporting, and control agents that are pathogenic to animals or humans, and to prevent their transfer via international trade in animals and animal products, while avoiding unjustified sanitary barriers to trade. Compare to the International Standards for Phytosanitary Measures on the IPPC website.

Sign, Animal: A health issue that is an objective, observable phenomenon or evidence of disease that can be identified by others.

Ptyalism: A condition that causes the overproduction of saliva.

Monitoring Survey: Surveillance designed to verify the status and various characteristics of an existing pest population within a defined area; Ongoing survey to verify the characteristics of a pest population (ISPM 5).

Scorch: Any symptom that resembles the result of flame or fire on the affected part, often seen at the margins of leaves.

Nuclear Magnetic Resonance?(NMR): A spectroscopic technique to observe local magnetic fields around atomic nuclei; an analytical chemistry technique used in quality control and research for determining the content and purity of a sample as well as its molecular structure; used to identify monomolecular organic compounds.

Exudate: A liquid excreted or discharged from diseased tissues.

Severe Acute Respiratory Syndrome (SARS): A viral respiratory disease caused by a SARS-associated coronavirus. It was first identified at the end of February 2003 during an outbreak that emerged in China and spread to 4 other countries.

Leaf Spot: A plant disease lesion typically restricted in development in the leaf after reaching a characteristic size; an obvious, defined lesion or area of diseased tissue, on a leaf.

Surveillance, Active: Proactive targeting of specific plant or animal populations over a period of time to collect detailed information on the health status of the population; An active search for cases or occurrences of the pest or disease.

International Standards for Phytosanitary Measures (ISPMs): Standards are adopted by the Commission on Phytosanitary Measures (CPM), which is the governing body of the International Plant Protection Convention (IPPC). Standards provide guidance to contracting parties in meeting the aims and obligations of the Convention. The intention of ISPMs is to harmonize phytosanitary measures for the purpose of facilitating international trade. ISPMs can cover a wide range of issues, including surveillance, pest risk analysis, establishment of pest free areas, export certification, phytosanitary certificates, and pest reporting. The IPPC encourages adoption of these standards, but they only come into force once contracting (members) and non-contracting parties to establish requirements in national legislative instruments. Compares with the Animal Health Codes on the OIE website. .

Foot-and-Mouth Disease (FMD) or Hoof-and-Mouth Disease (HMD): An infectious, and sometimes fatal, viral disease that affects cloven-hoofed animals, including domestic and wild cattle, buffalo, sheep, goats, and swine. FMD has severe implications for agricultural trade and farming and ranching, since it is highly infectious and easily spread through contact with contaminated equipment, vehicles, clothing, and feed, and by domestic and wild predators. Its containment requires considerable efforts in vaccination, strict monitoring, trade restrictions, quarantines, and the culling of both infected and healthy (uninfected) animals.

International Plant Protection Convention (IPPC): An intergovernmental treaty signed by over 180 countries, aiming to protecting the world's plant resources from the spread and introduction of pests, and promoting safe trade. The Convention introduced International Standards for Phytosanitary Measures (ISPMs) as its main tool to achieve its goals, making it the sole global standard setting organization for plant health. The IPPC is one of the “Three Sisters” recognized by the World Trade Organization's (WTO) Sanitary and Phytosanitary Measures (SPS) Agreement, along with the Codex Alimentarius Commission for food safety standards and the World Organization for Animal Health (OIE) for animal health standards. .

Symptom, Animal: A health issue that is apparent only to the patient and cannot be identified by anyone else; a subjective description by the patient of a health issue.

Necrosis: The death of cells or tissue, usually accompanied by darkening to black or brown color.

Zoonoses: Diseases and infections naturally transmitted between vertebrate animals and humans.

Morbidity: The state of being symptomatic or unhealthy for a disease or condition. It is usually represented or estimated using prevalence or incidence ( Hernandez & Kim, 2020 ).

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