Lecture 2: What is Medical Entomology? Flashcards
Entomology
The study of insects
Medical entomology
- The study of medically important insects
- Any aspect of biology that deals with insects that can transmit disease or cause harm
What is “medically important”?
- Cause or transmit a disease
- Cause physical injury or distress
- Cause immunological response
- Cause psychological response
Characteristics of insects
- Three pairs of legs
- Segmented body
- Often two pairs of wings
- Hard exoskeleton
- Molt
Characteristics of non-insect arthropods
- More than 3 pairs of legs
- Head and thorax sometimes fused
- Sometimes non-segmented body
- No wings
- Antennae/other appendages that differ from insects
Malaria
- A protozoan transmitted by a mosquito
- 1/3 to 1/2 of all human deaths since stone age
- 120 million new cases/year
- 33 million infected at any given time
Dengue
- A virus (arbovirus) transmitted by a mosquito
- 300 million cases/year
- Found in more than 100 countries
- Emerging pathogen
Vector
An organism that is capable of carrying a disease from one host and transmitting it to another
Disease transmission
Transmission if the transfer of a pathogen from one organism to another
Transmission cycle
Transmission cycle is any pattern or regular transfer of disease through specific phases
Arbovirus
Arthropod borne virus
Host
An organism that is considered the primary “target” of a disease or pathogen. An organism that harbors a disease.
Infected
An organism that is colonized by a pathogen
Infectious
The organism is capable of transmitting the pathogen
Endemic
- A pathogen that is able to be maintained through a “natural” transmission cycle
- Native to the area (not invasive)
Invasive
A pathogen that is not native to an area
Reservoir host
The organism/population that harbors a pathogen under natural conditions, but usually does not show any ill effects
Extrinsic incubation period
The period of time between infection and being infectious in a vector
Intrinsic incubation period
The period of time between infection and being infectious in a host
Emerging pathogen
A pathogen that is not common or normally found, may be invasive
Enzootic cycle
A transmission cycle between an animal reservoir host and the vector, not involving humans
Dead end host
A host that becomes infected but cannot pass the disease along
Epidemic
An outbreak with more cases than normal in a human population
What is an infectious disease?
Any disease that is transmitted by an arthropod vector
Ways infectious disease can impact us
Kill us, disable us, increase likelihood of death, reduce reproduction, financial impact
