Simbología en medicina y ciencias de la salud / Symbology in medicine and health sciences

La inclusión curricular de la historia de la medicina se hace cada vez más importante, y dentro de la misma el estudio de la simbología en medicina es un tema muy interesante y a veces polémico. Los símbolos asociados a la medicina usualmente presentan serpientes asociadas a los mismos, siendo los más reconocidos el bastón de Asclepio/Esculapio y el caduceo de Hermes/Mercurio. Las serpientes se encuentran asociadas a consideraciones positivas y negativas en las diferentes culturas del mundo. En el Antiguo Egipto eran símbolos de sabiduría y poder. En la Biblia tenían un rol dual y una participación en al menos un evento relacionado a curaciones masivas. La mitología griega nos provee de elementos que conectan a serpientes enrolladas en torno a una rama o vara directamente con la medicina. El tratamiento de la dracunculiasis nos otorga otra vía de conexión entre esta imagen y la medicina. El bastón de Asclepio/Esculapio se reconoce como símbolo de la medicina y las ciencias de la salud en general, mientras que el caduceo se asocia a otras profesiones no médicas.

The curricular inclusion of the history of medicine is becoming more and more important, and within it the study of symbology in medicine is a very interesting and sometimes controversial subject. The symbols associated with medicine usually present snakes associated with them, the most recognized being the rod of Asclepius/ Aesculapius and the Hermes/Mercury caduceus. Snakes are associated with positive and negative considerations in the different cultures of the world. In Ancient Egypt they were symbols of wisdom and power. In the Bible they had a dual role and a participation in at least one event related to massive healings. Greek mythology provides us with elements that connect snakes coiled around a branch or rod directly to medicine. The treatment of dracunculiasis gives us another way of connection between this image and medicine. The rod of Asclepius/ Aesculapius is recognized as a symbol of medicine and health sciences in general, while the caduceus is associated with other non-medical professions

Guinea worm: from Robert Leiper to eradication.

Guinea worm disease, dracunculiasis or dracontiasis, is an ancient disease with records going back over 4500 years, but until the beginning of the 20th century, little was known about its life cycle, particularly how humans became infected. In 1905, Robert Thomas Leiper was sent by the British colonial authorities to West Africa to investigate the spread of Guinea worm disease and to recommend measures to prevent it. While carrying out his investigations, he made important contributions to the aetiology, epidemiology and public health aspects of Guinea worm disease and provided definitive answers to many outstanding questions. First, he tested the validity of previous theories; second, he confirmed the role of water fleas, which he identified as Cyclops, as the intermediate hosts in the life cycle; third, he investigated the development of the parasite in its intermediate host; and fourth, he recommended measures to prevent the disease. [The crustacean Order Cyclopoida in the Family Cyclopidae contains 25 genera, including Cyclops which itself contains over 400 species and may not even be a valid taxon. It is not known how many of these species (or indeed species belonging to related genera) can act as intermediate hosts of Dracunculus medinensis nor do we know which species Fedchenko, Leiper and other workers used in their experiments. It is, therefore, best to use the terms copepod, or copopoid crustacean rather than Cyclops in scientific texts. In this paper, these crustaceans are referred to as copepods except when referring to an original text.] Leiper described the remarkable changes that took place when an infected copepod was placed in a dilute solution of hydrochloric acid; the copepod was immediately killed, but the Dracunculus larvae survived and were released into the surrounding water. From this, he concluded that if a person swallowed an infected copepod, their gastric juice would produce similar results. He next infected monkeys by feeding them copepods infected with Guinea worm larvae, and thus conclusively demonstrated that humans became infected by accidentally ingesting infected crustaceans. Based on these conclusions, he advocated a number of control policies, including avoidance of contaminated drinking water or filtering it, and these preventive measures paved the way for further research. The challenge to eradicate Guinea worm disease was not taken up until about seven decades later since when, with the support of a number of governmental and non-governmental organizations, the number of cases has been reduced from an estimated 3·5 million in 1986 to 25 in 2016 with the expectation that this will eventually lead to the eradication of the disease.

Towards global Guinea worm eradication in 2015: the experience of South Sudan.

For centuries, the Guinea worm parasite (Dracunculus medinensis) has caused disabling misery, infecting people who drink stagnant water contaminated with the worm's larvae. In 2012, there were 542 cases of Guinea worm reported globally, of which 521 (96.1%) were reported in South Sudan. Protracted civil wars, an inadequate workforce, neglect of potable water provision programs, suboptimal Guinea worm surveillance and case containment, and fragmented health systems account for many of the structural and operational factors encumbering South Sudan's Guinea worm eradication efforts. This article reviews the impacts of six established Guinea worm control strategies in South Sudan: (1) surveillance to determine actual caseload distribution and trends in response to control measures; (2) educating community members from whom worms are emerging to avoid immersing affected parts in sources of drinking water; (3) filtering potentially contaminated drinking water using cloth filters or filtered drinking straws; (4) treating potentially contaminated surface water with the copepod larvicide temephos (Abate); (5) providing safe drinking water from boreholes or hand-dug wells; and (6) containment of transmission through voluntary isolation of each patient to prevent contamination of drinking water sources, provision of first aid, and manual extraction of the worm. Surveillance, community education, potable water provision, and case containment remain weak facets of the program. Abate pesticide is not a viable option for Guinea worm control in South Sudan. In light of current case detection and containment trends, as well as capacity building efforts for Guinea worm eradication, South Sudan is more likely to eradicate Guinea worm by 2020, rather than by 2015. The author highlights areas in which substantial improvements are required in South Sudan's Guinea worm eradication program, and suggests improvement strategies.

Discovery and clinical importance of the filariases.

Macrofilariae have been recognized for many millennia. Microfilariae were, however, not demonstrable until microscopy attained an advanced degree of perfection. Demonstration of the mode of transmission of the various filariases (Wuchereria bancrofti, Onchocerca volvulus, and Loa loa), dominated by Manson's work on lymphatic filariasis, constitutes one of the most exciting phases inhuman parasitology.

When is a disease eradicable? 100 years of lessons learned.

Since the 1915 launch of the first international eradication initiative targeting a human pathogen, much has been learned about the determinants of eradicability of an organism. The authors outline the first 4 eradication efforts, summarizing the lessons learned in terms of the 3 types of criteria for disease eradication programs: (1) biological and technical feasibility, (2) costs and benefits, and (3) societal and political considerations.

Perceptions and priorities in disease eradication: dracunculiasis eradication in Africa.

Dracunculiasis, guinea worm disease, is an incapacitating disease affecting people in poor, remote areas of Africa, in Yemen, and a few remaining areas of the Indian subcontinent where there is poor access to protected water sources. The neglect of this preventable disease and its belated recognition are analyzed within the context of changing priorities for health since the 1870s, especially the shift from the paradigm of Imperial Medicine to Primary Health Care. A global eradication effort took off during the 1980s, and, although the original target date of December 1995 has passed, the program has achieved a remarkable recent diminution in the number of recorded cases, over 99% of which are now found in Africa. Eradication policies in Africa are briefly explored in relation to current concerns such as the incorporation of dracunculiasis eradication measures in cash-starved primary health care programs. The wider implications of an eradication campaign which is on the verge of success are also considered.

An ancient scourge: the end of dracunculiasis in Egypt.

This paper addresses the question of when guinea worm disease was last found in Egypt, and how written sources from the nineteenth and twentieth centuries which mention the disease should be evaluated. This enquiry is relevant to the global eradication campaign now in progress, and the need for countries in which dracunculiasis was once present to prepare a certification of eradication. Sudan, the country which has the largest number of cases today, is Egypt's southern neighbour. Because of the nature of the disease (in endemic areas it is most common among poor, rural people), it may not have come to the attention of urban-based health personnel. In the period before the details of the transmission cycle were known, the attitudes and mindsets of physicians and travellers also have to be taken into account in interpreting written reports of the disease. An examination of documentary sources from the nineteenth and twentieth centuries in European languages does not show any clear evidence for dracunculiasis transmission in Egypt during that period. Cases noted in Egypt, especially by the much quoted Dr Clot Bey in the 1820s, most likely originated beyond the borders of the country, in Sudan and, to a lesser extent, from endemic areas in the Middle East. However, many later commentators merely repeated what Clot Bey had written. A further difficulty is that some published reports which apparently concern dracunculiasis in Egypt, actually refer to cases in animals rather than humans.