Acari

(syn. Acaria, Acarina, Acarida) Subclass of Arachnida, includes ticks.

Acaricide

A chemical that will kill ticks and mites.

Adenopathy

A general term for glandular disease.

African Tick Typhus

(syn. Boutonneuse fever, Fièvre boutonneuse) One of the tick-borne rickettsial diseases of the eastern hemisphere, similar to Rocky Mountain spotted fever, but less severe.

Agarose

Polysaccharide created by purifying agar (extract from red algae). When it is heated and cooled, it forms a gel that is used as a support for many types of electrophoresis and immunodiffusion.

Amblyomma americanum

The Lone star tick. Receives its common name from the silvery spot on the apex of the scutum of the female. Most commonly found on large animals such as cattle, horses, deer, and dogs. A three-host tick that transmits the agents of Rocky Mountain spotted fever, babesiosis, and tularaemia to man and dogs. Potential vector of Borrelia burgdorferi (Lyme disease).

American dog tick

Dermacentor variabilis. The common name is given to it because this tick is the most widely distributed tick species in North America that commonly attacks the dog. In the southeastern and eastern United States, this tick is the primary vector of Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever in dogs and humans.

Anal grooves

In ixodid ticks, a groove adjacent to the anus. In species of the genus Ixodes, the anal groove originates on or near the posterior body margin and surrounds the anus anteriorly; in other hard ticks, the anal groove is smaller and lies posterior to the anus.

Anaplasma marginale

Tiny bacterium that infects the host animal's red blood cells, causing severe anaemia or even death.

Anaplasmosis

Bacterial disease transmitted by ticks, which causes severe anaemia and even death in the host animal that lacks immunity.

Antigenic

Having the properties of an antigen.

Arachnida

The class Arachnida includes spiders, scorpions, mites, ticks etc. Larval stages of ticks normally have three pairs of legs, the nymphs and adults have four pairs of legs. The mouthparts (palps, chelicerae and hypostome) together with the basis capituli form a capitulum or gnathosome.

Areae porosae

Clusters of tiny depressions on the dorsal surface of the basis capituli in ixodid females.

Argasidae

Family of soft ticks. Small family of 140 species belonging to four genera: Argas, Ornithodoros, Otobius, Antricola. Argasids live in nests, burrows, buildings, and sleeping places of their host animals.

Arthritis

An inflammatory condition that affects joints.

Arthropoda

Zoological phylum of ticks and mites. Besides ticks and mites, insects and crustaceans also belong to this phylum.

Arthroscopic

Direct visualisation of internal structures by the introduction of a thin fibreoptic scope into a joint space.

Asplenic

Having no spleen.

Atrioventricular

Pertaining to an atrium of the heart and to a ventricle.

Autoagglutination

The clumping together of an individual's red blood cells (erythrocytes) in his own serum, as a consequence of specific autoantibodies.

Autoantibodies

Antibodies (immunoglobulin molecules) that react with antigens that are normal components of the body.

Axial filaments

The central filaments of a flagellum or cilium. With the electron microscope it is seen as a complex of nine peripheral diplomicrotubules and a central pair of microtubules.

Babesia

Intraerythrocytic protozoan parasite. The classification of the genus Babesia is complex, and is currently undergoing change as the various species and subspecies are characterized using molecular technology.

Babesia canis

Intraerythrocytic protozoan parasite, which occurs singly or paired within the cells. Rhipicephalus sanguineus (Brown dog tick) is the primary vector. The B. canis complex formerly comprised three distinct subspecies with varying pathogenicity, which meanwhile are considered separate species: B. rossi, the prevalent strain in South Africa, which causes severe clinical disease; B. canis, the principle cause of babesiosis in Europe, which is moderately pathogenic, and B. vogeli, which causes relatively mild disease worldwide.

Babesia microti

Intraerythrocytic protozoan parasite, which is the most common cause of babesiosis in the USA. Voles are the principal natural reservoir of B. microti, and deer ticks of the family Ixodidae are the usual vectors.

Babesiosis

Malaria-like tick-borne disease with haemolytic anaemia caused by intraerythrocytic protozoan parasites of the genus Babesia. In the USA, B. microti is the most common cause of a mild human babesiosis. B. divergens transmitted by different ticks causes severe human babesiosis in some parts of Europe. Canine babesiosis is caused by three different species, which were formerly categorized as subspecies of B. canis (B. rossi in South Africa, B. canis in Europe, B. vogeli worldwide), and increasingly by B. gibsoni, which is extending its range in the USA and Europe.

Bacteria

Extremely small, unicellular microorganisms that multiply by cell division, possess circular DNA, have no internal membranes, and whose cell is typically contained within a cell wall. They are found in virtually all environments; some types cause diseases in humans and animals.

Bactericidal

Capable of killing bacteria.

Bartonellosis

A disease, endemic in certain valleys of the Andes in Peru, Chile, Ecuador, Bolivia, and Colombia, caused by Bartonella bacilliformis which is transmitted by the bite of the nocturnally biting sand fly, Phlebotomus verrucarum. Serum of some dogs seroreacts with B. henselae and B. clarridgeiae antigens; these Bartonella spp. are transmitted by fleas. Dogs infected with a Bartonella spp. are commonly coinfected with other agents like Ehrlichia spp. which may play a role in the pathogenesis of disease. Clinical findings or syndromes most frequently attributed to Bartonella spp.infections of dogs include endocarditis, fever, arrhythmias, hepatitis, granulomatous lymphadenitis, cutaneous vasculitis, rhinitis, polyarthritis, meningoencephalitis, thrombocytopenia, eosinophilia, monocytosis, immune-mediated haemolytic anaemia, epistaxis, and uveitis.

Basis capituli

The basal ring of cuticle to which the palps, chelicerae and hypostome are attached. The basis capituli may be moved in the dorso-ventral plane, and articulates with the body proper.

bid

bis in die - twice daily.

Biopsy

Procedure that involves obtaining a tissue specimen for microscopic analysis to establish a precise diagnosis. Biopsies can be accomplished with a biopsy needle (passed through the skin into the organ in question) or by open surgical incision.

Blacklegged (deer) tick

Ixodes (dammini) scapularis. The common name of this tick (deer tick) is given to it because the white-tailed deer was the first host that was identified to be infested with this new tick species. Adult ticks prefer to feed on large mammals such as deer, dogs, horses, and humans. A three-host tick. The deer or blacklegged tick plays an especially important role in the maintenance and spread of Borrelia burgdorferi among wild and domestic animals.

Borrelia

Bacterial genus included in the family Spirochaetaceae, and order Spirochaetales. The spirochete isolated from ticks and humans was described as Borrelia burgdorferi by Johnson, et al. in 1984. Canine borreliosis is transmitted by ticks of the genus Ixodes. There are at least 52 Borrelia species, including 21 in the Lyme borreliosis (LB) group.

Borrelia burgdorferi

Species of the bacterial family Spirochaetaceae, order Spirochaetales. Researchers isolated spirochetes from the blood of Lyme disease patients and from adult Ixodes scapularis. I. scapularis spirochetes were recognized as a new species and named Borrelia burgdorferi.

Boutonneuse fever

(syn. Fièvre boutonneuse, African tick typhus) One of the tick-borne rickettsial diseases of the eastern hemisphere, similar to Rocky Mountain spotted fever, but less severe.

Brown dog tick

Larvae, nymphs, and adults of Rhipicephalus sanguineus all feed on dogs and sometimes on man. Originally a tropical species, the Brown dog tick has taken advantage of central heating to spread into temperate zones, where it often generates enormous populations in homes, kennels, and veterinary hospitals; it cannot survive the winter outdoors in the north. R. sanguineus transmits canine piroplasmosis/babesiosis (Babesia canis) and tropical canine pancytopenia (Ehrlichia canis) interstadially.

Burgdorfer

In 1982, Dr. Willy Burgdorfer isolated a treponema-like spirochete from the midgut of adult Ixodes scapularis and suggested that this organism may be involved in the aetiology of Lyme disease.

Canine babesiosis

Malaria-like tick-borne disease of canids with haemolytic anaemia caused by the intraerythrocytic protozoan parasites Babesia canis, Babesia rossi, Babesia vogeli and increasingly by Babesia gibsoni. Although babesiosis primarily affects erythrocytes, it can result in multi-organ dysfunction. The disease is classified as either uncomplicated or complicated. Common complications include acute renal failure, acute respiratory distress syndrome, hepatopathy, haemoconcentration, cerebral babesiosis, and immune-mediated haemolytic anaemia. Canine Babesia species are found in Asia, Europe, North America and North and East Africa.

Canine ehrlichiosis

Canine ehrlichiosis is an acute to chronic infectious disease caused by the bacterium Ehrlichia canis (named after its discoverer, the German doctor Paul Ehrlich) and is endemic in the tropics, subtropics and in the Mediterranean. The pathogen affects the white blood cells, especially monocytes and lymphocytes. The disease was first observed in a dog in Algeria in 1935.

Capitulum

The movable anterior extension of the body which includes the palps and mouthparts. Homologous to the gnathosoma of other acarines.

Cardiomegaly

The enlargement of the cardiac muscle.

Carditis

Inflammation of the heart, including pericarditis, myocarditis and endocarditis, according to whether the enveloping outer membrane, the muscle or the inner lining is affected.

Castor bean tick

Ixodes ricinus, the castor bean or sheep tick, is the most common tick in northern Europe. The castor bean tick transmits the pathogens Babesia divergens and B. bovis, which cause Redwater fever. It also transmits Anaplasma marginale, which causes anaplasmosis in cattle and sheep. It acquired a new significance when in 1983 Burgdorfer identified I. ricinus as a vector of Lyme disease. Tick paralysis can also arise from its bite.

Cell wall

In gram-positive bacteria a thick layer of peptidoglycan containing teichoic and lipoteichoic acid complexed to the peptidoglycan layer; in gram-negative bacteria a thin layer of peptidoglycan covered by an outer membrane of lipoprotein and lipopolysaccharide containing endotoxin.

Cephalosporins

A class of tetracyclic triterpene broad-spectrum antibiotics, containing the beta-lactam moiety thia-azabicyclo-octane-carboxylic acid; they are effective against gram-positive bacteria.

Chelicerae

The first pair of appendages of ticks and other arachnids. The tick chelicerae consist of 3 segments, the cheliceral bases located within the basis capituli, the cheliceral shafts that originate within the basis capituli and extend anteriorly, and the cheliceral digits that bear the denticles.

Chelicerata

Subphylum of arthropoda, including the class Arachnida.

Chemosensilla

Sensory organs that detect chemical substances. Two major categories are known: olfactory sensilla and gustatory sensilla (smell, and taste).

Chromosome

A self-replicating genetic structure in cells containing cellular DNA that bears in its nucleotide sequence the linear array of genes.

Coagulopathy

A defect in the blood clotting mechanism.

Coombs' test

Haemagglutination test in which Coombs' reagent (antiglobulin, or anti-human globulin rabbit immune serum) is added to detect incomplete (non-agglutinating, univalent, blocking) antibodies coating erythrocytes.

Coxae

The basal segment of each leg that articulates with the body and to which body muscles attach. The leg coxae are only slightly movable.

Cultivation

To grow cells in an artificial environment.

Cuticle

Dead, outer part of the integument. It is secreted by the epidermis which forms the inner, living part of the integument.

CVBD – Companion Vector-Borne Diseases

Vector-borne diseases are defined as the diseases which are commonly transmitted through vectors. "Vector" is a term used broadly to refer to any animal that transmits disease pathogens or plays an essential role in the parasite’s life cycle. Especially those vector-borne diseases affecting dogs and cats (CVBD, companion vector-borne diseases), are transmitted by a variety of blood-feeding arthropods. Examples are Lyme disease, Rocky Mountain spotted fever, ehrlichiosis, babesiosis (transmitted by ticks), canine bartonellosis (transmitted by fleas), leishmaniosis (sand flies) or West Nile virus infection (mosquitoes).

Cytokine

A small protein or biological factor that is released by cells and has specific effects on cell-cell interaction, communication and behaviour of other cells. Cytokines differ from classical hormones in that they are not produced by specialised glands.

Cytoplasm

The entire contents of a cell exclusive of that of the nucleus; it consists of a continuous aqueous solution (cytosol) and the organelles and inclusions suspended in it and is the site of most of the chemical activities of the cell.

Deer tick

Ixodes (dammini) scapularis. The common name deer tick is given to it because the white-tailed deer was the first host that was identified to be infested with this new tick species. Alternative name: Blacklegged tick. Adult ticks prefer to feed on large mammals such as deer, dogs, horses, and humans. A three-host tick. The deer or blacklegged tick plays an especially important role in the maintenance and spread of Borrelia burgdorferi among wild and domestic animals.

Dermacentor variabilis

The common name American dog tick is given to it because this tick is the most widely distributed tick species in North America that commonly attacks dogs. In the southeastern and eastern United States, this tick is the primary vector of Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever in dogs and humans.

Diapause

Diapause is a neurohormonally mediated dynamic state of low metabolic activity, which may be manifested in the form of delayed morphogenesis, increased resistance to environmental extremes, and reduced behavioural activity. Animals enter diapause in response to external stimuli that signal the onset of adverse environmental conditions.
Two types of diapause occur in ticks: behavioural (host-seeking) diapause and morphogenetic (developmental) diapause.

Discs

Flattened depressions, usually subcircular in appearance, with a smooth or mottled surface, representing the sites of dorso-ventral muscle attachments. Usually arranged in distinct patterns.

Ectoparasites

Insects or acarides that live temporarily or permanently on the skin or hair of an animal or human.

Ehrlichia

Bacterial genus currently classified as a member of the family Anaplasmataceae, in the order Rickettsiales. The gram-negative Ehrlichia primarily invade leukocytes, the same cells which fight disease by destroying microorganisms that enter the body. Members of the Ehrlichia are implicated as pathogens of dogs, cats, cattle, horses and humans.

Encephalitides

Inflammations of the brain.

Encephalitis

Inflammation of the brain.

Encephalopathy

Any degenerative disease of the brain.

Endemic

Present or usually prevalent in a population or geographical area at all times, said of a disease or agent.

Endocytosis

Uptake of material into a cell by vesicles that originate as pinched off invaginations of the plasma membrane.

Enzyme-linked immunosorbent assay

(abbr. ELISA) A serologic test that links a measurable enzyme to either an antigen or antibody. In this way, it can then measure the presence of an antibody or an antigen in the serum.

Epidemiologic

Relating to or involving epidemiology, the science concerned with the study of factors determining and influencing disease, injury, and other health-related events and their causes in a defined population.

Epidemiology

Science concerned with the study of factors determining and influencing disease, injury, and other health-related events and their causes in a defined population.

Erythema chronicum migrans

The classic initial rash of Lyme disease. In the early phase of the illness, within hours to weeks of the tick bite, the local skin develops an expanding ring of unraised redness. There may be an outer ring of brighter redness and a central area of clearing.

Erythrocyte

A red blood cell, specialised for oxygen transport, having a high concentration of haemoglobin in the cytoplasm. Biconcave, anucleate discs, 7nm diameter, nucleus contracted.

Erythrophagocytosis

Uptake of red blood cells into cells of the immune system by vesicles that originate as pinched off invaginations of their plasma membrane.

External parasites

Insects or acarides that live temporarily or permanently on the skin or hair of an animal or human.

Family

A taxonomic classification between genus and order.

Femur

The third segment of the insect leg, beyond the trochanter and before the tibia.

Fibromyalgia

A disorder characterised by muscle pain, stiffness and easy fatigability.

Flagella

(sg. flagellum) In bacteria, whip-like motility appendages present on the surface of some species. Flagella are composed of a protein called flagellin. Bacteria can have a single flagellum, a tuft at one pole, or multiple flagella covering the entire surface. In eukaryotes, flagella are thread-like protoplasmic extensions used to propel flagellates and sperm. Eukaryotic flagella have the same basic structure as cilia, but are longer and present in much smaller numbers.

Flagellin

Subunit protein (40 kD) of the bacterial flagellum.

Flavivirus

A genus of Flaviviridae (a family of single-stranded RNA-containing viruses that cause haemorrhagic fever in a wide range of mammals), also known as group b arbovirus, containing several subgroups and species. They are transmitted by mosquitoes or ticks.

Gangrene

Death of tissue, usually in considerable mass and generally associated with loss of vascular supply and followed by bacterial invasion and putrefaction.

Gene

Unit of inheritance that occupies a specific locus on a chromosome, the existence of which can be confirmed by the occurrence of different allelic forms. Given the occurrence of split genes, it might be redefined as the set of DNA sequences (called exons) that are required to produce a single polypeptide.

Genome

The total set of genes carried by an individual or cell.

Genomic

Relating to a genome (the total set of genes carried by an individual or cell).

Genus

Taxonomic level that includes closely related species. Interbreeding between organisms within the same genus can occur.

Gnathosoma

The mouthparts of ticks (palps, chelicerae and hypostome) together with the basis capituli form a capitulum or gnathosome.

Gram-negative

Characteristic staining property of bacteria with a cell wall consisting of a thin layer of peptidoglycan covered by an outer membrane of lipoprotein and lipopolysaccharide. Gram-negative bacteria either do not stain or are decolourised by alcohol during Gram's method of staining.

Gram-positive

Characteristic staining property of bacteria with a cell wall consisting of a thick layer of peptidoglycan containing teichoic and lipoteichoic acid complexed to the peptidoglycan layer. Gram-positive bacteria retain the stain or are resistant to decolourisation by alcohol during Gram's method of staining.

Granulocyte

Leukocyte with a variable-shaped nucleus and a cytoplasm possessing enzyme-containing granules. There are three types: neutrophils, eosinophils, and basophils. These cells are involved in the immune defence against pathogens, parasites, and allergens.

Gravity sensilla

There is uncertainty on whether wind and gravity sensilla represent a distinct subclass. They are very fine, long hairs such as those found on the cerci of cockroaches and crickets. They are extremely sensitive to air movements. Their axons project into intermediate neuropil, the same region where proprioceptive axons terminate in the CNS.

Gustatory sensilla

Category of chemosensilla. These may occur setiform, usually with a single pore at the tip, or associated with cuticular pores.

Haematocrit

Relative volume of blood occupied by erythrocytes.

Haemobartonellosis

An acute or chronic disease occurring in cats as well as in dogs caused by haemotrophic/hemotropic mycoplasmas, also denominated haemoplasmas (hemoplasmas).

Haemoglobinuria

Haemoglobin in the urine.

Haemolysis

Disruption of the integrity of the red cell membrane causing release of haemoglobin.

Haemolytic

Destructive to blood cells, resulting in liberation of haemoglobin.

Haemolytic anaemia

Anaemia resulting from reduced red cell survival time and haemolysis.

Haller's organ

A sensory structure of the dorsal surface of the tarsus of leg I; present in all post-embryonic stages of all species of ticks.

Hard tick

Family Ixodidae. Members of this family have a shield or scutum that covers the entire dorsal surface of the male but only part of the dorsal surface of the female. Ixodids usually live outdoors and attach to passing host animals.

Haemoglobinuria

Haemoglobin in the urine.

Hepatosplenomegaly

Abnormal enlargement of both the liver and the spleen.

Host

An organism that is infected with or is fed upon by a parasitic or pathogenic organism.

Hunter's disease

Tularaemia. Francisella tularensis causes the infectious disease tularaemia (rabbit fever, deer fly fever, Ohara's disease), most commonly in people who handle infected wild rabbits. Other infected animals, ticks, or contaminated food or water also transmit the pathogen. The symptoms, high fever and severe institutional distress, appear suddenly within 10 days of exposure. One (or more) ulcerating lesions develop at the site of infection, such as the arm, eye, or mouth. The regional lymph nodes enlarge, suppurate, and drain. Pneumonia, meningitis, or peritonitis may complicate the infection, which mortality rate is about six percent.

Hyponatraemia

Low sodium level in the blood.

Hypostome

The median ventral extension of the basis capituli, between the palps, and covered with recurved teeth on its ventral surface; with a pronounced preoral canal (=hypostomal gutter) on its dorsal surface.

Idiosoma

Formed by the podosoma (leg-bearing portion) and the opisthosoma (portion behind the legs) of acarines. Assumed functions parallel to those of the abdomen, thorax and portions of the head in insects.

IFA

Indirect immunofluorescence assay. A laboratory test used to detect antibodies to an organism in serum or other body fluid. The specific antibodies are labelled with a compound that glows when observed microscopically under ultraviolet light.

Immunocompetent

Able to recognise and act against invading antigens.

Immunostaining

Laboratory process of detecting an organism in tissues with antibodies. These antibodies are labelled with a compound that is seen as a coloured deposit when viewed microscopically.

Inclusion bodies

Nuclear or cytoplasmic structures with characteristic staining properties, usually found at the site of virus multiplication.

Incubation period

Interval of time between infection by a microorganism and the onset of the illness or the first symptoms of the illness.

Indirect immunofluorescence assay

A laboratory test used to detect antibodies to an organism in serum or other body fluid. The specific antibodies are labelled with a compound that glows when observed microscopically under ultraviolet light.

Integument

The integument is composed of the epidermis and the cuticle.

Ixodes dammini

Ixodes scapularis. The common name deer tick is given to it because the white-tailed deer was the first host that was identified to be infested with this new tick species. Alternative name: Blacklegged tick. Adult ticks prefer to feed on large mammals such as deer, dogs, horses, and humans. A three-host tick. The deer or blacklegged tick plays an especially important role in the maintenance and spread of Borrelia burgdorferi among wild and domestic animals.

Ixodes ricinus

The castor bean or sheep tick is the most common tick in northern Europe. The castor-bean tick transmits the pathogen Babesia divergens and B. bovis, which cause Redwater fever. It also transmits Anaplasma marginale, which causes anaplasmosis in cattle and sheep. It acquired a new significance when in 1983 Burgdorfer identified I. ricinus as a vector of Lyme disease. Tick paralysis can also arise from its bite.

Ixodes scapularis

Ixodes dammini. The common name deer tick is given to it because the white-tailed deer was the first host that was identified to be infested with this new tick species. Alternative name: Blacklegged tick. Adult ticks prefer to feed on large mammals such as deer, dogs, horses, and humans. A three-host tick. The deer or blacklegged tick plays an especially important role in the maintenance and spread of Borrelia burgdorferi among wild and domestic animals.

Ixodidae

Family of hard ticks. Members of this family have a shield or scutum that covers the entire dorsal surface of the male but only part of the dorsal surface of the female. Ixodids usually live outdoors and attach to passing host animals.

No entry

Kennel tick

The brown dog tick or kennel tick Rhipicephalus sanguineus is one of the most widely distributed ticks on the world. Originally a tropical species, the brown dog tick has taken advantage of central heating to spread into temperate zones, where it often generates enormous populations in homes, kennels, and veterinary hospitals; it cannot survive the winter outdoors in the north. R. sanguineus transmits canine piroplasmosis/babesiosis (Babesia canis) and tropical canine pancytopenia (Ehrlichia canis) interstadially.

Lamellae

Region which consists of non-sclerotized protein and chitin in a protein matrix.

Leg segments

The legs of ticks are jointed and divided into seven segments: coxa, trochanter, femur, patella, tibia, tarsus and pretarsus.

Leishmaniosis

Leishmanioses are a group of zoonotic diseases transmitted to humans and animals by the bite of phlebotomine sand flies. The diseases are named after Sir William Boog Leishman, Director General Army Medical Services 1923-1926. The diseases are caused by intracellular parasitic protozoa. Worldwide, they are the third most important vector-borne disease (after malaria and sleeping sickness) and present as a large variety of disease manifestations differing markedly in their severity and health impact. Two types of leishmanioses can broadly be distinguished: 1. Zoonotic leishmanioses, in which the reservoir hosts are wild, commercial or domestic animals and 2. Anthroponotic leishmanioses, in which the reservoir is man. Clinical manifestation of the disease depends on the type of leishmaniosis, which could be life-threatening systemic infection (visceral), chronic skin sores (cutaneous), or dreaded metastatic complications, which cause facial disfigurement (mucosal).

Lesion

Any pathological or traumatic discontinuity of tissue or loss of function of a part.

Leukocyte

Generic term for a white blood cell.

Leukopenia

Abnormal decrease in the number of white blood cells.

Lone star tick

Receives its common name from the silvery spot on the apex of the scutum of the female. Amblyomma americanum is most commonly found on large animals such as cattle, horses, deer, and dogs. A three-host tick that transmits the agents of Rocky Mountain spotted fever, babesiosis, and tularaemia to humans and dogs. Potential vector of Borrelia burgdorferi (Lyme disease).

Louping ill

An acute tick-borne arbovirus infection causing meningoencephalomyelitis of sheep.

Lyme disease

A tick-transmitted, inflammatory disorder causing a rash that may be followed weeks to months later by neurologic, cardiac, or joint abnormalities. The disease was first identified in Lyme, Connecticut in 1975. Lyme disease is also found abroad in Germany and Scandinavia, as well as China, and Asia to Australia. Lyme disease or Lyme borreliosis is caused by the spirochete Borrelia burgdoferi, a spiral shaped bacterium. It is most commonly transmitted by the black-legged deer tick Ixodes scapularis, the lone star tick Amblyomma americanum, the castor bean tick Ixodes ricinus or Ixodes pacificus.

Lymphadenopathy

Swelling of the lymph nodes.

Lypmhocyte

Leukocyte with a large round nucleus and usually a small cytoplasm. Specialized types of lymphocytes have enlarged cytoplasms and produce antibodies. Other specialized lymphocytes are important in cellular immune responses.

Mammillae

Minute conical or truncated integumental elevations covering the body surface and legs in Ornithodoros ticks. Distinct from tubercles, or granulations found in other argasid species.

Mechanosensilla

Mechanosensilla are sensilla that contain neurotubular cytoskeletons. They respond to physical contact, i.e. touch.

Meningoencephalitis

Inflammation of both the brain and meninges (surrounding membranes of the brain and spinal cord).

Mesozoic

The time of the "middle life" or "the age of the reptiles" that was divided into three periods (Triassic, Jurassic, and Cretaceous); this era lasted 110 million years and was known as the time when the dinosaurs rose to dominance.

Microclimate

The physical environmental condition confined to a very small area or location, i.e. the microclimate of a woodland dormouse hole, wild dog den or termite mound.

Monocyte

Leukocyte with a large, usually kidney-shaped nucleus. Within tissues, monocytes develop into macrophages which ingest bacteria, dead cells, and other debris.

Nephritis

Inflammation of the kidney, a focal or diffuse proliferative or destructive process which may involve the glomerulus, tubule or interstitial renal tissue.

Neurilemma

Connective tissue sheath, covering the synganglion and all peripheral nerves of ticks.

Neutropenia

Leukopenia in which the decrease in white blood cells is chiefly in neutrophils.

Nitric oxide

Potent vasorelaxant that acts via elevation of intracellular cGMP in vascular smooth muscle.

NSAIDs

Non-steroidal anti-inflammatory drugs. A large group of anti-inflammatory agents that work by inhibiting the production of prostaglandins. They exert anti-inflammatory, analgesic and antipyretic actions.

Nucleus

The major organelle of eukaryotic cells, in which the chromosomes are separated from the cytoplasm by the nuclear envelope.

Odocoileus virginianus

White-tailed deer, the most commonly infested mammalian species of the blacklegged or deer tick (Ixodes scapularis/Ixodes dammini).

Olfaction

Smell (or olfaction) allows vertebrates and other organisms with olfactory receptors to identify food, mates, predators, etc. For both humans and animals, it is one of the important means by which our environment communicates with us. Olfaction is one modality by which ticks locate a blood meal. Major function of Haller's organ.

Olfactory sensilla

Category of chemosensilla. The pores are plugged with a cap-like structure. These pores are filled with an unknown material believed to be continuous with a film over the sensilla surface.

Opisthosoma

Portion behind the legs of acarines.

Order

A taxonomic classification between class and family.

Ornate

Symmetrical colour patterns in the sclerotized cuticle, usually iridescent, and confined to the scutum and/or the dorsum of the basis capituli of some ixodid ticks

OspA

Outer surface protein A.

OspB

Outer surface protein B.

Paleozoic

The time of "ancient life" and "the age of fishes and invertebrates" that was divided into six periods; this era came before the Mesozoic Era and lasted 352 million years.

Palps

The second pair of appendages, normally with 4 segments termed articles. Article I articulates with the basis capituli. In argasids, article I is elongated, about as long as articles II and III, and moveable. In ixodids, article I is usually immobile and shorter than articles II and III. Articles II and III vary in length, are almost always the longest segments in the palps, and are more flexible. Article IV is terminal in argasid ticks, but recessed in a cavity on the ventral side of article III in most ixodid ticks.

Parasite

An organism which obtains food and shelter from another organism.

Parasitaemia

The presence of parasites in the blood.

Parasites

Organisms which obtain food and shelter from another organism.

Patella

Segment of the tick's leg.

Pathogen

Any disease-causing microorganism.

Pathogenicity

The ability of a pathogen or parasite to inflict damage on the host.

PCR

Polymerase chain reaction. A system for in vitro amplification of DNA. Since the original DNA needs to be neither pure nor abundant, PCR has become widely used in research, in clinical diagnostics and forensic science.

Pedipalps

In ticks, one pedipalp (normally shortened to palp) is situated on either side of the subcapitulum and compromises four segments, termed articles, which are conventionally denoted I to IV.

Penicillins

A group of antibiotics that contain 6-aminopenicillanic acid with a side chain attached to the 6-amino group. The side chain structure determines many of the antibacterial and pharmacological characteristics.

Peptidoglycan

Cross linked polysaccharide peptide complex found in the inner cell wall of all bacteria (50% of the wall in gram-negative, 10% in gram-positive bacteria).

Perineurium

Thin layer of glial cells.

Periplasmic space

Region between the plasma membrane and the cell wall of gram-negative bacteria.

Peritreme

Slender channel, element of the respiratory system.

Peromyscus leucopus

White-footed mouse, is the principal host for ticks in the Northeast and upper Midwest of the United States and is a competent reservoir for the spirochete.

Phagosome

A membrane-bound cytoplasmic vesicle that forms around a particle (bacterial or other) by invagination of phagocytised material.

Phylum

(pl. phyla) In classification, a phylum is a group of related or similar organisms. A phylum contains one or more classes. A group of similar phyla forms a kingdom.

Plasmid

A small, independently replicating piece of extrachromosomal cytoplasmic DNA that can be transferred from one organism to another. Largely described from bacteria and protozoa.

Platelet

Small, irregularly-shaped bodies in the blood that contain granules. These cells are important components of the blood coagulation (clotting) system.

po

Per os. Oral.

Podosoma

Leg-bearing portion of acarines.

Polyarthritis

An inflammation of several joints.

Polymerase chain reaction

(abbr. PCR) System for in vitro amplification of DNA. Since the original DNA needs to be neither pure nor abundant, PCR has become widely used in research, in clinical diagnostics and forensic science.

Pretarsus

Tick leg segment, consists of a basal stalk, paired claws and a membranous pulvillus. The pulvillus is absent in argasid ticks.

Prevalence

The proportion of individuals in a population having an infection or disease.

Protocerebrum

The largest and most anterior part of the brain, which includes the optic lobes.

Protozoa

Single-celled eukaryotes, which have a membrane-bound nucleus with well-defined chromosomes and other cellular organelles that are characteristic of eukaryotes. Some types cause diseases in humans and animals.

Pulvillus

A pad-Iike structure on the terminal end of the tarsi, adjacent to the claws, in ixodid ticks; also present in the larvae of most argasid ticks.

Q-fever

An acute, self-limited febrile illness, caused by the bacterium Coxiella burnetii, a rickettsia which mainly afflicts sheep and cattle but can be transmitted to humans who have contact with infected animals. Symptoms resemble those of influenza and include sudden onset of fever, headache, malaise, and pneumonia, but no rash.

qid

Quattuor in die. Four times a day.

Questing

Waiting for direct contact with hosts, the ticks rest with their forelegs folded and the other legs holding the stem or grass blade. This is termed the questing pose. Often, the ticks rest with the anterior end of the body pointed down towards of ground, but this does not occur in all individuals or all species.

Redwater fever

(syn. for babesiosis) Malaria-like tick-borne disease with haemolytic anaemia caused by intraerythrocytic protozoan parasites of the genus Babesia. In the USA, B. microti is the most common cause of a mild human babesiosis. B. divergens transmitted by different ticks causes severe human babesiosis in some parts of Europe. Canine babesiosis is caused by three different species, which were formerly categorized as subspecies of B. canis (B. rossi in South Africa, B. canis in Europe, B. vogeli worldwide), and increasingly by B. gibsoni, which is extending its range in the USA and Europe.

Reservoir

A host or carrier that harbours pathogenic organisms, without injury to itself and serves as a source from which other individuals can be infected.

Rheumatoid arthritis

Chronic inflammatory disease in which there is destruction of joints.

Rhipicephalus sanguineus

Larvae, nymphs, and adults of Rhipicephalus sanguineus, the brown dog tick, all feed on dogs and sometimes on man. Originally a tropical species, the brown dog tick has taken advantage of central heating to spread into temperate zones, where it often generates enormous populations in homes, kennels, and veterinary hospitals; it cannot survive the winter outdoors in the north. R. sanguineus transmits canine prioplasmosis/babesiosis (Babesia canis) and tropical canine pancytopenia (Ehrlichia canis) interstadially.

Rickettsia

Bacterial genus included in the bacterial tribe Rickettsiae, order Rickettsiales, family Rickettsiaceae. This genus includes many other species of bacteria associated with human disease, including those in the spotted fever group and in the typhus group.

Rocky Mountain spotted fever

The most severe and most frequently reported rickettsial illness in the United States. The disease is caused by Rickettsia rickettsii, a species of bacteria that is spread to humans by ixodid (hard) ticks. Initial signs and symptoms of the disease include sudden onset of fever, headache, and muscle pain, followed by development of rash. The disease can be difficult to diagnose in the early stages, and can be fatal without prompt and appropriate treatment.

Scolopale

Internal receptors that are extraordinarily sensitive to vibration. Each scolopidium is composed of a neuron (1 or 2), scolopale, cap cell and ligament cell. Usually, many sensilla are clustered together, forming parallel arrays. They are often called chordotonal organs. The basic structure of the internal mechanoreceptor is the scolopidium characterized by a scolopale process.

Scutum

The dorsal sclerotized plate covering the anterior part of the body in ixodid ticks (entire dorsal surface in males). Not to be confused with the dorsal plate on the body of the larva in most argasid species.

Sensilla basiconicum

Single walled olfactosensilla in ticks.

Sensilla coeliconium

Double walled olfactosensilla in ticks.

Sensillae

Sensory organs for monitorig the status of the internal and external environment in insects and ticks. Functionally there are several types – chemosensilla, mechanosensilla, photosensilla and thermosensilla. Combinations of these, multifunctional sensilla, also occur. Many sensilla are diffusely dispersed over the body and appendages. Others are clustered in specialized organs such as the Haller's organ.

Serologic

Related to a branch of science dealing with the measurement and characterization of antibodies and other immunological substances in body fluids, particularly serum.

Serology

Branch of science dealing with the measurement and characterization of antibodies and other immunological substances in body fluids, particularly serum.

Seropositivity

Existence of antigenic determinants expressed on the surface of blood cells suggesting that individuals have experienced infection in the past.

Seroprevalence

The rate at which a given population tests positive for particular antibodies.

Seta

Peripheral organ of ticks with hair-like structure.

Sheep tick

Ixodes ricinus, the castor bean or sheep tick, is the most common tick in northern Europe. The castor bean tick transmits the pathogen Babesia divergens and B. bovis, which cause Redwater fever. It also transmits Anaplasma marginale, which causes anaplasmosis in cattle and sheep. It acquired a new significance when in 1983 Burgdorfer identified I. ricinus as a vector of Lyme disease. Tick paralysis can also arise from its bite.

Soft tick

Argasidae. Small family of 140 species belonging to four genera Argas, Ornithodoros, Otobius, and Antricola. Argasids live in nests, burrows, buildings, and sleeping places of their host animals.

Species

A taxonomic category subordinate to a genus. In taxonomic nomenclature, species are designated by the genus name followed by a Latin or Latinised adjective or noun.

Spirochetal

Relating to spirochetes, especially to infection with such organisms.

Spirochete

A gram-negative bacterium characterized by the flexibly spiral shape and the possession of axial filaments.

Splenectomy

Surgical removal of the spleen.

Splenomegaly

Enlargement of the spleen.

Subclinical

Without clinical manifestations; said of the early stage or a very mild form of an infection or other disease or abnormality before symptoms and signs become apparent or detectable by laboratory tests.

Subspecies

A group somewhat less distinct than species usually are; often a geographical variety or race.

Synganglion

The tick central nervous system is a synganglion: formed by the fusion of the brain ganglia and the abdominal nerve cord into a single mass.

Synovectomy

Excision of a portion or all of the synovial membrane of a joint.

Tarsus

The terminal portion of the leg of the tick, supporting the apotele (=pretarsus). On the dorsal surface of tarsus I, e.g., the Haller's organ, a complex sensory structure, is found.

Tetracyclines

Broad spectrum antibiotics that block binding of aminoacyl tRNA to the ribosomes of both gram-positive and gram-negative organisms (and those of organelles).

Thecogen

A cell that surrounds the glial cell and the outer section of a sensory neuron.

Thrombocytopenia

Low platelet count.

Thrombosis

The formation, development or presence of a thrombus (an aggregation of blood factors, primarily platelets and fibrin with entrapment of cellular elements).

Tibia

The fourth segment of the insect leg, beyond the femur and before the tarsus.

Tick paralysis

Dogs often exhibit hyperactivity before the onset of paralysis. Clinical signs appear between six to 14 days and vary from stumbling gait to complete flaccid paralysis. If partly engorged ticks are removed, paralysis may still occur 1-2 days later. The treatment of tick paralysis involves removal of ticks, neutralization of toxins and supportive therapy.

Tick-borne diseases

(abbr. TBD) Ticks transmit the widest variety of pathogens of any blood sucking arthropod, including bacteria, rickettsiae, protozoa, and viruses. Some human diseases of  importance caused by tick-borne pathogens include Lyme disease, ehrlichiosis, babesiosis, Rocky Mountain spotted fever, tick-borne encephalitis and tick paralysis.

tid

Ter in die. Three times a day.

Tormogen

tormo-: Greek for socket. An epidermal cell secreting a ring of cuticle that connects a cuticular hair to the cuticle. Tormogen cell secretes the socket of a mechanoreceptor. The tormogen and trichogen cells form a template.

Transaminase

Enzyme that catalyses the transfer of an amino group from a donor to an acceptor.

Trichogen

trich-: Greek for hair. An epidermal cell that secretes a cuticular process, such as a hair. The tormogen and trichogen cells form a template.

Trochanter

The second segment of the insect leg, between the coxa and femur.

Tularaemia

A rare infection of rabbits and rodents caused by the bacteria Francisella tularensis.

No entry

Vaccine

A suspension of attenuated or killed microorganisms (bacteria, viruses or rickettsiae) or parts of these pathogens, administered for the prevention, amelioration or treatment of infectious diseases.

Vasculitis

Inflammation of a vessel.

Vector

Organisms, which transmit parasites and other disease agents from one host to another, e.g. fleas or ticks.

Virus

Small infectious agents (20-300 nm) that are not cells but rather genetic material housed in a protective protein covering called the capsid. They are basically parasites of cells in that they must utilize the cell's metabolic and replicative machinery to survive.

West Nile virus (WNV)

West Nile virus is a mosquito-borne flavivirus and human, equine, and avian neuropathogen. Birds are the natural reservoir host, and the virus is maintained in nature in a mosquito-bird-mosquito transmission cycle. The virus has been isolated also in dogs. Most human WN viral infections are subclinical, and the remainder cause illnesses that can have a wide clinical spectrum. In areas where WNV circulates in most years, uncomplicated WN fever is a mild and common disease, easily overlooked. High prevalences of background immunity are present, increasing with age, and WN fever epidemics and WN meningoencephalitis cases are rare. In industrialised urban areas of the northern temperate zone with little or no previous WNV activity, ageing and largely immunologically naïve populations are encountering the virus for the first time and a preponderance of neuroinvasive disease cases has been observed.

Western immunoblot

Transfer of protein from an acrylamide gel to a paper-like membrane by an electric field, preserving the spatial arrangement. Once on the membrane, the molecules can be detected by antibody labelling.

White-footed mouse

The white-footed mouse (Peromyscus leucopus) is the principal host for ticks in the Northeast and upper Midwest of the United States and is a competent reservoir for the spirochete.

White-tailed deer

Odocoileus virginianus, the most commonly infested mammalian species of the blacklegged or deer tick (Ixodes scapularis/Ixodes dammini).

No entry

No entry

Zoonosis

(pl. zoonoses) Zoonoses are infections that are naturally transmitted between animals or non-human species and humans, or between humans and animals or non-human species.

Zoonotic

Relating to a transmission of a disease from an animal or non-human species to humans or vice versa.