Organism, Causative Agent, or Etiologic Agent
Group A streptococcus (GAS) invasive disease is caused by a type of bacteria called Streptococcus pyogenes.
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 blood stream 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 destroys 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 1 year of age against chickenpox (Some children get invasive GAS infection right after they've had chickenpox)
School Exclusion Policy
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 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.
Recent Texas Trends
In Texas, only invasive cases of Group A streptococcus disease are reportable. The number of reported cases of invasive group A streptococcus disease in Texas has continued to increase since 2004. Reported cases ranged from 273 (1.2 cases per 100,000 population) in the year 2004 to 601 (2.2 cases per 100,000 population) in 2014.
The highest age-specific incidence rates of invasive group A streptococcal disease are seen in adults aged 60 years and older: Out of the 601 cases reported in Texas in 2014, 246 (5.5 cases per 100,000 population) occurred in this age group. Other age groups with consistently higher incidence rates include adults aged 50-59 years and children less than one year of age.