Emergent Viruses Flashcards
What factors can contribute to the emergence of a new disease?
- Increased population/density/trade
- Increased travel
- Changes in social behavior
- Changes in environment
- Changes in technology
- Changes in the microorganism
What manner of trade can facilitate disease emergence?
What kinds of behaviors can facilitate disease emergence?
What environmental changes can facilitate disease emergence?
How can evolving technology facilitate disease emergence?
(sorry.)
Distribution of blood products, exotic animals.
Increased promiscuity, IVDU, antibiotic use, and use of daycares. Pets?
Climate change, destruction of habitat, migration.
New health care procedures generate opportunities for infection, things like food handling, etc.
Hantavirus
What type of virus is it?
What is the reservoir?
What are the symptoms of its infection?
Hantavirus
A bunyavirus (enveloped, segmented (-)RNA viruses with no capsids!)
Deer mice–transmitted via urine/feces.
Causes acute pulmonary edema, shock, hemorrhaging and many other symptoms. Hantavirus-induced pulmonary syndrome is fatal in up to 50% of cases.
Hantavirus
Where is it prevalent?
What caused it to emerge?
Hantavirus
Mostly eastern asia. In the US, the southwest.
Environmental changes resulting in increased mouse population (high rainfall, food).
Arboviruses
Name two examples. What family are they part of?
What are their common vectors?
West Nile virus and Dengue virus. Both are flaviviruses (enveloped, icosahedral ss(+)RNA viruses).
“Arbo” from “arthropod-borne”, they are both transmitted by mosquito.
West Nile Virus
What is the reservoir?
What are the symptoms of its infection?
How is it diagnosed?
Birds, which transver the virus to mosquitos. Humans are (probably) a dead-end host.
90% are asymptomatic, 10% experience flu-like symptoms, and 1% experience severe disease: meningitis, seizures, GI symptoms, ataxia, myelitis…
By “clinical suspicion” and IgM serology, must be considered especially in older patients in the autumn season. Are there dead birds in the area?
West Nile Virus
Where is it prevalent?
What caused it to emerge?
Is there a vaccine?
West Nile Virus
Originally in Africa, then spread to New York and across the US.
Not sure; probably environmental changes and mutation. I’m not sure if the vector has spread or was already endemic when the virus arrived.
There is for horses. The human vaccine is still under development.
Dengue Virus
Describe dengue fever.
Describe dengue shock syndrome.
What role does immunity have in these illnesses?
Dengue Fever
Infection via mosquito transmission causes a fever with serious bone/joint pain and lymphadenopathy.
Infection via mosquito transmission causes a shock-like syndrome due to microvasculature rupture and exsanguination. Infection of macrophages seems to be implicated.
Dengue shock syndrome occurs in people who are immune to one serotype, but were infected by one of the other three.
Dengue Virus
How can it be diagnosed?
Why is it emerging?
Is there a vaccine available?
Dengue Virus
Immunofluorescence, ELISA, and the “tourniquet test” (apply a tourniquet and look for broken capillaries).
The mosquito vector is spreading.
A tetravalent vaccine is currently under development.
Monkeypox
What type of virus is it?
What is the reservoir?
What are the symptoms of its infection?
Monkeypox
A poxvirus (related to smallpox, cowpox; complex enveloped dsDNA viruses).
Mostly small rodents (squirrels, rats, prairie dog)
After 12days incubation, experience flu-like symptoms (fever, myalgias, lymph swellign). Characteristic rash appears and scabs over.
Monkeypox
Where is it prevalent?
What caused it to emerge?
Is there a vaccine?
Monkeypox
Originally Africa, but recently in the US (including Wisconsin). The primary outbreak was traced to rodents shipped from Ghana…
Changes in behavior (pet choice) and the trade of exotic animals to meet this demand.
Sort of. The smallpox vaccine provides some decent resistance. Theoretically, cowpox would too.
Desribe the factors that lead HIV to become an emergent disease in the 1980s/1990s.
HIV originated in chimps, which eventually transmitted it to humans (environment).
Lifestyles and travel increased provided routes of transmission and spread.
Increased populational density amplifies the potential spread.
Technological advances inadvertently promoted its spread (infected tranfusions).
