Will bird flu become the next pandemic? An expert answers FAQs about the disease

Here are the solutions to some frequent questions concerning the illness.

What are avian influenza viruses?

Influenza viruses belong to the Orthomyxovirus household and are grouped into 4 species designated by the letters A (Alpha), B (Beta), C (Gamma) and D (Delta). Almost all influenza infections in people are brought on by influenza A and B viruses.

Influenza A viruses have been named avian (hen), swine (pig), equine (horse), canine (canine), chiropteran (bat) and human, based mostly on their pure reservoir (the organism the place they’re mostly discovered).

Avian influenza and different Influenza A viruses are categorized into subtypes in accordance with the composition of their hemagglutinin (H) and neuraminidase (N) floor proteins. There are 18 recognized H varieties (H1 to H18) and 11 recognized N varieties (N1 to N11). The mixture of an H sort and an N sort defines a selected influenza virus subtype (for instance, H5N1).

What can we find out about avian influenza?

Bird flu was first described within the late 1800s. It’s a extremely transmissible and often delicate illness of untamed birds akin to geese, swans, seagulls, shorebirds, and in addition home birds akin to chickens and turkeys. It is often brought on by influenza A viruses with an H5 or H7 hemaglutinin sort, for instance, H5N1 or H7N9.

While many types of these viruses are minimally virulent — that means they trigger delicate illness — some are extremely virulent, that means that they trigger extra critical illness. Millions of poultry deaths in Asia, Europe, the Americas and Australia have been attributed to extremely virulent types of H5N1, H5N8, H7N7 and H7N9, with H5N1 accounting for the overwhelming majority of circumstances.

In Canada and the US, outbreaks of H5N1 influenza in home and wild birds have been reported in most areas.

How is avian influenza transmitted to people?

Avian influenza viruses should not simply transmitted from birds to people or to different animals. Humans are unintentional hosts — that means that the virus doesn’t usually flow into amongst folks.

Humans could purchase the virus after inhaling birds’ respiratory droplets or publicity of their mucus membranes to hen feces, saliva or contaminated surfaces.

Bird flu can’t be transmitted by consuming cooked poultry merchandise.

Recently found mutations within the neuraminidase (N) gene of H5N1 viruses remoted from people seem to advertise bird-to-human transmission. Fortunately, human-to-human transmission is extraordinarily uncommon.

When was avian influenza first reported in people?

The first human circumstances of avian influenza have been reported in 1997 by public well being authorities in Hong Kong. These infections have been linked to poultry contaminated with a extremely virulent H5N1 subtype. Of the 18 affected people, six (33 per cent) succumbed to their sickness.

Since then, avian influenza has been chargeable for no less than 2,600 infections and over 1000 deaths in people worldwide. In nearly all of human circumstances, an infection was acquired following publicity to stay poultry moderately than wild birds.

Human infections attributable to avian influenza viruses have primarily been brought on by subtypes H5N1, H5N6, H7N7 and H7N9. All however two of the documented human fatalities up to now have occurred in low-to-middle-income international locations, seemingly as a consequence of the full case burden and lack of entry to antiviral medication.

What are the indicators and signs of avian influenza in people? How is it identified?

Early signs of avian influenza in people are just like these brought on by seasonal influenza viruses akin to H3N2 and H1N1. Typical signs embody fevers, chills, muscle aches, cough, sore throat, shortness of breath, headache and fatigue.

Infections brought on by extremely virulent types of H5N1 or H7N9 subtypes could comply with a extra extreme course of sickness characterised by inner bleeding, multi-organ failure and a excessive mortality price.

The mixture of an influenza-like sickness and a latest historical past of publicity to stay poultry ought to increase suspicion for avian influenza. The analysis is confirmed by detection of viral RNA in nasopharyngeal specimens utilizing assessments for particular subtypes.

What therapies can be found for avian influenza?

Antiviral medication belonging to the neuraminidase inhibitor (akin to oseltamivir) and endonuclease inhibitor lessons (for instance, baloxivir) seem like extremely efficient in opposition to most avian influenza subtypes, together with H5N1 and H7N9.

However, antiviral resistance has been nicely documented and represents a risk to the efficiency of those brokers within the face of fixed viral evolution.

Is there a human vaccine in opposition to avian influenza?

Licensed vaccines exist to guard people in opposition to avian influenza, though they don’t seem to be commercially accessible.

In 2007, the US Food and Drug Administration (FDA) permitted an H5N1 vaccine for adults ages 18 and older. These vaccines type a part of the US authorities’s Strategic National Stockpile (SNS) of medicines for deployment within the occasion of a public well being emergency.

In 2013, the FDA permitted a second H5N1 vaccine that can also be a part of the SNS.

Similar vaccines are licensed in different jurisdictions. All of those vaccines have been proven to be secure and efficient on the time of approval.

In distinction, H5N1 vaccines to be used in animals are commercially accessible. Vaccination of poultry has been extensively adopted in China and different low-to-middle revenue international locations.

The US and Europe are gearing up for an enormous poultry vaccination marketing campaign to curtail the unfold of hen flu.

How else can I shield myself in opposition to avian influenza?

Avoiding direct contact with stay poultry is maybe the one best measure to forestall the event of avian influenza.

If publicity to probably contaminated birds can’t be prevented, private protecting gear together with gloves, robes, face masks and eye shields must be worn. Hands must be completely washed with cleaning soap and water in any case potential exposures.

Alcohol-based hand sanitisers are much less efficient at inactivating influenza viruses in comparison with handwashing.

Are hen feeders secure to make use of?

Although there’s at the moment a negligible threat of growing avian influenza following wild hen publicity, there are divergent opinions on the position of hen feeders in probably spreading the illness.

The British Columbia Society for the Prevention of Cruelty to Animals recommends briefly abandoning the apply of utilizing yard hen feeders.

In distinction, the US Department of Agriculture doesn’t advocate in opposition to their use until poultry are being farmed within the space.

Is avian influenza the subsequent viral pandemic?

There isn’t any method to predict if avian influenza will evolve right into a pandemic affecting people.

Mitigation methods to forestall cross-species transmission embody large-scale pre-emptive vaccination of home birds and culling of contaminated flocks.

Of main concern is the potential for novel avian influenza subtypes to emerge by means of antigenic shift.

This phenomenon entails the reassortment of hemaglutinin and neuraminidase genes when a single host is contaminated with multiple viral subtype.

As such, avian influenza is a chief contender as a pandemic viral illness of animals and people alike.

Current stockpiles of avian influenza vaccines for human use will seemingly be insufficient to fulfill societal wants ought to there be a surge in human infections over time.