Rockville High School will reopen today after the Centers for Disease Control and Prevention in Atlanta changed its recommendation to close schools where there were probable cases of swine flu among students or staff.

The decision to reopen came just a day after Maryland closed a sixth school because of a suspected swine flu case and after officials denied an appeal by Montgomery County's superintendent to reopen Rockville High. On Monday night, a second Rockville High student was described as having a probable case of swine flu.

So far, the CDC has confirmed four cases of swine flu among Maryland's 15 suspected cases.

On Tuesday, however, the CDC reversed course and reported that there no longer was a reason to close schools when there were probable cases of the swine flu, also known as the H1N1 virus, because the outbreak was not as severe as originally feared, Health and Human Services Secretary Kathleen Sebelius said at a news conference Tuesday.

Plans had been to keep the six schools statewide closed for up to two weeks as a precaution against the spread of the disease.

Montgomery County Health Officer Ulder Tillman notified the County Council of the second student during an update Tuesday on the flu outbreak. Tillman was notified by state health officials of the second Rockville High case at 10:30 p.m. Monday.

The student began exhibiting flu symptoms May 1, Tillman said. Rockville High School has been closed since Friday, when county officials announced an autistic student as the first probable swine flu case. Like the second probable case, the autistic student has a sibling in the county's school system.

On Friday, county schools Superintendent Jerry D. Weast joined Tillman, County Executive Isiah Leggett, Gov. Martin O'Malley and the state's Deputy Secretary for Public Health Frances Phillips for a news conference announcing the indefinite school closing and urging students not to congregate at places such as malls and movie theaters to slow the flu's spread.

But by Monday, Weast had broken from the unified stance. In a letter to the school board Monday night, Weast said the closure was not the right decision, "given the lack of compelling evidence for continued closure" from state and county health officials. Weast's letter cited information received before Tillman's 10:30 p.m. notification of a second probable Rockville case.

On Tuesday, Leggett (D) urged county officials to remain unified in their stance regarding the flu response, specifically on school closures.

But the CDC's reversal spurred the county officials to change their views.

"It is critical that we get students back in school where they can continue their education," Weast said.

State officials said Monday that they expect the number of confirmed cases to rise, but the state had sufficient supplies to treat the public.

Phillips of the state Department of Health and Mental Hygiene said officials continued to monitor the situation closely because of concerns about the new virus, but some of the people becoming ill may have the regular flu, which has lasted beyond the normal flu season.

"The recommendation is if you haven't gotten a flu shot, it's not too late," Phillips said.

Shady Grove Adventist Hospital in Rockville has seen an increased volume of patients compared with this time last year, but it is unclear if the increase is related to the swine flu, hospital officials said.

In response to the spreading worry over the virus, Dr. Gaurov Dayal, the hospital's chief medical officer, said the hospital has been proactive in telling people how to limit its spread.

"The best thing to do if you're feeling sick is not go to work, not send your kids to school, to ensure we're not spreading this thing unnecessarily," he said.

The hospital's emergency department has a set of procedures in place to deal with patients who may be infected with swine flu, Dayal said.

"When the patient walks in they are instructed to wear a mask, and they're given hand sanitizer," he said. "Once they're in, they are triaged depending on if they've traveled, on their symptoms."

The hospital has "adequate" supplies of Tamaflu, an anti-viral medication used to treat the flu virus, he said.

Montgomery General Hospital spokeswoman Nikki Yeager said there have been no confirmed cases from patients coming to the hospitals, but some concerned people had shown up.

"We are definitely seeing an increase in emergency department traffic, not just people with flu symptoms, but other people who just want to be checked out for it," she said.

Across the county, precautions being taken by residents seemed to vary from location to location. Passengers weren't donning masks on MARC commuter trains, Metro subways or Ride On buses, but churches and synagogues were taking steps to prevent a possible spread.

At St. Raphael Catholic Church in Potomac, congregants temporarily stopped using the receptacle for holy water — a tray of consecrated water typically kept at the entrance to the sanctuary that parishioners use to bless themselves before entering.

"We have not used the holy water receptacle since so many hands and fingers go in there," said the Rev. Carlos Benitez, a priest at the church. "People have been very cooperative and also alert about washing their hands."

Also at St. Raphael's, parishioners have temporarily stopped using a shared cup to drink the symbolic blood of Christ during communion.

At Geneva Presbyterian Church in Potomac, congregants were set to receive communion by intinction Sunday — a bimonthly tradition in which congregants approach the altar to break off a piece of bread rather than receiving a piece on a tray that is passed through the aisles.

However, after news of swine flu, church officials changed the offering slightly. "Instead, we cut the bread up as a sort of reassurance because people are anxious," said the Rev. Anne Benefield.

As far as Benefield can tell, however, swine flu fears haven't kept members of the congregation away.

"I was really thrilled because I got a number of phone calls, and all of the people who were worried [about congregating at church] did come," she said. "We didn't know what to expect. One of the things that happens is that the concern feeds on itself, and sooner or later everyone is nervous."

Benefield spoke to congregants Sunday about the importance of taking sensible preventive steps to avoid contracting swine flu — but to also remain calm.

At Congregation B'Nai Tzedek in Potomac, officials continue to disinfect surfaces in the building and are recommending to congregants and children in the nursery school and Early Childhood Center to wash their hands and cough into their sleeves.

Staff writers Melissa Brachfeld, Janel Davis and Erin Donaghue contributed to this report.

To prevent the spread of swine flu, the following tips are offered by the Centers for Disease Control and Prevention:

-Avoid close contact

Avoid close contact with people who are sick. When you are sick, keep your distance from others to protect them from getting sick, too.

-Stay home when you are sick

If possible, stay home from work, school and errands when you are sick. You will help prevent others from catching your illness.

-Cover your mouth and nose

Cover your mouth and nose with a tissue when coughing or sneezing. It may prevent those around you from getting sick.

-Clean your hands

Washing your hands often will help protect you from germs.

-Avoid touching your eyes, nose or mouth

Germs are often spread when people touch something that is contaminated with germs and then touch their eyes, nose, or mouth.

-Practice other good health habits

Get plenty of sleep, be physically active, manage your stress, drink plenty of fluids and eat nutritious food.

Source: Centers for Disease Control and Prevention