The Health Ministry on Wednesday announced a recent rise in salmonella poisoning in Israel and in 14 European countries.

Eggs are suspected as the source of the poisoning, whose symptoms include stomach cramps, vomiting and diarrhea.

The bacteria enters the food chain in two ways: from outside, when laying hens come into contact with dead birds, excrement or other pollutants; and internally, when the bacteria pass from the hens’ reproductive systems straight to the eggs.

Children, the elderly, and people with weak immune systems are particularly susceptible.

The ministry advised households to keep all raw food away from cooked food, at temperatures of up to 5ºC (41ºF), but says eggs can be kept — for up to 21 days — at below 20ºC (68ºF).

It also advised against reusing egg boxes, as schools and kindergartens often do, because they, too, can carry salmonella.

It warned that washing eggs can cause the bacteria to pass through the shell into the egg.