Steps to be taken on Noticing Food Poisoning
- Secure a complete list of people involved and their history. All those who have partaken of the food should be interviewed. They may be supplied questionnaires concerning the foods eaten during the previous two days and the place of consumption, time of onset of symptoms, symptoms of illness (e.g. nausea, vomiting, diarrhea, abdominal pain, headache, fever, prostration, etc) in order of occurrence, personal data such as age, sex, residence, occupation, and any other helpful information. Questionnaires may be administered to kitchen employees and those working in dining halls.
- Laboratory Investigations
It is an important part of the investigations. The objective is not only to incriminate the causative agent from stools, vomit or remnants of food by inoculating into the appropriate media, but also to determine the total number of bacteria and relative numbers of each kind involved.
This will give a better indicator of the organism involved. Stool samples of the kitchen employees and food handlers should also be investigated. The samples should be examined aerobically and anaerobically. Phane typing of the organisms should be done to complete the laboratory investigation.
Kitchen - Animal Experiments
It may be necessary to feed Rhesus monkeys with the remnants of food. Protection tests are useful in the case of botulism, in this, a saline filtrate of foodstuff is injected subcutaneously into mice protected with anti–toxic sera, keeping suitable controls. - Blood for Antibodies
This is useful for retrospective diagnosis. - Environmental Study
This includes inspection of the eating place(s), kitchen(s) and questioning of food handlers regarding food preparation. - Data Analysis
The data should be analyzed according to the descriptive methods of time, place and person distribution. Food–specific attack rates should be calculated. A case control study may be undertaken to establish the epidemiological association between illness and the intake of a particular food.
