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Invasive streptococci
1Department of Microbiology, Bristol Royal Infirmary, UK.
Abstract:
Before the introduction of antibiotics, serious infections caused by Streptococcus pyogenes (Lancefield Group A streptococci) were common. Before World War II, this bacterium was responsible for as many as 50% of postpartum deaths and was the major cause of death in patients with burns. Also common were the sequelae of streptococcal infections-rheumatic fever and post-streptococcal glomerulonephritis. With the use of penicillin, however, Streptococcus pyogenes was believed to be virtually eliminated as a pathogen. The organism was consigned to the history books, but not for long. In the mid-1980s, focal resurgences of rheumatic fever began to be reported from different areas in the USA, such as Salt Lake City, Utah. In such communities, where increases in cases of rheumatic fever had been reported, the serotypes M-1, 3, 5, 6 and 18 were isolated which, on culture, produced characteristic mucoid colonies. At the same time, reports of increases in invasive streptococcal disease began to surface in both the USA and Europe. Two syndromes were described; invasive streptococcal infection, occurring in previously healthy children and adults, commonly associated with septicaemia resulting from a deep focus of infection such as bone or lung; and streptococcal toxic shock syndrome, involving a cutaneous focus, accompanied by necrotizing or bullous soft tissue changes. Septicaemia is rare in streptococcal toxic shock syndrome, but the most characteristic feature is one of rapidly progressing multi-organ failure. A high proportion of the strains of Streptococcus pyogenes associated with this condition are serotype M-1, and fatality rates approaching 50% have been reported.(ABSTRACT TRUNCATED AT 250 WORDS)
Insights
Streptococcus pyogenes infections, once thought eliminated by penicillin, resurged in the 1980s causing severe invasive disease and toxic shock syndrome. These outbreaks highlight the need for continued vigilance against this resilient pathogen.
Area of Science:
- Microbiology and Infectious Diseases
- Bacteriology
- Epidemiology
Background:
- Streptococcus pyogenes (Group A Streptococcus) historically caused severe infections and sequelae like rheumatic fever.
- Penicillin was believed to have virtually eliminated Streptococcus pyogenes as a significant pathogen.
- The mid-1980s saw focal resurgences of rheumatic fever and increased reports of invasive streptococcal disease.
Purpose of the Study:
- To document the resurgence of Streptococcus pyogenes infections.
- To describe the clinical syndromes associated with these resurgent infections.
- To identify specific serotypes involved in the outbreaks.
Main Methods:
- Review of reported cases of rheumatic fever and invasive streptococcal disease.
- Isolation and serotyping of Streptococcus pyogenes strains from affected communities.
- Clinical description of two distinct syndromes: invasive streptococcal infection and streptococcal toxic shock syndrome.
Main Results:
- Increased incidence of rheumatic fever linked to specific serotypes (M-1, 3, 5, 6, 18) producing mucoid colonies.
- Emergence of invasive streptococcal infections in healthy individuals, often with deep-seated infections and sepsis.
- Description of streptococcal toxic shock syndrome, frequently associated with serotype M-1, characterized by cutaneous focus, rapid multi-organ failure, and high fatality rates (approaching 50%).
Conclusions:
- Streptococcus pyogenes has re-emerged as a significant pathogen, challenging its prior perceived elimination.
- Specific serotypes, particularly M-1, are associated with severe invasive disease and toxic shock syndrome.
- The resurgences underscore the need for ongoing surveillance and understanding of Streptococcus pyogenes epidemiology and pathogenicity.