A team was en route a warehouse in Mexico yesterday to find and destroy a sample that had just been located, Stohr said. April 19, 2005 (CIDRAP News) What began as a routine attempt to measure laboratories’ testing proficiency has become a mission to track missing shipments of potentially lethal influenza viruses in Mexico, South Korea, and Lebanon. In South Korea, investigators were puzzling over conflicting accounts. Officials at three labs said they had never received shipments made last year, but the shipper had signatures showing they had been delivered, Stohr said. Canadian researchers discovered in March that the virus they had been sent was the same that emerged in 1957, prompting the call for the samples to be destroyed immediately. All three countries have made progress in tracing the missing shipments, and total destruction of the samples remains possible, Klaus Stohr, the influenza program chief for the World Health Organization (WHO), told the Associated Press (AP) from Geneva yesterday. In Lebanon, the shipper of a missing sample had released the virus to another shipper for local delivery, but it never arrived at the lab, Stohr told the AP. People were trying to locate the test kit and destroy the sample. The virus in question, influenza A(H2N2), was responsible for the flu pandemic of 1957-58, which killed an estimated 1 million to 4 million people. Samples of the pandemic virus had inadvertently been sent to 3,747 labs in 18 countries for a routine assessment that usually relies on more benign flu strains. All but about 75 labs that received the samples are in the United States, according to earlier reports. Fourteen labs are in Canada and 61 are in other countries. Most laboratories quickly complied with the WHO request on April 12 to destroy the samples. Labs in the United States had destroyed 98% of their samples as of yesterday, the AP reported. The College of American Pathologists paid a private company, Meridian Bioscience Inc. of Cincinnati, to prepare and send the samples. Why Meridian used the H2N2 virus has not yet been fully explained. Labs use such test kits to check their ability to identify viruses.