Does this test have other names?

CSF agglutination test

What is this test?

This test looks at fluid from your spinal cord to find out if you have an illness called brucellosis.

Brucellosis is an infectious disease. It's usually caused by handling animals or milk products infected with the brucella bacteria. If you have brucellosis, your body will make certain antibodies when it tries to fight these germs. Brucella antibodies can usually be found in your blood, liver, spleen, lymph nodes, or bone marrow.

In 2% to 7% of brucella infections, the bacteria infect the brain, spine, and other parts of the nervous system. This test looks at your cerebrospinal fluid (CSF) to find out if you have a brucella infection that has spread to your nervous system.

The disease is rare in the U.S., with fewer than 200 cases reported each year. It's more commonly found in Latin America, the Middle East, and the Mediterranean. This is why it's often called Mediterranean or Malta fever. It's also called Undulant fever, Bang's disease, and Gibraltar fever.

If brucellosis isn't treated after a few months, you may start to feel unusually weak. You may also get a fever and chills, headaches, backache, muscle and joint pain, and sweats. You may lose your appetite and look anorexic. If untreated, the bacteria can sometimes damage the heart, joints, or central nervous system. Or you may have infections that keep coming back. If you are pregnant and have brucellosis, it may cause a miscarriage or infect your unborn child.

Why do I need this test?

You may need this test if your healthcare provider thinks you may be infected with brucella bacteria and that the infection has spread to your brain. Some risk factors that may contribute to becoming infected are: 

• You work in a slaughterhouse and have symptoms of the illness.

• You work in a slaughterhouse, dairy, or farm and may have been in contact with the bacteria through a cut or open wound.

• You hunt deer, wild pigs, or other animals and have symptoms of the illness. You may have been in contact while cleaning a carcass without gloves.

• You have traveled to Spain, Greece, Mexico, or another country where brucellosis is common and have eaten unpasteurized milk, cheese, or ice cream.

• You are a veterinarian and may have come in contact with the bacteria. Or by accident you injected yourself with the vaccine used to protect cattle against brucella. People almost never get brucellosis from contact with dogs unless their immune system is very weak from HIV/AIDS or another condition.

• You work in a laboratory where you handle brucella bacteria.

What other tests might I have along with this test?

Your healthcare provider may also have ordered other tests before the spinal tap to find out whether you've come in contact with brucella bacteria.

Your provider may also order an MRI scan if you have back pain to see if you have damage to your spinal cord

What do my test results mean?

Test results may vary depending on your age, gender, health history, and other things. Your test results may be different depending on the lab used. They may not mean you have a problem. Ask your healthcare provider what your test results mean for you.

Normal results are negative. This means no brucella antibodies were found in your CSF. A negative result doesn't completely rule out an infection, though.

A positive result means that brucella antibodies were found and that you have an infection.

How is the test done?

This test needs a sample of CSF. This is taken through a lumbar puncture in your lower back. During this procedure, you either sit up and lean forward or lie down on your side. A healthcare provider inserts a needle into your spine and draws out a sample of fluid.

Does this test pose any risks?

It's rare to get complications after having this test. But possible risks include:

• Headache

• Infection

• Bleeding

• Cerebral herniation

• Nerve pain or numbness

• Back pain

Talk with your healthcare provider about the risks before the test. Be sure to tell your provider if you've had a seizure, increased pressure in your eyes, or other health problems. You may need to have other tests before having a lumbar puncture.

What might affect my test results?

Having the test too soon after infection can affect your results.

How do I get ready for this test?

You don't need to prepare for this test. Be sure your healthcare provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illegal drugs you may use.