Viruses 3 Emerging and Bioterrorism BLH Flashcards
Enterovirus 68
- Non-polio enterovirus
- Usually causes runny nose, sneezing, cough, and body and muscle aches
- Severe symptoms may include wheezing and difficulty breathing
- Acute flaccid myelitis -115 children in 34 states have developed polio-like paralysis in an arm or a leg and there is an epidemiologic putative association with enterovirus 68 B1 strain
Viral Hemorrhagic fevers
- RNA viruses
- Arenaviridae
- Filoviridae
- Bunyaviridae
- Flaviviridae
- Rhabdoviridae
- Have animal or insect host
- Usually rodent or insect vector
- Human to human transmission with Ebola, Marburg and Lassa fevers
- Systemic infections involving CNS
Arenaviridae
South American hemorrhagic fever viruses and Lassa Fever
Filoviridae Overview and Subtypes
(Ebola Hemorrhagic Fever)
•-ssRNA viruses (Filoviridae)
1) Ebola virus (Zaire ebolavirus)
2) Sudan virus (Sudan ebolavirus)
3) TaïForest virus (TaïForest ebolavirus, formerly Côte d’Ivoire ebolavirus)
4) Bundibugyovirus (Bundibugyoebolavirus
Bunyaviridae
Rift Valley fever & Crimean-Congo hemorrhagic fever
Flaviviridae
Dengue hemorrhagic fever
Rhabdoviridae
Bas-Congo virus hemorrhagic fever
Filoviridae or Ebola Transmission
- Fruit bats or primates are the most likely reservoirs
- Person-to-person transmission via blood or body fluids (urine, saliva, sweat, feces, vomit, breast milk, and semen)
Filoviridae or Ebola Sx, DX and RX
- Sx-Fever, severe headache, muscle pain, weakness, fatigue, diarrhea, vomiting, abdominal pain, hiccups, unexplained hemorrhage
- Symptoms appear 2 to 21 days after exposure
- 25-90% mortality
- Dx-ELISA and RT-PCR for viral proteins or RNA
- Rx –supportive
Dengue Fever Overview
Flavivirus; +ssRNA with no envelope
- Caused by any of four closely related RNA viruses, or serotypes: dengue 1-4
- Dengue is transmitted between people by the mosquitoes Aedesaegyptiand Aedesalbopictus
- 2009/10 –Key West outbreak 88 cases
- 2013 outbreak Martin county Florida 28 cases
Classi Dengue Fever
“break bone fever,” -acute onset of high fever 3–14 days after the bite, frontal headache, retro-orbital pain, myalgias, arthralgias, hemorrhagic manifestations, rash, and low white blood cell count
Dengue Hemorrhagic Fever
Fever lasting 2–7 days with any hemorrhagic manifestation, thrombocytopenia, evidence of increased vascular permeability. Can have severe abdominal pain, CNS symptoms, shock.
Dengue DX and RX
- Dx-virus isolation or detection of DENV RNA in serum
- Rx-supportive, IV fluids, Dextran 40
Powassan Virus Overview
- Flavivirus(similar to deer tick virus); +ssRNA
- Reservoir varies by tick species (mostly small mammals)
- Tick (Ixodes) borne virus found mostly in Canada, northeast and Great Lakes regions, and Russia
Powassan Virus SX, DX and RX
- 1 week to 1 month incubation and infections range from asymptomatic to encephalitis and meningitis
- Fever, headache, vomiting, weakness, confusion, loss of coordination, speech difficulties, and seizures
- 50% develop permanent neurologic deficits
- 10% die
- Dx -POW virus-specific IgM antibody in serum or CSF (performed at the CDC), PCR
- RX -supportive