After the third bedbug sighting since February at James Hillhouse High School last week, New Haven Public Schools parents are reacting with mixed feelings to the school district’s response.

Nijija-Ife Waters, a former Hillhouse employee and NHPS parent, said a teaching-support staff member found and reported the first bedbug on Feb. 22, at which time Waters was working as a parent liaison at the school. The paraprofessional who found the bug brought it to the school nurse, who sent it to a lab for testing, Waters said. On March 14, another paraprofessional found a second bedbug. Last week’s bedbug sighting on a computer keyboard elicited a formal response from the school district, which described the third sighting as an “isolated case” in an official statement sent to the Hillhouse community.

“Governing protocols were immediately implemented with Board of Education and Health Department staff in conjunction with other city departments in order to address the issues within the school as well as to properly investigate and treat the source,” read an official notice issued jointly by the Department of Education and Department of Health. “There is no reason at this time to believe that this isolated incident poses any risk to the larger building or student and staff population.”

The notice urged “responsible vigilance” among Hillhouse community members, noting that bedbug proliferation is “on the rise” in the Elm City.

The April 11 Hillhouse bedbug report came two weeks after an infestation surfaced at Harkness Hall, a 172-bedroom medical-student dorm directly across from Yale-New Haven Hospital. The Harkness infestation, which came to light on March 31, was the University-owned building’s sixth bedbug infestation since October.

Superintendent Garth Harries ’95 could not be reached for comment Monday. All NHPS schools are on spring break this week.

According to Waters, around 60 high school seniors refused to attend class last week after the third bedbug was discovered on the third floor of Hillhouse.

Waters, who also sits on the steering committee of New Haven Families Connect — a coalition of NHPS parents dedicated to providing feedback to the district — noted that many parents felt the school’s response was insufficient.

“Why is it that there are a lot of things happening in [Hillhouse High School] and you can’t give us a straight answer?” Waters asked. “We’re going around in circles.”

Waters said she and many other parents are concerned that information was being “swept under the rug.”

One Hillhouse parent who spoke on the condition of anonymity to avoid retaliation from NHPS said she thinks the district’s response has been contradictory because administrators called the first two sightings “rumors” and the third an “isolated incident.” The parent, whose daughter is an eleventh grader at Hillhouse, said she plans to meet with New Haven alders to discuss the problem. She added that she believes many Hillhouse teachers, parents and students fear retaliation for speaking about the “out of control” situation publicly.

Hillhouse parent Eva Perry, however, said she was satisfied with how the district addressed the bedbug sighting.

“Apparently they’ve handled the issue and I’m fine with it,” Perry said.

Waters said since students attend different classes in different rooms at Hillhouse, it is difficult to contain a bedbug outbreak to one isolated classroom.

The region spanning Hartford to New Haven ranked 34th on a list of markets with the highest number of bedbug treatments during 2015, compiled by nationwide pest-control leader Orkin.