Archaeoparasitology
Encyclopedia
Archaeoparasitology, a multi-disciplinary field within paleopathology
, is the study of parasites
in archaeological
contexts. It includes studies of the protozoa
n and metazoan
parasites of humans in the past, as well as parasites which may have affected past human societies, such as those infesting domesticated animals.
Reinhard suggested that the term "archaeoparasitology" be applied to "... all parasitological remains excavated from archaeological contexts ... derived from human activity" and that "the term 'paleoparasitology
' be applied to studies of nonhuman, paleontological material." (p. 233) Paleoparasitology includes all studies of ancient parasites outside of archaeological contexts, such as those found in amber
, and even dinosaur
parasites.
The first archaeoparasitology report described calcified eggs of Bilharzia haematobia (now Schistosoma haematobium)
from the kidneys of an ancient Egyptian mummy. Since then, many fundamental archaeological questions have been answered by integrating our knowledge of the hosts
, life cycles
and basic biology of parasites, with the archaeological
, anthropological
and historical
contexts in which they are found.
s are organisms which live in close association with another organism, called the host, in which the parasite benefits from the association, to the detriment of the host
. Many other kinds of associations may exist between two closely allied organisms, such as commensalism
or mutualism.
Endoparasites (such as protozoa
ns and helminths
), tend to be found inside the host, while ectoparasites (such as tick
s, lice and flea
s) live on the oustide of the host body. Parasite life cycles
often require that different developmental stages pass sequentially through multiple host species in order to successfully mature and reproduce. Some parasites are very host
-specific, meaning that only one or a few species of hosts are capable of perpetuating their life cycle. Others are not host-specific, since many different hosts appear to harbor and pass on the infective stages of the parasite.
Most archaeoparasitology reports involve species which are considered to be true parasites of humans today. However, incidental parasitism (referred to by some authors as "pseudoparasitism", "false parasitism" or "accidental parasitism") occurs when a parasite which does not normally utilize a host for the perpetuation of its lifecycle is found in that host incidentally. One example is finding the eggs of Cryptocotyle lingua (a fish parasite) in the stomach contents of an Eskimo mummy
. It is estimated that 70% of the "parasite" species reported from present-day humans are actually only incidental parasites. Some incidental parasites do cause harm to the infested pseudohosts.
s, or midden
s (dumps for domestic waste). A cyst of Echinococcus granulosus was even retrieved from cemetery soil in Poland. Ectoparasites may be found on the skin or scalp, as well as wigs, clothing, or personal grooming accessories found in archaeological sites. Ectoparasite eggs may be found attached to individual hairs. The International Ancient Egyptian Mummy Tissue Bank in Manchester, England, provides tissue samples for a variety of uses, including parasitological studies.
Since 1910, parasite remains have been found in archaeological samples from Africa, the Americas, Asia, Europe, the Middle East, and New Zealand. The age of archaeological sites yielding human parasite remains ranges from approx. 25,000-30,000 years ago to late 19th-early 20th century. Parasite remains have also been found in domestic animal remains at archaeological sites.
Human skeletal remains may exhibit indirect evidence of parasitism. For example, hookworm
(Ancyslostoma duodenale) parasitism may lead to anemia
, and anemia is one factor associated with the skeletal changes of cribra orbitalia and porotic hyperostosis
. Thus, hookworm parasitism may be a causal factor in observed cribra orbitalia and porotic hyperostosis, though dietary factors may also lead to anemia.
Information on the presence of intermediate hosts
, required for life cycle completion by many parasites, is also useful in determining the likelihood that a parasite may have infected a particular ancient society. One example is the identification of molluscan intermediate hosts of schistosomiasis
in an Islamic archaeological context.
Artifacts depicting the appearance of individuals may also indicate cases of parasitism. Examples include the characteristic facial deformities of leishmaniasis
found on pre-Columbian Mochica
pottery, and morphological features of certain ancient Egyptian figurative art
. Literary sources also provide valuable information regarding not only the parasites present in historic societies, but also the knowledge and attitudes that the people had towards their parasitic infestations. However, specific parasitological diagnoses reported in ancient and medieval texts must always be read with some degree of skepticism.
.
In cases where the intact bodies of parasites are not found, protein or DNA from the parasite may still be present. Antigenic and immunological assays (including enzyme-linked immunoassay - ELISA
,), and DNA sequencing
are used to identify the source of these chemical remains, often to the species level.
practices, cultural contacts, ethnomedicine, and the overall health of various human societies. Archaeoparasitology data, combined with our knowledge of present host-parasite associations, also contributes to our understanding of the co-evolution of human host-parasite interactions. Our understanding of the geographic origins, evolution
and biogeography
of the parasites themselves and human diseases associated with them has also benefitted tremendously from archaeoparasitological studies.
Paleopathology
Paleopathology, also spelled palaeopathology, is the study of ancient diseases. It is useful in understanding the past history of diseases, and uses this understanding to predict its course in the future.- History of paleopathology :...
, is the study of parasites
Parasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
in archaeological
Archaeology
Archaeology, or archeology , is the study of human society, primarily through the recovery and analysis of the material culture and environmental data that they have left behind, which includes artifacts, architecture, biofacts and cultural landscapes...
contexts. It includes studies of the protozoa
Protozoa
Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...
n and metazoan
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
parasites of humans in the past, as well as parasites which may have affected past human societies, such as those infesting domesticated animals.
Reinhard suggested that the term "archaeoparasitology" be applied to "... all parasitological remains excavated from archaeological contexts ... derived from human activity" and that "the term 'paleoparasitology
Paleoparasitology
Paleoparasitology is the study of parasites from the past, and their interactions with hosts and vectors; it is a subfield of Paleontology, the study of living organisms from the past. Some authors define this term more narrowly, as "Paleoparasitology is the study of parasites in archaeological...
' be applied to studies of nonhuman, paleontological material." (p. 233) Paleoparasitology includes all studies of ancient parasites outside of archaeological contexts, such as those found in amber
Amber
Amber is fossilized tree resin , which has been appreciated for its color and natural beauty since Neolithic times. Amber is used as an ingredient in perfumes, as a healing agent in folk medicine, and as jewelry. There are five classes of amber, defined on the basis of their chemical constituents...
, and even dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
parasites.
The first archaeoparasitology report described calcified eggs of Bilharzia haematobia (now Schistosoma haematobium)
Schistosoma haematobium
Schistosoma haematobium is an important digenetic trematode, and is found in the Middle East, India, Portugal and Africa. It is a major agent of schistosomiasis; more specifically, it is associated with urinary schistosomiasis....
from the kidneys of an ancient Egyptian mummy. Since then, many fundamental archaeological questions have been answered by integrating our knowledge of the hosts
Host (biology)
In biology, a host is an organism that harbors a parasite, or a mutual or commensal symbiont, typically providing nourishment and shelter. In botany, a host plant is one that supplies food resources and substrate for certain insects or other fauna...
, life cycles
Parasitic life cycles
Parasite life cycles can take a variety of forms, all involving the exploitation of one or more hosts. Those that must infect more than one host species to complete their life cycles are said to have complex or indirect life cycles, while those that infect a single species have direct life...
and basic biology of parasites, with the archaeological
Archaeology
Archaeology, or archeology , is the study of human society, primarily through the recovery and analysis of the material culture and environmental data that they have left behind, which includes artifacts, architecture, biofacts and cultural landscapes...
, anthropological
Anthropology
Anthropology is the study of humanity. It has origins in the humanities, the natural sciences, and the social sciences. The term "anthropology" is from the Greek anthrōpos , "man", understood to mean mankind or humanity, and -logia , "discourse" or "study", and was first used in 1501 by German...
and historical
History
History is the discovery, collection, organization, and presentation of information about past events. History can also mean the period of time after writing was invented. Scholars who write about history are called historians...
contexts in which they are found.
Parasitology basics
ParasiteParasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
s are organisms which live in close association with another organism, called the host, in which the parasite benefits from the association, to the detriment of the host
Host (biology)
In biology, a host is an organism that harbors a parasite, or a mutual or commensal symbiont, typically providing nourishment and shelter. In botany, a host plant is one that supplies food resources and substrate for certain insects or other fauna...
. Many other kinds of associations may exist between two closely allied organisms, such as commensalism
Commensalism
In ecology, commensalism is a class of relationship between two organisms where one organism benefits but the other is neutral...
or mutualism.
Endoparasites (such as protozoa
Protozoa
Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...
ns and helminths
Parasitic worm
Parasitic worms or helminths are a division of eukaryoticparasites that, unlike external parasites such as lice and fleas, live inside their host. They are worm-like organisms that live and feed off living hosts, receiving nourishment and protection while disrupting their hosts' nutrient...
), tend to be found inside the host, while ectoparasites (such as tick
Tick
Ticks are small arachnids in the order Ixodida, along with mites, constitute the subclass Acarina. Ticks are ectoparasites , living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians...
s, lice and flea
Flea
Flea is the common name for insects of the order Siphonaptera which are wingless insects with mouthparts adapted for piercing skin and sucking blood...
s) live on the oustide of the host body. Parasite life cycles
Parasitic life cycles
Parasite life cycles can take a variety of forms, all involving the exploitation of one or more hosts. Those that must infect more than one host species to complete their life cycles are said to have complex or indirect life cycles, while those that infect a single species have direct life...
often require that different developmental stages pass sequentially through multiple host species in order to successfully mature and reproduce. Some parasites are very host
Host (biology)
In biology, a host is an organism that harbors a parasite, or a mutual or commensal symbiont, typically providing nourishment and shelter. In botany, a host plant is one that supplies food resources and substrate for certain insects or other fauna...
-specific, meaning that only one or a few species of hosts are capable of perpetuating their life cycle. Others are not host-specific, since many different hosts appear to harbor and pass on the infective stages of the parasite.
Most archaeoparasitology reports involve species which are considered to be true parasites of humans today. However, incidental parasitism (referred to by some authors as "pseudoparasitism", "false parasitism" or "accidental parasitism") occurs when a parasite which does not normally utilize a host for the perpetuation of its lifecycle is found in that host incidentally. One example is finding the eggs of Cryptocotyle lingua (a fish parasite) in the stomach contents of an Eskimo mummy
Mummy
A mummy is a body, human or animal, whose skin and organs have been preserved by either intentional or incidental exposure to chemicals, extreme coldness , very low humidity, or lack of air when bodies are submerged in bogs, so that the recovered body will not decay further if kept in cool and dry...
. It is estimated that 70% of the "parasite" species reported from present-day humans are actually only incidental parasites. Some incidental parasites do cause harm to the infested pseudohosts.
Sources of material
In archaeological contexts, endoparasites (or their eggs or cysts) are usually found in (i) fossilized human or animal dung (coprolites), (ii) the tissues and digestive contents of mummified corpses, or (iii) soil samples from latrines, cesspitCesspit
A cesspit, or cesspool is a pit, conservancy tank, or covered cistern, which can be used to dispose of urine and feces, and more generally of all sewage and refuse. It is a more antiquated solution than a sewer system. Traditionally, it was a deep cylindrical chamber dug into the earth, having...
s, or midden
Midden
A midden, is an old dump for domestic waste which may consist of animal bone, human excrement, botanical material, vermin, shells, sherds, lithics , and other artifacts and ecofacts associated with past human occupation...
s (dumps for domestic waste). A cyst of Echinococcus granulosus was even retrieved from cemetery soil in Poland. Ectoparasites may be found on the skin or scalp, as well as wigs, clothing, or personal grooming accessories found in archaeological sites. Ectoparasite eggs may be found attached to individual hairs. The International Ancient Egyptian Mummy Tissue Bank in Manchester, England, provides tissue samples for a variety of uses, including parasitological studies.
Since 1910, parasite remains have been found in archaeological samples from Africa, the Americas, Asia, Europe, the Middle East, and New Zealand. The age of archaeological sites yielding human parasite remains ranges from approx. 25,000-30,000 years ago to late 19th-early 20th century. Parasite remains have also been found in domestic animal remains at archaeological sites.
Human skeletal remains may exhibit indirect evidence of parasitism. For example, hookworm
Hookworm
The hookworm is a parasitic nematode that lives in the small intestine of its host, which may be a mammal such as a dog, cat, or human. Two species of hookworms commonly infect humans, Ancylostoma duodenale and Necator americanus. A. duodenale predominates in the Middle East, North Africa, India...
(Ancyslostoma duodenale) parasitism may lead to anemia
Anemia
Anemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...
, and anemia is one factor associated with the skeletal changes of cribra orbitalia and porotic hyperostosis
Porotic hyperostosis
Porotic hyperostosis, also known as osteoporosis symmetrica, or Tara Grufferty syndrome is a disease that causes bone tissue to appear spongyand become soft...
. Thus, hookworm parasitism may be a causal factor in observed cribra orbitalia and porotic hyperostosis, though dietary factors may also lead to anemia.
Information on the presence of intermediate hosts
Host (biology)
In biology, a host is an organism that harbors a parasite, or a mutual or commensal symbiont, typically providing nourishment and shelter. In botany, a host plant is one that supplies food resources and substrate for certain insects or other fauna...
, required for life cycle completion by many parasites, is also useful in determining the likelihood that a parasite may have infected a particular ancient society. One example is the identification of molluscan intermediate hosts of schistosomiasis
Schistosomiasis
Schistosomiasis is a parasitic disease caused by several species of trematodes , a parasitic worm of the genus Schistosoma. Snails often act as an intermediary agent for the infectious diseases until a new human host is found...
in an Islamic archaeological context.
Artifacts depicting the appearance of individuals may also indicate cases of parasitism. Examples include the characteristic facial deformities of leishmaniasis
Leishmaniasis
Leishmaniasis is a disease caused by protozoan parasites that belong to the genus Leishmania and is transmitted by the bite of certain species of sand fly...
found on pre-Columbian Mochica
Moche
'The Moche civilization flourished in northern Peru from about 100 AD to 800 AD, during the Regional Development Epoch. While this issue is the subject of some debate, many scholars contend that the Moche were not politically organized as a monolithic empire or state...
pottery, and morphological features of certain ancient Egyptian figurative art
Figurative art
Figurative art, sometimes written as figurativism, describes artwork—particularly paintings and sculptures—which are clearly derived from real object sources, and are therefore by definition representational.-Definition:...
. Literary sources also provide valuable information regarding not only the parasites present in historic societies, but also the knowledge and attitudes that the people had towards their parasitic infestations. However, specific parasitological diagnoses reported in ancient and medieval texts must always be read with some degree of skepticism.
Techniques and methods
Parasite remains in archaeological samples are identified by a variety of techniques. Very durable remains, such as eggs and cysts, may remain intact for many thousands of years. In some cases, relatively intact soft-bodied adult helminths and ectoparasitic arthropods have been found. All of these forms can be identified to the family, genus or species level by compound or electron microscopyMicroscopy
Microscopy is the technical field of using microscopes to view samples and objects that cannot be seen with the unaided eye...
.
In cases where the intact bodies of parasites are not found, protein or DNA from the parasite may still be present. Antigenic and immunological assays (including enzyme-linked immunoassay - ELISA
ELISA
Enzyme-linked immunosorbent assay , is a popular format of a "wet-lab" type analytic biochemistry assay that uses one sub-type of heterogeneous, solid-phase enzyme immunoassay to detect the presence of a substance in a liquid sample."Wet lab" analytic biochemistry assays involves detection of an...
,), and DNA sequencing
DNA sequencing
DNA sequencing includes several methods and technologies that are used for determining the order of the nucleotide bases—adenine, guanine, cytosine, and thymine—in a molecule of DNA....
are used to identify the source of these chemical remains, often to the species level.
Fundamental questions
Archaeoparasitological studies have provided information on many fundamental archaeological, historical, and biogeographical questions. These questions may be grouped into the following broad categories: past dietary and farming practices, animal domestication, migration patterns, climate change, sanitarySanitation
Sanitation is the hygienic means of promoting health through prevention of human contact with the hazards of wastes. Hazards can be either physical, microbiological, biological or chemical agents of disease. Wastes that can cause health problems are human and animal feces, solid wastes, domestic...
practices, cultural contacts, ethnomedicine, and the overall health of various human societies. Archaeoparasitology data, combined with our knowledge of present host-parasite associations, also contributes to our understanding of the co-evolution of human host-parasite interactions. Our understanding of the geographic origins, evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...
and biogeography
Biogeography
Biogeography is the study of the distribution of species , organisms, and ecosystems in space and through geological time. Organisms and biological communities vary in a highly regular fashion along geographic gradients of latitude, elevation, isolation and habitat area...
of the parasites themselves and human diseases associated with them has also benefitted tremendously from archaeoparasitological studies.