Stomach flu is the inflammation of the gastrointestinal tract, both in the stomach and the small intestine. This condition is also known under the names of gastric flu or the gastroenteritis. The infection usually results in acute diarrhea and many other accompanying symptoms. The disease is usually caused by certain viruses or by bacteria, their toxins, parasites, or an adverse reaction to something in the diet or medication. This disease is very frequent in world's poorest nations. It is estimated that about 4.6 million children in the third world die each year of viral stomach infection. Stomach flu is a leading cause of death among infants and children under the age of five, who have a very weak immune system.
Causes of stomach flu
Stomach flu is usually contracted in contact with an infected person or upon ingestion of contaminated food or water. Sharing utensils, towels and food with other people is also considered risky for contracting viral infection. The seafood, shellfish, and raw foods are among the most frequent sources of infection.
The infection is commonly due to viruses. Rotavirus is the most common cause of stomach virus in infants and children worldwide. Children usually contract the virus by putting their fingers in the mouth.
Many subtypes of noroviruses can also cause stomach flu, accompanied with diarrhea, nausea and vomiting, muscle aches, headache, fatigue and low-grade fever. Noroviruses spread easily among people in limited spaces, but one can easily catch it even from water.
The first symptoms of the infection will occur anytime within 18 to 72 hours after the exposure to the virus.
For how long is a person contagious?
The viral gastroenteritis is a contagious disease, but for how long a person will stay contagious depends on a type of virus that causes the infection.
Rotavirus, which usually affects children and infants, needs one to two days to develop an infection. However, patient will be contagious even before the first symptoms become visible. This period between the first contact with the virus, and the first symptoms of infection, is known as the “incubation period”. The patient will normally remain contagious for two weeks after the complete recovery. However, children and people with a weak immune system may stay contagious for a longer period than otherwise healthy adults may.
Norovirus has the incubation period that lasts no less than one to three days. However, with norovirus, a person is contagious from the moment when the symptoms develop and the patient starts feeling sick. The recovery typically starts after a day or two, but it takes at least three days before a person stops being contagious. With norovirus, the contagious period may last up to two weeks.