Emerging viruses Flashcards
What 2 viruses are members of the Filovirus family and have curved virion structures?
Marburg and Ebola viruses
Describe the life cycle of filoviruses
How is Ebolavirus transmitted?
Contact with bodily fluids (generally droplet transmission)
T/F: Ebola can never be sexually transmitted
falsehood (apparently): ebola can persist and high levels of it can accumulate in sperm so it can become an STI
Describe the transmission cycle of Ebolavirus
Bat>> other animals (non-human primates) >> human beings
What are the clinical symptoms of Ebola?
Fever, Headache, Diarrhea, Vomiting, Stomach pain, Muscle pain
(develops into hemorrhage/bleeding from ears, nose, rectum, raised rash, severe weight loss, internal bleeding)
What is a feature of Ebola virus that is necessary for the virus to cause recurrent infection?
Persistence
T/F: There are currently no Ebola vaccines available
False. There are 2 vaccines available:
ChAd3-ZEBOV
rVSV-ZEBOV (V920) - currently being used
(there are also monoclonal abs: REGN-EB3, and mAb114)
___ is an enveloped, bi-segmented ssRNA virus member of the Arenavirus family that causes Lassa Fever
Lassa Fever virus
**note that it had L and S segments that encode the viral proteins, and GP1 and GP2 alpha-dystroglycan receptor that are the immunodominant antigens**
How is Lassa fever virus transmitted?
Its a zoonotic virus that transmitted via rodent urine + feces; person – person close contact
Spread by Mastomys natalensis
What are the symptoms of Lassa fever in initial infection vs later stages?
Initial infection: inapparent infection/asymptomatic
Later on (Lassa fever): severe high fever, severe myalgia, coagulopathy, hemorrhagic skin rash, sometimes necrosis of liver and spleen
How do you Dx Lassa fever and how do you treat it?
Clinical presentation
ELISA antibody testing
PCR for Lassa fever rna (detects w/in7 - 10 days)
Rx: there is no real rx. It’s palliative care and maybe Ribavarin (general antiviral so has minimal effect and high toxicity)
Describe the structure and genomic make up of corona viruses
Enveloped, +ve sense ssRNA viruses; virion has spike glycoproteins which bind receptor on cells
Which viruses make up the corona viruses? (3)
SARS-CoV (severe acute respiratory distress syndrome)
MERS-CoV (middle east respiratory syndrome)
“Common cold”
Which coronavirus is ass’d with nosocomial infections?
MERS
How are coronaviruses transmitted and what are their resevoirs?
Transmission: respiratory
Resevoirs: originally the bat, then civet cat (SARS) and camels (SARS and camels)
How do SARS and MERS present?
Fever, cough, shortness of breath, progressing to pneumonia/ARDS
What are 3 co-morbidities linked to MERS? (which one is the most common?)
Diabetes
Heart disease
Immunosuppression
Which viral infection/disease process is indicated here?
MERS CoV
**
Edema, Diffuse alveolar damage,
thickening of alveolar septa,
multinucleated syncytial cells
___ is a respiratory Bunyavirus that is spread thru contact with the urine and feces of the deer mouse
Hantavirus
What 2 syndromes are caused by Hanta virus? Of the 2, which one is more dangerous?
Hantavirus pulmonary syndrome
Hemorrhagic fever with renal syndrome (worse than the pulmonary syndrome)
**note that they are caused by different strains of Hanta virus
Describe the structure of Hantavirus
-ve sense ssRNA linear virus with enveloped, spherical virion
**note that the virus has S, L and M segments, which recombine to create different strains. Also, the virus has to bring with it its own RNA polymerase**
The milder form of hemorrhagic fever w/ renal syndrome is called ___
Nephropathia epidemica (NE)
HFRS is caused by which 2 subsets of Hanta virus?
Hantaan virus
Dobrava virus
(Hunting with Bravo)
How does HFRS present? What 2 conditions are the hallmark of HFRS?
High fever, flu-like prodrome, hypotension, thrombocytopenia
Bleeding, Petechiae >> Disseminated intravascular coagulation
Renal dysfunction/failure
**hallmarks of this disease: coagulopathy and renal dysfunction
The Sin Nombre virus (North America), Laguna negra virus, and Andes virus (South America) all cause ___
What is the presentation of this disease?
Hantavirus Pulmonary Syndrome
Symptoms: high fever, headache, myalgia, pulmondary edema
**hallmark of infection: respiratory symptoms LATE in the infection period**
How do you dx Hantavirus infection?
Main Dx: History
Otherwise: blood test looking for atypical lymphocytes (large), thrombocytopenia, hypoxia
Hantavirus specific IgM/IgG and PCR positivity
Which two viruses fall into the Henipavirus family?
Describe the structure of these viruses
Hendra virus
Nipah virus
**
Enveloped, single stranded, negative sense RNA viruses in the Paramyxovirus family (same as measles, mumps)
How are Nipah and Hendra transmitted?
From bats to animals (horses) to humans
How does Henipavirus present?
Incubation period is approximately 5–16 days
- Severe influenza-like illness: fever, myalgia, headache, and dizziness
- Develop severe encephalitis: confusion, abnormal reflexes, seizures, and coma
- Relapsing or late-onset encephalitis possible
How do you Dx Henipa virus infection?
A. Eosinophilic viral inclusions in Nipah encephalitis
B. Acute Hendra encephalitis
C. Nipah antigen positive neurons
D. Hendra positive neuron cluster
How do you Rx Henipavirus infection?
For both viruses, Rx = supportive care
