Lassa fever: Difference between revisions
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*endemic to parts of West Africa | *endemic to parts of West Africa | ||
**100,000-300,000 infections every year | **100,000-300,000 infections every year | ||
*Animal vector: Multimammate | *Animal vector: Multimammate rat (Mastomys natalensis) | ||
*Lassa fever is a [[viral hemorrhagic fever]] | *Lassa fever is a [[viral hemorrhagic fever]] | ||
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{{Fever in Traveler DDX}} | {{Fever in Traveler DDX}} | ||
== | ==Diagnostic Evaluation== | ||
*IgM or IgG ELISA or RT-PCR may be used to diagnose acute infections | *IgM or IgG ELISA or RT-PCR may be used to diagnose acute infections | ||
*Lymphopenia and elevated transaminases are non-specific, | *Lymphopenia and elevated transaminases are non-specific, but may indicate worse prognosis | ||
==Management== | ==Management== | ||
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**Overal mortality rates are much less; around 5000 deaths per 100,000-300,000 infections annually | **Overal mortality rates are much less; around 5000 deaths per 100,000-300,000 infections annually | ||
*Admit, isolation, possible ICU for serologic results and clinical observation/supportive care | *Admit, isolation, possible ICU for serologic results and clinical observation/supportive care | ||
==External Links== | |||
*Lassa Fever http://www.cdc.gov/vhf/lassa/index.html | |||
==See Also== | ==See Also== | ||
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==References== | ==References== | ||
<references/> | <references/> | ||
[[Category:ID]] | [[Category:ID]] | ||
[[Category:TropMed]] | [[Category:TropMed]] | ||
Revision as of 08:39, 6 September 2015
Background
- RNA virus of arenaviridae family
- endemic to parts of West Africa
- 100,000-300,000 infections every year
- Animal vector: Multimammate rat (Mastomys natalensis)
- Lassa fever is a viral hemorrhagic fever
Transmission
- Infected Multimammate rats shed virus in urine and droppings
- Inhalation, ingestion, or direct contact of excrement or soiled food
- Direct contact with bodily fluids of infected human
Clinical Features
- Incubation period: 1-3 weeks
- 80% of infections are mild
- Undiagnosed or low fever, malaise, headache
- 20% of infections are severe
- vomiting, diarrhea, respiratory distress, facial swelling, body pain, hemorrhage, shock
- death within 2 weeks due to multi-system organ failure
- Occasional neurologic symptoms: hearing loss, tremors, encephalitis
Differential Diagnosis
Fever in traveler
- Normal causes of acute fever!
- Malaria
- Dengue
- Leptospirosis
- Typhoid fever
- Typhus
- Viral hemorrhagic fevers
- Chikungunya
- Yellow fever
- Rift valley fever
- Q fever
- Amebiasis
- Zika virus
Diagnostic Evaluation
- IgM or IgG ELISA or RT-PCR may be used to diagnose acute infections
- Lymphopenia and elevated transaminases are non-specific, but may indicate worse prognosis
Management
- Isolation precautions: standard, contact and droplet
- Isolate in a single room with the door closed
- Limit entry and maintain a log of people who enter the room
- Use standard, contact, and droplet precautions
- Ribavirin has been shown to decrease mortality
- Most effective when given early (within 6 days)
- Supportive care
Disposition
- Those that seek medical care are more likely to have serious infections:
- Hospital mortality rates can reach 25%
- Overal mortality rates are much less; around 5000 deaths per 100,000-300,000 infections annually
- Admit, isolation, possible ICU for serologic results and clinical observation/supportive care
External Links
- Lassa Fever http://www.cdc.gov/vhf/lassa/index.html