Staphylococcal enterotoxin B-specific electrochemiluminescence and lateral flow device assays cross-react with staphylococcal enterotoxin D

Area of Science:

• Foodborne illness outbreaks
• Microbiology
• Public health

Background:

• A significant food poisoning outbreak occurred among school children and faculty in Guam.
• Symptoms included vomiting, nausea, abdominal cramps, and diarrhea, consistent with staphylococcal food poisoning.
• The outbreak affected 297 individuals, with 130 treated at local hospitals and 61 admitted.

Purpose of the Study:

• To identify the causative agent of the food poisoning outbreak.
• To evaluate the accuracy of initial diagnostic methods used during the investigation.
• To highlight the importance of specific and sensitive assays in foodborne illness investigations.

Main Methods:

• Initial food testing utilized a lateral flow device and electrochemiluminescence.
• Confirmatory testing involved traditional enzyme-linked immunosorbent assays (ELISAs).

Main Results:

• Initial tests incorrectly identified staphylococcal enterotoxin B as the cause.
• Subsequent ELISAs accurately identified staphylococcal enterotoxin D as the causative agent.
• The incorrect initial identification led to confusion and partial activation of emergency response.

Conclusions:

• Accurate identification of the food poisoning agent is critical for effective outbreak response.
• The use of more specific and sensitive diagnostic assays can prevent misidentification and streamline investigations.
• This outbreak underscores the importance of reliable laboratory methods in public health emergencies.