What is the purpose of obtaining a urine specimen through the clean catch midstream collection method?

• To confirm the diagnosis of a urine infection. The usual symptoms of a urine infection are pain when you pass urine and passing urine frequently. However, symptoms are not always typical, particularly in children and the elderly, so a urine test may be needed.
• To decide the best antibiotic to use. Some germs (bacteria) are resistant to some antibiotics. If the test shows that bacteria are in the urine then the bacteria are tested against various antibiotics. This finds which antibiotics will kill the bacteria in the urine.

The aim is to obtain a sample (specimen) of urine from the middle of your bladder. Urine does not normally have any germs (bacteria) in it (urine should be sterile). If bacteria are found in the sample, it means that the urine is infected. A midstream specimen of urine (MSU) is best, as the first bit of urine that you pass may be contaminated with bacteria from the skin.

Before doing an MSU, wash your hands and ideally your genitals as well.

Women - hold open the entrance to the vagina (your labia). Men - pull back your foreskin. Pass some urine into the toilet. Then, without stopping the flow of urine, catch some urine in a clean (sterile) bottle. (The bottle is usually provided by a doctor or nurse.) Once you have enough urine in the bottle, finish off passing the rest of your urine into the toilet.

Do not open the sterile bottle until you are ready to take the sample. Avoid touching any part of your genitals with the bottle, as this will increase the risk of contamination. Put the cap back on the container. You do not need to fill the bottle to the top; a small amount will do. Some specimen bottles contain a powder which helps the sample last longer for testing (a preservative). If this is the case, a mark on the bottle will indicate the ideal amount of urine. However, if that is difficult, any amount is better than none.

The sooner the sample is given in to the doctor's surgery, or to the laboratory, the better. Within two hours is best. If that is not possible, put the sample in the fridge until you take it to the doctor or laboratory.

If it is difficult to aim your urine stream into the bottle, you may use another container such as a jam jar or a disposable plastic cup. You can then pour the urine into the sterile bottle. If you do this, make sure the container you pass water into is as clean as possible. Wash it well and rinse it with boiling water. You should still pass the first part of your urine stream into the toilet. In this way, you are collecting the urine from the bladder.

The result of an MSU takes 2-7 days.

It is not easy to obtain a pure midstream specimen of urine (MSU) in young children and babies. The following methods may be used:

The usual way is to catch some urine in the specimen bottle whilst the child is passing urine. This is called the clean catch method. Just be ready with the open bottle as the child passes urine. (Be careful not to touch the open rim of the bottle with your fingers, as this may contaminate the specimen with germs (bacteria) from your fingers.)

For babies the following might work: take the nappy off about one hour after a feed. Tap gently with a finger (about once a second) just at the bottom of the tummy (abdomen) above the genitals. Have the open bottle ready. Quite often, within about five minutes, the baby will pass urine. Try to catch some in the bottle.

One method is to place a special absorbent pad in a nappy. Your doctor or nurse will provide the special pad and tell you how to use it. Basically, when you place the pad in the nappy, check the pad every 10 minutes to see if it is wet with urine. Do not leave in for longer than 30 minutes as this may increase the risk of contamination. Therefore, replace the pad with a fresh one every 30 minutes until urine has been passed. Then, use the syringe provided to suck the urine from the pad. Then, transfer the urine in the syringe into a sterile container. Do not use any other type of pads, cotton wool balls or gauze as they could alter the results.

These are bags which are placed inside the nappy to collect urine. They are stuck to the skin around the genitals. When the infant passes urine, it collects in the bag. You then take off the bag, cut the corner of the bag and pour the urine into the sterile bottle. Always wash your child's genital area and dry it carefully before sticking the bag on. This is so germs from the skin are not mixed in with the urine.

The MSU test is primarily performed to check for infection (see above). However, there are occasions when the urine is clear of infection, but other abnormalities are detected, such as blood in the urine. These abnormalities may also be detected by other tests such as the urine dipstick test. For more information, see our separate leaflets called Urine Dipstick Test and Blood in Urine.

You have been given a container to collect a sample of urine from your child to test for a urinary tract infection. It is important that the urine sample is not contaminated by germs from the skin when it is collected as this may lead to a wrong diagnosis.

Follow these steps to collect a clean urine sample:

1. Get some clean plastic tweezers, gauze (or cotton balls) and a container of sterile water ready. If gauze or cotton balls are not available, you can use baby wipes.
2. Wash your hands well (you may wish to wear gloves).
3. Ensure the child’s privacy is protected and remove your child’s nappy or underpants so that the genital area is exposed (you may wish to sit or lay your child on a towel or hospital bluey to avoid a mess).
4. Use the tweezers to pick up the gauze (or cotton balls) and soak in sterile water. Use the tweezers and soaked gauze, follow the instructions below to gently wash the genital area:
   Girls: Wipe the genital area several times from front to back, using a new gauze (or cotton ball or baby wipe) for each wipe.
   Boys: Wipe the head of the penis using a new gauze (or cotton ball or baby wipe) for each wipe.
5. Try not to let your skin or your child’s skin touch the area that has been cleaned.
6. Loosen the yellow lid of the collection container (but do not remove).
7. Watch and wait until your child starts to wee.
8. As soon as the wee starts, take the lid off the container and put it under the stream of urine. Hold the container away from your child (do not let it touch their skin). Do not touch the inside of the container.
9. Once you have at least a teaspoon of urine in the container put the lid back on firmly and give it to the nurse, so it can be sent to the laboratory for testing. If you have collected the sample at home, it needs to be stored in the fridge and taken to the laboratory within 24 hours.
10. Dry your child’s genital area and replace their nappy or underpants.

Resource No: FS091. Developed by Emergency Department. Updated: August 2019. All information contained in this sheet has been supplied by qualified professionals as a guideline for care only. Seek medical advice, as appropriate, for concerns regarding your child’s health. Image reproduced from Kaufman J, Fitzpatrick P, Tosif S, et al. Faster clean catch urine collection (Quick-Wee method) from infants: randomised controlled trial. BMJ. Apr 7 2017;357:j1341.

A clean catch is a method of collecting a urine sample to be tested. The clean-catch urine method is used to prevent germs from the penis or vagina from getting into a urine sample.

Alternative Names

Urine culture - clean catch; Urinalysis - clean catch; Clean catch urine specimen; Urine collection - clean catch; UTI - clean catch; Urinary tract infection - clean catch; Cystitis - clean catch

How the Test is Performed

If possible, collect the sample when urine has been in your bladder for 2 to 3 hours.

You will use a special kit to collect the urine. It will most likely have a cup with a lid and wipes.

Wash your hands with soap and warm water.

GIRLS AND WOMEN

Girls and women need to wash the area between the vagina "lips" (labia). You may be given a special clean-catch kit that contains sterile wipes.

• Sit on the toilet with your legs spread apart. Use two fingers to spread open your labia.
• Use the first wipe to clean the inner folds of the labia. Wipe from the front to the back.
• Use a second wipe to clean over the opening where urine comes out (urethra), just above the opening of the vagina.

To collect the urine sample:

• Keeping your labia spread open, urinate a small amount into the toilet bowl, then stop the flow of urine.
• Hold the urine cup a few inches (or a few centimeters) from the urethra and urinate until the cup is about half full.
• You may finish urinating into the toilet bowl.

BOYS AND MEN

Clean the head of the penis with a sterile wipe. If you are not circumcised, you will need to pull back (retract) the foreskin first.

• Urinate a small amount into the toilet bowl, and then stop the flow of urine.
• Then collect a sample of urine into the clean or sterile cup, until it is half full.
• You may finish urinating into the toilet bowl.

INFANTS

You will be given a special bag to collect the urine. It will be a plastic bag with a sticky strip on one end, made to fit over your baby's genital area.

If the collection is being taken from an infant, you may need extra collection bags.

Wash the area well with soap and water, and dry. Open and place the bag on your infant.

• For boys, the entire penis can be placed in the bag.
• For girls, place the bag over the labia.

You can put on a diaper over the bag.

Check the baby often and remove the bag after the urine collects in it. Active infants may displace the bag, so you may need to make more than one attempt. Drain the urine into the container you were given and return it to the health care provider as directed.

AFTER COLLECTING THE SAMPLE

Screw the lid tightly on the cup. Do not touch the inside of the cup or the lid.

• Return the sample to the provider.
• If you are at home, place the cup in a plastic bag and put the bag in the refrigerator until you take it to the lab or your provider's office.

References

Germann CA, Holmes JA. Selected urologic disorders. In: Walls RM, Hockberger RS, Gausche-Hill M. Rosen's Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier; 2018:chap 89.

Nicolle LE, Norrby SR. Approach to the patient with urinary tract infection. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 284.

Review Date: 06/28/2018