Does Global Climate Change Aggravate Bird Flu Threats ?

CLAIM: Climate change aggravating avian flu transmission  

Bird flu has become a hot topic of discussion these days. The World Health Organization  (WHO) recently warned the general public about a possible pandemic caused by this bird flu. They stated that vaccines are being manufactured to fight the flu. Consequently, there are several arguments stating that climate change causes Avian Influenza pandemics

The Climate Fact Checks team investigated whether Climate Change really has an impact on such pandemics. But first we need to understand what bird flu is and how it is caused.

What is Bird Flu?

Bird flu, commonly known as avian influenza (AI), is a “type A influenza virus”. Bird flu spreads between both wild and domesticated birds. Bird flu transmits from infected birds to mammals and especially humans. However, there are no proper evidences to prove that it passes from human to human. Some research findings conclude that bird flu is rarely transmitted from human to human especially when the virus is in its development stage. This means that there is no possibility a caregiver would catch the virus by treating a patient down with the bird flu. When looking at human cases the incubation period of bird flu is estimated to be about 3-10 days.

The symptoms of bird flu in humans are similar to those of regular influenzas such as fever, cough, sore throat, aching muscles and headache. Additional symptoms include eye infections, pneumonia, acute respiratory distress and inflammation of the brain and heart.

How is this virus transmitted to mammals?

Avian flu viruses are adapted to bind to birds’ receptor cells. Humans and other mammals have some avian-like receptors, but they’re typically buried deep in the lungs. Because of this anatomical quirk, it would take a huge load of the virus H5N1 strain for one infected mammal to infect another mammal.

This condition existed in the past too, but most infected people who eat meat and work with birds. However, this time it is quite serious as new viral strains are emerging. Health experts are more concerned about the H5N1 virulent strain of avian influenza, that develops in mammal bodies. Scientists examined that the original H5N1 mutation had a 50% to 60% mortality rate in humans.

Has Climate Change increased the spread of viruses causing bird flu?

Climate change can have a significant impact on bird migration patterns. That can affect birds in several ways. Changes in temperature and weather patterns can impact the timing of bird migration. For example, if temperatures remain warmer for longer periods in the fall, birds may delay their migration southward. Climate change can affect breeding patterns also, which in turn can impact migration. As well, climate change can alter habitat availability and suitability, which can impact bird populations. For example, if a bird’s wintering habitat is no longer suitable due to changing temperatures or rainfall patterns, it may impact the bird’s ability to migrate successfully.

Climate change would almost certainly alter bird migration, influence the AI virus transmission cycle and directly affect virus survival outside the host. However, these changes are unpredictable, but it is possible that AI virus circulation in water bird populations will carry on endless adaptation and evolution. Although this is very severe in commercial cultivation, it can be controlled without the impact of possible climate change. However, under natural conditions, it is quite difficult.

We looked into some research findings and one interesting research has been carried out by collecting air samples regularly for two years near a large wetland in East Asia. Researchers have used real-time polymerase chain reaction technique to analyze air samples. Then the team compared the results with weather data and their log of bird species present during the migratory season. It proved that lower daily temperatures were linked to higher levels of influenza A, H7 and H9 (AI Viral strains) in the air. In addition, the presence of certain migratory bird species, including ones from the orders Anseriformes, Charadriiforms and Pelecaniformes, was linked to higher amounts of H7 and H9 viral copies. Moreover, sudden changes in the atmosphere have been indirectly linked to the spread of AI.

How Climate Change impacts Avian life and increase AI spread.

Changes in climate can impact the timing of plant and insect growth, which can impact food availability for native and also migrating birds. Birds start moving to other areas to escape the lack of food. It causes to widely spread of AI disease in different ranges. On the other hand, if birds move to take care of themselves food should be available when birds arrive at their destination, if not it can impact their ability to survive.

As temperatures warm, some bird species may shift their range northward, altering migration patterns or causing certain species to overlap in areas where they did not before causing a threat to birds’ geographical range. Overall, climate change can have complex and far-reaching effects on AI spread and avian life.   

Avian flu mitigation

Enlarge the geographical context and methods of research spanning the influenza transmission cycle to help determine which climatological factors affect influenza transmission and prepare for future influenza scenarios.

Changing food systems and population density and also changing land use, biodiversity changes, and water scarcity induce climate change and the transmission cycle of influenza. Advanced research needs to identify the relationship between climate change and health issues and the distribution of bird flu disease. 

In summary

Bird flu, also known as avian influenza, is a viral infection that primarily affects birds, but can also be transmitted to humans. The virus is usually spread through contact with infected birds or their feces, but it can also be spread through air. There is some evidence to suggest that climate change could potentially have an effect on the spread of bird flu.

Climate change could impact the spread of bird flu by altering the distribution and migration patterns of birds. As temperatures and weather patterns change, birds may shift their ranges or migrate to different areas, potentially coming into contact with new populations of birds and increasing the risk of virus transmission. Additionally, changes in water availability and temperature could impact the survival and spread of the viruses in water sources where birds congregate, such as wetlands or lakes.

According to our investigation we realize that climate change has indirect impacts on distribution of bird flu. However, it’s important to note that the relationship between climate change and bird flu is complex, and more research is needed to fully understand the potential impacts.

Resources

https://www.acs.org/pressroom/newsreleases/2022/november/temperature-nearby-

https://givingcompass.org/article/the-impact-of-climate-change-on-bird-flu-transmission

https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/bird-flu-avian-influenza

https://grist.org/health/as-climate-change-disrupts-ecosystems-a-new-outbreak-of-bird-flu-spreads-to-mammals/

https://www.sciencedirect.com/science/article/pii/S266727822100081X)