Enlarge By George Widman, AP In July, Teva Pharmaceuticals recalled propofol made in California after 41 patients developed post-operative fever and other symptoms the company said may indicate exposure to bacterial toxins. FOLLOW @USATODAYHEALTH FOLLOW @USATODAYHEALTH At least 43 drug factories supplying medication to thousands of U.S. consumers have received government warnings in recent months for failing to correct shoddy manufacturing practices that may have exposed patients to health risks, a USA TODAY review of records shows. Violations serious enough to prompt warning letters from the U.S. Food and Drug Administration include plants using equipment and ingredients contaminated with bacteria or insects, failing to do proper testing to ensure drug strength and purity, and ignoring consumer complaints that products were making them sick. The 43 warning letters, issued since January 2009, reflect only some of the most serious manufacturing violations the FDA finds during facility inspections. During 2002-06, for example, more than half of inspections at domestic drug plants and 62% at foreign plants supplying the U.S. had violations that didn't prompt warning letters, but were classified as requiring correction, FDA data published by the Government Accountability Office show. The FDA declined to provide more recent numbers. The House oversight committee will hold a hearing Thursday into the April 30 recall of children's liquid Tylenol and other medicine made at a Pennsylvania plant. "We want to make certain that medications are safe, and the only way we can do that is to bring in the folks responsible," said committee Chairman Edolphus Towns, D-N.Y. TYLENOL RECALL: Plant in recall cited in 2009 for tainted ingredient Drug industry officials said manufacturing problems are rare. "The U.S. regulatory system for prescription drugs is the toughest and safest in the world," said Ken Johnson at the Pharmaceutical Research and Manufacturers of America. Among violations identified in FDA warning letters: • Anesthesiologists are grappling with a nationwide shortage of propofol, an injectable drug used during surgeries, because two of the three companies that supply the U.S. had safety recalls. In July, Teva Pharmaceuticals recalled propofol made in California after 41 patients developed post-operative fever and other symptoms the company said may indicate exposure to bacterial toxins. In December, the FDA issued a warning letter to Teva for not doing proper bacterial testing. In November and March, a North Carolina plant run by Hospira recalled propofol because of contamination with steel particles. Safety is "absolutely critical" for such potent drugs, said American Society of Anesthesiologists president Alexander Hannenberg. Teva's Denise Bradley said the company's plant has not resumed manufacturing. Hospira's Dan Rosenberg said: "We're making improvements." • An Illinois plant run by Balchem that makes calcium carbonate, an ingredient in antacids and a menopause medication, sent out products made with water the plant knew was contaminated with coliform bacteria. Balchem didn't respond to interview requests. • A Massachusetts plant run by Braintree Laboratories failed to properly investigate 21 consumer complaints of bug parts or spiders in five of its medicine products, according to the May warning letter. The company did not respond to interview requests. • Several species of bacteria were found on equipment at a Puerto Rico plant that makes drugs and cosmetics for Procter & Gamble, according to an April 2009 warning letter. The letter also cited the company for failing to investigate 198 complaints in the previous year alleging health problems associated with a Vicks Sinex product made there. In November, the company separately recalled Vicks Sinex nasal spray made in Germany because of bacterial contamination. "We are confident these issues are isolated," said company spokesman Paul Fox. Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more