It is “not time to panic yet” about swine flu, a top scientist said on Tuesday, as health officials announced the discovery of the first human case of a new strain in the UK.
Dr Andrew Catchpole, chief scientific officer at infectious disease testing firm hVIVO, said that public health authorities would only be concerned if they discovered “sustained human to human transmission” of the virus.
The UK Health Security Agency on Monday announced that the first human case of swine flu A(H1N2)v – which has been circulating in pigs - had been detected by routine surveillance in a GP surgery.
The person suffered a mild illness and made a full recovery, but UKHSA officials are carrying out contact tracing to prevent further spread of the disease. It is not known at this stage how transmissible the strain is or if there could be other cases in the UK.
There have been about 50 reported human cases worldwide of the H1N2 virus since 2005, none of them related genetically to this strain.
Reacting to the news, Dr Catchpole said: “it is not time to panic yet. This is not an unprecedented event worldwide, albeit still rare. Almost always such cases cause very little between person transmission and are quickly cleared from the community.
“The concern only comes when there is clear evidence of sustained human to human transmission for a virus that has not previously been circulating in the community such that the community has little protective immunity. Currently, there is no such evidence for this latest event.”
John Edmunds, professor of infectious disease modelling at the London School of Hygiene and Tropical Medicine, said: “These events are always serious and need to be carefully investigated. In this instance, it appears that the case was picked up from routine surveillance. This is worrisome as it might imply that the virus has already spread to some extent.”
The patient was tested by their GP in North Yorkshire after experiencing respiratory symptoms. The strain was identified via polymerase chain reaction (PCR) testing and genome sequencing.
The transmission of pathogens from wild animals to humans is known as zoonotic spillover. Between 60 and 75 per cent of human infectious diseases are derived from pathogens that originally circulate in animals, according to the World Health Organisation.
Animal influenza viruses are distinct from human influenza viruses and do not easily transmit to humans.
In 2009, there was a pandemic in humans caused by flu strain H1N1, commonly referred to as swine flu.
This now circulates in humans seasonally.
The UKHSA said people with respiratory symptoms should continue to follow the existing guidance – avoiding contact with other people while suffering symptoms and taking particular care around vulnerable people and the elderly.
