Lassa fever laboratory findings: Difference between revisions
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{{SK}} Lassa hemorrhagic fever; LHF | {{SK}} Lassa hemorrhagic fever; LHF | ||
==Overview== | ==Overview== | ||
The mainstay of diagnosis of Lassa fever is detection of either Lassa antibodies in the patient's serum. Additional investigations are also required following diagnosis to monitor the course of the disease for development of complications and target organ damage. | |||
==Serology== | ==Serology== | ||
*The mainstay of diagnosis of Lassa fever is detection of | *The mainstay of diagnosis of Lassa fever is detection of Lassa antibodies in the patient serum. | ||
*Patients with acute Lassa fever | *Patients with acute Lassa fever typically have high concentration of Lassa IgG antibodies, whereas patients already infected in the past have high IgM Lassa antibodies. | ||
==Other Laboratory tests== | ==Other Laboratory tests== | ||
* The following table summarizes the lab tests and | * Additional work-up is necessary following diagnosis to monitor the course of the disease for development of complications and target organ damage. | ||
* The following table summarizes the lab tests and findings associated with Lassa fever: | |||
{| style="border: 2px solid #DCDCDC; font-size: 90%; width: 60%;" | {| style="border: 2px solid #DCDCDC; font-size: 90%; width: 60%;" | ||
|+ '''Laboratory findings''' | |+ '''Laboratory findings''' | ||
|- | |- | ||
! style="width: 100px; background: #4479BA; text-align: center;"|{{fontcolor|#FFF|Lab tests}} | ! style="width: 100px; background: #4479BA; text-align: center;" |{{fontcolor|#FFF|Lab tests}} | ||
! style="width: 720px; background: #4479BA; text-align: center;"| {{fontcolor|#FFF|Laboratory findings}} | ! style="width: 720px; background: #4479BA; text-align: center;" | {{fontcolor|#FFF|Laboratory findings}} | ||
|- | |- | ||
| style="background: #F5F5F5; padding: 5px; text-align: center;"| '''[[Complete Blood Count]]''' | | style="background: #F5F5F5; padding: 5px; text-align: center;" | '''[[Complete Blood Count]]''' | ||
| style="background: #DCDCDC; padding: 5px;"| [[Lymphocytopenia]], [[thrombocytopenia]] | | style="background: #DCDCDC; padding: 5px;" | [[Lymphocytopenia]], [[thrombocytopenia]] | ||
|- | |- | ||
| style="background: #F5F5F5; padding: 5px; text-align: center;"| '''[[Liver function tests]]''' | | style="background: #F5F5F5; padding: 5px; text-align: center;" | '''[[Liver function tests]]''' | ||
| style="background: #DCDCDC; padding: 5px;"| Elevated [[aspartate aminotransferase]] ([[AST]]) | | style="background: #DCDCDC; padding: 5px;" | Elevated [[aspartate aminotransferase]] ([[AST]]) | ||
|- | |- | ||
| style="background: #F5F5F5; padding: 5px; text-align: center;"| '''[[Urinalysis]]''' | | style="background: #F5F5F5; padding: 5px; text-align: center;" | '''[[Urinalysis]]''' | ||
| style="background: #DCDCDC; padding: 5px;"| [[Proteinuria]] | | style="background: #DCDCDC; padding: 5px;" | [[Proteinuria]] | ||
|- | |- | ||
| style="background: #F5F5F5; padding: 5px; text-align: center;"| '''[[Chest X-rays]]''' | | style="background: #F5F5F5; padding: 5px; text-align: center;" | '''[[Chest X-rays]]''' | ||
| style="background: #DCDCDC; padding: 5px;"| Chest X-rays typically demonstrates basilar [[pneumonitis]] and [[pleural effusions]]. | | style="background: #DCDCDC; padding: 5px;" | Chest X-rays typically demonstrates basilar [[pneumonitis]] and [[pleural effusions]]. | ||
|- | |- | ||
| style="background: #F5F5F5; padding: 5px; text-align: center;"| '''[[Viral culture]]''' | | style="background: #F5F5F5; padding: 5px; text-align: center;" | '''[[Viral culture]]''' | ||
| style="background: #DCDCDC; padding: 5px;"| The [[virus]] often delays the diagnosis and may be cultured in 7 to 10 days | | style="background: #DCDCDC; padding: 5px;" | The [[virus]] often delays the diagnosis and may be cultured in 7 to 10 days | ||
|- | |- | ||
| style="background: #F5F5F5; padding: 5px; text-align: center;"| '''Viral isolation''' | | style="background: #F5F5F5; padding: 5px; text-align: center;" | '''Viral isolation''' | ||
| style="background: #DCDCDC; padding: 5px;"| Viral isolation is the most sensitive technique, but is infrequently used. The virus may be observed under electron microscopy. Obtain samples from blood, urine, pleural effusion, or throat swab of living patients or from tissue samples (either liver, kidney, spleen, or heart) of dead patients. | | style="background: #DCDCDC; padding: 5px;" | Viral isolation is the most sensitive technique, but is infrequently used. The virus may be observed under electron microscopy. Obtain samples from blood, urine, pleural effusion, or throat swab of living patients or from tissue samples (either liver, kidney, spleen, or heart) of dead patients. | ||
|} | |} | ||
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===Transporting Specimens Within the Hospital/Institution=== | ===Transporting Specimens Within the Hospital/Institution=== | ||
* Specimens should be placed in a durable, leak-proof secondary container for transport within a facility. To reduce the risk of breakage or leaks, do not use any pneumatic tube system for transporting suspected [[virus]] specimen. | * Specimens should be placed in a durable, leak-proof secondary container for transport within a facility. To reduce the risk of breakage or leaks, do not use any pneumatic tube system for transporting suspected [[virus]] specimen. | ||
* Packing and shipping infectious substances must be performed by people trained and certified in compliance with DOT or International Air Transport Association requirements.<ref name=CDC | * Packing and shipping infectious substances must be performed by people trained and certified in compliance with DOT or International Air Transport Association requirements.<ref name="CDC">{{cite web | title = CDC GUIDELINES FOR SPECIMEN COLLECTION, TRANSPORT, TESTING AND SUBMISSION FOR PUI | url =http://www.scemd.org/files/Plans/Mass_Casualty/Appendix_H_-_CDC_Guidelines_for_Specimen_Collection_Transport_Testing_and_Submission_for_PUI_-_19_Dec_2014.pdf }}</ref> | ||
==References== | ==References== | ||
Revision as of 12:42, 10 June 2015
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Lassa fever Microchapters |
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Diagnosis |
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Treatment |
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Case Studies |
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Lassa fever laboratory findings On the Web |
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American Roentgen Ray Society Images of Lassa fever laboratory findings |
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Risk calculators and risk factors for Lassa fever laboratory findings |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Ammu Susheela, M.D. [2]
Synonyms and keywords: Lassa hemorrhagic fever; LHF
Overview
The mainstay of diagnosis of Lassa fever is detection of either Lassa antibodies in the patient's serum. Additional investigations are also required following diagnosis to monitor the course of the disease for development of complications and target organ damage.
Serology
- The mainstay of diagnosis of Lassa fever is detection of Lassa antibodies in the patient serum.
- Patients with acute Lassa fever typically have high concentration of Lassa IgG antibodies, whereas patients already infected in the past have high IgM Lassa antibodies.
Other Laboratory tests
- Additional work-up is necessary following diagnosis to monitor the course of the disease for development of complications and target organ damage.
- The following table summarizes the lab tests and findings associated with Lassa fever:
| Lab tests | Laboratory findings |
|---|---|
| Complete Blood Count | Lymphocytopenia, thrombocytopenia |
| Liver function tests | Elevated aspartate aminotransferase (AST) |
| Urinalysis | Proteinuria |
| Chest X-rays | Chest X-rays typically demonstrates basilar pneumonitis and pleural effusions. |
| Viral culture | The virus often delays the diagnosis and may be cultured in 7 to 10 days |
| Viral isolation | Viral isolation is the most sensitive technique, but is infrequently used. The virus may be observed under electron microscopy. Obtain samples from blood, urine, pleural effusion, or throat swab of living patients or from tissue samples (either liver, kidney, spleen, or heart) of dead patients. |
Handling of Laboratory Samples
Guidance for Collection, Transport, and Submission of Specimens for Virus Testing
- Lassa virus is graded as biosafety level 4 according to The Centers for Disease Control and Prevention (CDC) classification.
- Ideally, specimens should be taken when a symptomatic patient reports to a healthcare facility and is suspected of having an exposure to the disease. However, if the onset of symptoms is <3 days, a later specimen may be needed to completely rule-out virus, if the first specimen tests negative.
- A minimum volume of 4 mL of whole blood preserved with EDTA is preferred, but whole blood preserved with either sodium polyanethol sulfonate, citrate, or clot activator may be submitted for testing. Heparin tubes are not recommended.
- Specimens should be shipped at 2-8°C or frozen on cold-packs, but not in glass containers.
Transporting Specimens Within the Hospital/Institution
- Specimens should be placed in a durable, leak-proof secondary container for transport within a facility. To reduce the risk of breakage or leaks, do not use any pneumatic tube system for transporting suspected virus specimen.
- Packing and shipping infectious substances must be performed by people trained and certified in compliance with DOT or International Air Transport Association requirements.[1]