Sixty Manteca Unified classes are being taught with long-term substitute teachers as the district scrambles to fill positions almost two weeks into the school year.

But unlike other districts to the west of the Altamont Pass, most of the positions are filled with new hires but they can’t start until exhaustive background checks are completed.

“We expect to have the majority of the teachers in the classroom fairly soon,” noted Manteca Unified Superintendent Jason Messer.

The toughest positions for Manteca to fill have been science and math teachers. That is the case in much of the rest of the state as well in addition to localized shortages in special education, bilingual, and even multi-disciplined credentialed teachers.

Messer noted substitute teachers assigned to classes awaiting fulltime teachers are kept in place and not moved around to assure continuity for students.

At the same time he stressed most of the teachers are hired but just have to go through background checks. That contrasts sharply with many Bay Area districts such as Oakland that as of Friday still had 77 positions they hadn’t hired anyone to fill.

Part of Manteca’s increased need for teachers is due to the fact the district is slowly reducing class sizes now that revenue is rebounding. Manteca Unified has 1,200 teachers at 30 campuses serving 23,500 students.

Statewide educators are blaming retirements, high attrition rates and a lack of new recruits for contributing to the shortage. In 2008, just as the recession started, almost 45,000 people were enrolled in teacher preparation programs in California. By 2013, there were fewer than 20,000, according to the state Commission on Teacher Credentialing.

The teacher shortage is tighter in urban areas such as the Bay Area due to skyrocketing housing costs that are prompting many teachers to look elsewhere including in the Northern San Joaquin Valley for jobs. Los Angeles and the San Francisco Bay Area are now the two least affordable urban areas for housing in the nation.