One of the most frequent foodborne illnesses worldwide, Staphylococcal food poisoning is a form of gastroenteritis caused by ingestion of thermostable Staphylococcus aureus enterotoxins, originating primarily from improperly handled or inadequately stored food. A majority of cases present with nausea and intense vomiting (potentially causing dehydration) along with abdominal cramps, while diarrhea may or may not be present. The diagnosis is based on clinical presentation and diet history of the patient, while laboratory confirmation is warranted only in a suspected epidemic.
Staphylococcal food poisoning (SPF) occurs due to ingestion of food containing enterotoxins produced by Staphylococcus aureus bacteria   . The bacterial growth and subsequent toxin synthesis are favored in food cooked or stored at an inadequate temperature and increase with the time during which the food was kept tepid (between 6°C and 46°C) .
Following the consumption of contaminated food, the onset of SFP is rapid. Symptoms can occur as soon as 30 minutes after ingestion  , although the incubation period varies among patients as well as with the toxin exposure level, and may last for up to 8 hours  . The most typical symptoms are nausea and profuse, vigorous vomiting. Patients also experience painful abdominal cramps. Diarrhea may be present, but the absence of this symptom does not preclude the diagnosis   . Fever is usually mild or absent  . Additionally, patients may present with nonspecific signs and symptoms such as dizziness, shivering and general weakness or even headaches, prostration and low blood pressure, depending on illness severity . Excessive vomiting can lead to different levels of dehydration in susceptible patients . In spite of the rapid and severe onset most cases resolve spontaneously and without hospitalization, with the potential exception of children, elderly and patients weakened by another condition  . A majority of patients recover after 1 to 3 days, with diarrhea and general weakness being the last symptoms to resolve  .
Clinical presentation and patient history are the starting point of establishing a diagnosis of SFP poisoning. In addition to gastrointestinal symptoms (with special attention to characteristic "projectile" vomiting), the short incubation period can be indicative of SFP. In such cases, anamnesis should include detailed food history.
Staphylococcal contamination of food originates from several sources, but the common denominator usually is and inadequate temperature of storing the food at some stage. Hence, the pre-cooked food is most frequently associated with SFP. Enterotoxins have been shown to develop in sandwiches, salads, cream-filled desserts, and pastries, as well as egg, dairy, meat (especially poultry) products, and processed meats such as ham .
Given the short duration and spontaneous recovery of patients, laboratory diagnostics is usually not performed in isolated cases. However, in case, of a suspected epidemic (especially common-source outbreak), laboratory findings are used to confirm the diagnosis . Two approaches can be applied: isolating the bacteria from suitable samples or detecting one of the staphylococcal enterotoxins in suspected food samples   .
The sources of contamination vary from colonized persons handling the food to unsanitary surfaces or environment and even raw materials (especially milk) used to produce the food  . Hence, environmental swabs (including hand and nasal cavities swabs) make a good sample for isolation of Staphylococcus aureus . In addition, food samples and biological material obtained from the patients (stool samples) are used for isolation  . However, the bacteria can remain undetected by this method if the food was cooked after the toxin was produced . Due to the thermostability of staphylococcal enterotoxins, they will be present in the food even after high temperature has destroyed the causative agent.
For detection of enterotoxins in contaminated food, immunoassays, bioassays and methods of molecular biology are used  .