The genetic make-up of A (H1N2)v exhibits similarity to swine influenza viruses discovered in the U.Okay.
| Photo Credit: CDC/Dr. F.A. Murphy
On 27 November 2023, the United Kingdom Health Security Agency (UKHSA) reported the first identified human case of influenza A (H1N2)v in the UK, a variant of the influenza virus beforehand not identified to trigger infections in people. Following detection, public well being companies in the UK are actually working quickly in direction of characterizing the pathogen and assessing the danger it could current to human well being.
Several subtypes of the influenza virus are assigned in response to mixtures of mutations in the proteins on the floor of the virus – hemagglutinin (H) and neuraminidase (N). The former binds to sialic acid receptors in the host. New influenza viruses can emerge by means of a course of referred to as reassortment the place the co-infecting viruses might swap genomic fragments. Influenza A H1N2 is a subtype of influenza that’s endemic in pigs and is never reported in people. Swine influenza viruses usually don’t infect people, nonetheless, in uncommon circumstances, sporadic infections can happen particularly with shut contact with animals carrying the virus. In such occurrences, the infecting influenza pressure is named a “variant virus” denoted by including “v” after the subtype.
The case of influenza A (H1N2)v was detected as half of the complete nationwide influenza surveillance in the UK led by UKHSA. The affected person, a 75-year-old particular person, who has now totally recovered, introduced with gentle respiratory and flu-like signs. Genome sequencing revealed that the virus belonged to a definite clade 1B.1.1 of influenza viruses. While distinct from latest human circumstances of A(H1N2), its genetic make-up confirmed similarity to swine influenza viruses discovered in the UK and no different mutations of concern have been detected in this variant. Although the affected person resides in an space in proximity to pig farms, no direct contact with animals might be established. Instances of human-to-human transmission of the virus have additionally not but been detected, nonetheless, the detection of the virus in a case with no contact with animals might probably imply {that a} restricted and undetected human-to-human transmission might have occurred. “But there is no definitive evidence,” says the WHO.
Sporadic human infections with A(H1N2)v have been detected beforehand. Since 2005, nearly 50 circumstances of human A(H1N2)v infections have been reported from throughout the world, nonetheless, that is the first time {that a} case has been reported from the UK. Recently in August 2023, a human an infection was reported in the United States of America linked to an agricultural truthful. Cases have additionally been reported in Austria, Denmark, France, Netherlands, Brazil, Canada, China and Australia. Infections with H1N2 variant viruses usually are related in signs and severity to seasonal influenza viruses and there’s restricted proof of human-to-human transmission. “Current evidence suggests that these swine-origin influenza viruses have limited ability for sustained transmission among humans,” the WHO says.
According to the UKHSA, the variant influenza virus presents a low danger to the basic public. However, folks with direct common publicity to pigs could also be at the next danger of buying this virus. Influenza viruses have the potential to spill over into human populations and trigger extreme diseases though the variant virus detected in the UK doesn’t present any traits suggestive of pandemic potential. As public well being authorities in the UK proceed to observe up on the case, it is very important underscore complete surveillance of pathogens, notably quickly evolving respiratory viruses like influenza and talent to quickly characterize viral variants utilizing genome sequencing varieties the cornerstone of public well being motion and preparedness and our capability to mitigate the danger of a world outbreak.
(Bani Jolly is a senior scientist at Karkinos Healthcare and Vinod Scaria is a senior advisor at Vishwanath Cancer Care Foundation)
