Spanish flu infects birds humans and
Why has there been so much concern about the bird flu outbreaks involving A H5N1?
The ecology of influenza A viruses is dynamic and complex involving multiple host species and viral genes. Tumpey et al. The rise in international travel could speed the spread of viruses around the world.
Spanish flu infects birds humans and
Other avian influenza A H5 subtype viruses have also resulted in both outbreaks in poultry and human infections. This is only one estimate undertaken for planning and there are others estimates that can be made which will look worse or better. It was caused by an H1N1 influenza A virus that scientists believe mutated from an influenza virus that was previously infecting only birds. In , after failing for several years to contain geographic spread of the virus, China instituted a policy of vaccinating chickens. We still don't know exactly why or how this happened or how it continues to happen , we only know that it did. This is achieved through the rapid detection of poultry outbreaks and the emergency introduction of control measures, including the destruction all infected or exposed poultry stock, and the proper disposal of carcasses. Chan et al. Viruses that cause severe disease in poultry and result in high death rates are called highly pathogenic avian influenza HPAI. Although it is unusual for people to get influenza virus infections directly from animals, sporadic human infections and outbreaks caused by certain avian influenza A viruses and swine influenza A viruses have been reported.
To date, there has been little evidence to suggest that AI can spread among humans. Commercially available RDTs in general cannot provide subtype information. Given the persistence of the A H5 and A H7N9 viruses in some poultry populations, control will require long-term commitments from countries and strong coordination between animal and public health authorities.
But in a real pandemic the pattern will always be more complicated.
Spanish flu timeline
But pandemics have been planned for in every European country to greater or lesser extents. The influenza virus is highly mutable and can adapt into a form that can also infect humans. So far in there have been none. However, in , H3N2 viruses from humans were introduced into the pig population and caused widespread disease among pigs. They have not caused pandemics but they have required inclusion in the seasonal vaccines. About the Author. Whether currently-circulating avian, swine and other zoonotic influenza viruses will result in a future pandemic is unknown. The preceding example shows that pigs could transmit novel viruses from an avian reservoir to other mammalian species. In the fall of , the second wave of the pandemic started. It causes a high death rate, proving that humans have a low immunity to the disease. As previously noted, the viruses that caused the Asian and Hong Kong influenza pandemics are reassortant viruses of human and avian origin viruses Kawaoka et al, This is only one estimate undertaken for planning and there are others estimates that can be made which will look worse or better. Although it is unusual for people to get influenza virus infections directly from animals, sporadic human infections and outbreaks caused by certain avian influenza A viruses and swine influenza A viruses have been reported. And an H5N1 virus is in fifth spot in a CDC risk assessment ranking of flu viruses with pandemic potential.
Conjunctivitis has also been reported in influenza A H7. They were not in the pandemic. Both are highly pathogenic, meaning they kill domestic poultry.
Some experts believe that if a pandemic is found just after it has started, if it is still in a single locality, if it is in a rural area without too many communications, if the right actions are taken quickly and if the plans work well, then an influenza pandemic might be contained and averted.
The pathogen There are four types of influenza viruses: types A, B, C and D: Influenza A viruses infect humans and many different animals. Slaughtering, defeathering, handling carcasses of infected poultry, and preparing poultry for consumption, especially in household settings, are also likely to be risk factors.
based on 16 review