Gastroenteritis

Diarrheal disease is responsible for significant morbidity and mortality worldwide, with nearly 1.7 billion cases [1] and at least two million deaths per year, many resulting from consumption of contaminated food [2]. Acute infectious gastroenteritis is defined as disorder of the physiological functions of stomach, small, and large intestine (see chapter “ Overview ” under part “Gastrointestinal tract”) due to inflammation of the digestive tract, resulting from bacterial, viral, or parasitic infections (Fig. 1). Noninfectious gastroenteritis may also occur after ingestion of certain types of food and medicines but is less common. Common symptoms include diarrhea, vomiting, abdominal pain, headache, nausea, fatigue, and occasionally fever and chills [3]. Infectious gastroenteritis can occur year-round, but bacterial cases are seen more commonly in warm or summer months because bacterial pathogens can replicate in vitro after contamination of food or water. These diseases are more common in developing nations where sanitation conditions are poor and visitors to these nations commonly develop traveler’s diarrhea. Viral pathogens are not able to replicate in vitro, but tend to survive longer in cold conditions, which facilitates their spread via person-to-person contact. Therefore, viral diseases are more common in the fall/winter seasons when people are indoors more often [4].