Mcb 7 Flashcards
(44 cards)
What is the primary reservoir for Lassa virus?
Multimammate rat (Mastomys natalensis)
This rodent may excrete the virus in urine for the rest of its life.
What are common complications associated with viral hemorrhagic fever (VHF) infection?
- Retinitis
- Orchitis
- Encephalitis
- Hepatitis
- Transverse myelitis
- Uveitis
Deafness is the most common complication in patients recovering from Lassa fever.
How is Lassa fever primarily transmitted?
- Ingestion
- Inhalation of urine and droppings
- Direct contact with infected materials
Person-to-person transmission may occur through exposure to blood, tissue, secretions, or excretions of an infected individual.
What is the incubation period for Lassa fever?
2-21 days
What is the estimated annual incidence of Lassa fever infections?
100,000-300,000 infections per year
Which regions are most affected by Lassa fever?
- Nigeria
- Sierra Leone
- Guinea
- Liberia
Other arenaviruses cause sporadic VHF outbreaks in South America.
What are the initial symptoms of Lassa fever?
- High fever
- Headache
- Fatigue
- Abdominal pain
- Myalgias
- Prostration
Progression may lead to hematemesis and bloody diarrhea.
Which laboratory findings are predictive of high mortality in Lassa fever?
Elevated hepatic transaminases
True or False: Ribavirin is recommended for the treatment of Lassa fever.
True
What are some key management strategies for viral hemorrhagic fever?
- Fluid and electrolyte balance
- Supportive therapy
- Avoid IM injections
- Minimize invasive procedures
Barrier nursing is essential to prevent transmission.
What is the virology of Lassa fever virus?
It is an enveloped, circular, single-stranded ambisense segmented RNA virus with helical symmetry.
What are the classic findings as Lassa fever progresses?
- Pharyngitis
- Conjunctival injection
- Nondependent edema
- Petechial or ecchymotic rash
- GI bleeding
- Hypotension and/or shock
What is the recommended approach for laboratory testing in suspected Lassa fever cases?
Perform the minimum necessary laboratory testing due to risks associated with handling infectious materials.
Fill in the blank: Lassa fever is one of the agents of _______.
Viral hemorrhagic fevers (VHFs)
What are the four viral families known to cause VHF disease in humans?
- Arenaviridae
- Bunyaviridae
- Filoviridae
- Flaviviridae
What are the mainstay therapies in the management of viral hemorrhagic fever?
- Fluid & electrolyte balance
- Supportive therapy
- Blood and blood products as clinically indicated
What is a potential risk associated with the reuse of unsterile needles in VHF?
Transmission of VHF
What are the criteria for classifying viruses?
Host types, Disease syndrome, Viral structure & symmetry, Nucleic acid types (Genome), mRNA production mechanism, Modern taxonomy (Phylogenetic)
What is the Baltimore classification of viruses based on?
Nucleic Acid types and mRNA production mechanism
What are the six groups of viruses in Baltimore’s classification?
- ds-DNA viruses
- ss-DNA viruses
- ds-RNA viruses
- ss-RNA viruses with positive strands (+ve polarity)
- ss-RNA viruses with negative strands (-ve polarity)
- ss-RNA viruses associated with the enzyme reverse transcriptase
Name three medically important double-stranded DNA viruses.
- Poxviridae
- Herpesviridae
- Hepadnaviridae
DNA viruses can be classified into what categories?
- Enveloped viruses
- Non-enveloped viruses
What family does Parvovirus belong to?
Family: Parvoviridae
What is the order of the Parvovirus?
Order: Piccovirales
