The One Health Concept.

The concept of One Health has been developed as the appreciation that human health is intricately connected to those of other animals and the environment that they inhabit. In recent years, the COVID-19 pandemic and noticeable effects of climate change have encouraged national and international cooperation to apply One Health strategies to address key issues of health and welfare. The United Nations (UN) Sustainable Development Goals have established targets for health and wellbeing, clean water and sanitation, climate action, as well as sustainability in marine and terrestrial ecosystems. The One Health Quadripartite comprises the World Health Organization (WHO), the World Organization for Animal Health (WOAH-formerly OIE), the United Nations Food and Agriculture Organization (FAO) and the United Nations Environment Programme (UNEP). There are six areas of focus which are Laboratory services, Control of zoonotic diseases, Neglected tropical diseases, Antimicrobial resistance, Food safety and Environmental health. This article discusses the concept of One Health by considering examples of infectious diseases and environmental issues under each of those six headings. Biomedical Scientists, Clinical Scientists and their colleagues working in diagnostic and research laboratories have a key role to play in applying the One Health approach to key areas of healthcare in the 21st Century.

The colonisation of remains by the sarcophagid fly Sarcophaga argyrostoma (Robineau-Desvoidy) (Diptera: Sarcophagidae).

This article discusses the ability of the sarcophagid fly Sarcophaga argyrostoma (Robineau-Desvoidy) to exploit various food sources. These include living, freshly dead, and highly decayed remains. It also considers the factors affecting larval thermogenesis and compares S. argyrostoma with Lucilia sericata (Meigen). In addition, the ability of S. argyrostoma to colonise buried baits, those out of reach, and those protected by bandaging is considered. Both fresh and decayed liver stimulated ovoviviposition by S. argyrostoma and oviposition by L. sericata. Even liver that had decayed for 840 days supported larval development by both species to adulthood. Thermogenesis during larval development was dependent upon larval density. There was no difference in thermogenesis characteristics between S. argyrostoma and L. sericata or between diets of fresh liver and fresh minced pork. Thermogenesis was less pronounced on 840-day-old liver than on fresh liver but was still dependent upon larval density and there was no species effect. When starved, third instar S. argyrostoma larvae did not exhibit cannibalism or attack third instar L. sericata larvae. Sarcophaga argyrostoma adults could detect fresh liver baits buried at 20 cm in loose soil and ovoviviposited on the soil surface. The larvae then rapidly crawled through the soil to reach the baits and completed their development below ground. Sarcophaga argyrostoma also colonised baits that were at least 5 cm out of reach by dropping larvae onto them. They could infest baits through gauze bandages but not wound dressings. The adults would not ovoviviposit on living invertebrates but dead snails and dead L. sericata third instar larvae were infested and supported larval growth to adulthood. The adults were willing to ovoviviposit on human faeces and it supported larval growth to adulthood. Human urine stimulated very limited ovoviviposition and the larvae all died shortly afterwards and without developing. They did not ovoviviposit on banana or melon.

The exploitation of fresh remains by Dermestes maculatus De Geer (Coleoptera, Dermestidae) and their ability to cause a localised and prolonged increase in temperature above ambient.

This article discusses the ability of adults of the coleopteran beetle Dermestes maculatus (De Geer) to colonise fresh remains. It also considers whether colonisation results in localised thermogenesis in a similar manner to that induced by blowfly larvae. In the laboratory, adult D. maculatus instantly colonised fresh killed rats and mice. The adults entered the oral cavity within 1-2 h and the eyes and ears were among the first parts of the body consumed. Egg laying occurred on the torso and head within an hour of death and eggs hatched within 3-4 days. The larvae remained on the body whilst the adults (>70%) rested in the surrounding wood chippings when not feeding or laying eggs. Larvae grew rapidly on the dead bodies and some were starting to pupate within 28 days. The dermestids consumed the corpses predominantly from the head downwards and weight loss correlated with the number of larvae produced. In both rats and mice, colonisation of the abdominal region was associated with an increase in temperature. The maximum abdominal temperature and the length of time the temperature remained 1 °C or more above ambient correlated with the number of larvae produced. This rise in temperature would probably be sufficient to increase the rate of development of dermestid larvae and that of any other invertebrate or microbe in the region. In the absence of dermestids, the internal temperature rarely rose 1 °C above ambient. Although there are previously published accounts of dermestid beetles consuming fresh corpses, they are reputed to favour older desiccated remains. This paper confirms that D. maculatus rapidly consumes and reproduces on fresh remains. The fact that dermestid beetles are seldom found on fresh remains under field conditions is therefore probably a result of inter-specific competition among decomposing insects rather than food preference. This information could be useful when determining the forensic significance of D. maculatus recovered from dead bodies.

The colonisation of remains by the muscid flies Muscina stabulans (Fallén) and Muscina prolapsa (Harris) (Diptera: Muscidae).

In the field, the muscid flies Muscina stabulans (Fallén) and Muscina prolapsa (Harris) only colonised buried baits in June, July and August. The two-species co-occurred on baits buried at 5cm but only M. prolapsa colonised baits buried at 10cm. Other species of insect were seldom recovered from buried baits regardless of the presence or absence of Muscina larvae. In the laboratory, both M. stabulans and M. prolapsa preferentially colonised liver baits on the soil surface compared to those buried at 5cm. Baits buried in dry soil were not colonised by either species whilst waterlogged soil severely reduced colonisation but did not prevent it entirely. Dry liver presented on the soil surface was colonised and supported growth to adulthood but if there was no surrounding medium in which the larvae could burrow then they died within 24h. M. stabulans showed a consistent preference for ovipositing on decaying liver rather than fresh liver, even when it had decayed for 41 days. The results for M. prolapsa were more variable but it was also capable of developing on both fresh and very decayed remains. Blood-soaked soil and dead slugs and snails stimulated egg-laying by both species and supported larval growth to adulthood. Mushrooms, melon, and bananas also stimulated egg-laying although to a much lesser extent and very few larvae survived to adulthood. Horse faeces stimulated extensive egg-laying but the larvae invariably died during the first or second instar and none survived to pupariation. This information could be useful when determining the forensic significance of Muscina larvae recovered from dead bodies.

The ability of the blowflies Calliphora vomitoria (Linnaeus), Calliphora vicina (Rob-Desvoidy) and Lucilia sericata (Meigen) (Diptera: Calliphoridae) and the muscid flies Muscina stabulans (Fallén) and Muscina prolapsa (Harris) (Diptera: Muscidae) to colonise buried remains.

The blowflies Calliphora vomitoria (Linnaeus), Calliphora vicina (Rob-Desvoidy) and Lucilia sericata (Meigen) exhibited a limited ability to colonise pig liver baits buried in loose soil. Calliphora vomitoria colonised baits buried at 5 cm but no deeper whilst C. vicina and L. sericata colonised remains at 10 cm but not at 20 cm. The baits were colonised by larvae hatching from eggs laid on the surface of the soil. Both C. vomitoria and L. sericata were able to develop from eggs through to adulthood on baits that were infested before being buried and the larvae developed at similar rates and pupariated at similar depths to larvae developing on baits on the soil surface. The muscid flies Muscina stabulans (Fallén) and Muscina prolapsa (Harris) colonised remains buried in loose soil at a depth of 40 cm and even when presented with baits on the soil surface their larvae tended to remain in the soil beneath the baits. In compacted soil, M. stabulans colonised baits buried at 10 cm but M. prolapsa only colonised those buried at 5 cm. In both muscid species, the adult flies were instantly attracted to feed on fresh blood and laid eggs in the soil above buried baits within 30min of them being introduced into the cages. The adult muscid flies did not attempt to burrow into the soil and their larvae colonised the baits from eggs laid on the soil surface. This information could be useful in determining whether a body was stored above ground before being buried and/or the time since burial occurred.