Tests Show Norovirus Likely Spread Among Campers at Walker Creek

Marin County Health officials have confirmed norovirus was present at the Walker Creek Ranch when about 60 people got sick at science camp last week.

The health department released a letter today about lab tests of stool samples, which showed some people who got sick at the ranch had norovirus in their systems.

The letter sent to parents at Elementary in Danville, San Ramon Elementary in Novato and Redwood Day School in Oakland,  said the investigation "indicates that the illness likely spread directly between children, rather than through contaminated food or water."

The letter went on to say "the first person who became sick was likely already  infected and incubating the illness when they arrived at science camp last week."

The department said in the letter it will continue to interview students who did and did not become sick. Additional lab tests will also be conducted, the letter said.

More than 250 people were at Walker Creek Ranch, a residential science camp in West Marin, when the stomach illness made five dozen people sick at the camp starting late Tuesday night.

Among the stricken group were 34 people from Danville, including students and a teacher from and high school camp counselors. There were 103 people from Danville on the trip, said San Ramon Valley Unified School District Community Relations Director Terry Koehne.

One high school student, Matti Ruetman, an 18-year-old senior at , was in the hospital for a couple of days being treated for the illness.

On Friday, all Tassajara Hills fifth-graders who went to the camp were told to stay home. 

On Thursday last week, Walker Creek ranch was evacuated as a precaution upon a recommendation by officials at Marin General Hospital. The facility had been checked earlier in the week by state and county agencies for water quality and food preparation.

The Marin County Health Department is asking students and adults with the illness not to return to school or work until they have been symptom-free for at least 24 hours.

Because norovirus is contagious and passed directly between people, additional cases may develop among family members and other contacts of those who became ill at the ranch.

Walker Creek Ranch has rescheduled campers for this week, until their is a final confirmation of the source of outbreak.

Because norovirus is contagious and passed directly between people, additional cases may develop among family members and other contacts of those who became ill at the ranch.

Walker Creek Ranch is a campus of the Marin County Office of Education. It is in unincorporated Marin County and made up of an outdoor school, conference center and summer camp, according to the facility's website.