Saudi Arabia confirmed one cholera infection and three other suspected cases in an area bordering Yemen, where an epidemic has killed more than 2,300 people, state TV reported on Sunday, citing a health ministry official.

The report said the patient, identified only as non-Saudis, were receiving care at Mauwassem General Hospital in Jizan, about 1,000 km southwest of the capital, Riyadh.

The incubation period for cholera, which spreads through ingestion of faecal matter and causes acute watery diarrhea, is a matter of hours. Once symptoms start, it can kill within hours if the patient does not receive treatment.

The WHO has rolled out an emergency treatment programme, based on the vestiges of Yemen's shattered health system, to try to catch new cases early and stop the explosive spread of the disease.

More than 1.1 million suspected cholera cases have been recorded in Yemen since April 2017, according to the latest WHO figures, with more than 2,300 associated deaths.

It was the largest and fastest-spreading epidemic on record - and its rapid spread was caused by the destruction of sewerage and sanitation systems during the country's civil war.

Although cases have reduced dramatically in 2018, the UN warned last month about a possible "third wave" of the epidemic.