Thorough hand-washing with soap and warm water helps to prevent the spread of Shigella.
(CNN)Kansas City, Missouri, health officials are urging residents to take preventative measures after a big spike in cases of an infectious diarrheal disease.
Normally, there are about 10 Shigellosis cases a year in Kansas City, according to the city's health department. So far in 2015, more than 150 cases have been reported, mostly among children in day care and elementary schools.
Shigellosis is caused by a group of bacteria called Shigella.
There were 16 cases between January 1 and July 1. Since July, more than 134 additional cases have been reported.
Reasons for the spike are unclear, a spokesman for the Kansas City, Missouri Health Department said.
"We really don't have any idea why. We know that the Shigella pattern is that we usually have an outbreak every five years," said health department spokesman Bill Snook.
This year's outbreak is in line with that trend and the department is urging strong preventative measures to fight several antibiotic-resistant strains of the bacteria.
Symptoms typically start one to two days after exposure, according to the Centers for Disease Control and Prevention, and include diarrhea, fever and abdominal pain.
Shigella is transmitted by direct or indirect fecal-oral contact. Transmission can occur from improper hygiene during food preparation or through contaminated water in pools and lakes.
Frequent, thorough hand-washing with soap and warm water helps to prevent the spread of Shigella and other contagious illnesses.
It's also important to use paper towels to dry hands rather than cloth towels, where the bacteria can be transferred with reuse.
"Don't use a cloth towel because Shigella is unique in some respects in that it only takes 7 to 10 organisms to get you infected," Snook said.
Infected persons should not prepare food or drinks for others, health officials warn, and diaper changing should be done correctly: disposing of soiled diapers in closed-lid containers, followed by the disinfection of changing areas and thorough hand washing.
Cases of Shigellosis usually resolve within seven to seven days without antibiotic treatment, according to the CDC. Those with mild cases may need only fluids and rest to recover.
While antibiotics may reduce the infectious period, Kansas City is seeing three different strains that are resistant to some antibiotics.
That resistance is not unusual, according to the CDC's website, which says "resistance to traditional first-line antibiotics such as ampicillin and trimethoprim-sulfamethoxazole is common among Shigella globally, and resistance to some other important antibiotics is increasing."
Lab tests can be used to detect Shigella in stool samples. Testing helps doctors determine which antibiotics will be helpful to treat specific strains.
In Kansas City, some people with confirmed cases require one or more negative stool cultures before returning to work or day care.
Children in day care and day care providers require one negative stool sample. Food handlers and health-care workers require two negative tests.
Annually, there are about 500,000 cases of Shigellosis in the United States, according to the CDC.