Contamination of food and water may occur due to:
- leaving cooked foods at temperatures that allow for bacterial growth
- infection transmitted from the persons handling the food
- under-cooking or inadequate reheating of food especially meats, poultry and seafood
- Contamination of cooked foods by contact with dirty surfaces or raw foods.
- Unpasteurized dairy products such as milk, cheese etc.
- Raw seafood
Mostly, food poisoning is a mild illness which resolves even without treatment. However, in some cases, this can be a severe illness that requires admission into hospital for treatment.
- Abdominal pain
In severe cases, complications such as dehydration may affect the kidneys, liver or even the central nervous system leading to death.
The organisms associated with food poisoning infect the bowel with or without invading the lining of the intestines. This difference is usually evident in the diarrhea that results. Where the lining of the intestines is not invaded or inflamed, the diarrhea tends to be watery without blood or pus, and the abdominal pain is minimal. However, where the lining of the intestines is invaded and inflamed, abdominal pain is severe and is accompanied by bloody or mucus-like. In this later case, fever may also be a symptom.
The diarrhea without inflammation is often voluminous, leading to loss of water and subsequent dehydration. This is not common in the cases of inflammation since the diarrhea tends to be less.
For a diagnosis of food poisoning to be made, the symptoms usually affecting the gastrointestinal tract should be present in at least 2 people, with specific food identified as the source of the infection.
The symptoms usually help to narrow down the possible cause of the infection. After examination, laboratory tests are required to confirm the diagnosis.
- Examination of a stool sample under the microscope to identify the infective organism and check for any presence of blood, or pus or white blood cells in the stool.
- Stool culture – this allows for growth of the bacteria causing the infection in the laboratory.
- Blood tests – these are done for patients with fever and include blood counts and culture.
- Other tests such as electrolyte levels may do in cases of dehydration.
As mentioned earlier, most mild cases resolve even without specific treatment within 3 days.
However, moderate to severe cases require treatment which is as follows;
- Rehydration – this is the main goal of treatment, together with replacement of the electrolytes that are lost due to diarrhea and/or vomiting. This is mainly achieved by use of oral rehydration salts (ORS), which are readily available. In severe cases of dehydration or where vomiting is persistent. Intravenous (IV) solutions can be used to replace lost fluids and electrolytes.
- Diet – when diarrhea is ongoing, it is advisable to avoid milk and other dairy products since diarrhea reduces an enzyme in the intestines that digests foods containing lactose.
- Anti-diarrheal – these are drugs that reduce the number of bowel movements, usually by increasing the absorption of water in the intestines, reducing the secretion of fluids by the intestines or reducing the peristaltic movements of the intestines. These reduce the frequency of diarrhea but do not alter the course of the illness. These should however be avoided where fever is present or diarrhea is bloody.
- Specific treatment with antibiotics – where symptoms persist after 3 days, it is crucial for the specific organism causing infection to be identified. Based on the findings, an appropriate antibiotic will be prescribed.
- Strict personal hygiene when handling food
- Proper washing of the hands using soap and water before handling any food
- Food handlers need to be tested and treated for diseases like amoeba and typhoid fever
- Store foods at appropriate temperatures
- Cook foods adequately
- Avoid contamination of cooked foods by raw foods
- Avoid unpasteurized dairy products
- Treat any cases of food poisoning as soon as possible