The Santa Clara County Public Health Department has officially completed its investigation on the cause of the gastrointestinal illness that afflicted students in Florence Moore Hall (FloMo) late October. No conclusions were drawn on the original source of the outbreak, but health officials state norovirus was likely the cause.
“We know the county did an exhaustive investigation, but sometimes it’s not possible to get an exact source,” said Lisa Lapin, University spokeswoman.
Between the afternoon of Oct. 29 and Nov. 5, a total of 62 residents from FloMo—two of whom were faculty—reported stomach-flu-like symptoms, including vomiting and in some cases, diarrhea, Lapin said. Seven students were eventually treated at Stanford Hospital for dehydration and released.
These numbers do not include the cases of the same symptoms of illness in Wilbur Hall. However, it cannot be assumed these cases were spread from the FloMo cases, said Ira Friedman, director of Vaden Health Center, who emphasized that norovirus is extremely common at this time of year.
Shortly after the outbreak, the county public health department began a weeklong investigation to determine the cause and detail an exposure history of the gastrointestinal illness. This investigation included a remotely-run exposure history survey, an attempt at acquiring stool samples and an in-person survey of the FloMo residences, said Cornell.
More than 200 residents participated in the survey, which collected information from both healthy and sick students. Administered by the county public health department, the survey included questions that asked about recent food exposures as well as the symptoms and time of onset of illness. The survey did not produce conclusive results that could identify the source of the norovirus-like illness, and the county could acquire any positive specimen.
“We were hoping to get samples from some of the students but were not able to get any,” said Sarah Cody, Santa Clara County health official. “After everyone got ill, we made plans early to collect stool samples but after that, no one came in and we did not end up getting a specimen.”
However, the symptoms associated with the gastrointestinal illness matched very well with norovirus, and the county closed its investigation concluding that the illness was likely due to norovirus.
During the outbreak, the county also focused on preventative measures to stop a secondary spread of the suspected virus; however, according to Cody, the illness was already well contained.
“It was remarkable, the lack of secondary spread made me really wonder whether it was actually norovirus,” Cody said.
Friedman attributes this containment to the “early warning reporting system” that was already in place in all the dorms through the peer health educators (PHEs) in the dormitories. During training, all PHEs are taught to report illnesses and the symptoms associated with them as soon as possible.
“What was unique about Stanford was the early warning system in place and that the control measures that were implemented right away,” Cody said. “It was a luxury to come into the situation where everyone was already on top of things. And I’m assuming that’s what got it under control so fast.”
To date, there are no more reported cases of gastrointestinal illness, Friedman said. Additionally, janitorial cleaning at FloMo has returned to normal, back from the two-shift cleaning periods implemented to sanitize the dorm facilities.
Contact Catherine Zaw at czaw13 ‘at’ stanford.edu.