OIE, 2020. Terrestrial Animal Health Code: New world screwworm (Cochliomyia hominivorax). Chapter 8.12. World Organisation for Animal Health (OIE). Accessed 19 October 2020.
" }, "editorialNote": { "en": [ "source:UNDRR HIPS" ] }, "scopeNote": { "en": [ "The New World screwworm, Cochliomyia hominivorax, is a blow fly that is an obligate parasite of warm-blooded animals in tropical and subtropical regions of South America and the Caribbean. Females seek animals and lay their eggs on the skin, often near open wounds. Larvae feed on the animal’s tissues, enlarging the wound, which can cause death if not treated. The period between oviposition at a wound site and the expression of disease due to burrowing larvae can be as short as one to two days. After cessation of feeding, larvae leave the animal and pupate in the soil. The life cycle takes approximately three weeks. Infestation of tissue by fly larvae is known as ‘myiasis’ (OIE, 2013). Economic losses due to screwworm infestation of livestock are significant. In 2005, it was estimated that in South America alone annual losses were approximately USD 3.6 billion (Scott et al., 2020). New World screwworm eradication programmes have eliminated this myiasis from Curacao, Puerto Rico, the Virgin Islands, the USA, Mexico and in Central America, from Guatemala, Belize, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama. New World screwworm is presently found in the northern countries of South America southwards to Uruguay, northern Chile and northern Argentina. The parasite spread from the Americas to Libya when it was identified in 1988 by Libyan veterinarians in the northwest part of the country. The mode of introduction and the country from which the pest came remain unknown. Positive taxonomic identification of the pest was made by British scientists, and the Food and Agriculture Organization of the United Nations (FAO) confirmed the presence of the screwworm myiasis disease in Libya in March 1989 (Lindquist and Abusowa, 1991). Many cases of screwworm myiasis have been documented in humans. The disease can quickly become debilitating if it affects the eyes, mouth, nasal or frontal sinuses, or the ears (CFSPH, 2016). Clinical presentation of screwworm is always associated with a variety of pre-established wounds and should be considered in the event of any myiasis. Wounds may manifest draining, suppuration and/or enlargement; signs of infestation with serosanguineous discharge often accompanied by distinctive odour. Animals with screwworm myiasis often display discomfort and appear unthrifty and depressed; separate from group and may also manifest anorexia and reduced milk production. Morbidity, although variable, in areas with high screwworm populations may reach up to 100% in naval wounds of newborns. If untreated, animals may die within one to two weeks due to toxicity and/or secondary bacterial infection (OIE, 2013). Laboratory diagnosis is by identification of the parasites under the microscope. Field diagnosis of screwworm larvae, even with a microscope or magnifying glass, is difficult. Adult screwworms are rarely seen. They are also difficult to distinguish from other flies. Other techniques used mainly in research laboratories include cuticular hydrocarbon analysis, analysis of mitochondrial DNA, and random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) assays. Serology is not used (CFSPH, 2016). Screwworm infestations can be treated in both endemic and non-endemic regions; euthanasia of the animal is not usually required. Although some wounds may be surgically excised, most are treated with a suitable larvicide and allowed to heal without closure. Treatment is usually repeated at intervals until the wound has healed. Removal of necrotic tissue may be necessary, and antibiotics may be given when secondary bacterial contamination is present. In non-endemic regions, the animal is quarantined until treatment is complete and the wound has healed. Treatment of the environment may also be necessary. Larvae that are removed from the wound must be placed in alcohol preservative or destroyed. If any larvae leave an infested wound and mature into adults, screwworms can become established in an area (CFSPH, 2016)." ] }, "inScheme": [ { "id": "http://connectivity-hub.com/terms/", "title": { "en": "Climate Connectivity Taxonomy" } } ], "inSchemeAll": [ { "id": "http://connectivity-hub.com/terms/" } ], "topConceptOf": [ { "id": "http://connectivity-hub.com/terms/", "title": { "en": "Climate Connectivity Taxonomy" } } ], "@context": { "@version": 1.1, "id": "@id", "type": "@type", "@vocab": "http://www.w3.org/2004/02/skos/core#", "xsd": "http://www.w3.org/2001/XMLSchema#", "dct": "http://purl.org/dc/terms/", "dc": "http://purl.org/dc/elements/1.1/", "schema": "https://schema.org/", "vann": "http://purl.org/vocab/vann/", "ldp": "http://www.w3.org/ns/ldp#", "owl": "http://www.w3.org/2002/07/owl#", "title": { "@id": "dct:title", "@container": "@language" }, "dc:title": { "@id": "dc:title", "@container": "@language" }, "dc:description": { "@id": "dc:description", "@container": "@language" }, "description": { "@id": "dct:description", "@container": "@language" }, "license": { "@id": "dct:license", "@container": "@language" }, "issued": { "@id": "dct:issued", "@type": "xsd:date" }, "created": { "@id": "dct:created", "@type": "xsd:date" }, "modified": { "@id": "dct:modified", "@type": "xsd:date" }, "creator": "dct:creator", "publisher": "dct:publisher", "preferredNamespacePrefix": "vann:preferredNamespacePrefix", "preferredNamespaceUri": "vann:preferredNamespaceUri", "isBasedOn": "schema:isBasedOn", "source": "dct:source", "prefLabel": { "@container": "@language" }, "altLabel": { "@container": [ "@language", "@set" ] }, "hiddenLabel": { "@container": [ "@language", "@set" ] }, "definition": { "@container": "@language" }, "note": { "@container": [ "@language", "@set" ] }, "changeNote": { "@container": [ "@language", "@set" ] }, "editorialNote": { "@container": [ "@language", "@set" ] }, "historyNote": { "@container": [ "@language", "@set" ] }, "scopeNote": { "@container": [ "@language", "@set" ] }, "notation": { "@container": "@set" }, "example": { "@container": "@language" }, "narrower": { "@container": "@set" }, "related": { "@container": "@set" }, "relatedMatch": { "@container": "@set" }, "narrowerTransitive": { "@container": "@set" }, "broaderTransitive": { "@container": "@set" }, "broadMatch": { "@container": "@set" }, "narrowMatch": { "@container": "@set" }, "closeMatch": { "@container": "@set" }, "exactMatch": { "@container": "@set" }, "hasTopConcept": { "@container": "@set" }, "inScheme": { "@container": "@set" }, "topConceptOf": { "@container": "@set" }, "deprecated": { "@id": "owl:deprecated", "@type": "xsd:boolean" }, "isReplacedBy": { "@id": "dct:isReplacedBy", "@container": "@set" } } }