LYNN – Two St. Pius V School students have been diagnosed with the H1N1 virus, commonly known as swine flu, the Boston Archdiocese confirmed Friday.Principal Paul Maestranzi has contacted parents and informed them of the situation and will keep the school open going forward.In a letter sent home to parents provided by the Archdiocese, Maestranzi informed parents that the physician for two students had contacted the school to confirm that both have swine flu this week.Both of those students have been sent home for the full seven day recovery period and Maestranzi said three other students showing flu symptoms have also been sent home as a precaution.Maestranzi said the school nursing staff would be in close contact with those students’ physicians in the coming weeks and would be keeping a close eye out for other students who exhibit flu-like symptoms.Following the state Department of Public Health’s guidelines for swine flu outbreaks, the school will remain open going forward and will receive a thorough cleaning over the weekend.”As always the administration and nursing staff will monitor symptoms reported by any student who is seen by the school nurse and the school will follow all guidelines recommended by the Department of Public Health,” he said in a letter home to parents. “Having reviewed the nursing records for this week, three students were sent home with fevers and the administration will be in contact with these families.”A spokesperson for the Boston Archdiocese said the school has been in very close contact with them throughout this process and they have supported Maestranzi’s decision to keep the school open, even though some parents have protested the move.He also said that approximately 30 of the 484 students at the school stayed home Friday, around 6 percent.”(Maestranzi) is doing what he is supposed to do and that is communicating with the families,” said Spokesman Terrance Donilon. “Just from the numbers we are seeing it doesn’t appear that he has to do anything drastic. They will keep the school open and they will do some additional cleaning this weekend.”The confirmed cases at St. Pius V are the second and third cases to emerge in city schools since the swine flu epidemic first surfaced in April. A Harrington Elementary School teacher also came down with the new strand of influenza in mid-May, but that school has also remained open with little incident.While the swine flu has proven contagious in most cases, health officials say the disease is no worse than the traditional seasonal flu, which is common among students at this time of year.Concerned parents both at St. Pius V and Harrington have questioned why the schools remain open when cities like Boston have been closing schools with confirmed cases and questioned why students who have not been vaccinated for this particular strand of the flu would be considered safe at school.Director of Public Health Maryanne O’Connor assured parents Friday that they have nothing to be concerned about as long as they follow flu-prevention guidelines.O’Connor said she had not been informed of a confirmed case at St. Pius V, which is not uncommon given that it is a private, Catholic school.”Even if there is (a confirmed case), that’s OK. We know it is here (in the city),” she said. “Chances are if you have flu symptoms you probably have the swine flu, because that is the dominant strain that is around right now.”O’Connor reiterated that the DPH has said that swine flu is actually less severe than the traditional seasonal influenza and in most cases has recommended that students go to school as long as they are feeling well.”There really is no need for people to be upset,” she said.The DPH recommends frequent hand washing and sanitizing and strongly encourages parents to keep students out of school if they are not feeling well and to be sure to contact the school and explain the situation.Along with his letter home to parents, Maestranzi provided a flu symptom check list fo