Infectious Disease Flashcards
(253 cards)
What is a carrier
A person or animal that harbors the infectious agent/disease and can transmit it to others but does not demonstrate signs of the disease
i.e. - COVID-19 living dormant in the body
What is contact
Exposure to a source of an infection; a person who has been exposed. Contact does not imply infection, it implies possibility of infection
What is a host
An organism that harbors a parasitic, mutualistic, or commensalism guest. The host is the house and the parasite is the freeloader
What is zoonosis
A pathogen that is transmissible from non-human animals (typically vertebrates) to humans
i.e. swine flu, bird flu
What is arbovirus (arthropod-borne virus)
Any of a group of viruses that are transmitted between hosts by mosquitoes, ticks, and other arthropods
i.e. malaria, dengue, WNV, Lyme, RMSF
What is herd immunity
When a majority of a given group is resistant/immune to a pathogen, they achieve “herd immunity”. This confers protection to unvaccinated or susceptible individuals/group by reducing the likelihood of infection or spread
What is passive immunity
Transfer of active humoral immunity of ready-made antibodies produced by another host or synthesized. Passive immunization is used when there is a high risk of infection and insufficient time for the body to develop its own immune response. Short term!
What is a parasite
An organism that lives on or in a host organism and gets its food from or at the expense of its host
What are the main classes of human parasites
Protozoa
Helminths
Ectoparasites
What is the organism type of a protozoa
One-celled organisms that are free-living or harbors on a host
What harbor in human GI track that are transmitted via fecal-oral route through contaminated food or water, or person-to-person contact
Protozoa
Protozoa are classified further into groups based on mode of movement
Sarcodina - the ameba
Mastigophora - the flagellates (Giardia, Leishmania)
Ciliophora - the cilates
Sporozoa - non motile adult stage organisms (Cryptosporidium - the leading cause of waterborne disease in the US
What is a large multicellular organism visible to the naked eye in adult stage, that are free-living or harbors on a host
Helminths
What are the types of helminths that reside in the GI tract
Flatworms (platyhelminths) - blood flukes and tape worms
Thorny-headed worms (acanthocephalins)
Roundworms (nematodes) - also reside in blood, lymph system or subcutaneous tissues such as hookworms or pinworms
What are some examples of ectoparasites
Ticks, fleas, lice, and mites - burrow into the skin and remain there for weeks to months. This category of parasites also include other blood-sucking arthropods such as mosquitos
What is the treatment for parasitic infections
Treatment is based on the affected organ, symptoms, specific parasite, and other disease secondary from parasite
What type of organism is West Nile Virus (WNV)
Single-stranded RNA virus of the family Flaviviridae and the leading cause of domestically acquired arboviral disease in the US
How is WNV transmitted
Primarily via the Culex mosquito
What is the incubation period for WNV
2-6 days, but can range from 2-14 days
Is WNV reportable
Yes
What percentage of people are asymptomatic with WNV
70-80% of human WNV infections are subclinical or asymptomatic
What is the typical patient presentation of WNV
An acute systemic febrile illness may be accompanied by:
Headache, weakness, myalgia, or arthralgia
GI symptoms
TRANSIENT MACULOPAPULAR RASH
<1% of infected patients develop neuroinvasive what? Which typically manifests as meningitis, encephalitis, or acute flaccid paralysis
West Nile virus
What lab diagnosis is used to diagnose WNV
Diagnosis via identifying IgM in serum or CSF
ELISA is used to detect IgM antibody