From the Guidelines
Group A Streptococcus (GAS) can colonize multiple sites in the human body, primarily the throat (pharynx) and tonsils, as well as the skin, vagina, rectum, nose, and scalp, as reported in the most recent study 1. The primary site of GAS colonization is the throat (pharynx) and tonsils, where it can exist as part of the normal flora or cause pharyngitis (strep throat) 1. Some key points to consider about GAS colonization sites include:
- GAS can colonize the skin, particularly in areas with minor cuts, abrasions, or burns, which can lead to impetigo or cellulitis 1.
- The organism can colonize the vagina in women, potentially causing puerperal fever in postpartum cases 1.
- GAS may also be found in the rectum, nose, and scalp 1.
- In more severe invasive infections, GAS can spread to deeper tissues including muscle (causing necrotizing fasciitis), blood (bacteremia), lungs (pneumonia), and even the heart valves (endocarditis) 1. The bacterium's ability to colonize these various sites is facilitated by its numerous virulence factors, including M protein, which helps it adhere to host tissues, and hyaluronic acid capsule, which protects it from phagocytosis 1. Understanding these colonization sites is important for diagnosing GAS infections and implementing appropriate treatment strategies, as emphasized in the guidelines for prevention and control of group A streptococcal infection in acute healthcare and maternity settings in the UK 1.
From the Research
Sites Colonized by GAS
The sites that Group A Streptococcus (GAS) can colonize in the body include:
- Throat: GAS typically infects the throat, causing mild infections such as pharyngitis 2
- Skin: GAS can also infect the skin, causing infections such as impetigo 2
- Other sites: GAS can cause life-threatening conditions including necrotizing fasciitis, streptococcal toxic shock syndrome (STSS), and bacteremia, which can affect various parts of the body 2
Specific Sites and Infections
Some specific sites and infections caused by GAS include:
- Tonsillopharyngitis: GAS can cause tonsillopharyngitis, which can be diagnosed using throat culture or rapid antigen detection testing 3, 4
- Skin infections: GAS can cause skin infections, which can be treated with antibiotics such as penicillin, cotrimoxazole, macrolides, and cephalosporins 5
- Pharyngitis: GAS is a common cause of pharyngitis, which can be diagnosed using clinical scoring systems, rapid antigen detection tests, throat culture, nucleic acid amplification tests, and machine learning and artificial intelligence 6