Group A Streptococcus Infections

Infection Control in Healthcare Personnel: Epidemiology and Control of Selected Infections Transmitted Among Healthcare Personnel and Patients

Recommendations
  1. Postexposure prophylaxis and work restrictions are not necessary for healthcare personnel who have an exposure to group A Streptococcus.

  1. For healthcare personnel with known or suspected group A Streptococcus infection, obtain a sample from the infected site, if possible, for group A Streptococcus and exclude from work until group A Streptococcus infection is ruled out, or until 24 hours after the start of effective antimicrobial therapy, provided that any draining skin lesions can be adequately contained and covered.
  • For draining skin lesions that cannot be adequately contained or covered (e.g., on the face, neck, hands, wrists), exclude from work until the lesions are no longer draining.

  1. Work restrictions are not necessary for healthcare personnel with known or suspected group A Streptococcus colonization, unless they are epidemiologically linked to transmission of the organism in the healthcare setting.

  1. For healthcare personnel with group A Streptococcus colonization who are epidemiologically linked to transmission of the organism in the healthcare setting:
  • Administer chemoprophylaxis in accordance with CDC recommendations AND
  • Exclude from work until 24 hours after the start of effective antimicrobial therapy AND
  • Obtain a sample from the affected site for group A Streptococcus testing 7 to 10 days after completion of chemoprophylaxis; if positive, repeat administration of chemoprophylaxis and again exclude from work until 24 hours after the start of effective antimicrobial therapy.
Abbreviations
  • CDC = Centers for Disease Control and Prevention
  • CLIA = Clinical Laboratory Improvement Amendments
  • GAS = Group A Streptococcus
  • HCP = Healthcare Personnel
  • HICPAC = Healthcare Infection Control Practices Advisory Committee
  • PEP = Postexposure Prophylaxis
  • PPE = Personal Protective Equipment
  • RADT = Rapid Antigen Detection Test
  • STSS = Streptococcal Toxic-Shock Syndrome

Narrative

Background

Group A Streptococcus (GAS) is a bacterium that can cause many different infections, including strep throat, scarlet fever, impetigo, and others. A common cause of pharyngeal, skin, and other soft tissue infections, GAS can also cause severe, life-threatening invasive disease, including pneumonia, streptococcal toxic-shock syndrome (STSS) and necrotizing fasciitis.1 Healthcare-associated transmission of GAS has been documented from patients to healthcare personnel (HCP) and from HCP to patients.1-10

Prevention of transmission of GAS in healthcare settings involves:

  1. in addition to using Standard Precautions, placing patients with known or suspected GAS infection in recommended transmission-based precautions according to their clinical manifestations of GAS disease11;
  2. rapidly diagnosing and treating patients with clinical infection; and
  3. excluding potentially infectious HCP from work.

Occupational Transmission

There are no recommended actions, such as administering postexposure prophylaxis (PEP) or work restrictions, after HCP exposure to GAS. Contact or dispersal of respiratory secretions are the major modes of transmission of GAS in healthcare settings.

HCP who were GAS carriers have been linked to outbreaks of surgical site, postpartum, and burn wound infections. In these outbreaks, GAS carriage was documented in the pharynx, the skin, the rectum, and the female genital tract of the colonized personnel.1,9,12-22

Transmission from patients to HCP has been described, with potential contributing factors including gross contamination of surgical attire during extensive wound debridement, presence of dermatitis, not using gloves when providing wound care, and sharps injury.2,3,10,23,24

Although rare, spread of GAS infections may also occur via food. Foodborne outbreaks of pharyngitis have occurred due to improper food handling, and HCP have been linked to foodborne transmission of GAS, causing pharyngitis.25,26

Clinical Features

GAS infections can have a wide variety of clinical presentations. GAS pharyngitis is fairly common and characterized by sudden-onset sore throat, pain when swallowing, fever, inflamed tonsils, petechiae on the soft or hard palate, and swollen lymph nodes in the front of the neck.25 GAS pharyngitis is typically not associated with cough, rhinorrhea, hoarseness, or conjunctivitis – symptoms more frequently associated with viral pharyngitis.25 Because clinical signs and symptoms of viral pharyngitis can mimic those of GAS pharyngitis, laboratory testing for GAS is necessary to make an accurate GAS pharyngitis diagnosis.27

Persons with GAS pharyngitis who are treated with an appropriate antibiotic are generally non-infectious after the first 24 hours of treatment.

In addition, GAS can cause an array of both superficial (e.g., impetigo) and invasive (e.g., cellulitis, abscesses) skin and soft tissue infections. Many invasive GAS infections – such as pneumonia, meningitis, necrotizing fasciitis, and STSS – are associated with high morbidity and mortality rates in the United States.28 The portal of entry is unknown in most invasive GAS infections, but is presumed to be skin or mucous membranes.29 Necrotizing fasciitis, a life-threatening condition, can be caused by GAS and is often initially characterized by development of a red or swollen area of skin that spreads quickly; severe pain, including pain beyond what is expected on physical examination; and fever.30

Toxin-producing GAS strains can cause STSS that typically manifests as a severe acute systemic illness characterized by fever, hypotension, and signs of multiorgan system failure.29 STSS can occur without an identifiable focus of infection, although the presence of concomitant local soft tissue infection is common.29

The incubation period of GAS pharyngitis is approximately 2 to 5 days.25 The incubation period is variable for other GAS infections. The incubation period for STSS has been as short as 14 hours when associated with penetrating trauma or other methods resulting in subcutaneous inoculation of organisms.29

Testing and Diagnosis

Because the signs and symptoms of GAS pharyngitis are similar to other infections, laboratory testing is necessary to confirm the diagnosis.25,27 Any Clinical Laboratory Improvement Amendments (CLIA)-approved testing method for GAS pharyngitis may be used to test for infection as well as to confirm eradication of colonization among HCP. Rapid antigen detection tests (RADT) have high specificity for GAS, but varying sensitivities when compared to throat culture, which remains the gold standard diagnostic test.25,27

Invasive GAS disease is usually confirmed by isolation of GAS from a normally sterile body site through culture.14

Postexposure Prophylaxis

Although PEP is not routinely administered after HCP exposure to GAS, if clinical symptoms compatible with GAS infection develop, GAS infection may be the underlying etiology and testing and treatment may be indicated.

Outbreaks

Even one case of postpartum or postsurgical GAS infection typically prompts an epidemiological investigation because of the potential for prevention of additional cases.14 CDC maintains recommendations for screening HCP during GAS outbreaks in healthcare settings (https://academic.oup.com/cid/article/35/8/950/330363), including which HCP to select for screening and which body sites to culture.14 When screening of HCP is performed, sites from which specimens are obtained and cultured include the throat, anus, vagina, and any skin lesions.14

Colonization with GAS does not necessitate treatment unless the carrier is epidemiologically linked to GAS transmission in the healthcare setting. Information regarding dosage and administration of chemoprophylaxis for GAS-colonized HCP who are epidemiologically linked to transmission is available in the document Prevention of Invasive Group A Streptococcal Disease among Household Contacts of Case Patients and among Postpartum and Postsurgical Patients: Recommendations from the Centers for Disease Control and Prevention (https://academic.oup.com/cid/article/35/8/950/330363).14 

References

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  2. Ahmed SS, Diebold KE, Brandvold JM, Ewaidah SS, Black S, Ogundimu A, et al. The Role of Wound Care in 2 Group A Streptococcal Outbreaks in a Chicago Skilled Nursing Facility, 2015‒2016. Open Forum Infect Dis. 2018;5(7):ofy145-ofy145.
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