Parasitology is the study of parasites, their 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...

s, and the relationship between them. As a biological discipline, the scope of parasitology is not determined by the organism or environment in question, but by their way of life. This means it forms a synthesis of other disciplines, and draws on techniques from fields such as cell biology

Cell biology

Cell biology is a scientific discipline that studies cells – their physiological properties, their structure, the organelles they contain, interactions with their environment, their life cycle, division and death. This is done both on a microscopic and molecular level...

, bioinformatics

Bioinformatics

Bioinformatics is the application of computer science and information technology to the field of biology and medicine. Bioinformatics deals with algorithms, databases and information systems, web technologies, artificial intelligence and soft computing, information and computation theory, software...

, biochemistry

Biochemistry

Biochemistry, sometimes called biological chemistry, is the study of chemical processes in living organisms, including, but not limited to, living matter. Biochemistry governs all living organisms and living processes...

, molecular biology

Molecular biology

Molecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry...

, immunology

Immunology

Immunology is a broad branch of biomedical science that covers the study of all aspects of the immune system in all organisms. It deals with the physiological functioning of the immune system in states of both health and diseases; malfunctions of the immune system in immunological disorders ; the...

, genetics

Genetics

Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....

, 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 ecology

Ecology

Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...

.

Fields

The study of these diverse organism

Organism

In biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...

s means that the subject is often broken up into simpler, more focused units, which use common techniques, even if they are not studying the same organisms or diseases. Much research in parasitology falls somewhere between two or more of these definitions. In general, the study of prokaryote

Prokaryote

The prokaryotes are a group of organisms that lack a cell nucleus , or any other membrane-bound organelles. The organisms that have a cell nucleus are called eukaryotes. Most prokaryotes are unicellular, but a few such as myxobacteria have multicellular stages in their life cycles...

s falls under the field of bacteriology

Bacteriology

Bacteriology is the study of bacteria. This subdivision of microbiology involves the identification, classification, and characterization of bacterial species...

 rather than parasitology.

Medical parasitology

One of the largest fields in parasitology, medical parasitology is the subject which deals with the parasites that infect man, the diseases caused by them, clinical picture and the response generated by man against them. It's also concerned with the various methods of their diagnosis, treatment and finally their prevention & control.
A parasite is an organism that live on or within another organism called the host .
These include organisms such as:

• Plasmodium
  Plasmodium
  Plasmodium is a genus of parasitic protists. Infection by these organisms is known as malaria. The genus Plasmodium was described in 1885 by Ettore Marchiafava and Angelo Celli. Currently over 200 species of this genus are recognized and new species continue to be described.Of the over 200 known...
  
  spp., the protozoan parasite which causes malaria
  Malaria
  Malaria is a mosquito-borne infectious disease of humans and other animals caused by eukaryotic protists of the genus Plasmodium. The disease results from the multiplication of Plasmodium parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases...
  
  . The four species of malaria parasites infective to humans are Plasmodium falciparum,Plasmodium malariae, Plasmodium vivax & Plasmodium ovale.
• Leishmania donovani, the unicellular organism which causes 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...
  
  
• Entamoeba
  Entamoeba
  Entamoeba is a genus of Amoebozoa found as internal parasites or commensals of animals.In 1875, Fedor Lösch described the first proven case of amoebic dysentery in St Petersburg, Russia. He referred to the amoeba he observed microscopically as 'Amoeba coli'; however it is not clear whether he was...
  
  and Giardia
  Giardia
  Giardia is a genus of anaerobic flagellated protozoan parasites of the phylum Metamonada in the supergroup "Excavata" that colonise and reproduce in the small intestines of several vertebrates, causing giardiasis, commonly known as Beaver fever...
  
  , which cause intestinal infections (dysentery and diarrhoea)
• Multicellular organisms and worms such as Schistosoma
  Schistosoma
  A genus of trematodes, Schistosoma, commonly known as blood-flukes and bilharzia, includes flatworms which are responsible for a highly significant parasitic infection of humans by causing the disease schistosomiasis, and are considered by the World Health Organization as the second most...
  
  spp., Wuchereria bancrofti
  Wuchereria bancrofti
  Filaria, is a parasitic filarial nematode spread by a mosquito vector. It is one of the three parasites that cause lymphatic filariasis, an infection of the lymphatic system by filarial worms. It affects over 120 million people, primarily in Africa, South America, and other tropical and...
  
  , Necator americanus
  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...
  
  (hookworm) and Taenia
  Taeniasis
  Taeniasis is a form of tapeworm infection which is caused by tapeworms of the genius Taenia.The two most important human pathogens in the genus are Taenia solium and Taenia saginata . Infection is acquired by eating undercooked contaminated meat. The adult worms live in the lumen of the intestine...
  
  spp. (tapeworm)
• 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, scabies
  Scabies
  Scabies , known colloquially as the seven-year itch, is a contagious skin infection that occurs among humans and other animals. It is caused by a tiny and usually not directly visible parasite, the mite Sarcoptes scabiei, which burrows under the host's skin, causing intense allergic itching...
  
   and lice
  Louse
  Lice is the common name for over 3,000 species of wingless insects of the order Phthiraptera; three of which are classified as human disease agents...
  
  

Medical parasitology can involve drug

Medication

A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...

 development, epidemiological

Epidemiology

Epidemiology is the study of health-event, health-characteristic, or health-determinant patterns in a population. It is the cornerstone method of public health research, and helps inform policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive...

 studies and study of zoonoses

Zoonosis

A zoonosis or zoonoseis any infectious disease that can be transmitted from non-human animals to humans or from humans to non-human animals . In a study of 1415 pathogens known to affect humans, 61% were zoonotic...

.

Veterinary parasitology

The study of parasites that cause economic losses in agriculture

Agriculture

Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...

 or aquaculture

Aquaculture

Aquaculture, also known as aquafarming, is the farming of aquatic organisms such as fish, crustaceans, molluscs and aquatic plants. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the...

 operations, or which infect companion animals. Examples of species studied are:

• Lucilia sericata, a blowfly, which lays eggs on the skins of farm animals. The maggot
  Maggot
  In everyday speech the word maggot means the larva of a fly ; it is applied in particular to the larvae of Brachyceran flies, such as houseflies, cheese flies, and blowflies, rather than larvae of the Nematocera, such as mosquitoes and Crane flies...
  
  s hatch and burrow into the flesh, distressing the animal and causing economic loss to the farmer
• Otodectes cynotis, the cat
  Cat
  The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
  
   ear mite
  Ear mite
  Ear mites are mites that live in the ears of animals. The most commonly seen species is Otodectes cynotis .-Contagion:...
  
  , responsible for Canker.
• Gyrodactylus salaris, a monogenea
  Monogenea
  Monogenea are a group of largely ectoparasitic members of the flatworm phylum Platyhelminthes, class Monogenea.-Characteristics:Monogenea are very small parasitic flatworms mainly found on skin or gills of fish....
  
  n parasite of salmon
  Salmon
  Salmon is the common name for several species of fish in the family Salmonidae. Several other fish in the same family are called trout; the difference is often said to be that salmon migrate and trout are resident, but this distinction does not strictly hold true...
  
  , which can wipe out populations which are not resistant.

Structural parasitology

This is the study of structures of proteins from parasites. Determination of parasitic protein structures may help to better understand how these proteins function differently from homologous proteins in humans. In addition, protein structures may inform the process of drug discovery

Drug discovery

In the fields of medicine, biotechnology and pharmacology, drug discovery is the process by which drugs are discovered or designed.In the past most drugs have been discovered either by identifying the active ingredient from traditional remedies or by serendipitous discovery...

.

Quantitative parasitology

Parasites exhibit an aggregated distribution among host individuals, thus the majority of parasites live in the minority of hosts. This feature forces parasitologists to use advanced biostatistical methodologies.

Parasite ecology

Parasites can provide information about host population ecology. In fisheries biology

Fishery

Generally, a fishery is an entity engaged in raising or harvesting fish which is determined by some authority to be a fishery. According to the FAO, a fishery is typically defined in terms of the "people involved, species or type of fish, area of water or seabed, method of fishing, class of boats,...

, for example, parasite communities can be used to distinguish distinct populations of the same fish species co-inhabiting a region. Additionally, parasites possess a variety of specialized traits and life-history strategies that enable them to colonize hosts. Understanding these aspects of parasite ecology, of interest in their own right, can illuminate parasite-avoidance strategies employed by hosts

Conservation biology of parasites

Conservation biology

Conservation biology

Conservation biology is the scientific study of the nature and status of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction...

 is concerned with the protection and preservation of vulnerable species, including parasites. A large proportion of parasite species are threatened by extinction, partly due to efforts to eradicate parasites which infect humans or domestic animals, or damage human economy, but also caused by the decline or fragmentation of host populations and the extinction of host species.

Taxonomy and phylogenetics

The huge diversity between parasitic organisms creates a challenge for biologists who wish to describe and catalogue them. Recent developments in using DNA

DNA

Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...

 to identify separate species and to investigate the relationship between groups at various taxonomic

Taxonomy

Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...

 scales has been enormously useful to parasitologists, as many parasites are highly degenerate

Degeneracy

Degeneracy may refer to:* DegenerationIn science and mathematics:* Degeneracy , a property of quantum states sharing the same energy levels...

, disguising relationships between species.

See also

• List of publications in parasitology
• Parasitism
  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...
  
  
• Parasitologists

External links

• Online lectures in parasitology, University of South Carolina
  University of South Carolina
  The University of South Carolina is a public, co-educational research university located in Columbia, South Carolina, United States, with 7 surrounding satellite campuses. Its historic campus covers over in downtown Columbia not far from the South Carolina State House...
  
  
• Companion Animal Parasite Council
• American Society of Parasitologists
• ARC-NHMRC Research Network for Parasitology
• Australian Society for Parasitology
• British Society for Parasitology
• Chinese Society of Parasitology
• Czech Society for Parasitology
• European Scientific Counsel Companion Animal Parasites
• Hungarian Society of Parasitologists
• Indian Society of Parasitology
• Israel Society for Parasitology, Protozoology and Tropical Diseases
• Japanese Society of Parasitology
• Korean Society for Parasitology
• Nederlandse Vereniging voor Parasitologie
• New Zealand Society for Parasitology
• Scandinavian and Baltic Societies for Parasitology
• Department of Parasitology, Cluj-Napoca, Romania
• An Introduction to Parasitology
• Parasites World
• Institute of Parasitology, McGill University
  McGill University
  Mohammed Fathy is a public research university located in Montreal, Quebec, Canada. The university bears the name of James McGill, a prominent Montreal merchant from Glasgow, Scotland, whose bequest formed the beginning of the university...