In this rural hamlet 60 miles southeast of Boston, a bright, quiet 12-year-old boy with AIDS has been walking the scuffed linoleum of Joseph Case Junior high school from biology class to English class to physical education and eating lunch in the cafeteria with his fellow eighth-graders.

There have been no pickets on the school lawn. None of the boy's teachers has refused to teach him. Students have not withdrawn en masse to protest his presence in school.

When school officials decided last month that the boy should attend school as usual, Swansea became the first public school system knowingly to admit a child with acquired immune deficiency syndrome, according to the federal Centers for Disease Control in Atlanta.

The boy, a hemophiliac who contracted AIDS from contaminated blood products, was admitted this week to Rhode Island Hospital in Providence for treatment of an infected ankle caused by hemorrhaging. He was listed in satisfactory condition.

The decision to let him attend school when he is able, supported by state education and health officials, is being hailed as courageous and exemplary -- but it has not met with unanimous approval or left parents entirely at peace.

At a meeting this week, health and school officials sought to dispel parents' fear that their children will contract the disease, which attacks the body's immune system, and their anger over the decision to let the boy begin class, unannounced, Aug. 27. The Associated Press reported that several parents accused school Superintendent John E. McCarthy of sidestepping when he declined to guarantee that their children would not be infected.

"It's a deadly disease and I want to find out if they're going to guarantee my kid's safety," said Len Cabral, whose son attends the school. "I want to be sure my kid isn't going to get it or that kid isn't coming to school."

Studies have shown that AIDS is transmitted through body fluids. Massachusetts allows its victims to attend school if they do not have open sores or a tendency to bite other children.

"I still believe that if people are informed, most of the time they'll do the right thing," McCarthy said at the meeting. "And in this case it's to keep their children in school and support the continuance of this student in a school setting."

"We have nothing but great admiration for Swansea ," said Mary Breslauer, spokeswoman for Massachusetts' Department of Human Services. "They made a very responsible and compassionate decision . . . . They did such a good job, they really have a community that's rallied around not only the principal and the superintendent but around this poor child with AIDS."

"Good? I don't know if we did a good thing. We did the right thing," McCarthy said in an interview earlier this week.

McCarthy is blunt-spoken and friendly man, a former football coach and junior high principal. He dismisses praise for his decision to admit the young man, a hemophiliac who contracted AIDS from contaminated blood products.

"I get kind of lost when people say it takes courage to do the right thing," he said. "I did a lot of research, there's no danger. And these kids belong in school. Their progress is much better in a school setting."

McCarthy said he is proud of his town's support for the boy, whose identity is being concealed. "I get some of these when I walk around," he said, flashing a thumbs-up sign. "I appreciate that. I want people with me, not against me."

Officials permitted the boy to pitch for his Little League team this summer despite widespread knowledge that he had AIDS.

"I heard about it through the grapevine early this summer, and I really felt devastated for the kid and his family," said Alice Gunn, mother of a seventh grader who played Little League ball with the boy. Asked if she was concerned for her son's health, she said: "It never even dawned on me to be."

According to the CDC, 164 children under 13 have contracted AIDS, and 115 of those have died. The disease is usually fatal within several years.

Parents of two of the 640 students at Case Junior High kept their children home last week, according to Principal Harold G. Devine Jr., who said one of those students was back in school this week. He called the student body's generally supportive response "remarkable": Several students approached him seeking to organize a fund-raising effort on the boy's behalf.

"And I feel very proud of the faculty," Devine said. "Every day they are buying into this a little more and a little more."

Lynn Sullivan, the boy's biology teacher, is a cancer patient with no spleen, an organ that helps protect against disease, and when she learned the boy had AIDS, "I immediately called my own doctor because he gets upset if I get a common cold. I figured if anybody could get it, it would be me first. He said there was no danger at all.

"And that's been reassuring for other people," she continued. "People figure, if it's okay for me, it must be okay for them."