Rock-bottom interest rates and low home prices have created an increase in work for mortgage officers in Tampa Bay and around the country. Mortgage applications jumped 23.1 percent nationally last week on low rates and a dramatic upswing in refinancing activity, the Mortgage Bankers Association said Wednesday. New applications for home purchases rose 10.4 percent from the previous week. Andy Wood of American Mortgage Services in Tampa has closed 17 loans this month and has five more closings scheduled. He attributed the increase to lower home prices.He said this January will be his best January since 1999."People have been on the fence for several years," said Wood, who doesn't handle refinancings. "Two or three years ago, prices of many homes were much higher. Buyers are now competing with multiple bids on many houses." The Tampa Bay Times reported Wednesday that home sales and median prices rose last month in Tampa Bay, continuing a monthslong trend. The increases have led some real estate experts and economists to think the area's worst housing days are over.Brian Lamb, Fifth Third Bank's Tampa Bay president, said the fourth quarter of 2011 was the best quarter of the year for new mortgages and refinance applications for the lender. Although he cautioned that it's still early in the economic recovery, the bank is seeing an uptick with customers needing loans for newly built homes."Builders are going vertical," Lamb said. "They're starting to move some inventory."New loan applications are up about 15 percent at United Mortgage Affiliates in Apollo Beach. Loan officer Carole Gardner doesn't typically process refinance applications but has seen an influx of requests from former customers.Gardner cautioned that January has always been a busy month in her office. But the low rates, she said, are driving the application increase, along with buyers returning to the market after the holidays. The average rate on a 30-year fixed mortgage is at a record low 3.89 percent.She added: "People could be feeling a little more confident, but most buyers have been actively looking for a while." The Mortgage Bankers Association reported that refinancing is at its highest level since August.Alan Lucas, a senior loan officer at BB&T in Tampa, said he has heard from several builders who plan to start offering new homes again in Tampa Bay, adding: "Activity has picked up, but refinancing is primarily fueling it."Mark Puente can be reached at [email protected] or (727) 893-8459. Follow him on Twitter at twitter.com/markpuente.