Two weeks ago, the state Department of Public Health determined a fifth-grade science experiment involving the dissection of owl pellets was responsible for a salmonella outbreak, in which 28 students were confirmed to have the bacterial infections.

In all, at least 50 students came down with related symptoms.

More than 40 parents and residents have issued a letter, stating that school officials ignored basic sanitary precautions and jeopardized the health of students and parents. The letter alleges children were told they did not need to wash their hands or sanitize their desks after they conducted experiments; students were permitted to eat snacks at their desks after the experiments; and one student who brought in latex gloves for the experiment was told she could not wear them.

Donna Rheaume, a DPH spokesman, said her department would issue additional guidelines in coming months when a full report on the outbreak is released.