Sterile sample containers

Plastic bags (disposable or Whirl-pak type), wide-mouth jars (0.3 to 1.5 liter capacity) with screw-on tops, bottles for water samples (the bottles for chlorinated water should contain enough sodium thiosulfate to provide a concentration of 100 mg per liter of sample), tin foil or heavy wrapping paper, metal cans.

Sterile and wrapped instruments for sample collection.

Spoons, scoops, tongue depressors, butcher’s knife, forceps, tongs, spatulas, drill bits, metal tubes (1.25 to 2.5 cm in diameter: 30 to 60 cm long) pipettes, scissors, swabs, Moore swabs (compact pads of gauze made of 120 by 15 cm strips, tied in the center with a long sturdy twine or wire for samples taken from sewers, drains, streams, pipes, etc).

Equipment for collecting specimens

Cardboard containers (with lids) for stool specimens, bottles containing a preservative solution for transport media, protective canisters or cartons for stool specimens, sterile swabs, rectal swab sets, sterile gauze pads 10 x 10 cm, tubes of transport media.

Equipment for recording temperature

Bayonet-type thermometers (for meat) for temperatures between -17.8 to 104^o C (-0,04ºF to 219,2ºF), at least 13 cm long (preferably 20 cm) in a protective container, bulb thermometer (-17.8 to 104^o C)
(-0,04ºF to 219,2ºF) in a protective container, fine point felt-tip marker, roll of adhesive tape, labels, waterproof cardboard strips with eyelets and tied with wire, flashlight, electric drill, matches, 0.1% peptone water, buffered distilled water (5 ml in screw-capped tubes), test tube rack, insulated chest, reporting forms.

General equipment

Fine-point marker, roll of adhesive tape, labels, perforated waterproof cards and wire, flashlight, electric drill, matches, peptone or buffered distilled water (5 ml in tubes with screw caps), test tube rack, insulated chest, pH meter, stream gauge, guidelines for investigation.

Sterilizing agents

95% ethanol, propane torch.

Refrigerants

Canned ice, refrigerant in plastic bags, liquid in cans, plastic or rubber bags or bottles that can be filled with water and frozen, heavy-duty plastic bags for ice.

Clothing

White laboratory coats, paper hats, disposable plastic gloves, disposable plastic boots (optional).

Solid food or mixtures of two foods

Cut or separate portion of food with a sterile knife or other utensil, if necessary. Collect aseptically at least 200 g of the sample with a sterile utensil and transfer to a sterile plastic bag or wide mouth glass jar. Collect several samples from top, center and elsewhere as considered necessary. Keep sample refrigerated.

Label. Place refrigerant around the sample container. Do not freeze or use dry ice. Take sample to the laboratory or send by the most rapid means possible.

Liquid food or beverages

Stir or shake. Collect the sample using one of the following methods:

1. Using a sterile utensil, place at least 200 ml of sample in a sterile container. Keep refrigerated.

As above.

2. Place a long sterile tube in the liquid and cover the top opening with the finger or the palm. Transfer the liquid to a jar or to a sterile bag and keep refrigerated.

As above.

3. Dip a Moore swab in the receptacle containing the liquid food or insert it into the pipe so the liquid circulates around it. Leave in place for several hours, if possible. Transfer the swab to a jar containing enrichment both.

Take the sample to the laboratory as soon as possible. Refrigeration is usually not necessary.

4. If the liquid is not too thick, pour 1 or 2 liters through a membrane filter. Transfer the filter pad aseptically to a jar containing enrichment broth.

As above.

Frozen foods

Use one of the following procedures:

Keep frozen, using dry ice if necessary. Take or send sample in insulated chest.

1. Send or take small frozen samples to the laboratory, without thawing or opening.

2. Using a large-diameter sterilized drill, drill from one side at the top of the container diagonally through the center to the bottom on the opposite side. Repeat from the other side until at least 200g of sample have been collected.

3. Break the frozen material using a sterilized hammer and chisel and collect the pieces using a sterile utensil. Transfer at least 200g to a sterile container and keep frozen, using dry ice if necessary. Take or send in insulated container.

Raw meat or poultry

Collect the sample using one of the following procedures:

Same as for solid or liquid food, except if they are in an enrichment broth, in which case the sample should be taken to the laboratory as soon as possible.

1. With a sterile implement or sterile plastic glove, place the poultry carcass or a large piece of meat in a large, sterile plastic bag. Add 100 to 300 ml of enrichment broth. Remove sample and seal the bag.

2. Wipe a sterile sponge over a large section of the carcass or piece of meat. Place the swab in a jar containing enrichment broth.

3. Moisten a swab with buffered distilled water, or 0.1% peptone water. Wipe the swab over a large section of the carcass or piece of meat with the swab. Place it in the enrichment broth for the pathogen being tested for.

4. Using a sterile plastic glove, wipe the carcass with sterile gauze pads and then place the pads in a jar containing enrichment broth.

5. Aseptically cut a piece of meat or skin from different parts of the carcass or piece of meat, or remove a part of the carcass. Put at least 200g of sample in a sterile plastic bag or glass jar. Refrigerate.

6. Put entire or part of poultry carcass or large piece of meat in a large, sterile plastic bag. Add 100 ml of enrichment broth and shake. Remove sample and seal the bag.

Dried food

Insert a sterile hollow tube near one edge of the top of one side of the container diagonally through the center to the bottom on the opposite side. Keep the top part and transfer it to a sterile container. Repeat on the other side until at least 200g have been collected. An alternative method consists of collecting material with a spoon, spatula, town depressor or similar utensil, provided it is sterile. Transfer the sample to a sterile container.

Keep in a water- and air-tight container. Take or to send to the laboratory.

Scrapings, material from air filters, sweepings, dust, waste, etc.

Cut or collect at least 200g of material with a sterile tongue depressor, spatula, spoon, or tongs, and place in sterile plastic bags or wide-mouth jars.

As for above, depending on the material.

Environmental swabs or swabs taken from equipment surfaces.

Moisten the swab with 0.1% peptone water or buffered distilled water and wipe over contact surfaces of equipment or environmental surfaces. Place in enrichment broth.

Pack, label, and send using same procedure as for rectal swab.

Air

Touch the plate or liquid with the device for sampling air, or let air-borne particles settle on the broth or plates.

Seal with insulation tape, label, and take to the laboratory. Refrigerate liquid samples.

Water

Collect samples from suspected areas, including water from bottles in refrigerators, ice cubes and basins. Before taking a water sample from the tap, let the water run for 10 seconds. For source samples, let it run for 5 minutes. Place a sterile jar under the running water and fill up to 2.5 cm from the top. Collect from 1 to 5 liters. Membrane filters may also be used. Moore swabs can be used to collect water samples in streams or plumbing, leaving them in place up to 48 hours, and then transferring them to jars containing enrichment broth.

Seal with insulation tape and label. Pack in absorbent material. Place in box and take or send to the laboratory. Refrigeration is usually not necessary.

Subungueal

1. Moisten a swab in sterile saline or Muller-Hinton broth.

2. Collect specimen and deposit immediately in the transport medium (Stuart’s).

Transport immediately to laboratory at ambient temperature. If this is not possible, can be left up to maximum of 24 hours, at which time the swab should be placed on ice.

Fecal E.Coli

Salmonella

Shigella

Staphylococci

Skin lesions:

boils, abscesses

secretions in general

(mainly in arms, hands, fingers, neck, and face)

1. Clean the skin with physiological solution or weak disinfectant to prevent contamination with saprophytic germs.

2. Apply pressure to the lesion using sterile gauzes and collect specimen on a sterile swab, trying to get as much secretion as possible.

3. If the lesion is closed, disinfect the skin and extract specimen using sterile syringe.

If it is not possible to send to the laboratory immediately, place the swab or specimen collected using the syringe in a sterile tube or transport medium (Stuart’s).

If it is not possible to send within 24 hours, store on ice until it can be delivered to the laboratory.

Staphylococci

Oropharynx and nasal fossae

Collect specimen with a sterile swab and immediately place in transport medium.

Send immediately to the laboratory. If it is not possible to send within 24 hours, store on ice until it can be delivered.

Staphylococci

Vomit

The patient can vomit directly into a sterile container or in a plastic bag.

It can be collected from a clean container or receptacle with a spoon or spatula and placed in sterile container.

Keep refrigerated until the analysis id done, but UNFROZEN

Send immediately to the laboratory.

Pathogens

Toxins

Urine

Clean the area around the urethral orifice with a 4% iodine solution. Collect up to 30 ml in a sterile flask and cover.

Keep refrigerated but UNFROZEN up to analysis.

Send immediately to the laboratory

Pathogens

Chemical and natural toxins

Blood

Collect the blood from the mid-anticubital vein, 15 ml from an adult, 3 ml from a child. Centrifuge the blood and place serum in a small vial and keep at –18^o C. Another method is to leave the blood in its current state, extract the serum with a pipette and place in a vial.

Refrigerate the blood. Never freeze blood because the red blood cells lyse and alter the nature of the sample.

The serum may be frozen.

Antibodies, agents, and toxins

When to collect

Within the 48-72 hours following the onset of the disease.

During periods of active diarrhea (preferably as soon as possible after onset of the disease).

Any time after the onset of the disease (preferably as soon as possible).

Quantity of specimen to collect

As much as possible from each of 10 sick people (at least 10 cc per person); 10 control samples may also be collected.

Two rectal swabs or swabs taken from fresh stool from each of 10 sick people; 10 control samples may also be collected.

A fresh stool from each of 10 sick people; 10 control samples may also be collected.

Method of collection

Place fresh stool (preferably liquid) that has not been mixed with urine, in clean, dry containers, (for example, containers for collecting urine samples).

Soak two rectal swabs in the Cary-Blair transport medium, then insert sequentially 1-1.5 inches into the rectum, slowly rotate and remove. Place both swabs in a single tube containing Cary-Blair transport medium. Break off the upper ends of the swab sticks and discard.

Collect stool that has not been mixed with urine and place in a clean container. Place part of each specimen in a preservative solution of formaldehyde and polyvinyl alcohol at a rate of 1 part specimen to 3 parts preservative. Mix well.

Holding of specimen after collection

Refrigerate immediately at 4ºC (39,2ºF). DO NOT FREEZE if specimen is to be examined under electron microscope.

Refrigerate immediately at 4ºC (39,2ºF) if the tests are to be done within the 48 hours of collection; otherwise freeze the specimen at -70ºC (-94ºF).

Keep at room temperature or refrigerate at 4ºC (39,2ºF). DO NOT FREEZE.

Transport

Keep specimens refrigerated. Place specimens in sealed bags and pack them on ice or on refrigerant packages in an insulated container. Send by express mail. DO NOT FREEZE.

Refrigerate as indicated for viral specimens. Frozen samples should be sealed in bags and placed on dry ice. Send in an insulated container by overnight mail.

Refrigerate as indicated for viral specimens. Specimens kept at room temperature should be sent in waterproof containers. DO NOT FREEZE.