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Epidemic streptococcal sore throat following a community picnic

J B McCormick, P Hayes, R Feldman

    JAMA
    |August 30, 1976
    PubMed

    Insights

    A group A beta-hemolytic Streptococcus outbreak occurred at a picnic, primarily linked to potato salad. The epidemic strain was identified, with higher illness rates in individuals over 10 years old.

    Area of Science:

    • Epidemiology
    • Microbiology
    • Public Health

    Background:

    • Group A beta-hemolytic streptococci (GABHS) can cause outbreaks of illness.
    • Identifying the source and strain of GABHS is crucial for controlling transmission.

    Purpose of the Study:

    • To investigate an outbreak of illness following a picnic.
    • To identify the causative agent and transmission route of the outbreak.
    • To determine risk factors associated with illness.

    Main Methods:

    • Case finding among picnic attendees.
    • Throat culturing and GABHS strain typing.
    • Food preference and consumption data collection.
    • Comparison of attack rates between age groups.

    Main Results:

    • Nearly half of picnic attendees became ill.
    • The epidemic strain of GABHS (type T-3/13/B3264) was isolated from attendees and implicated potato salad.
    • The epidemic strain was found in significantly more attendees than non-attendees.
    • Individuals over 10 years old had a higher attack rate and case-to-infection ratio.

    Conclusions:

    • Potato salad was the likely vehicle for GABHS transmission during the picnic.
    • Age is a significant factor influencing susceptibility and severity in this outbreak.
    • Chemoprophylaxis could potentially reduce the number of cases.

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