Hyderabad: First there was the Sars Cov-2 or Coronavirus raging down the country. Along with it came the lockdown and the seesawing in the number of deaths and the infected. Then when we stepped into the Unlock period, resuming most services, came the UK strain of the Coronavirus (VUI-202012/01), which is believed to be more contagious but not more lethal than other strains. And now, there is an addition to the arsenal.
Sending shivers down the country's spine as more number of states get affected by it, avian influenza or bird flu, is the latest scare for India.
As the National Institute of High Security Animal Diseases in Bhopal confirmed the presence of avian influenza virus in Rajasthan after several hundreds of crows found dead, the Centre has already issued a bird flu alert to states. Cases have so far been reported from Madhya Pradesh, Rajasthan, Himachal Pradesh and Kerala.
What is Avian Influenza?
Avian influenza (AI), more commonly called as bird flu, is an infectious disease of birds caused by type A influenza viruses. These viruses most commonly infect poultry like domestic chickens, turkeys, ducks, quails and geese. Wild aquatic birds – particularly certain wild ducks, geese, swans, gulls, shorebirds and terns – are the natural hosts for most influenza type A viruses.
How Avian Influenza virus affects birds?
Experts says, infected birds can shed Avian Influenza-A viruses through their saliva, nasal secretions and feces. Susceptible birds become infected when they come in contact with the virus, after it is shed by the infected birds. They also can become infected through contact with surfaces that are contaminated with virus from infected birds.
How Bird Flu infects humans?
Not all avian influenza viruses cause disease in humans. However, some can infect humans and cause severe ailments. But, virologits say it is difficult to transmit the infection from person to person. H5N1, the original avian influenza virus and its sub-type H7N9 have history of causing serious implications and sometimes fatal infections in people. According to the World Health Organisation, when people get infected, the mortality rate is about 60%.
How many strains are there?
Since its reemergence in 1997, almost twenty years later its first outbreak in 1950, constant mutations and reassortment of the viruses have resulted to more than 33 strains in 77 countries across the world. With the ongoing circulations of various avian influenza virus strains such as H5N1, H5N2, H5N8, H7N8 outbreaks of avian influenza continue to be a global public health concern.
Is this bird flu virus contagious?
Avian influenza viruses are usually classified into two categories according to the severity of the disease in poultry. Low pathogenic, where the strains cause few or no clinical signs in poultry and the Highly pathogenic strains, which cause severe clinical signs and high mortality rates among poultry. Although small in size and simple in structure, influenza viruses are sophisticated organisms with highly mutagenic genomes. In simple terms, they can react with genes and can affect the body in a harmful way.
Which strain had hit India earlier?
The first outbreak of the H5N1 virus in India was in 2006 and was reported from Navapur in the Nandurbar district of Maharashtra. Since then it has been recurring in the country. In most of the outbreaks, the H1N1 virus strain has been found.
So, what is the new strain?
The National Institute of High Security Animal Disease has confirmed the presence of two strains of viruses, the H5N1 and the H5N8, in the samples sent to them from five states. Cases of bird flu have been found in migratory birds in Himachal Pradesh, crows in Madhya Pradesh and Rajasthan and in chicken in Haryana and poultry ducks in Kerala.
How different is the new strain from the earlier one?
The H5N1 strain falls under the Highly Pathogenic category and can cause severe clinical signs and high mortality rates among poultry. The H5N8, which is the new virus strain in India, is categorised as a Low Pathogenic category virus. That eventually means, few or no clinical signs in poultry.
Spread of Virus in India so far So far 12 epicenters in four states have been indentified across the country.
Himachal Pradesh
The first case of avian influenza virus outbreak was reported from the Pong Reservoir after 2,500 migratory birds were found dead. Bar headed geese were the worst hit. The state administration has ordered a ban on sale of poultry and fish in Fatehpur, Dehra, Jawali and Indora sub-divisions as a precautionary measure.
Rajasthan
16 out of 33 districts have been affected by the recent bird flu outbreak. Chief Minister Ashok Gehlot has instructed closure of parks, sanctuaries and has also issued advisory to step up the vigilance in all places where birds flock.
Madhya Pradesh
According to the state Animal Husbandry department, as many as 376 crows were found dead, which includes 146 in Indore, 112 in Agar-Malwa, 100 in Mandsaur, 13 in Khargone and nine in Sehore. Chief Minister Shivraj Singh Chouhan has said, the state will not allow entry of chicken consignments from Kerala and other southern states for the next 10 days in view of the bird flu scare.
Kerala
In Kerala, around 48,000 ducks have been culled so far after bird flu outbreak was reported in the Alappuzha and Kottayam districts. After samples were sent to the National Institute of High Security Animal Diseases in Bhopal, avian influenza sub-type H5N8 has been detected.
What is the government doing?
Controlling the spread of avian influenza viruses in poultry is essential in reducing the risk of human infection. Accordingly, the Centre had asked the affected states to step up the vigil, in an effort to contain the virus spread. Affected states have already set up control rooms in the areas wherefrom cases have been reported and released advisories with the Do’s and Don'ts in case of an outbreak.
Rapid response teams have been kept active to report fatalities, contain the spread of the virus and follow culling of the infected birds as per the 2015 National Avian Influenza Plan.
Is chicken safe for consumption?
There is no evidence to suggest that A(H5), A(H7N9) or other avian influenza viruses subtypes can be transmitted to humans through properly cooked poultry or eggs. But, at the same time there are instances of eggs getting contaminated, both outside and inside of the shell. So, nutritionists say it is better to avoid runny yolks.
Meat is considered to be safe if is heated above 70 degrees centigrade. As a standard precaution, WHO recommends that poultry and poultry products should always be prepared following good hygienic practices. As of now, there is no big risk regarding the consumption of chicken.
Is there any panic selling?
“From last few months, the sale of eggs have increased because of Covid as more people became aware of the nutritional value of eggs. The consumer pattern is not yet affected by recent news of bird flu outbreak,” says Suresh Chitturi, Chairman of International Egg Commission. But, reports are there that sale figures have started to see a down slide across Tamil Nadu and prices have dropped marginally in that state.
Precautions
According to the World Health Organisation, consumers in areas with outbreaks need to be aware of the risks of cross-contamination between raw poultry and other foods that will not be cooked prior to their consumption. Juices from raw poultry or poultry products should never be allowed, during food preparation, to touch or mix with items eaten raw. When handling raw poultry or raw poultry products, persons involved in food preparation should wash their hands thoroughly and clean and disinfect surfaces in contact with the poultry products. Soap and hot water are sufficient for this purpose
For people working at poultry farms
Almost all cases of H5N1 infection in people have been associated with close contact with infected live or dead birds, or H5N1-contaminated environments. The virus does not infect humans easily and spread from person to person appears to be unusual. But, activities like slaughtering, defeathering, handling carcasses of infected poultry, and working in poultry farms, preparing poultry for consumption, especially in household settings, are also likely to be risk factors.
“Bird flu is not new in India but unfortunately the bio safety measures are not followed by most farms,” claims Suresh Chitturi. “Safety measures like wearing masks while working in the farms and washing hands can help. Also unlike countries like China and Vietnam, in India birds and mammals are reared separately. So, the widespread of the flu can be easily contained,” he said.
How to prevent an outbreak
“Monitoring of bird flu, which is spread through migratory birds is not easy. And, it is going to be extremely costly. So, in my view, vaccination is the best solution and they should allow it immediately,” said Suresh Chitturi adding, “vaccination of the poultry birds have yielded results in neighbouring countries like Bangladesh, China”.
What are the symptoms of avian influenza in humans?
The symptoms of infection may include high fever and malaise, cough, sore throat, and muscle aches. Other early symptoms may include abdominal pain, chest pain and diarrhoea. The infection may progress quickly to severe respiratory illness (for example, difficulty in breathing or shortness of breath, pneumonia, Acute Respiratory Distress Syndrome) and neurologic changes (altered mental status or seizures).
How is avian influenza in humans treated?
In most cases, avian influenza in humans develops into a serious disease that should be treated promptly
at the hospital and may require intensive care. According to WHO, the antiviral medicine Oseltamivir can
reduce the severity of illness and prevent death, and should be used in all cases.
Is there a vaccine?
Seasonal influenza vaccination does not protect against H5N1 infection. Candidate vaccines to prevent H5N1 infection have been developed, but are not ready for widespread use.
Why is there so much concern about avian influenza H5N1 virus?
Influenza viruses constantly undergo genetic changes. It would be a cause for concern, should the H5N1 virus become more easily transmissible among humans. H5N1 infection in humans can cause severe disease and has a high mortality rate. If the H5N1 virus were to change and become easily transmissible from person to person while retaining its capacity to cause severe disease, the consequences for public health could be serious.
