under the microscope
5.2 million outpatient visits for non-invasive GAS infections ,
20,000 to 27,000 cases of invasive GAS infections
1,800 and 2,400 deaths .
under the microscope
By Priya Dhagat , MS , MLS ( ASCP ) CM , CIC
Group A Strep : A Menacing Bacteria Responsible for a Multitude of Infections
• In the United
States , the CDC estimates that each year there are about
5.2 million outpatient visits for non-invasive GAS infections ,
between
20,000 to 27,000 cases of invasive GAS infections
( iGAS ), and between
1,800 and 2,400 deaths .
Streptococcus pyogenes – Greek for “ a chain ; berries ” and “ pus forming ” – is a contagious bacteria that can cause numerous non-invasive and invasive infections , such as pharyngitis ( i . e ., strep throat ), scarlet fever , impetigo , cellulitis , streptococcal toxic shock syndrome ( STSS ), rheumatic fever , pneumonia with bacteremia , meningitis , and necrotizing fasciitis . It can be found on the skin and in the throat and is ubiquitous in the environment . People who are colonized may not show symptoms but the bacteria can easily spread from person to person through respiratory droplets via coughing or sneezing .
Also called Group A Streptococcus ( GAS ) per the Lancefield classification of carbohydrate and antigen composition on the bacterial cell wall , GAS can infect the skin and upper respiratory tract , secreting numerous enzymes and toxins that trigger inflammation , prohibit recruitment of immune cells to the site of infection , and prevent immune cell function . GAS is a deceptively well-adapted human pathogen that uses a unique immune evasion strategy – called molecular mimicry – in which bacterial proteins lyse human red blood cells and then coat itself with red blood cell fragments in order to imitate host cells and promote survival .
In the United States , the CDC estimates that each year there are approximately 5.2 million outpatient visits for non-invasive GAS infections , between 20,000 to 27,000 cases of invasive GAS infections ( iGAS ), and between 1,800 and 2,400 deaths . Around 1 in 3 iGAS infections are now resistant to erythromycin and clindamycin .
Over the past couple of years , many countries have noted a rise in severe iGAS infections . In 2022 , several European countries ( France , Ireland , the Netherlands , Sweden , and the U . K .) observed an increase of iGAS disease and scarlet fever cases affecting children under 10 years of age . Australia experienced an increase of iGAS in 2022 compared to 2020 and 2021 . In the United States , GAS infections reached a 20-year high in 2023 per the CDC . As of June 15 , 2024 , there have already been 403 reported cases of STSS , compared to last year ’ s total of 412 cases . Japan has recently reported a surge is STSS cases – over 1,000 cases just in the first half of 2024 . STSS occur when GAS produces exotoxins that spread into tissues and the bloodstream , inducing a strong immune response , called a cytokine cascade , which leads to the body going into shock . Initial symptoms include fever , chills , muscle aches , nausea , and vomiting . Infection rapidly progresses within 24-to 48 hours causing hypotension , tachycardia , tachypnea , and organ failure . Patients require prompt medical care and hospitalization for immediate antibiotic treatment and sepsis management . The mortality rate for STSS can exceed 30 percent regardless of treatment .
Differential diagnosis of STSS may be difficult for healthcare providers which can include other viral or bacterial infections . The case definition of STSS includes hypotension , organ involvement , and bacterial isolation of group A strep . CDC recommendations for healthcare providers include following protocols for sepsis diagnosis and management , beginning antibiotic therapy as soon as possible , obtaining culture for suspected iGAS infections , monitoring patient progress , and reassessing antibiotic therapy as needed . In healthcare settings , healthcare professionals should adhere to infection prevention and control measures , including hand hygiene , to prevent outbreaks and secondary transmission to other patients and healthcare personnel . This includes following contact , droplet , and standard precautions when caring for patients with skin infections and draining wounds that cannot be covered with a dressing , and droplet and standard precautions when caring for patients with pharyngitis and invasive disease for 24 hours after effective antibiotic therapy .
Priya Dhagat , MS , MLS ( ASCP ) CM , CIC , is an infection preventionist and the associate director of the system-wide Special Pathogens Program within the Department of Emergency Management at New York City Health + Hospitals , overseeing special pathogen preparedness and response efforts across New York City Health + Hospitals frontline healthcare facilities . Additionally , she supports and offers subject matter expertise for infection prevention topics for the National Emerging Special Pathogens Training and Education Center ( NETEC ).
References :
To view national trends in Group A Strep ( case rates , death rate , syndromes , antibiotic resistance , etc ):
• ABCs Bact Facts Interactive Data Dashboard | ABCs | CDC
• To learn more about Group A Strep ( for the public and for healthcare personnel )
• Healthcare Provider Home | Group A Strep | CDC
• Group A Strep Infection | Group A Strep | CDC
8 • www . healthcarehygienemagazine . com • july 2024