Public Health Guidance for Community-Level Preparedness and Response to
Severe Acute Respiratory Syndrome (SARS) Version 2

Supplement F: Laboratory Guidance

Appendix F4

Guidelines for Collecting Specimens from Potential SARS Patients

Before collecting and shipping specimens for SARS-CoV testing, consult
with the state health department/state epidemiologist to determine
whether the patient meets the SARS case definition. Health department
contact information is available at:
[www.cste.org/members/state_and_territorial_epi.asp](http://www.cste.org/members/state_and_territorial_epi.asp).

When possible, collect multiple respiratory specimens for testing. For
example, collect specimens from two different sites on the same day
(e.g., one nasopharyngeal swab and a stool specimen or another
respiratory specimen) or from two different times during the illness.
The chart on the last page specifies recommended specimen types for
SARS-CoV diagnostics by stage of illness, including postmortem specimen
collection.

A signed consent form is recommended when collecting specimens for
SARS-CoV RT-PCR or antibody testing. Information on the consent process
for collection of respiratory specimens, blood or stool for RT-PCR
testing is provided at:
[www.cdc.gov/ncidod/sars/lab/rtpcr/index.htm](http://www.cdc.gov/ncidod/sars/lab/rtpcr/index.htm).
Information on the consent process for the collection of blood/serum for
antibody testing is provided at:
[www.cdc.gov/ncidod/sars/lab/eia/index.htm](http://www.cdc.gov/ncidod/sars/lab/eia/index.htm).

> **RT-PCR Diagnostics**
>
> Although studies to date have not definitively determined the best
> specimens for SARS RT-PCR diagnostics, it is reasonable to collect:
>
> *During the first week of illness:* Nasophyaryngeal (NP) swab plus
> oropharyngeal (OP) swab and a serum or plasma specimen
>
> *After the first week of illness:* NP swab plus OP swab and a stool
> specimen
>
> **Serologic Diagnostics**
>
> Serum specimens for SARS-CoV antibody testing should be collected when
> the diagnosis is first suspected and at later times if indicated. An
> antibody response is occasionally detected during the first week of
> illness, likely to be detected by the end of the second week of
> illness, and sometimes may not be detected until \>28 days after onset
> of symptoms.

## 

## I. Collecting Respiratory Specimens

Eight types of respiratory specimens may be collected for viral and/or
bacterial diagnostics: 1) nasopharyngeal wash/aspirates, 2)
nasopharyngeal swabs, 3) oropharyngeal swabs, 4) broncheoalveolar
lavage, 5) tracheal aspirate, 6) pleural fluid tap, 7) sputum; and 8)
post-mortem tissue. Nasopharyngeal wash/aspirates are the specimen of
choice for detection of most respiratory viruses and are the preferred
specimen type for children under age 2 years.

In contrast to most respiratory pathogens for which respiratory
specimens are optimally collected within 72 hours after the onset of
symptoms, levels of SARS-CoV may be higher later in the course of the
illness.

Before collecting specimens, review the infection control precautions in
Supplement I.

### 

### A. Collecting specimens from the upper respiratory tract 

> **1. Nasopharyngeal wash/aspirate**
>
> Have the patient sit with head tilted slightly backward. Instill 1
> ml-1.5 ml of nonbacteriostatic saline (pH 7.0) into one nostril. Flush
> a plastic catheter or tubing with 2 ml-3 ml of saline. Insert the
> tubing into the nostril parallel to the palate. Aspirate
> nasopharyngeal secretions. Repeat this procedure for the other
> nostril. Collect the specimens in sterile vials. Label each specimen
> container with the patient's ID number and the date collected. If
> shipping domestically, use cold packs to keep the sample at 4°C. If
> shipping internationally, pack in dry ice.
>
> **2. Nasopharyngeal or oropharyngeal swabs**[\
> ]{.underline}
>
> Use only sterile dacron or rayon swabs with plastic shafts. Do
> [not]{.underline} use calcium alginate swabs or swabs with wooden
> sticks, as they may contain substances that inactivate some viruses
> and inhibit PCR testing.
>
> **Nasopharyngeal swabs** \-- Insert a swab into the nostril parallel
> to the palate. Leave the swab in place for a few seconds to absorb
> secretions. Swab both nostrils.\
> **Oropharyngeal swabs** \-- Swab the posterior pharynx and tonsillar
> areas, avoiding the tongue.
>
> Place the swabs immediately into sterile vials containing 2 ml of
> viral transport media. Break the applicator sticks off near the tip to
> permit tightening of the cap. Label each specimen container with the
> patient's ID number and the date the sample was collected. If shipping
> domestically, use cold packs to keep sample at 4°C. If shipping
> internationally, pack in dry ice.

### B. Collecting specimens from the lower respiratory tract

> **1. Broncheoalveolar lavage, tracheal aspirate, pleural fluid tap**
>
> Centrifuge half of the specimen, and fix the cell pellet in formalin.
> Place the remaining unspun fluid in sterile vials with external caps
> and internal O-ring seals. If there is no internal O-ring seal, then
> seal tightly with the available cap and secure with Parafilm^®^. Label
> each specimen container with the patient's ID number and the date the
> sample was collected. If shipping domestically, use cold packs to keep
> sample at 4°C. If shipping internationally, ship fixed cells at room
> temperature and unfixed cells frozen.
>
> **2. Sputum**
>
> Educate the patient about the difference between sputum and oral
> secretions. Have the patient rinse the mouth with water and then
> expectorate deep cough sputum directly into a sterile screw-cap sputum
> collection cup or sterile dry container. If shipping domestically, use
> cold packs to keep sample at 4°C. If shipping internationally, pack in
> dry ice.

## 

## II. Collecting Blood Components

Serum and blood (plasma) should be collected early in the illness for
RT-PCR testing. The reliability of RT-PCR testing performed on blood
specimens decreases as the illness progresses.

Both acute and convalescent serum specimens should be collected for
antibody testing. To confirm or rule out SARS-CoV infection, it is
important to collect convalescent serum specimens \>28 days after the
onset of illness.

### 

### A. Collecting serum for antibody or RT-PCR testing

Collect 5 ml-10 ml of whole blood in a serum separator tube. Allow the
blood to clot, centrifuge briefly, and collect all resulting sera in
vials with external caps and internal O-ring seals. If there is no
internal O-ring seal, then seal tightly with the available cap and
secure with Parafilm^®^. The minimum amount of serum preferred for each
test is 200 microliters, which can easily be obtained from 5 mL of whole
blood.

A minimum of 1 cc of whole blood is needed for testing of pediatric
patients. If possible, collect 1 cc in an EDTA tube and in a clotting
tube. If only 1cc can be obtained, use a clotting tube.

Label each specimen container with the patient's ID number and the date
the specimen was collected. If unfrozen and transported domestically,
ship with cold packs to keep the sample at 4°C. If frozen or transported
internationally, ship on dry ice.

### B. Collecting EDTA blood (plasma) for RT-PCR

Collect 5 ml-10 ml of blood in an EDTA (purple-top) tube. Transfer to
vials with external caps and internal O-ring seals. If there is no
internal O-ring seal, then seal tightly with the available cap and
secure with Parafilm^®^. Label each specimen container with patient's ID
number and date of collection. Store and ship blood specimens with cold
packs to keep the sample at 4°C.

## 

## III. Collecting Stool Specimens for PCR

Begin collecting stool specimens as soon as possible in the course of
the illness. Although collecting earlier specimens is ideal, SARS-CoV
has been detected in stool as late as one month after the onset of
symptoms.

Place each stool specimen \-- as large a quantity as can be obtained (at
least 10 cc) \-- in a leak-proof, clean, dry container, and refrigerate
at 4°C. Patients may drape plastic kitchen wrap across the back half of
the toilet, under the toilet seat, to facilitate collection of stool
specimens.

IMPORTANT: Refrigerate or freeze tubes after specimens are placed in
them. If specimens will be examined within 48 hours after collection,
they can be refrigerated. If specimens must be held longer than 48
hours, freeze them as soon as possible after collection. Although
storage in an ultra-low freezer (-70°C) is preferable, storage in a
home-type freezer (if properly set at -20°C) is acceptable for short
periods.

Specimens from possible and known SARS cases must be packaged, shipped,
and transported according to the current edition of the International
Air Transport Association (IATA) Dangerous Goods Regulations at
([www.iata.org/dangerousgoods/index](http://www.iata.org/dangerousgoods/index))
and US DOT 49 CFR Parts 171-180
([hazmat.dot.gov/rules.htm](http://hazmat.dot.gov/rules.htm)).

Step-by-step instructions on appropriate packaging and labeling are
available at:
[www.cdc.gov/ncidod/sars/pdf/packingspecimens-sars.pdf](http://www.cdc.gov/ncidod/sars/pdf/packingspecimens-sars.pdf).

![](media/image1.png)

+----------------------+-------------+-------------+------------------+
| **Specimens for      |             |             |                  |
| SARS-CoV Testing:**  |             |             |                  |
|                      |             |             |                  |
| **Priority Specimens |             |             |                  |
| and Timing for       |             |             |                  |
| Collection**         |             |             |                  |
|                      |             |             |                  |
| The likelihood of    |             |             |                  |
| detecting infection  |             |             |                  |
| is increased if      |             |             |                  |
| multiple specimens,  |             |             |                  |
| e.g., stool, serum,  |             |             |                  |
| and respiratory      |             |             |                  |
| tract specimens, are |             |             |                  |
| collected during the |             |             |                  |
| course of illness.   |             |             |                  |
+----------------------+-------------+-------------+------------------+
| **Specimen, by test  | **\<1 week  | **1-3 weeks | **\>3 weeks      |
| type**               | after       | after       | after symptom    |
|                      | symptom     | symptom     | onset**          |
|                      | onset**     | onset**     |                  |
+----------------------+-------------+-------------+------------------+
| RT-PCR^1^ for viral  |             |             |                  |
| RNA detection        |             |             |                  |
+----------------------+-------------+-------------+------------------+
| > Sputum^2^          | √^3^        | √√          | √                |
+----------------------+-------------+-------------+------------------+
| > Bronchoalveolar    | √           | √√          | √                |
| > lavage, tracheal   |             |             |                  |
| > aspirate, or       |             |             |                  |
| > pleural fluid      |             |             |                  |
| > tap^4^             |             |             |                  |
+----------------------+-------------+-------------+------------------+
| > Nasopharyngeal     | √           | √√          | √                |
| > wash/aspirate      |             |             |                  |
+----------------------+-------------+-------------+------------------+
| > Nasopharyngeal and | √           | √√          | √                |
| > oropharyngeal      |             |             |                  |
| > swabs              |             |             |                  |
+----------------------+-------------+-------------+------------------+
| > Serum (serum       | √√          | √           | not recommended  |
| > separator tube)    |             |             |                  |
+----------------------+-------------+-------------+------------------+
| > Blood (plasma)     | √√          | √           | not recommended  |
| >                    |             |             |                  |
| > (EDTA/purple top   |             |             |                  |
| > tube for plasma)   |             |             |                  |
+----------------------+-------------+-------------+------------------+
| > Stool (minimum 10  | √           | √√          | √√               |
| > cc specimen)       |             |             |                  |
+----------------------+-------------+-------------+------------------+
| EIA^1^ for antibody  |             |             |                  |
| detection            |             |             |                  |
+----------------------+-------------+-------------+------------------+
| > Serum^5^ (serum    | √√          | √√          | √√               |
| > separator tube)    |             |             |                  |
+----------------------+-------------+-------------+------------------+

^1^ Because of the investigational nature of both the SARS RT-PCR
(reverse transcription-polymerase chain reaction) and the SARS EIA
(enzyme immunoassay), it is recommended that the clinician obtain a
signed informed consent form from the patient. The consent form for the
RT-PCR test can be found at:
[www.cdc.gov/ncidod/sars/lab/rtpcr/consent.htm](http://www.cdc.gov/ncidod/sars/lab/rtpcr/consent.htm).
The consent form for the EIA test can be found at:
[www.cdc.gov/ncidod/sars/lab/eia/consent.htm](http://www.cdc.gov/ncidod/sars/lab/eia/consent.htm).

^2^ A sputum specimen is preferred if the patient has a productive
cough.

^3^ The more checks, the better the results from a particular specimen
at a specific point in the illness.

^4^ Consider these specimen types if sputum is not available.

^5^ Also collect a convalescent specimen \>28 days post onset.

For more information, visit
[www.cdc.gov/ncidod/sars](http://www.cdc.gov/ncidod/sars/) or call the
CDC public response hotline\
at (888) 246-2675 (English), (888) 246-2857 (Español), or (866) 874-2646
(TTY)