TEMPO.CO, Geneva - The World Health Organization (WHO) said a cholera epidemic in Yemen could spread during the annual hajj pilgrimage in Saudi Arabia in September.

The cholera epidemic has infected more than 332,000 people in Yemen, the health organization said Friday, July 14.

The pilgrimage draws 2-4 million Muslims every year, including 1.5-2 million foreigners, raising the risk from diseases such as dengue, yellow fever, Zika virus and meningococcal disease as well as cholera, the WHO said.

"The current highly spreading outbreak of cholera in Yemen, as well as in some African countries, may represent a serious risk to all pilgrims during the (hajj) days and even after returning to their countries," a WHO bulletin said.

Dominique Legros, a WHO cholera expert, said Saudi Arabia had not had a cholera outbreak in many years thanks to reinforced surveillance and rapid tests to detect cases early.

"Don’t forget that today we are speaking of Yemen but they are receiving pilgrims from a lot of endemic countries, and they managed not to have an outbreak, essentially by making sure that living conditions, access to water in particular, hygienic conditions, are in place," he told a regular U.N. briefing.

"They are well-prepared in my view."

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

But people with symptoms are just the tip of the iceberg because 80 percent of patients show no symptoms, Legros said.

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

REUTERS