Invertebrates are very common vectors of disease. A vector is an organism which spreads disease from one host to another. Invertebrates spread bacterial, viral and protozoan pathogens by two main mechanisms. Either via their bite, as in the case of malaria spread by mosquitoes, or via their faeces, as in the case of Chagas' Disease spread by Triatoma bugs or epidemic typhus spread by human body lice.
Many invertebrates are responsible for transmitting diseases. Mosquitoes are perhaps the best known invertebrate vector and transmit a wide range of tropical diseases including malaria, dengue fever and yellow fever. Another large group of vectors are flies. Sandfly species transmit the disease leishmaniasis, by acting as vectors for protozoan Leishmania species, and tsetse flies transmit protozoan trypansomes (Trypanosoma brucei gambiense and Trypansoma brucei rhodesiense) which cause African Trypanosomiasis (sleeping sickness). Ticks and lice form another large group of invertebrate vectors. The bacterium Borrelia burgdorferi, which causes Lyme Disease, is transmitted by ticks and members of the bacterial genus Rickettsia are transmitted by lice. For example, the human body louse transmits the bacterium Rickettsia prowazekii which causes epidemic typhus.
Although invertebrate-transmitted diseases pose a particular threat on the continents of Africa, Asia and South America, there is one way of controlling invertebrate-borne diseases, which is by controlling the invertebrate vector. For example, one way of controlling malaria is to control the mosquito vector through the use of mosquito nets, which prevent mosquitoes from coming into contact with humans.
This is a list of diseases spread by invertebrates.
Disease | Vector | Causative organism | Host | Symptoms | Area | Treatment |
---|---|---|---|---|---|---|
African horse sickness | Culicoid midge | Orbivirus (virus) | Equids | Fever, lung, heart or mucous membrane symptoms. | Europe, Africa | Vaccination |
Babesiosis | Tick | Babesia (protozoan) | Humans, rodents, dogs, cattle | Fever, hemolytic anemia, chills, sweating, thrombocytopenia | South Europe, Central United States | Antibiotics |
Bluetongue disease | Culicoid midge | Orbivirus (virus) | Cattle, sheep | Fever, salivation, swelling of face and tongue | Europe, Africa | Vaccination |
Chagas disease (American trypanosomiasis) | Various assassin bugs of subfamily Triatominae | Trypanosoma cruzi (protozoan) | Mild symptoms, then chronic heart or brain inflammation | Central and South America | Antiparasitic drugs; treatment of symptoms | |
Chikungunya | Mosquito | Chikungunya virus | Human | Abdomen pain, eye pain, joint pain, muscle pain, fever, chills, fatigue, headache, skin rash | Asia | Antibiotics |
Dengue fever | Mosquito | Flavivirus (virus) | Fever then arthritis | (Sub) tropics and South Europe | Observation/supportive treatment | |
Dirofilariasis | Mosquito | Dirofilaria | Dogs, wolves, coyotes, foxes, jackals, cats, seals, sea lions, muskrats, bears, rabbits, raccoons, reptiles, beavers, ferrets, monkeys, | Chest pain, fever, pleural effusion, cough, nodules under the skin or lung granulomas | Worldwide | Heartworm medicine |
Tick-borne encephalitis | Tick | Tick-borne encephalitis virus | Ill with flu then meningitis | Central and North Europe | prevention and vaccination | |
Heartland virus disease | Tick | Heartland virus | Fever, lethargy, headache, myalgia, diarrhea, nausea, loss of appetite, anorexia, thrombocytopenia, leukopenia, arthralgia | Missouri and Tennessee, USA | Supportive treatment | |
Leishmaniasis | Sandfly | Leishmania (protozoan) | Fever, damage to the spleen and liver, and anaemia | South hemisphere and Mediterranean Countries | Treatment of infected | |
Lyme disease | Tick | Borrelia burgdorferi (bacterium) | Deer, human | Bull's-eye pattern skin rash around bite, fever, chills, fatigue, body aches, headache, joint pain. Sometimes neurological problems. [1] | Europe, North Africa, and North America | Prevention and antibiotics |
Malaria | Mosquito | Plasmodium (protist) | Human | Headache then heavy fever | (Sub) tropics | Prevention and anti-malaria |
Plague | Flea | Rats, Human | Fever, weakness and headache. In the bubonic form there is also swelling of lymph nodes, while in the septicemic form tissues may turn black and die, and in the pneumonic form shortness of breath, cough and chest pain may occur | Central Asia, India, US, Africa, Peru, Brazil | Antibiotics | |
Pogosta disease Synonyms: Karelian fever Ockelbo disease Sindbis fever | Mosquito | Sindbis virus | Skin rash, fever, in severe cases - arthritis | Scandinavia, France, Russia | unknown | |
Rickettsial diseases: Typhus rickettsialpox Boutonneuse fever African tick bite fever Rocky Mountain spotted fever etc. | Tick, mite, lice | Rickettsia species (bacteria) | Fever with bleeding around the bite | Global | Prevention and antibiotics | |
Tularemia | Deer flies, ticks | Francisella tularensis (bacterium) | Birds, lagomorphs, rodents | Skin ulcer, swollen and painful lymph glands, fever, chills headache, exhaustion | North America | Streptomycin, gentamicin, doxycycline, ciprofloxacin |
African trypanosomiasis (sleeping sickness) | Tsetse fly | Trypanosoma brucei (protozoan) | Wild mammals, cattle, human | Fever, joint pain, swollen lymph nodes, sleep disturbances | Sub-Saharan Africa | Various drugs |
Lymphatic filariasis | Mosquito | Wuchereria bancrofti | Human | Fever, swelling of limbs, breasts, or genitalia | Africa, Asia. | Various drugs |
West Nile fever | Mosquito | West Nile virus | Birds, human | Fever, headaches, skin rash, body aches. | Africa, Asia, North America, South and East Europe | None |
Yellow fever | Mosquito | Yellow fever virus | Human | Muscle pain, abdomen pain, loss of appetite, fatigue, jaundice, fever, chills, headache, nausea, vomiting, bleeding, delirium | South America, Africa | Yellow fever vaccine |
Zika fever | Mosquito | Zika virus | Monkeys, human | Fever, eye pain, conjunctivitis, rash, headache, vomiting, joint pain, muscle pain, fatigue, chills, sweating, loss of appetite | South America, Mexico, Asia, Africa | Decreasing mosquito bites, condoms |
Epidemic typhus, also known as louse-borne typhus, is a form of typhus so named because the disease often causes epidemics following wars and natural disasters where civil life is disrupted. Epidemic typhus is spread to people through contact with infected body lice, in contrast to endemic typhus which is usually transmitted by fleas.
Rickettsia is a genus of nonmotile, gram-negative, nonspore-forming, highly pleomorphic bacteria that may occur in the forms of cocci, bacilli, or threads. The term "rickettsia" has nothing to do with rickets ; the bacterial genus Rickettsia instead was named after Howard Taylor Ricketts, in honor of his pioneering work on tick-borne spotted fever.
Trench fever is a moderately serious disease transmitted by body lice. It infected armies in Flanders, France, Poland, Galicia, Italy, Macedonia, Mesopotamia, Russia and Egypt in World War I. Three noted cases during WWI were the authors J. R. R. Tolkien, A. A. Milne, and C. S. Lewis. From 1915 to 1918 between one-fifth and one-third of all British troops reported ill had trench fever while about one-fifth of ill German and Austrian troops had the disease. The disease persists among the homeless. Outbreaks have been documented, for example, in Seattle and Baltimore in the United States among injection drug users and in Marseille, France, and Burundi.
Arbovirus is an informal name for any virus that is transmitted by arthropod vectors. The term arbovirus is a portmanteau word. Tibovirus is sometimes used to more specifically describe viruses transmitted by ticks, a superorder within the arthropods. Arboviruses can affect both animals and plants. In humans, symptoms of arbovirus infection generally occur 3–15 days after exposure to the virus and last three or four days. The most common clinical features of infection are fever, headache, and malaise, but encephalitis and viral hemorrhagic fever may also occur.
Tick-borne diseases, which afflict humans and other animals, are caused by infectious agents transmitted by tick bites. They are caused by infection with a variety of pathogens, including rickettsia and other types of bacteria, viruses, and protozoa. The economic impact of tick-borne diseases is considered to be substantial in humans, and tick-borne diseases are estimated to affect ~80 % of cattle worldwide.
Murine typhus, also known as endemic typhus or flea-borne typhus, is a form of typhus transmitted by fleas, usually on rats, in contrast to epidemic typhus which is usually transmitted by lice. Murine typhus is an under-recognized entity, as it is often confused with viral illnesses. Most people who are infected do not realize that they have been bitten by fleas. Historically the term "hunger-typhus" was used in accounts by British POWs in Germany at the end of World War I when they described conditions in Germany.
Meningoencephalitis, also known as herpes meningoencephalitis, is a medical condition that simultaneously resembles both meningitis, which is an infection or inflammation of the meninges, and encephalitis, which is an infection or inflammation of the brain tissue.
Relapsing fever is a vector-borne disease caused by infection with certain bacteria in the genus Borrelia, which is transmitted through the bites of lice or soft-bodied ticks.
Borrelia is a genus of bacteria of the spirochete phylum. Several species cause Lyme disease, also called Lyme borreliosis, a zoonotic, vector-borne disease transmitted by ticks. Other species of Borrelia cause relapsing fever, and are transmitted by ticks or lice, depending on the species of bacteria. A few Borrelia species as Candidatus Borrelia mahuryensis harbor intermediate genetic features between Lyme disease and relapsing fever Borrelia. The genus is named after French biologist Amédée Borrel (1867–1936), who first documented the distinction between a species of Borrelia, B. anserina, and the other known type of spirochete at the time, Treponema pallidum. This bacterium must be viewed using dark-field microscopy, which make the cells appear white against a dark background. Borrelia species are grown in Barbour-Stoenner-Kelly medium. Of 52 known species of Borrelia, 20 are members of the Lyme disease group, 29 belong to the relapsing fever group, and two are members of a genetically distinct third group typically found in reptiles. A proposal has been made to split the Lyme disease group based on genetic diversity and move them to their own genus, Borelliella, but this change is not widely accepted. This bacterium uses hard and soft ticks and lice as vectors. Testing for the presence of the bacteria in a human includes two-tiered serological testing, including immunoassays and immunoblotting.
A canine vector-borne disease (CVBD) is one of "a group of globally distributed and rapidly spreading illnesses that are caused by a range of pathogens transmitted by arthropods including ticks, fleas, mosquitoes and phlebotomine sandflies." CVBDs are important in the fields of veterinary medicine, animal welfare, and public health. Some CVBDs are of zoonotic concern.
The discipline of medical entomology, or public health entomology, and also veterinary entomology is focused upon insects and arthropods that impact human health. Veterinary entomology is included in this category, because many animal diseases can "jump species" and become a human health threat, for example, bovine encephalitis. Medical entomology also includes scientific research on the behavior, ecology, and epidemiology of arthropod disease vectors, and involves a tremendous outreach to the public, including local and state officials and other stake holders in the interest of public safety.
Andrew Spielman was a prominent American public health entomologist and Professor of Tropical Public Health in the Department of Immunology and Infectious Disease at the Harvard School of Public Health (HSPH).
In epidemiology, a disease vector is any living agent that carries and transmits an infectious pathogen to another living organism; agents regarded as vectors are organisms, such as parasites or microbes. The first major discovery of a disease vector came from Ronald Ross in 1897, who discovered the malaria pathogen when he dissected a mosquito.
Rhipicephalus sanguineus, commonly called the brown dog tick, kennel tick, or pantropical dog tick, is a species of tick found worldwide, but more commonly in warmer climates. This species is unusual among ticks in that its entire lifecycle can be completed indoors. The brown dog tick is easily recognized by its reddish-brown color, elongated body shape, and hexagonal basis capituli. Adults are 2.28 to 3.18 mm in length and 1.11 to 1.68 mm in width. They do not have ornamentation on their backs.
RID is an Australian brand of personal insect repellent sold and distributed in Australia, New Zealand, and online.
Typhus, also known as typhus fever, is a group of infectious diseases that include epidemic typhus, scrub typhus, and murine typhus. Common symptoms include fever, headache, and a rash. Typically these begin one to two weeks after exposure.
Queensland tick typhus is a zoonotic disease caused by the bacterium Rickettsia australis. It is transmitted by the ticks Ixodes holocyclus and Ixodes tasmani.
Rickettsia australis is a bacterium that causes a medical condition called Queensland tick typhus. The probable vectors are the tick species, Ixodes holocyclus and Ixodes tasmani. Small marsupials are suspected reservoirs of this bacterium.
Rickettsia felis is a species of bacterium, the pathogen that causes cat-flea typhus in humans, also known as flea-borne spotted fever. Rickettsia felis also is regarded as the causative organism of many cases of illnesses generally classed as fevers of unknown origin in humans in Africa.
Global climate change has increased the occurrence of some infectious diseases. Those infectious diseases whose transmission is impacted by climate change include for example the vector-borne diseases dengue fever, malaria, tick-borne diseases, leishmaniasis, zika fever, chikungunya and Ebola virus disease. One of the mechanisms for increased disease transmission is that climate change is altering the geographic range and seasonality of the insects that can carry the diseases. Scientists stated a clear observation in 2022: "the occurrence of climate-related food-borne and waterborne diseases has increased ."