Human parasites are parasites that a person is exposed to. The general definition of the word “parasite” applies not only to multicellular animals and protozoa living at the expense of their host and to the detriment of the latter, but also viruses , bacteria and fungi [1] [2] . According to historical tradition, and from the point of view of medical parasitology , it is customary to call parasites any creatures that lead a parasitic lifestyle, except for viruses and bacteria [3] with similar qualities.
Parasitism is only a special case of symbiosis (in the broad sense of the word), between parasitism and other types of cohabitation (indifferent, mutually and one-sidedly useful), there are gradual transitions and sometimes they cannot be sharply differentiated [4] . According to the habitat in the host organism, parasites are divided into external, or ectoparasites (e.g. blood-sucking insects, some leeches, etc.), and internal, or endoparasites (e.g. protozoa, helminths) living in internal organs, tissues and cells of the host .
Cysts and eggs of endoparasites can be found in laboratory analysis of feces, blood, visual examination, which help in the detection and identification of parasites [5] . Although there are many ways in which a person can become infected with parasitic infections, following the basics of personal and public hygiene reduces its likelihood.
Content
Human parasites in ancient history
Archaeological information
The study of parasites in ancient people is based on the study of feces and other petrified material. The earliest parasites found in humans were Paragonimus westermani eggs from northern Chile , found in petrified feces and dating to approximately 5900 BC. e. In Brazil , hookworm eggs from 5000 BC were also found. e., in Peru - eggs of nematodes from 2330 BC. e. And the Egyptian mummies dating back to 2000, 1250, and 1000. BC e. contained tapeworm eggs, along with a well-preserved female worm [6] .
Written sources
The first written evidence of parasites is given in ancient Egyptian papyrus scrolls from 3000 to 400 years. BC e. They identify parasites such as roundworms, Dracunculus medinensis (the causative agent of dracunculiasis ), pinworms , and some tapeworms of unknown species. Ebers Papyrus contains one of the first notes on hookworm in ancient texts. This disease has no obvious specific symptoms and has been mentioned in general terms, but papyrus definitely associates the disease with a parasite [6] . Elephant disease is also described, the symptoms of which are very visible, since it causes extreme swelling of the legs, chest, and genitals. The features of the statues of the pharaoh Mentuhotep II indicate that he probably suffered from elephantiasis. The fact that the disease of schistosomiasis was extremely common in ancient Egypt was noted as a result of studies of mummies, but schistosomiasis as a separate disease was not noted in the texts of that time. The only truly defining symptom is bloody urine , but several other diseases show the same symptom. However, apparently, the main reason for the lack of identification of schistosomiasis as a separate disease is its widespread prevalence. In the same way, the ancient Greeks and Romans did not recognize the existence of the common cold due to its frequent occurrence [6] .
In ancient Greece, several parasites were described in Corpus hippocraticus . In this book, Hippocrates and Aristotle recorded the presence of worms and other parasites in fish, domesticated animals, and humans. For example, the presence of porcine tapeworm (Taenia solium) in pigs has been shown along with its larval stages. The eggs of the tapeworm were also described by Aristotle in the section on pig diseases in his book “The History of Animals”, and were also mentioned in the production of Aristophanes as “gradients”. Echinococcus cysts were also known in ancient cultures, mainly because of their presence in the liver of sacrificial animals [6] .
A small number of parasitic diseases noted in ancient Greek and Roman texts are caused by the attribution of their symptoms to influenza , runny nose and dysentery . However, several diseases, such as dracunculiasis , hookworm disease , elephantiasis , schistosomiasis , malaria and amoebiasis , cause unique and clear symptoms, which are why they are registered. The most described, of course, was dracunculiasis, mainly because an adult female worm emerges from the skin of the legs, and the strong irritation and ulcer caused by it cannot be simply ignored. This disease was mentioned by Hippocrates, Pliny the Elder , Galen , Aetius from Amida and Pavel Eginsky . Curiously, this disease was never noted in Greece, even though it was described in detail [6] .
The ancient Chinese mainly recorded diseases, not the parasites associated with them. Chinese texts, for example, contain references to hookworm, but do not trace any connection with hookworm [6] . Emperor Qin Shi Huandi recorded malaria in his text Ney Ching . This earliest known mention of malaria (2700 BC) lists chills, headaches and fever as the main symptoms, and distinguishes the disease from other types of fevers.
The Indian texts of Karak Samhit and Susrut Samhit highlight malaria and list its main symptoms - fever and enlarged spleen. [6] Brigu Samhita from 1000 BC e. contains the earliest allocation of amoebiasis as a disease with a sign of bloody diarrhea [6] .
Major parasites
Statistics and Pest Control
Tapeworms
In Berlin for the period 1866-1875 16% of all opened corpses contained worm larvae. Bull tapeworm (Taeniarhynchus saginatus) was especially common where raw cattle meat was eaten. In St. Petersburg , according to Kessler, 3.66% of the persons studied by him (1888) suffered from this tapeworm. Pork tapeworm (Taenia solium) is found everywhere where raw or semi-raw pork meat is eaten. In St. Petersburg at the end of the 19th century, about 3% of the population suffered from this parasite. When raw meat began to be avoided, the percentage of diseases dropped extremely — for example, in Denmark from 53% to 20% over 10-12 years. Dypilidium caninum lives in the intestines of dogs and cats and rarely in the intestines of children. Cases of infection of children at the end of the XIX century were known from England, Germany, Denmark - infection occurs exclusively when swallowing fleas.
Antiparasitic drugs
- Thiabendazole
- Pirantela Pamoat
- Mebendazole
- Praziquantel
- Niclosamide
- Bithionol
- Oksamikhin
- Ivermectin
- Albendazole
- Benznidazole
- Nifurtimox
- Metronidazole
Notes
- ↑ TSB , article “Parasitism”
- ↑ Medical Encyclopedia, article “Parasite”
- ↑ Karl Zimmer "Parasites: The Secret World", - M: Alpina non-fiction, 2011, P. 11. ISBN 978-5-91671-081-6
- ↑ ESBE , article “Parasitism”
- ↑ Krumhardt, Barbera, PhD. Human Parasites. 2008 Archived December 16, 2008.
- ↑ 1 2 3 4 5 6 7 8 (English) Cox, Francis EG PhD, DSc. “History of human parasitic diseases.” Infectious Disease Clinics of North America June 2004
Literature
- Knipovich N.M. Worms // Brockhaus and Efron Encyclopedic Dictionary : in 86 volumes (82 volumes and 4 additional). - SPb. , 1890-1907.