Russian and Ukrainian authorities said outbreaks of typhoid, a disease usually confined to less developed countries, had hit Moscow and southern Ukraine, saying poor sanitation was to blame.

Epidemiologists, quoted by Russian media, reported two cases in a family just outside Moscow, with a third relative under observation. All had eaten food purchased at a local market.

“This is quite unusual for Moscow, though less so for other parts of the former Soviet Union,” a medical source said on Tuesday. “It is no cause for alarm, but amounts to a lesson not to buy food at markets where there is no proper refrigeration.”

Typhoid, which causes severe fever and diarrhoea and spreads quickly, is caused by bacteria generally linked to poor quality water, inadequate sewage systems or low hygiene standards.

Diseases like typhoid and diphtheria were virtually eliminated during the Soviet period, but have made a comeback since the fall of communism due to a decline in health care.

In Ukraine, health officials reported 13 cases in the Black Sea port of Odessa, traced to a local market. They said the infection had come from outside Ukraine and the market had been closed down a number of times before.