Virginian Pilot/Washington - US health officials have ordered all imports ot the blood thinner, heparin, stopped at the border for testing to detect a contaminant linked to 19 deaths. The Food and Drug Administration announced the move Friday, the latest step in it's investigation of reactions linked to Baxter International's heparin injections. The FDA found the contaminant in 20 of 28 samples of raw heparin that the agency tested from Baxter's main supplier, a Chinese factory owned by Wisconsin based Scientic Protein Laboratories. A different brand of heparin also has been recalled in Germany after 80 patients there got sick and the German manufacturer said Friday that it was narrowing down the source to another Chinese supplier.