Staphylococcus aureus Food Poisoning
The most likely aetiology is d) Staphylococcus aureus, given the extremely rapid onset of symptoms (1 hour after eating) and the common-source outbreak pattern affecting multiple individuals who shared the same meal. 1
Key Diagnostic Features Supporting Staph aureus
The clinical presentation is pathognomonic for bacterial toxin-mediated food poisoning:
Incubation period of 1 hour is characteristic of preformed bacterial toxins, specifically from Staphylococcus aureus, Bacillus cereus, or Clostridium perfringens, which cause symptoms within 1-72 hours of ingestion 1
Abrupt onset of nausea, vomiting, and abdominal cramps within 1-4 hours after eating contaminated food is the hallmark presentation of enterotoxin-producing foodborne strains, particularly S. aureus 1, 2
Common-source outbreak pattern (both individuals who ate together developed identical symptoms) strongly indicates a foodborne toxin rather than person-to-person transmission 1
Absence of fever and inflammatory signs is expected with preformed toxin-mediated illness, distinguishing it from invasive bacterial pathogens 1
Why Other Options Are Less Likely
Enterotoxigenic E. coli (ETEC)
- ETEC typically has an incubation period of 12-72 hours, far too long for this 1-hour presentation 1
- Predominantly causes watery diarrhea rather than the vomiting-predominant picture seen here 1
Shigella and Salmonella
- Both require 12-48 hours incubation period for symptoms to develop 1
- These invasive pathogens typically cause fever, bloody stools, and systemic symptoms 1
- The 1-hour timeframe is incompatible with these organisms 1
Vibrio cholerae
- Incubation period is 24-48 hours 1
- Presents with profuse "rice water" diarrhea rather than vomiting and abdominal pain 1
- Requires exposure to brackish water or undercooked shellfish, not typical street food 1
Expected Clinical Course
Symptoms resolve within 24-48 hours with supportive care alone, which is characteristic of toxin-mediated food poisoning 1
Diarrhea may develop 5-10 hours after the initial vomiting, but the illness remains self-limited 2
No antibiotic therapy is indicated as this is toxin-mediated rather than an active infection requiring antimicrobial treatment 1
Critical Clinical Pitfall
Do not confuse this presentation with viral gastroenteritis or invasive bacterial infection requiring antibiotics. The extremely rapid onset (1 hour) and common-source pattern are diagnostic of preformed bacterial toxin, specifically S. aureus in this context. 1, 2 Viral gastroenteritis would have a longer incubation period (typically 24-48 hours) and would last several days rather than resolving within 24-48 hours. 2