The most common presentation is abdominal pain or cramps, vomiting and diarrhea. The patient may also present with fever and chills. Depending upon the causative agent, the pattern of presentation varies slightly. Typically, the symptoms may start within few hours after consumption of food or can start even weeks later. Significant loss of fluid can lead to dehydration. Other organ systems can be affected and depending upon that the presentation varies. Bacterial agents such as Staphylococcus aureus, Bacillus cereus and Clostridium perfringens have a short incubation period of less than 24 hours. Vomitting and diarrhoea occur immediately.

Campylobacter, Shigella and Salmonella mainly affect the large intestine [6] and produce bloody mucous diarrhea accompanied by severe abdominal cramps. They have an incubation period of 1 to 3 days. Similarly, Escherichia coli is responsible for traveller’s diarrhea but shows no fever or dysentery. Vibrio cholerae produce rice water diarrhea. Hemorrhagic Escherichia coli has a long incubation period of 3-5 days and produces inflammation of colon along with dysentery which if not treated can lead to hemolytic uremic syndrome (HUS) and ultimately lead to kidney failure [7]. Viral food borne illness tends to cause fever with chills, headache and vomiting. 

A complete and detailed history regarding the onset, frequency of bowel movements and accompanying systemic symptoms should be noted [8]. A physical examination to determine the level of dehydration should be carried out. Dry mouth with reduced urine output and decreased sweating indicate mild dehydration. Drop in blood pressure, skin denting and sunken eyes indicate moderate dehydration. Confusion, tachycardia and shock require immediate hospitalization and indicate severe dehydration.

Rectal examination should be done to examine rectal mucosa to rule out any lesions if dysentery is present. Stool test and stool culture to check for blood as well as causative agents are done. Specific laboratory tests are also useful to determine specific agents [9].

Symptomatic treatment is given depending upon the presentation of the patient. Correction of fluid and electrolyte imbalance takes precedence. Antibiotics are not always required as most times the infections are self limiting and overuse of antibiotics and partial treatment of infections is the major reason for emergence of resistant organisms. Hygiene should be maintained during illness. If illness does not resolve within 3 to 4 days, stool culture should be done and empirical treatment for possible organisms started.

Generally, most of the cases are self limiting and resolve on their own within a couple of days. They are treatable at home with adequate hydration and dietary precautions. Elderly [5], immunocompromised and infants are at a higher risk of complications. The mortality and morbidity is higher in such cases. Depending upon the type of infection and underlying medical status of an individual, organ damage and death may occur without adequate treatment. The most common complication of food poisoning is dehydration which if not attended to immediately can lead to shock and death.

Food poisoning is a general term for gastroenteritis. This usually happens when edible food gets contaminated which can occur at any level from processing, packaging to handling. When a person consumes this contaminated food or beverage, food poisoning occurs. Most common causative agents are bacterial [2] or viral. Common agents are:

Bacteria

• Campylobacter
• Salmonella
• Shigella
• Clostridium perfringens
• Staphylococcus aureus
• Bacillus cereus
• Clostridium botulinum
• Brucella

Viruses

• Hepatitis virus A
• Rota virus
• Noroviruses (Norwalk-like viruses)

Parasites

• Taenia
• Ascaris

Toxins

• Shellfish and oyster poisoning
• Heavy metals (Arsenic, mercury, lead)

Common conditions which can lead to food getting contaminated by these agents are:

• Cooked food left at temperatures which allow bacteria to grow.
• Undercooked food or inadequate heating.
• People who are themselves infected and handling food.
• Cross contamination of food.

Routes of transmission are mainly through contaminated food with or without subsequent spread from person to person by feco-oral route. [3] Fresh fruits and vegetables if not washed properly prior to consumption, may be contaminated with animal manure or human sewage harbouring the infectious agent. Salmonella can contaminate eggs. Unwashed hands of infected food handlers can transmit Shigella and hepatitis A virus. Raw foods like meat, poultry, eggs, unpasteurized milk and shellfish are most likely to be contaminated.

Food poisoning is a notifiable disease, most of the cases are either individual or sporadic. About 75-80% cases are of bacterial origin. About 1 in 10 individuals in the United States of America [4] suffers from food borne illnesses. The CDC reports 97% cases are due to unhygienic food handling. In most of the sporadic cases the cause remains undetermined. As eating out is almost a habit for most people, 58% of cases arise due to some level of contamination from commercial food setups.

An epidemic or outbreak occurs when two or more people have similar symptoms after consuming food from a common source. Most of these outbreaks are reported and identified by public health authorities. In the year 2000, on a global level, about 2.1 million children died due to diarrhea. Even in well developed countries, 30% of population suffers from some sort of food borne illness every year. Food trade, travel and migration increase chance of cross border transmission of diseases. It can affect all ages and both sexes equally but elderly, infants and immunocompromised individuals are at a higher risk.

The diarrhea in food poisoning is either of inflammatory or non-inflammatory types.

• Non-inflammatory diarrhea occurs when the enterotoxins which can either be formed before or after ingestion, act on the mucosa of the gut without invading it. This leads to watery diarrhea without presence of leukocytes. Clostridium perfringes, Giardia lamblia, Rotavirus and Norwalk virus cause this type. This is also called as secretory diarrhea.
• In inflammatory diarrhea, cytotoxins invade and destroy the mucosa of the gut; this leads to diarrhea which is bloody and consists of pus and leukocytes. Occasionally, these organisms not only invade the mucosa but also proliferate in the lymphatic tissue followed by spread all over the body. This can lead to sepsis which can be fatal. Campylobacter jejuni, enteroinvasive Escherichia coli, Entamoeba histolytica, Salmonella and Shigella cause this type of diarrhea.

Simple precautions can be taken to prevent any food borne illness such as:

• Thorough cooking of meat, poultry and eggs.
• Prompt refrigeration of leftovers.
• Avoidance of cross contamination of food by washing hands, utensils and cutting board after contact with meat or poultry.
• Washing fruits and vegetables to remove dirt.
• Strict standards of personal hygiene [10].
• Reporting of food borne illness to local health authorities, thus preventing further spread of illness.
• Food borne illness is a major health issue worldwide. A primary physican plays a critical role in surveillance and early reporting of food borne illness along with basic education of food safety.

Food borne diseases are caused by consuming contaminated food or beverages. Many different types of microbes or pathogens can contaminate the food, in addition, poisonous chemicals or other harmful substances present in the food can also cause food borne illness. Food poisoning is an acute illness with a very short incubation period. The causes have changed dramatically during the past decade owing to urbanization, industrialization, travel and expansion of commercial food services.

Most of the cases of food poisoning are not severe and do not require any specific treatment unless complications arise. They are self limiting and resolve on their own within a couple of days. Some cases may require hospitalization, hydration and antibiotic therapy. Immediate medical attention must be given if an individual has fever with blood in stools and shows signs of dehydration. The key is prevention by maintaining high standards of hygiene and cleanliness while handling food [1].

Many recent outbreaks linked with traditional food borne pathogens like Campylobacter and Salmonella have occurred. Apart from these, a number of new agents such as Escherichia coli or Listeria have also been identified and implicated.

Food poisoning is an acute medical condition which occurs on consumption of food contaminated with bacteria, viruses, parasites or any other chemical toxins. Most cases occur due to bacteria and occur through contaminated food or beverage intake. Food poisoning tends to affect more than one individual. This occurs when food handling hygiene is not maintained. It can occur when raw fruits and vegetables are not washed, people handling food are infected, due to intake of raw uncooked food especially meat and eating unpasteurized dairy products.

The symptoms usually start within few hours of consumption of contaminated food in the form of stomach cramps, diarrhea or vomiting. In severe cases fever may also present. Most of the cases resolve on their own with simple home remedies such as maintaining fluid balance in body and strict precautions in intake of food. Patient is advised increased intake of water.

In case of severe dehydration where there is severe loss of water and salt in the body it may lead to a drop in blood pressure and pulse. Immediate hospitalisation should be done. Anitibiotics may be given in cases which do not settle within few days. Contact your health provider if you have blood in stools, severe vomiting and unable to take water.

Prevention is the key to food poisoning, especially in elderly people, infants and pregnant women. It is crucial to maintain an strict standard of hygiene while food preparation and consumption.

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