As a result of the third outbreak of salmonella at the College in the past month, University officials will ban all interhouse dining beginning at lunch today, and take other steps to contain the outbreak, including the removal of possible carrier foods from salad bars.

The state Department of Public Health laboratories diagnosed three cases of salmonella at Kirkland House yesterday morning, Dr. Warren E.C. Wacker, director of University Health Services (UHS), said yesterday.

After the laboratories identified the three cases of salmonella, all contracted within 24 hours of each other last week, health department officials consulted with Wacker, Dean Fox and Archie C. Epps III, dean of students, and advised them to take the following actions:

* Temporarily ban all part-time help, including students who work in dining halls of Houses they do not live in;

* Temporarily ban interhouse dining, including Dudley House students, but excluding Faculty members;

* Remove hard-boiled eggs and grated cheese from the salad bars, because these foods could help to transmit the infection;

* Take stool cultures of all people working in the central kitchen and the five dining halls it serves -- Lowell, Leverett, Winthrop, Eliot and Kirkland.

Fox and Wacker outlined these steps in a letter distributed to all undergraduate Houses and the Freshman Union last night. The letter also urges all students and staff to wash their hands carefully after using the bathroom and before eating.

The University is taking these steps because investigators of the salmonella outbreak believe a person, probably a student, is transmitting the disease by handling food, Wacker said.

"This is being spread from person to person, and we hope to limit any outbreak within the individual dining halls," he added.

"We believe this is the prudent and correct thing to do at this time. This will not be popular, and I'm sorry for any inconvenience, but my first responsibility is the health of the undergraduates," Fox said yesterday.

If no further cases of salmonella are diagnosed over the weekend, Wacker and Fox said they will consider lifting the ban on interhouse dining next week.

Dr. Nicholas J. Fiumara, director of the communicable disease division of the state Department of Public Health, said yesterday outbreaks such as these often occur at universities and that salmonella is not a serious infection. Its main symptoms are diarrhea, cramps and a slight fever, he added.

Investigators identified the first salmonella cases at the Union and the Varsity Club about a month ago and traced the outbreak to a kitchen worker who contracted the disease in Mexico. Two weeks ago, a new outbreak occurred at Winthrop House, infecting a total of about 25 people, Wacker said.

Wacker said he does not know if the strains of salmonella that caused the Union and Winthrop House outbreaks are the same, or if a similar strain is responsible for the three Kirkland House cases.

UHS will keep its labs open to continue testing cultures throughout the weekend, Wacker said.