SARASOTA, Fla., Nov. 9 — A Democrat who narrowly lost the Congressional race here is seeking a recount after dozens of people reported problems using Sarasota County’s touch-screen voting machines and a significant number of ballots had no recorded votes in the high-profile race.

The Democrat, Christine Jennings, lost to her Republican opponent, Vern Buchanan, by just 373 votes out of a total 237,861 cast — one of the closest House races in the nation. More than 18,000 voters in Sarasota County, or 13 percent of those who went to the polls Tuesday, did not seem to vote in the Congressional race when they cast ballots, a discrepancy that Kathy Dent, the county elections supervisor, said she could not explain.

In comparison, only 2 percent of voters in one neighboring county within the same House district and 5 percent in another skipped the Congressional race, according to The Herald-Tribune of Sarasota. And many of those who did not seem to cast a vote in the House race did vote in more obscure races, like for the hospital board.

More than 100 voters have told the Jennings campaign that their votes for her did not show up on the summary screen at the end of the touch-screen voting process, and that they had to re-enter them. The candidate’s lawyers said they feared that not everyone had noticed the problem or realized that they could re-enter the vote.