Studied by 49 peopleHow do arthropods impact humans and animals?
Allergies to proteins or venom Annoyance Fear and mental stress Parasitism Transmission of disease pathogens
Delusory parasitosis
A psychological state where p a person mistakenly believes that they are being bitten or are infested by a parasite
Myiasis
invasion of host tissue by fly larvae
Epidemiology
The study of factors determining the occurrence of disease in population
Biocenosis
Term widely adopted in disease relationships to refer to the interacting organisms involved in a disease
Biogeocenosis
Includes environmental factors as well as the interacting organisms involved in a disease
Epidemic
Usually large number of cases of a human disease
Epizootic
Epidemic associated with an animal disease outbreak
Incidence
Number of new cases in a defined population during a time interval
Incidence rate
Number of new cases per unit of time
Prevalence
Number of cases in a population at a given time
Endemic
Disease is stable, new cases balanced with increases in disease-free hosts
Enzootic
Animal version of endemic
Arthroponoses
Disease only occurs in humans
Primary or definitive host
Sexual reproduction of the pathogen, required for maintenance of transmission
Secondary or intermediate host
No sexual reproduction, not essential, but may enhance amplification
Immunity
All properties of the host that confer resistance to infection
Natural immunity
Immunity with no prior exposure to disease
Acquired immunity
Immunity due to previous exposure, either transient or lifelong
Amplification
General increase in the number of parasites in a given area
Amplification host
Often short-term, may develop disease
Reservoir Host
supports parasite development, infected for long periods of time, disease usually not acute
Dead-end host
Either do not support infection level sufficient for transmission or become ill and die before parasite completes development
Bovine Piroplasmosis
Cattle fever
What are the six principal arthropod orders?
Diptera Siphonaptera Phthiraptera Hemiptera Blatteria Metastigmata
Obligate parasite
Parasitism is the only means of existence, they have to parasitize to live
Facultative parasites
A free-living form that infests a host, they do not have to parasitize to live
Extrinsic incubation period
Time required after infection of arthropod vector until the pathogen can be transmitted
Intrinsic incubation period
Time for pathogen to develop and cause clinical signs of disease symptoms in vertebrate host
Venereal
Abovirus' also are transovarially transmitted Infected male infects during mating
Horizontal transmission
Vector to non-arthropod
Anterior-station
Parasites leave vector through mouthparts or salivary glands
Posterior-station
Parasites transmitted via feces
Salivarian transmission
Salivary secretions injected during feeding
Stercorarian transmission
Parasites passed in feces host causes entrance by scratching
Regurgitation transmission
Parasites mass and prevent successful blood feeding Leishmannia and Yersinia
Assisted escape/passive transfer
Host macerates annoying arthropod vector
Active escape transmission
Filariae break out of the vector's mouthparts
Ingestion of vector
Grooming
Vector Competence
Susceptibility of an arthropod to infection with a parasite and ability to transmit the parasite
What factors make a competent vector?
Maintaining or increasing the pathogen size of the vector population limited or extensive groups of hosts vector longevity feeding frequency and probing behavior vector mobility physiological and behavioral plasticity
Anautogenous
Eggs matured w/aid of blood meal
Autogenous
Eggs produced without a blood meal
What are some mosquito-transmitted viruses?
Yellow fever Dengue Zika Rift Valley Fever Chikungunya Encephalitis
What are some biting midge transmitted viruses?
Bluetongue Vesicular stomatitus
What is a tick-transmitted virus?
African Swine fever
What are the three grate plague pandemics?
Justinian's plague Black Death 1855-1950 Asia
Justinian's plague
AD541- Africa/<ed. Europe 40 mil deaths
Black Death
1347- from Asia trade routes 25 mil deaths in Europe, lasted 200 years
1855-1950 Asia
Over 12 mil deaths in India alone Plague was introduced into US from this outbreak
The golden age for med/vet entomology started when?
1877 (was a 50 year period)
What happened in 1848?
Josiah Nott published belief mosquitoes produced malaria and yellow fever
What happened in 1850?
Livingstone published the bite of poisonous tsetse fly caused death of animals
What did Partick Manson observe in 1877?
development of Muchereria bancroft in the body of a mosquito
What is Koch's Postulate?
– Micro-organism always present in diseased host – Micro-organism isolated from diseased host and grown – Micro-organism obtained from pure culture injected into new host to produce disease – Micro-organisms isolated from the experimentally infected host.
What is the first mosquito-borne virus?
Yellow Fever
What happened in 1902?
Discovered dengue is transmitted by mosquitoes
What happened in 1903?
The first transmission of spirochetes by soft tick
What year did the USDA cattle fever tick eradication program start?
1906
Why did Sanibel island eradication fail?
Because they were too close to the mainland, screwworm flies kept coming back (1954)
What happened in 1908?
Chagas discovered trypanosomes transmitted by bugs
What was the first virus transmitted by ticks?
Nairobi sheep disease
What was eradicated in 1943
cattle tick fever
Physical control
The use of various types of energy to control, attract or repel insects
Mechanical control
The removal or destruction of insects by hand or by devices that are mechanical in nature
Environmental control
One or more components of the environment are modified to the pests detriment
Why were the entomologists drop from the program?
Less than 1000 cases of screwworm so they didn't need them
1935
Baumhover - 1.2 million known cases of screwworm in the southern US
1936
Laake found separation in primary and secondary screwworm flies
1938
Knipling proposed sterile male control program for screwworms
1961
Eradication program in Florida completed 400 males to 1 female per square mile released per week
When were screwworms eradicated in Florida?
1959
When were screwworms totally out of the US?
1966
What are 4 of the 6 internationally quarantinable diseases?
yellow fever louse-borne typhus plague louse-borne relapsing fever
What happened in 1889?
Babesia bigemina was discovered in cattle blood by Theobald Smith, the first zoonotic agent found
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