The calls, about 30 a day, usually start before 6 a.m. as teacher after teacher in Alexandria's public schools telephones to take off one of their 11 allotted sick days a year. Illness seems to strike teachers hard around weekends and holidays, particularly, school officials say, around warm weekends and holidays.

"Fridays and Mondays aren't our best days," says school leave clerk Debra Critchfield. "A few weeks ago we had 72 sick calls."

The 5.8 percent average sick leave absentee rate among Alexandria's 700 teachers is about average for public school teachers, but it is almost twice the 3 percent average rate among private employes and higher than the 4 percent average among public employes in the nation. And in Alexandria and other school systems in the Washington area moves are afoot to lower the teacher sick rate because of its unusually high cost to schools.

"We have to put a substitute in the classroom every time a teacher is out," says Alexandria School Board member Norman Draper, who recently proposed a plan to pay teachers not to take sick leave. Besides the $335,000 Alexandria schools paid to substitute teachers last year, he says teachers' absences are disruptive to students.

Some teachers say their absentee rate is actually low. "Kids come up and sneeze in your face and there you are," said Mary Sue Garner, a mathematics teacher at Alexandria's George Washington Junior High School. Others argue that sick teachers should not be enticed into classrooms. "We're going to run into trouble if we start encouraging people to come in sick," said one former Alexandria teacher.

Draper's proposal, akin to the federal government's sick leave policy, would credit accumulated sick leave to the total years of service on which a teacher's pension is based. That could add as much as $500 a year to a teacher's pension. The most an Alexandria teacher now could receive at retirement for unused sick leave is about $1,200. Draper says no studies have been done to determine the possible overall savings to the system.

The School Board will vote on Draper's plan Dec. 15. If the plan is approved it must then be approved by the Virginia state legislature, which presumably would make the change apply to employes of all public schools in the state. Draper is not alone in his attempts to keep teachers in the classroom:

* District schools, which allow teachers to accrue unlimited sick days over the years, are implementing a plan allowing the system to "buy back" unused leave time from its 5,300 teachers. A teacher who takes no leave could opt to receive as much as $500 a year instead. Last year, the District paid more than $2 million to substitute teachers.

* Montgomery County teachers with more than five years of service are already paid at retirement for a portion of their unused sick time. "As far as I know, [the policy] has been working well," said Armando Gutierrez, director of staffing in the system that employes 6,000 teachers. Last year, about $1.7 million was spent to put substitutes in county classrooms.

* Prince George's County teachers are now paid a fraction of their accumulated sick leave when they retire after at least 12 years of service. The system, which employs about 5,000 teachers, expects to pay $2 million to substitute teachers this year.

The Education Association of Alexandria, which represents city public school teachers, has endorsed Draper's plan, though association president Hazel Rigby says most teachers don't abuse their sick leave. Only one of 140 teachers at T.C. Williams High School called in sick the day before Thanksgiving, she says.

Nonetheless, school records show that the highest rate of teacher absenteeism in Alexandria schools this year came on the days before and following a weekend in October when 89 teachers, 12 percent of the total staff, were absent through a combination of personal, professional and sick leave.

Says Draper of his proposal: "If someone wakes up with a headache, rather than stay home, they can come in and save the sick leave."

Representatives of Alexandria's public school teachers have initially backed the plan but stress that teachers are not abusing sick leave on any widespread basis.