| Clinical Features |
Noninvasive disease (strep throat, impetigo); invasive disease (necrotizing fasciitis [NF], streptococcal toxic shock syndrome [STSS], cellulitis, bacteremia, pneumonia puerperal sepsis); nonsuppurative sequelae (acute rheumatic fever, post-streptococcal glomerulonephritis). STSS is a severe illness characterized by shock and multiorgan failure. NF presents with severe local pain and rapid destruction of tissue. Rheumatic fever is a leading cause of acquired heart disease in young people worldwide. |
| Etiologic Agent |
Streptococcus pyogenes or group A Streptococcus. |
| Incidence |
Approximately 9,000-11,500 cases of invasive disease (3.2 to 3.9/100,000 population) occur each year in the U.S.; STSS and NF each accounted for approximately 6%-7% of cases. Over 10 million noninvasive GAS infections (primarily throat and superficial skin infections) occur annually. |
| Sequelae |
Death occurs in 10%-15% of all invasive cases, over 35% of patients with STSS and approximately 25% of NF cases die from their infection. Organ system failure (STSS) and amputation (NF) also may result. |
| Transmission |
Person to person by contact with infectious secretions from the nose or throat of infections persons or by contact with infected skin lesions. Asymptomatic pharyngeal carriage occurs among all age groups but is most common among children. |
| Risk Groups |
Invasive disease: elderly, immunosuppressed, persons with chronic cardiac or respiratory disease, diabetes, skin lesions (i.e. children with varicella [chicken pox], persons with penetrating trauma or surgical wounds, intravenous drug users) African-Americans, American Indians. Noninvasive disease: children (especially elementary school age) at highest risk. |
| Surveillance |
National passive surveillance for invasive infection and STSS since 1995. Active, population-based surveillance is conducted in 10 sites in the Emerging Infection Program (2008 total population: ~39 million). |
| Trends |
Worldwide, rates of severe invasive disease (STSS and NF) increased from the mid-1980s to early 1990s. Increases in the severity of disease was associated with increases in prevalence of M-1 and M-3 serotypes (emm types 1 and 3). Rates of invasive disease have been stable over the last 7 years in the United States. Resistance to erythromycin has increased worldwide. |
| Challenges |
Improve recognition and diagnosis by clinicians; evaluate disease burden and organism characteristics to guide vaccine development; develop control strategies to prevent spread in families, institutions, and other high-risk settings, including the growing population of elderly in long-term care facilities. |
| Opportunities |
Improved surveillance permits monitoring disease trends and risk groups. CDC development of new genotyping system for GAS isolates (emm typing) allows better strain identification and promotion of vaccine development. Investigating clusters will help identify interventions to prevent the spread of infection. |
