A runaway mouse, escapee ferrets and the accidental mailing of dangerous bacteria by a bioterrorism lab are among incidents which have heightened concern in the US Congress and wider population about controls on laboratory work with deadly pathogens.

Scientists wearing spacesuit-like protective gear searched for hours in May for a mouse - infected with Lassa virus, which causes Ebola-like symptoms - that went AWOL for a day inside Rocky Mountain Laboratories in Montana, one of the federal government’s highest-security research facilities.

The same month, a laboratory worker in Memphis suffered a cut while trying to round up escaped ferrets that had been infected with a deadly strain of avian influenza. Four days later at Colorado State University’s bioterrorism lab, a worker failed to ensure dangerous bacteria had been killed before shipping specimens - some of them still able to grow - to another lab where a worker unwittingly handled them without key protective gear.

The details of the May incidents were revealed in minutes of those labs’ institutional biosafety committees and related reports obtained by Edward Hammond, former director of the Sunshine Project, an independent lab watchdog group that operated from 1999-2008, until it lost funding.

Hammond told USA Today it is difficult for policymakers and the public to judge the safety of labs and weigh the risks and benefits of proliferating bioterror-related research projects without data on how often incidents occur and details about what happened. “We need to require reporting and for reporting to be public,” said Hammond, now a researcher based in Austin.

House Oversight and Investigations Subcommittee member Diana DeGette said: “It used to be we only had a few labs doing this very high level and risky research,” but now it was work conducted in a wide range of institutions including hospitals. “It appears none of these breaches have led to any kind of infection. But it’s only a matter of time,” she warned.