NAME: Streptococcus pyogenes
SYNONYM OR CROSS REFERENCE: Group A (Beta hemolytic) streptococci, streptococcal sore throat, scarlet fever, impetigo, erysipelas, puerperal fever, necrotizing facsciitis
CHARACTERISTICS: Gram-positive cocci occurring in pairs or chains, facultatively anaerobic, nonmotile, beta hemolysis on blood agar; 80 serologically distinct types
PATHOGENICITY: Cause a variety of diseases; streptococcal sore throat (fever, exudative tonsillitis, pharyngitis), streptococcal skin infections (impetigo or pyoderma - usually superficial), scarlet fever (skin rash, fever, nausea, case fatality rate of 3%), puerperal fever (bacterial invasion of genital tract), septicemia, erysipelas (fever, leukocytosis, red spreading lesion), perianal cellulitis, mastoiditis, otitis media, pneumonia, peritonitis and wound infections; acute glomerulonephritis may result; acute rheumatic fever; toxic shock-like syndrome (hypotension, renal impairment, thrombocytopenia, disseminated intravascular coagulation, bilirubin elevation, adult respiratory distress syndrom, necrotizing fasciitis; necrotizing fasciitis is a serious, often fatal, rare infection of the skin and subcutaneous tissue characterized by swelling, appearance of violet colour, blister formation, fever; serious cases progress rapidly with high mortality
EPIDEMIOLOGY: Common in temperate zones, well recognized in semitropics and less frequently recognized in tropical climates; in North America, may be endemic, epidemic or sporadic; highest incidence during late winter and spring; 3-15 year age group most often affected; impetigo occurs in young children in late summer and fall in hot climates; erysipelas most common after 20 years of age and in infants (sporadic occurrence); Streptococcus pharyngitis is unusual under 3 years of age, peaks in age group 6-12
HOST RANGE: Humans
INFECTIOUS DOSE: Not known
MODE OF TRANSMISSION: Large respiratory droplets, direct or intimate contact with patient or carrier (especially nasal); rarely by indirect contact through objects or hands; organisms may be recovered from skin 1-2 weeks before impetigo lesions and same strain appears in throat late in course of skin infection; anal, vaginal, skin and pharyngeal carriers responsible for noscomial outbreaks of wound infections; dried streptococci in dust etc. viable but non-infectious for mucous membranes or intact skin; group A streptococci may be transmitted to cattle from human carriers then spread through raw milk from these cattle; ingestion of contaminated foods (milk products, eggs) may result in explosive outbreaks; necrotizing fasciitis more often begins with skin infection at site of minor wounds or punctures
INCUBATION PERIOD: Short; usually 1-3 days, rarely longer
COMMUNICABILITY: In untreated uncomplicated cases period of communicability is 10-21 days; in untreated conditions with purulent discharges, period may extend to weeks or months; with adequate treatment, transmissibility generally is terminated within 24-48 hours; streptococcal pharyngitis is contagious for 2- 3 weeks if untreated
RESERVOIR: Humans
ZOONOSIS: None
VECTORS: None
DRUG SUSCEPTIBILITY: Sensitive to penicillin (benzathine penicillin G); clindamycin or a cephalosporin can be used when penicillin and erythromycin are contraindicated
DRUG RESISTANCE: Resistant to tetracyclines; macrolide-resistant strains in the increase
SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to many disinfectants - 1% sodium hypochlorite, 70% ethanol, glutaraldehyde, formaldehyde, iodines
PHYSICAL INACTIVATION: Sensitive to moist heat (121° C for at least 15 min) and dry heat (160-170° C for at least 1 hour)
SURVIVAL OUTSIDE HOST: Dust - up to 195 days; flies caught in hospital carried organism on their feet; survives in milk at 20 to 37° C; cheese - up to 126 days; pus - up to 110 days; blankets - 120 days; rim of drinking glass - 2 days
SURVEILLANCE: Monitor for symptoms; confirm by bacteriological and serological testing
FIRST AID/TREATMENT: Antibiotic therapy with penicillin (erythromycin for penicillin-sensitive patients); necrotizing fasciitis - early medical treatment critical (penicillin along with aggressive surgical debridement), limb amputation may be necessary in advanced cases
IMMUNIZATION: None
PROPHYLAXIS: Administer penicillin (long-term prophylaxis with long-acting benzathine penicillin G for persons whom recurrent streptococcal infections constitutes a special risk)
LABORATORY-ACQUIRED INFECTIONS: 78 recorded cases with 4 deaths up to 1976; 5th most common laboratory acquired infection
SOURCES/SPECIMENS: Respiratory specimens, skin lesions, blood, urine, wound exudates (pus etc.)
PRIMARY HAZARDS: Inhalation of infectious aerosols; accidental parenteral inoculation; ingestion; direct contact of mucous membranes and skin lesions
SPECIAL HAZARDS: None
CONTAINMENT REQUIREMENTS: Biosafety level 2 practices, containment equipment and facilities for all activities involving known or potentially infected clinical materials or cultures; animal biosafety level 2 facilities for studies utilizing infected animals
PROTECTIVE CLOTHING: Laboratory coat; gloves when contact with infectious materials in unavoidable
OTHER PRECAUTIONS: None
SPILLS: Allow aerosols to settle; wearing protective clothing, gently cover spill with absorbent paper towel and apply 1% sodium hypochlorite, starting at perimeter and working towards the centre; allow sufficient contact time (30 min) before clean up
DISPOSAL: Decontaminate before disposal: steam sterilization, chemical disinfection, incineration
STORAGE: In sealed containers that are appropriately labelled
Date prepared: June, 2001
Prepared by: Office of Laboratory Security, PHAC
Although the information, opinions and recommendations contained in this Material Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.
Copyright ©
Health Canada, 2001