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"Infection
Control for Viral Haemorrhagic Fevers
In the African Health Care Setting"
Annexes
11-12
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Annex 11 Laboratory Testing for VHFs |
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Always
wear protective clothing when handling specimens from suspected VHF cases.
Label all tubes carefully with name, date of collection and hospital number.
Provide a patient summary or fill out a clinical signs
and symptoms form (Annex 12). Contact your district officer for special
instructions about collecting and shipping specimens.
Diagnostic
Test |
Samples
required |
Preparation
&
Storage |
Shipping
|
Viruses
to be
confirmed |
|
ELISA
(Serology)
Detects:
- Viral antigen
- IgM and
IgG antibody
|
Whole
blood*
Serum or plasma
Acute and
convalescent** |
Freeze
or refrigerate
(as cold as possible) |
Frozen
on dry ice or ice packs or both**** |
Ebola
Lassa
CCHF
Rift Valley
Marburg
Yellow fever |
|
PCR
Detects:
DNA, RNA
(genetic
material) from virus
|
Whole blood
or clot***
Tissues (fresh frozen)
Serum/plasma
|
Refrigerate
or freeze
Freeze
|
Frozen
on dry ice
or ice packs or
both**** |
Ebola
Lassa
CCHF
Rift Valley
Marburg
Yellow fever |
Immunohisto-chemistry
(liver)
Detects:
Viral antigen in cells |
Liver
biopsy from
fatal cases |
Fix
in formalin
(can be stored up to 6 weeks) |
Room
temperature
(Do not freeze) |
Ebola
Lassa
CCHF
Rift Valley
Marburg
Yellow fever |
Immunohisto-chemistry
(skin)
Detects:
Viral antigen in cells |
Skin
biopsy from
fatal cases
(any site) |
Fix
in formalin (can be stored up to 6 weeks) |
Room
temperature
(Do not freeze) |
Ebola
Lassa |
Immunohisto-chemistry
(other tissues)
Detects:
Viral antigen in cells |
Tissue biopsy
from fatal cases
(other tissues,
spleen, lung,
heart, kidney)
|
Fix
in formalin
(can be stored up to 6 weeks) |
Room
temperature
(Do not freeze) |
Possible
detection of
Ebola, Lassa,
CCHF, Rift
Valley, Marburg,
Yellow Fever |
* Whole blood can be used
for enzyme-linked immunosorbent assay (ELISA) and may be frozen. Do
not centrifuge suspected VHF specimens because this increases risk to
the lab worker. If serum specimens have already been prepared these
can be used. Place specimens in plastic tubes for shipping and storage
and be sure that the tubes are sealed and properly labeled.
** Collect acute-phase specimen when patient is admitted to hospital
or diagnosed as suspected case and collect convalescent-phase specimen
at death or when discharged from the hospital.
*** Whole blood or tissue is preferred, although serum or plasma
may provide results.
**** Use both ice packs and dry ice to provide best results.
If dry ice or ice packs are not available, sample may be shipped at
room temperature and still provide valid results in most cases.
| Annex
12 Skin Biopsy on Fatal Cases for Diagnosis of Ebola |
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Ebola virus can be
detected in fatal cases from a skin specimen using immunohistochemistry
or RT-PCR tests developed by the Centers for Disease Control and Prevention (CDC). The skin specimen is fixed in
formalin or chaotrope which kills the virus. The specimen is no longer infectious once
it is placed in formalin or chaotrope and the outside of the vial has been decontaminated.
This vial can be shipped by mail or hand carried to the lab without risk.
Results are available within a week after the specimen arrives at the
CDC.
CDC provides Skin
Biopsy Kits for the collection of skin samples in formalin and chaotrope. If these are
available in your area, follow the simple instructions that are provided
in the kit. An example of the instructions is on the following pages.
If a kit is not available, the biopsy can still be collected and sent
for diagnosis to
Centers for Disease Control and Prevention
Infectious Diseases Pathology G-32
c/o DASH
Building 4, Room B-35
1600 Clifton
Road, NE
Atlanta, GA 30329-4018
 English: Skin Biopsy Kit (251 KB)
French: Skin Biopsy Kit (263KB)
Portuguese: Skin Biopsy Kit (316KB)
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| Infection
Control For VHFs Manual |
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