Chembio Diagnostics Inc. lost money in the first three months of this year on lower sales of its tests for the infectious diseases HIV and syphilis.
The Medford-based manufacturer reported Thursday a loss of $225,000 in the January through March period compared with a profit of $317,000 in the same time a year ago.
Sales in the first quarter fell 13 percent to $5.8 million.
The company's new chief executive John J. Sperzel III blamed the red ink on "variability in purchasing levels that we often see in this sector."
He also said Chembio's move to create its own U.S. sales force was "aligned with our objective to improve sales performance and predictability." He said a number of sales people had been hired, including a sales director and senior marketing director.
The company released its earnings before Thursday's stock market opening. Chembio shares fell 26 cents to $2.87 per share on the Nasdaq exchange.