Group A Strep (GAS) Infection

The bacteria Streptococcus pyogenes are spread through direct contact with respiratory secretions from the nose or throat of infected persons who are coughing or sneezing. Some infected people do not have symptoms but can spread the disease through respiratory secretions. The bacteria can also be spread by touching infected wounds or sores on the skin.

Streptococcus pyogenes can cause both invasive diseases (such as meningitis or bloodstream infections) and non-invasive diseases (such as strep throat). Only invasive disease is reportable to the Texas Department of State Health Services. Non-invasive illness may result in strep throat or a skin infection such as impetigo. Group A streptococcus infections can also begin as a non-invasive infection and then spread to parts of the body where bacteria are not normally found, like the blood or muscle tissue. When the bacteria get into these parts of the body the infections are called invasive. Two of the most severe kinds of invasive Group A streptococcus infections are necrotizing fasciitis and streptococcal toxic shock syndrome. In necrotizing fasciitis, the bacteria destroy muscle, fat, and skin tissue and because of this it has been described as "flesh-eating bacteria." Streptococcal toxic shock syndrome is an infection that moves quickly, causing shock and internal organs such as the kidneys, liver, and lungs to fail. Both necrotizing fasciitis and streptococcal toxic shock syndrome are rare.

Very few people who come in contact with Group A streptococcus will develop invasive disease. Most people, if they get sick, will have a throat or skin infection, and some people may have no symptoms at all. Although healthy people can get Group A streptococcus invasive disease, people with chronic illnesses like cancer, diabetes, and chronic heart or lung disease, and those who use medications such as steroids have a higher risk. Persons with skin lesions (such as cuts, chicken pox, and surgical wounds), the elderly, and adults with a history of alcohol abuse or injection drug use also have a higher risk for disease.

The following steps will help prevent the spread of infection:

• Keep cuts, scratches, sores and wounds clean and covered
• Cover your mouth and nose when you sneeze and cough
• Wash your hands often using hot water and soap
• Don't share toothbrushes or eating utensils
• Vaccinate children over one year of age against chickenpox (Some children get invasive GAS infection right after they've had chickenpox)

Children with streptococcal sore throat and scarlet fever should be kept out of school or childcare until 24 hours from the time antibiotic treatment was begun and until they are fever-free for 24 hours without the use of fever-suppressing medications. Children with wounds or skin and soft tissue infections should be kept out of school or childcare until drainage from wounds or skin and soft tissue infections is contained and maintained in a clean dry bandage. When these children return to school or childcare, they should be restricted from situations that could result in the infected area becoming exposed, wet, soiled, or otherwise compromised. 

Children with other infections from Group A Streptococcus should be kept out of school or childcare until they are fever-free for 24 hours without the use of fever-suppressing medications. Rules for the exclusion of sick children from school and childcare are outlined in the Texas Administrative Code, specifically Rule 97.7 for schools and Rule 746.3603 for childcare.

GAS is no longer a reportable condition in Texas. Reported cases have gradually increased from 281 in 2007 to 971 in 2019.

The highest age-specific incidence rates of invasive group A streptococcal disease are seen in adults aged 60 years and older: Out of the 971 cases reported in Texas in 2019, 466 (8.8 cases per 100,000 population) occurred in this age group. Other age groups with higher incidence rates include adults aged 40-49 and 50-59 years of age.

There is no vaccine for Group A Streptococcus.

Texas VPD and IRID Surveillance Guidelines:  Group A (PDF, 105 KB)

Centers for Disease Control and Prevention, Division of Bacterial and Mycotic Diseases General Information; Technical Information: About Group A Strep Infection | Group A Strep | CDC

"Strep" is short for Streptococcus - a specific type of bacteria. Strep bacteria are divided into groups. Most strep that can cause disease in people belong to Group A. The bacteria often are found in the throat or on the skin, but they don't cause illness. Group A strep (also known as GAS) can cause very different diseases like strep throat, rheumatic fever, scarlet fever, impetigo, ear infections, and pneumonia. Special types of Group A strep, known as types M-1 and M-3, can invade body tissues. This is why the word "invasive" is used with the name of the infection.

If Group A strep bacteria infect the throat, the patient will have strep throat: a severe sore throat with a fever and swollen glands. Doctors will usually test to see if the patient has strep throat. There are two reasons for doing this test. First, if strep are found, the doctor knows to treat the patient with antibiotics and to keep the strep from spreading to other parts of the body. Second, because strep throat is contagious, the patient can be told to stay home from school, work, or other activities until the antibiotics fight the infection. The Group A strep involved in strep throat are not usually the invasive type.

The M-1 and M-3 types of Group A strep, on the other hand, have specific characteristics that let them quickly infect and spread throughout the body. A massive infection can lead to a dangerous, life-threatening condition.

There can be many different types of symptoms of this disease because the bacteria can affect so many different parts of the body. Only a doctor can tell whether the illness is Group A strep.

Invasive Group A strep infection can feel like the flu, but the symptoms get worse instead of better after a couple of days. Invasive GAS can also begin in a part of the body such as a hand or leg and spread to parts of the body where bacteria are not normally found, like the blood, muscles, and lungs.

Two of the most severe kinds of invasive GAS disease are called necrotizing fasciitis and streptococcal toxic shock syndrome. But they are also the forms that people are least likely to get.

In necrotizing fasciitis, the GAS bacteria destroy muscle and fat. Because of this, people sometimes call it "flesh-eating bacteria." Streptococcal toxic shock syndrome is an infection that moves quickly, causing shock and injury to internal organs such as the kidneys, liver, and lungs.

The bacteria are spread when infected people cough or sneeze. However, people who look healthy and who carry the bacteria can also spread the disease. But this type of infection is not as contagious. The bacteria can also be spread by touching infected wounds or sores. Many people come in contact with GAS bacteria, but few get sick at all (not even a sore throat). Even fewer people will get invasive GAS disease.

Antibiotics are very effective in treating invasive GAS disease if they are given to patients early. However, even antibiotics can't always prevent illness or even death in some cases.

The following steps will help prevent the spread of infection:

• Keep sores clean and covered.

• Cover your mouth and nose when you sneeze and cough.

• Wash your hands often using hot water and soap.

• Don't share toothbrushes or eating utensils.

• Vaccinate children over 1 year of age against chickenpox (Some children get invasive GAS infection right after they've had the chickenpox).

Consult a physician if

• You are an adult with a temperature of 101F or more or your child has a temperature of 103F or more.

• You have a sore throat with fever.

• You feel like you have the flu but feel worse after 3 or 4 days.

• You have pain for no known reason or a sore that becomes red, swollen, and painful.

• Your child has chickenpox and a fever that lasts more than 3 days.

• Three or 4 days after your child gets chickenpox, his or her temperature goes up, or the child has difficulty breathing, loss of appetite, or sores that look infected.

About one-fourth of the population has GAS bacteria in their noses and throats during winter months. No one knows why some people get sick and others don't.

Most strep infections, including strep throat and invasive GAS, normally occur during December, January, and February. More cases are seen in some years than in others, however, invasive GAS infection is a very rare disease.