A new virus has broken out in Germany causing thousands of children to start vomiting.

Within the last few days, the cases of children being affected with a type of gastroenteritis has rised from 4,500 to over 8,400, say the Germany's health authorities.

The cases began in Berlin and on Saturday the outbreak has reached neighboring states. Children became infected by eating school cafeteria food, but they recovered from vomiting and diarrhea within a few days, Associated Press reported.

An investigation into the cause of the mysterious outbreak is currently being done as more children are being infected.  According to the Robert Koch Institute, which is affiliated with the German government, there is likely a single supplier of food that is to blame for the outbreak.

The most common cause for the types of gastroenteritis that has affected the German children is most likely related to cases of norovirus which the German news agency DAPD confirmed was in Saxony. These viruses are developed from contamination related to fecal matter reaching an oral cavity usually through food digestion of human contact.

Infections of norovirus tend to arise in close-knit communities and people living in cramped sleeping spaces to allow easier transmission through human touch and shared food. These generally include hospitals, prisons, ships and long-term care facilities.

The symptoms of norovirus are closely related to those of food poisoning, according to WebMD. Vomiting, nausea, stomach cramps and diarrhea are common and happen to greater affect in children with the virus. It's crucial that those infected try to stay hydrated and they usually can get over the virus in a few days of rest without the need for antibiotics.

Until the investigation comes to a close, the culprit for the virus will likely continue to strike the stomachs of German children.