Safety breaches at UK labs that handle harmful bacteria, viruses and fungi have spread infections to staff and exposed others to potentially lethal diseases, the Guardian has learned.

The Health and Safety Executive (HSE) has investigated a series of mistakes over the past two years that led to scientists falling ill at specialist labs run by hospitals, private companies, and even Public Health England (PHE), the government agency which exists to protect and improve the nation’s health and wellbeing.



One scientist at a PHE laboratory became sick after contracting Shigella, a highly contagious bacterial infection that causes most cases of dysentery in Britain. The incident led the HSE to send the agency an enforcement letter to improve its health and safety practices.



The HSE held formal investigations into more than 40 mishaps at specialist laboratories between June 2015 and July 2017, amounting to one every two to three weeks. Beyond the breaches that spread infections were blunders that led to dengue virus – which kills 20,000 people worldwide each year – being posted by mistake; staff handling potentially lethal bacteria and fungi with inadequate protection; and one occasion where students at the University of the West of England unwittingly studied live meningitis-causing germs which they thought had been killed by heat treatment.

Of the scientists who became infected in the line of work, one was admitted to hospital after falling ill with salmonella poisoning at Pall Life Sciences, a private medical company. Another picked up a paratyphoid infection at Nottingham University Hospitals NHS Trust; four contracted Shigella at Brighton and Sussex University Hospitals NHS Trust, and a biomedical scientist at The Royal Free Hospital in London became sick with two different strains of gastrointestinal bug after testing an infected stool sample.



Quick Guide Accidents in the lab Show Scientists have had accidents with dangerous bugs for as long as they have studied them. In the past half century alone, lethal viruses responsible for foot and mouth disease, smallpox, and Sars have all escaped from labs and caused illness or death.

The most recent major incident traced to a lab in Britain was the 2007 foot and mouth outbreak. More than 1,500 cattle had to be culled to contain the virus at farms around the government’s high security Pirbright lab near Guildford. Investigators found that vehicles had carried the virus to farms after driving through mud at Pirbright which had been contaminated by waste from a faulty drainage pipe. The outbreak cost an estimated £200m. Older mishaps at UK labs cost human lives. In 1972, an assistant at the London School of Hygiene and Tropical Medicine contracted smallpox after the virus was handled on the lab bench. The assistant survived, but infected two people visiting a patient in the neighbouring hospital bed, both of whom died. In 1978, Janet Parker, a medical photographer who worked above the smallpox lab at Birmingham Medical School, became the last recorded person to die from the disease. Investigators concluded that the virus had probably wafted up an internal duct to her room. Other labs around the world have been blamed for accidental releases of Sars virus. The labs in Singapore, China and Taiwan, had been studying samples from the 2003 epidemic which killed more than 750 people when it spread to at least 29 countries. Despite regular accidents and near-misses at UK germ laboratories, there is rarely any risk to public health because labs have multiple layers of containment, and staff are typically immunised or otherwise protected against the organisms they handle.

In Britain, microbes that are a risk to human health are ranked by hazard groups. The most harmful are listed in groups 3 and 4. Group 3 bugs, such as those that cause anthrax and leprosy, can pose a serious hazard to employees, and may spread to the community, but there is usually a vaccine or treatment. Group 4 pathogens, such as Ebola, are more dangerous. These are a serious threat to employees and the community, and there is often no vaccine or treatment. The germs must be handled in labs that meet strict safety and security requirements.



The HSE investigated a number of close shaves. In August 2015, scientists at Bristol University accidentally posted live dengue virus – a group 3 germ carried by mosquitoes in south-east Asia – to Glasgow University’s Centre for Virus Research. Because the person who packed the material had no idea it contained live dengue, the parcel did not meet safety requirements for posting dangerous agents. With luck, the package did not leak; it arrived in one piece and was spotted on arrival at the lab, where staff destroyed the material.



On another occasion, a diagnostic lab called Viapath posted a sample of the hazard group 3 bacteria called Chlamydia psittaci, which can cause pneumonia, to PHE’s infectious disease unit in north London. The sample was improperly labelled and, on arrival, was handled in a way that could have infected the PHE lab worker. The HSE found failings on both sides.

“The sector has a good health and safety record, with a high level of control of the most hazardous organisms,” an HSE spokesperson said. “There have been a limited number of instances over the past two years where biological agents have been received by UK labs from other labs within the UK that were unsolicited, mislabelled or unlabelled. However these cases are in the minority and there was no significant threat to public health.”

In other incidents, the airflows that are carefully controlled to contain airborne bugs failed at a lab run by the Medicines and Healthcare Products Regulatory Agency, while at a high security lab run by the same regulator, an egg containing flu virus fell off a tray and smashed on the floor, prompting a hurried evacuation of the lab.



Other potentially dangerous bugs have arrived from outside the UK. In 2015, the US Army revealed that its chemical and biological defence facility at Dugway Proving Ground in Utah unwittingly shipped live anthrax to seven countries after failing to kill the spores properly. Responding to Freedom of Information requests from the Guardian, the US army said it shipped one batch to a UK lab in 2007, and 13 more to three UK labs in 2009. One of the 2009 batches contained a vial of yet another unsolicited pathogen: live but weakened Yersinia pestis, the bacteria that cause the plague. Scientists at Dugway spotted the mistake the same day and called ahead to warn the UK authorities, who hastily drew up a plan to move the bugs to a more secure lab for disposal.



Tim Trevan, a former UN weapons inspector who now runs Chrome Biosafety and Biosecurity Consulting in Maryland, said safety breaches are often wrongly explained away as human error. “Blaming it on human error doesn’t help you learn, it doesn’t help you improve. You have to look deeper and ask: ‘what are the environmental or cultural issues that are driving these things?’”



“There is nearly always something obvious that can be done to improve safety,” he added. “One way to address issues in the lab is you don’t wait for things to go wrong in a major way: you look at the near-misses. You actively scan your work on a daily or weekly basis for things that didn’t turn out as expected. If you do that, you get a better understanding of how things can go wrong.”



“Another approach is to ask people who are doing the work what is the most dangerous or difficult thing they do. Or what keeps them up at night. These are always good pointers to where, on a proactive basis, you should be addressing things that could go wrong.”