Late on a Friday night Dr Mike Beadsworth left the Royal Liverpool hospital after a “pretty hellish couple of weeks”. The clinical director of tropical and infectious diseases and his team had spent weeks trying to save the life of a Middle Eastern man who had been diagnosed with a deadly virus.

The man had contracted Middle East Respiratory Syndrome (Mers), the first such diagnosis in the UK since 2013.

Beadsworth said his chances of survival were slim. Of the previous four cases, three had died. After weeks of painstaking, meticulous care in the world-renowned tropical diseases unit, however, the man survived.

For Beadsworth, 50, and his team, there would be little respite. He was driving home when he received a phone call. A person in the UK had contracted monkeypox for the first time. The airborne disease was diagnosed in a Nigerian national staying at a naval base in Cornwall.

“We were literally stepping down the unit after looking after the Mers case. This guy had survived and we were really pleased for him,” he said.

“But then I got a call to say we would have to reactivate the network because of a probable monkeypox case in Cornwall. My first thought was: ‘You’ve got to be joking.’ We had just had a pretty hellish couple of weeks and now we had this.”

Following the Ebola crisis of 2014, when the West African epidemic was declared an international emergency, Beadsworth and other health professionals came up with a contingency plan if a deadly infectious disease were to enter the UK. Now this plan from the High Consequence Infectious Diseases Network – comprising five NHS trusts – was being tested in reality.

Infectious disease experts took part in a teleconference call and plans to contain monkeypox were discussed. “The call lasted around 30 minutes. It was a business call and quick decisions were made,” Beadsworth said. “Although we regard ourselves as specialists in tropical medicine, no one here had seen a case in the UK. There was a lot of rapid literature reading that night.”

Dr Mike Beadsworth, consultant in tropical and infectious diseases at Royal Liverpool hospital Photograph: Royal Liverpool and Broadgreen University Hospitals NHS Trust

The patient was sent to the Royal Free hospital in London, one of five centres in the UK able to care for patients with highly infectious diseases. Beadsworth was relieved. The emergency action plan had worked, the patient had been isolated and the risk had seemingly been contained.

Four days later, however, the “most unimaginable” thing happened. A second, unrelated case of monkeypox was diagnosed in Blackpool. The patient had also just returned to the UK from Nigeria.

“It was fairly unimaginable to have a Mers case, and then it was unimaginable to have one case of monkeypox in Cornwall. Then to have a second one, it really was like lightning striking twice,” he said.

The patient was taken to the Blackpool Victoria hospital before being transferred to Liverpool.

Consultants, registrars and nurses undertook a process called “donning and doffing” to minimise the risk of spreading the disease and catching it themselves. It included wearing extra protective clothing, fitted masks, goggles, and three pairs of gloves. After each contact with the patient all their clothing was incinerated.

Beadsworth said: “The patients tend to be very scared because they have suddenly been moved and they have got all these individuals wearing these space suits and they can’t see faces. But you can’t breach, you can’t make a mistake.”

The rare viral infection, normally confined to African states, was first discovered in monkeys in 1958. It is similar to smallpox, but not as deadly. The first case in a human was identified in the Democratic Republic of the Congo in 1970, and cases have since been reported in other central and west African countries.

On 26 September a third case of monkeypox was diagnosed in the UK in a female healthcare worker briefly involved in the treatment of the second patient at Blackpool Victoria hospital.

The 40-year-old healthcare assistant from Fleetwood is now being looked after in the specialist unit at Royal Victoria Infirmary in Newcastle. It is understood that the woman’s colleagues at Blackpool Victoria and patients at her GP surgery have been offered the smallpox vaccine, which protects against the monkeypox virus.

On Wednesday the Blackpool Gazette reported that residents in Fleetwood were alarmed by the sight of paramedics in white overalls and face masks at a house. A woman was taken to hospital but tests have since confirmed she had not contracted the disease.

Public Health England, the government agency leading the effort to contain the UK outbreak, confirmed it was linked to the monitoring of monkeypox.

For Beadsworth it has been challenging but also fascinating to deal with monkeypox in the UK. Samples taken from the UK patients and sent to the to the rare and imported pathogens laboratory near Salisbury will now help to develop vaccines.

“It has been incredibly rewarding because this is what we have set this unit up for,” he said. “But the single most important thing that has come out of this is that the network that was set up after Ebola has worked. It may not appear like that to the public at the moment, but behind the scenes it has worked really, really well.”