Tests for Streptococcus Pyogenes

Strep throat is caused by the highly contagious bacteria known as Streptococcus pyogenes (also referred to as group A streptococcus). The majority of viruses that cause throat soreness are not Streptococcus pyogenes, and symptoms go away on their own without treatment. But strep throats that are triggered by streptococcus pyogenes require antibiotic treatment in order to be cured.

Causes

• Streptococcus bacteria is commonly spread through droplets that move through the air when a person with the infection sneezes or coughs. You can also catch the bacteria by touching items such as kitchen utensils and door knobs that have been exposed to the bacteria and then handling your mouth or nose. You can help ward off streptococcus bacteria by regularly washing your hands with soap and water.

  According to the Mayo Clinic, some people can be carriers of streptococcus bacteria and not become sick. However, other people may catch the bacteria from a carrier.

Symptoms

• Several typical symptoms are associated with strep throat. They include throat pain that includes discomfort while swallowing. Your tonsils may become red and swollen. In some cases, there will be strips of pus or white patches. You may have swollen lymph nodes in your neck along with a headache, fever or rash.

Diagnosis

• Your doctor will conduct a physical exam when diagnosing the cause of your sore throat. He or she will check for enlarged lymph nodes and fever. A thorough check of your throat and tonsils with the use of a tongue depressor can show signs of an infection. However the only way to absolutely determine whether your signs and symptoms are caused by streptococcal bacteria is to conduct certain laboratory tests.

Throat Culture

• The streptococcal bacteria can be detected through a quick and painless test known as a throat culture. This diagnostic test involves rubbing a sterile swab over the back of the throat and tonsils to get a sample of tissue secretions. It can take up to 48 hours to get back culture results from the lab, where it will be tested for the existence of bacteria.

Rapid Tests

• Because of the waiting period involved in learning the results of a conventional throat culture, it's possible your doctor may order a rapid-antigen test on the swab sample. While this test can identify strep bacteria in a matter of minutes, it also has the potential to overlook some strep infections.

  Another relatively new rapid test makes use of DNA technology to identity strep bacteria in 24 hours or less from a throat swab. This test is as accurate as a throat culture, but is much faster.

Treatment

• Strep throats are typically treated with antibiotic medications. These may include penicillin, amoxicillin (Amoxil, Trimox), azithromycin (Zithromax), clarithromycin (Biaxin) or clindamycin (Cleocin).

  The effects of these medications should be felt in a day or so. It's important to continue taking your antibiotics even when you begin to feel better, otherwise there is a risk of recurrence and complications including rheumatic fever.

  You doctor also may recommend ibuprofen (Advil, Motrin) or acetaminophen (Tylenol) to lower fever and lessen throat pain.