One person has died and 12 are admitted at Kipini Hospital in Tana Delta with choler-like symptoms.
The outbreak began early in the year after fishermen showed symptoms.
County director of medical services Oscar Endekwa said the outbreak may have begun in Lamu.
Experts have been sent to Kipini to investigate, he said.
“We found 35 people infected by the diarrhoea bacteria and by yesterday 12 patients were admitted at Kipini Hospital. The rest were sent home,” the doctor said.
The fishermen have been quarantined in one village.
Treatment and prevention measures are being implemented.
The dead person was buried under the supervision of public health officers.
“We have taken some samples from all water sources in the region and also some blood samples and sent them to the laboratory for further screening at Kipini Hospital. Others will be sent to Malindi District Hospital,” Endekwa said.
He said they are treating water sources and monitoring them.
