Viral Hemorrhagic Fevers Flashcards
(100 cards)
1
Q
What are Viral Hemorrhagic Fevers (VHFs)?
A
A group of illnesses caused by several distinct families of viruses.
2
Q
What systems are affected by VHFs?
A
Multiple organ systems in the body.
3
Q
How do VHFs impair the body?
A
By damaging the vascular system and impairing the body’s ability to regulate itself.
4
Q
How are VHFs classified in terms of biosafety?
A
Biosafety level four (BSL4) pathogens.
5
Q
How are VHFs classified as biological agents?
A
Classified as Category A Agent.
6
Q
Into how many families are VHFs grouped?
A
Four distinct families.
7
Q
Name the four distinct families of viruses causing VHFs.
A
Arenaviridae, Filoviridae, Bunyaviridae, Flaviviridae.
8
Q
Which family does Ebola belong to?
A
Filoviridae.
9
Q
Which family does Marburg belong to?
A
Filoviridae.
10
Q
Which family does Lassa hemorrhagic fever belong to?
A
Arenaviridae.
11
Q
Which family does Crimean-Congo hemorrhagic fever belong to?
A
Bunyaviridae.
12
Q
Which family does Rift Valley fever belong to?
A
Bunyaviridae.
13
Q
Which family does Dengue fever belong to?
A
Flaviviridae.
14
Q
Which family does Yellow fever belong to?
A
Flaviviridae.
15
Q
What is the geographic distribution of Ebola and Marburg?
A
Africa.
16
Q
What is the vector for Lassa hemorrhagic fever?
A
Rodent.
17
Q
What is the vector for Crimean-Congo hemorrhagic fever?
A
Tick.
18
Q
What is the vector for Rift Valley fever?
A
Mosquito.
19
Q
What is the vector for Dengue fever?
A
Mosquito.
20
Q
What is the vector for Yellow fever?
A
Mosquito.
21
Q
Which VHFs have a rodent as their natural reservoir?
A
Arenaviridae viruses like Lassa and New World arenaviruses.
22
Q
What are the hosts for Ebola and Marburg?
A
Unknown hosts.
23
Q
How are VHFs transmitted to humans?
A
Through exposure to urine, fecal matter, saliva, or other body excretions from infected reservoir hosts or vectors.
24
Q
How is person-to-person transmission of VHFs achieved?
A
By contact with body fluids from an infected person.
25
What is the incubation period for VHFs?
2 to 21 days.
26
What is the mortality range for VHFs?
0.5 to 90%.
27
What is the classification of Arenaviridae?
Old World and New World groups.
28
What is the natural reservoir for Arenaviridae viruses?
Rodents.
29
How was the Tacaribe virus discovered?
In 1956 as Tacaribe virus.
30
Name an Old World Arenavirus.
Lassa virus.
31
Name a New World Arenavirus.
Junin virus.
32
How are Arenaviruses transmitted to humans?
Contact with excretions or materials contaminated with excretions of an infected rodent.
33
What are the possible modes of transmission for Arenaviruses?
Inhalation of tiny particles soiled with rodent urine or saliva, agricultural work, and domestic settings.
34
What are secondary modes of transmission for Lassa and Machupo viruses?
Person-to-person and nosocomial transmission.
35
When and where was the Marburg virus first identified?
1967 in Marburg, Germany and Yugoslavia.
36
When and where was the Ebola virus first identified?
1976 in Zaire and Sudan.
37
How many species of Ebola virus have been identified?
Four species identified: Ivory Coast, Sudan, Zaire, and Reston.
38
What is the source of human infection for Filoviridae viruses?
Unknown.
39
What is the incubation period for Filoviridae viruses?
3-16 days.
40
What is the mortality rate for Filoviridae viruses?
High mortality rate.
41
How are Filoviridae viruses transmitted?
Through contact of contaminated fingers with oral mucosa or conjunctiva, or by small droplet airborne nuclei.
42
What type of exposure leads to Filoviridae infection in experimental animals?
Mucosal exposure.
43
What are the main families within Bunyaviridae?
Phlebovirus, Nairovirus, Hantavirus.
44
What disease is caused by Phlebovirus?
Rift Valley fever.
45
What disease is caused by Nairovirus?
Crimean-Congo hemorrhagic fever.
46
What disease is caused by Hantavirus?
Hemorrhagic fever with renal syndrome.
47
What is the natural reservoir for Hantavirus?
Rodent.
48
What is the incubation period for Bunyaviridae diseases?
2-5 days for Rift Valley fever, 3-12 days for Crimean-Congo hemorrhagic fever, 9-35 days for Hantavirus.
49
Which virus causes Yellow fever?
Flaviviridae.
50
Which virus causes Dengue hemorrhagic fever?
Flaviviridae.
51
What is the source of human infection for Kyasanur forest disease?
Tick.
52
What is the source of human infection for Omsk hemorrhagic fever?
Tick, Muskrat-contaminated water.
53
How long can Ebola be found in seminal fluid after symptom onset?
82-101 days.
54
How long can Marburg be found in seminal fluid after symptom onset?
83 days.
55
How long can Lassa be found in seminal fluid after symptom onset?
90 days.
56
How long can Junin be found in seminal fluid after symptom onset?
7-22 days.
57
How long can Lassa fever virus be found in urine after symptom onset?
32 days.
58
What are the nonspecific clinical manifestations of VHFs?
High fever, malaise, headache, arthralgias, myalgias, nausea, abdominal pain, and nonbloody diarrhea.
59
What is the overall incubation period for VHFs?
2 – 21 days.
60
What are the early signs of VHFs?
High fever, hypotension, relative bradycardia, tachypnea, conjunctivitis, and pharyngitis.
61
Which viruses have an abrupt onset of symptoms?
Filoviruses, Rift Valley fever, and flaviviruses.
62
Which viruses have a more insidious onset of symptoms?
Arenaviruses.
63
What are the typical early signs of VHFs?
Fever, hypotension, relative bradycardia, tachypnea, conjunctivitis, and pharyngitis.
64
What are some severe clinical manifestations of VHFs?
Cutaneous flushing or a skin rash, petechiae, mucous membrane and conjunctival hemorrhage, hematuria, hematemesis, melena, DIC, and circulatory shock.
65
What is the characteristic rash associated with Marburg disease?
A diffuse maculopapular rash.
66
What is the characteristic rash associated with Bolivian hemorrhagic fever?
Erythematous rash.
67
What are the distinctive clinical features of Ebola?
Severe hemorrhagic manifestations, multi-organ failure, and shock.
68
What are the distinctive clinical features of Marburg?
Similar to Ebola: fever, severe headache, muscle pain, vomiting, diarrhea, stomach pain, and unexplained bleeding or bruising.
69
What is the mortality rate for Ebola?
25% to 90%, depending on the outbreak and healthcare support.
70
What is the mortality rate for Marburg?
23% to 90%, similar to Ebola.
71
What are the distinctive clinical features of Lassa fever?
Gradual onset with fever, weakness, and malaise followed by headache, sore throat, muscle pain, chest pain, nausea, vomiting, diarrhea, cough, and abdominal pain. Severe cases may involve hemorrhaging.
72
What are the distinctive clinical features of Yellow fever?
Fever, chills, severe headache, back pain, general body aches, nausea, vomiting, fatigue, and weakness. Severe cases can involve jaundice and bleeding.
73
What is the mortality rate for Lassa fever?
15% to 20% in severe cases.
74
What is the mortality rate for Yellow fever?
20% to 50% in severe cases.
75
What are the distinctive clinical features of Rift Valley fever?
Flu-like symptoms, and severe cases can lead to hemorrhagic fever, encephalitis, or hepatitis.
76
What is the mortality rate for Rift Valley fever?
Less than 1% for mild cases, up to 10% for hemorrhagic cases.
77
What are the distinctive clinical features of Omsk hemorrhagic fever?
High fever, severe headache, severe muscle pain, vomiting, gastrointestinal symptoms, and bleeding.
78
What is the mortality rate for Omsk hemorrhagic fever?
About 2% to 10%.
79
What are the distinctive clinical features of Kyasanur Forest disease?
High fever, severe headache, severe muscle pain, vomiting, gastrointestinal symptoms, and bleeding.
80
What is the mortality rate for Kyasanur Forest disease?
About 10%.
81
What are the common lab abnormalities in VHFs?
Thrombocytopenia, leukopenia, elevated liver enzymes, prolonged prothrombin and partial thromboplastin times, proteinuria, and hematuria.
82
What is typically seen in urinalysis of VHF patients?
Proteinuria and hematuria.
83
What are the main tests for diagnosing VHFs?
Polymerase chain reaction (PCR) testing, enzyme-linked immunosorbent assay (ELISA), virus isolation, and immunohistochemistry.
84
What are the main public health actions for VHFs?
Immediate isolation of patients, contact tracing, implementation of infection control measures, and public health notifications.
85
What should be done when a VHF case is reported?
Isolate the patient, notify public health authorities, initiate contact tracing, and implement strict infection control measures.
86
How should case contacts be managed in a VHF outbreak?
Monitor for symptoms, restrict activities, and provide prophylactic treatment if available.
87
What are the personal protective measures for healthcare workers dealing with VHFs?
Use of personal protective equipment (PPE), strict hand hygiene, and adherence to infection control protocols.
88
What is the prophylaxis recommendation for VHFs?
Prophylaxis with antiviral drugs (e.g., ribavirin for Lassa fever), vaccination where available (e.g., yellow fever vaccine), and post-exposure prophylaxis.
89
What is the mainstay of treatment for VHFs?
Supportive care (e.g., fluid and electrolyte management, treatment of secondary infections), use of antiviral drugs where effective, and critical care for severe cases.
90
What should be done if a case of VHF is suspected?
Implement isolation precautions, notify public health authorities, and start diagnostic testing.
91
What should be done if infection with Arenaviruses or Bunyaviruses is confirmed?
Isolation, supportive care, and administration of antiviral drugs if indicated.
92
What should be done if infection with Filovirus or Flavirus is confirmed?
Similar to Arenaviruses/Bunyaviruses, with additional precautions due to higher transmission risk.
93
What are the measures for protecting employee health in VHF outbreaks?
Ensure proper training on PPE use, provide mental health support, and monitor for health issues.
94
What is the recommended environmental disinfection method for VHFs?
Use of hospital-grade disinfectants effective against viruses, ensuring thorough cleaning of surfaces and equipment.
95
What are the infection control measures for handling VHFs?
Isolation of infected individuals, use of PPE, and strict hand hygiene and environmental cleaning protocols.
96
What is the incubation period for Lassa fever?
6-21 days, typically 10 days.
97
What is the vector for Yellow fever?
Aedes mosquito.
98
What are the zoonotic hosts for Arenaviridae?
Rodents.
99
What is the geographic distribution for Crimean-Congo hemorrhagic fever?
Africa, Asia, the Middle East, and the Balkans.
100
What are the symptoms of VHFs?
High fever, fatigue, dizziness, muscle aches, loss of strength, and exhaustion. Severe cases involve bleeding under the skin, in internal organs, or from orifices like the mouth, eyes, or ears.
