Family of viruses for Hantavirus, Yellow Fever, Dengue, Ebola, Marburg, Lassa fever
Hantavirus – bunyaviridae
Yellow fever and Dengue- flaviviridae
Ebola and Marburg – Filoviridae
Lassa- Arenaviridae
T/F: Ebola and Marburg are in the same family—filoviridae
True
Yellow fever and dengue belong to ______ family
Flaviviridae
T/F: Hemorrhagic fever often result in hypertension and shock
False; it often ends up with hypotension instead of hypertension
What happens to the capillaries in Viral hemorrhagic fever syndrome?
Capillary leak leading to bleeding and bruising and shock
T/F: Flaviviridae infections, hemorrhages is part of the infection
True; Dengue and Yellow fever
All four families of that VHFs have _____ genome and _____ (with/ without) envelope.
RNA genomes
Enveloped
Which of the VHFs have a vaccine available?
Yellow fever (a live attenuated vax, should not be given to 3rd trimester pregnant ladies or immunocompromised folks)
Prodromal stage of VHF syndrome clinical findings include:
Very general symptoms- headache, myalgia, arthralgia, abd pain, nausea and non-bloody diarrhea
Maculopapular rash is a clinical symptom often seen in ______; while jaundice and “black vomit” is seen in _____.
Dengue fever
Yellow fever
Late stages of VHF syndrome clinical findings include:
Azotemia, oliguria (reduced pee), hematuria- basically anything having to do with losing fluid
Conjunctival, mucosal hemorrhage
DIC
Hypovolemic shock
CNS involvement such as delirium
Shock
Death
T/F: prodromal stage of VHF can have CNS involvement such as delirium, convulsions or coma
False; CNS involvement is seen in later stages
DIC, hypovolemic shock, and multi-organ system failure and hemorrhagic complication is seen in _____ stage of VHF
Later
T/F: Ribavirin can be used to treat most of the VHF infections
False; ONLY LASSA FEVER can be treated with ribavirin other ones treat with supportive care such as fluid resuscitation.
Reservoir, vector and host for Filoviridae:
Reservoir- African Fruit Bat (for sure in Marburg, unsure for Ebola)
Vector- none. Not insect borne, aka not arbovirus
Host- Non-human primates so like monkeys
T/F: Person-to-person contact transmission is seen in filoviridae
True; ebola is primarily transmitted through fluid contact
Genome basics and replication for Filoviridae:
(ebola and Marburg)
ssRNA negative
Non-segmented, linear
Replicates in the cytoplasm via RNA dependent RNA polymerase
Which is the most virulent human virus that needs to be cultured in highest biosafety containment (BSL-4)?
Filoviridae = ebola/ Marburg
Ebola is usually seen in _______ Africa, and Marburg is seen _____ Africa
West ie Sierra Leone
East/Central-ish ie Kenya, Uganda, Congo and Angola
Which virus can survive in male semen long after recovery?
Ebola
Handling bushmeat could be a buzzword for which viral transmission?
Ebola
Ebola long-term complications can include:
Joint and vision problems
Ebola viral virulence factor include ______(type of protein) killing our_____ cells causing blood to leak into tissues, resulting in ______.
Glycoprotein
Endothelial
Hemorrhage
T/F: some ebola viral protein can inhibit induction and action of interferon, turning the body’s immune warning signal off
True
Which cell are killed as a result of ebola infection in our body?
Lymphocytes, macrophages, and dendritic cells
T/F: Renal cells are also killed in Ebola infection, leading to acute kidney failure.
False; Hepatocytes are killed in Ebola infection, leading to liver failure. Kidney failure is seen in hantavirus
Diagnosis for filoviridae?
ELISA to detect viral antigen in serum
IgM in serum
PCR for Viral RNA within 48 hours of symptom onset
Patient presents with acute febrile illness with joint pain and vision complaints, history revealed that he recently spent time in Western Africa playing with monkeys and burring them when they died, you immediately suspect:
EBOLA!
Reservoir, vector and host for Bunyviridae:
Reservoir: old world urban rats
Vector: none. Not arthropod-borne aka not arbovirus
Host: wild rodents
Genome basics for Hantavirus?
ssRNA negative
3 circular segments of RNA
Glycoprotein Gn and Gc interact with beta 3 integrins
Rats are reservoir for which virus(es):
Hantavirus- rodent poop and pee
Lassa Fever – multimammate rat urine and droppings
These two can be transmitted through inhalation or ingestion of rat poops
Which virus can cause interstitial nephritis as a complication?
Hantavirus. Can lead to acute renal insufficiency, renal failure, generalized hemorrhage and shock. Permanent renal damage also likely
Patient who is a rodent researcher recently returned from a trip around the Eastern Hemisphere, having visited East Asia, Russia and Europe presents with acute febrile flu-like illness, SUSPECT:
Hantavirus. And definitely check kidney functions and liver too
Classic dengue vs dengue hemorrhagic fever?
Classic dengue- breakbone fever – severe joint and back pain
Dengue hemorrhagic fever- much more severe, happens after having had one dengue exposure
Which of the viruses is an arbovirus?
Flaviviridae – dengue virus and yellow fever virus.
Others are zoonotic, no insect vectors in those
T/F: dengue is the most common insect-borne viral disease in the world.
True; plasmodium malaria is not a virus!
Which is the virus family that has ssRNA positive genome?
Flaviviridae
Reservoir, vector and host for Flaviviridae- Yellow and Dengue:
Reservoir: human (urban cycle of yellow fever)
Vector: Aedes mosquitos
Host: iono
Which virus(es) have non-segmented, linear genome?
Flaviviridae and filoviridae
Difference between them is Flaviviridae is ssRNA+, and filoviridae is ssRNA-
Hantavirus and Lassa virus both have rodent exposure in common, to tell the difference, Hantavirus has _____ genome and Lassa virus has ____ genome.
Hanta- 3 circular
Lassa- 2 segmented
Using a tourniquet test and a positive test means there is ______ rash seen, and this is highly indicative for ____ infection
Maculopapular
Dengue infection
T/F: Dengue virus infects skin dendritic cells after injection by mosquitoes and spread to lymph nodes
True
Months ago, Jack Sparrow took time off his pirate life in the Caribbean and came to your clinic with complaints of some really severe muscle pain, rash on his arms and fever. It was not too big of a deal because it was ______, but today he is complaining of severe vomiting, stomach pain and feeling light-headed (low BP), you are concerned because it might be _____
Classic dengue fever (backbone fever)
Dengue hemorrhagic fever – can result in shock, difficulties affecting heart, lungs and liver
How many dengue serotypes are there? Why is infection with a different dengue serotype so bad?
5 serotypes
Previous exposure to classic dengue- antibody is produced against that viral serotype, however when infected with another dengue serotype, the booster antibody (from initial serotype) response results in non-nuetralizing antiviral proteins facilitating virus entry into host cells, activating host complements, leading to a huge amount of cytokines being released
Secondary dengue infection results in increased Ig_____ from the get-go, which would lead to increased ____
IgG
Cytokines
Patient comes in this morning looking as yellow as sponge bob and complains of fevers, headache, photophobia and vomiting blood, he said he woke up like this and was fine last night, you’re most concerned with how these organs are functioning:
Liver, kidneys and heart
Yellow fever is sudden onset jaundice and fever with upper GI hemorrhage
Symptoms of “Black vomit”, think:
Yellow fever
What are councilman bodies?
Eosinophilic globules (pink dot) in the liver
This is associated with yellow fever virus
How long do yellow fever virus replicate in the mosquito. And what is the incubation period in human after bitten by an infected mosquito?
Virus must replicated in the mosquito for almost 2 weeks
After the infected mosquito bites the person, incubation period is 3 to 6 days = sudden onset
Reservoir, vector and host for Arenaviridae:
Reservoir: multimammate rat
Vector: none
Host: iono
Which virus is ambisense, wtf does that mean?
Lass fever virus
Means protein is translated in both orientations
T/F: Much like Ebola and Marburg, Lassa fever can also be transmitted via person-person contact
True; the other two (Flaviviridae and Hanta virus are not transmitted person-to-person). Lassa fever can also be through ingestion or inhalation of rat poop
Which type of patient is most susceptible to Lassa fever virus infection?
Pregnant women
Pregnant lady comes in with fever and hypotension, you freak out because it’s _______ infection, and these have a 95% mortality rate in pregnant women. You are most worried about what that might come next?
Lassa Fever
Spontaneous abortion, Maternal death
How is lassa fever treated? A Third of survivor have this symptom____.