The recent discovery of critical changes in the global distribution and evolution of highly pathogenic avian H5 influenza viruses has drawn considerable attention. This phenomenon holds significance due to the viruses’ potential adverse effects on both avian and mammalian species, including humans.
Key Study Findings
Previously centered in Asia, the study portrays that the epicenter of these viruses has extended to new territories in Africa and Europe. As further bad news, two H5 strains deriving from African and European bird populations evolved through genetic reassortment with low-pathogenic viral variants during their spread. Genetic reassortment, a process leading to new genetic sequences through mixing genes of two organisms, plays a pivotal role in driving the evolution and diversification of these diseases.
The study highlighted an additional point of concern – the increasing existence of avian influenza in wild bird populations is expediting the evolution and spread of new viral strains. Wild birds serve a significant role as transmitters and amplifiers of these viruses, thereby contributing to their ongoing evolution.
Understanding Genetic Reassortment
Genetic reassortment results in the creation of a recombinant, a brand new genetic sequence. It can intensify genetic diversity during the evolution of seasonal viruses, and even lead to the development of novel, potentially lethal viruses.
About Avian Influenza
Commonly known as bird flu, avian influenza is a severely contagious viral infection primarily impacting birds. In particular, it affects wild birds and domestic poultry. The highly pathogenic avian influenza H5N1 virus was first identified in domestic waterfowl in Southern China in 1996, and it was named A/goose/Guangdong/1/1996.
Transmission to Humans and Symptoms
Although instances of H5N1 avian influenza transmission to humans are sporadic, the infection’s person-to-person transmission is challenging. As per the World Health Organisation (WHO), the mortality rate for infected individuals is approximately 60%. Symptoms vary from mild flu-like manifestations – fever, cough, and muscle aches, to severe respiratory complications like pneumonia and difficulties in breathing. Cognitive problems such as altered mental status and seizures may also occur.
Avian Influenza in India
In India, the first outbreak of Highly Pathogenic Avian Influenza (HPAI) H5N1 occurred in 2006, followed by yearly outbreaks; H5N8 was first observed in 2016. The disease has been reported in 24 states and union territories so far. India follows a “detect and cull” policy as per the National Action Plan for Prevention, Control, and Containment of Avian Influenza (revised – 2021) to control the spread of the virus.
Treatment Measures
Antivirals have been effective in treating avian influenza virus infections in humans, decreasing severity and risk of death.
Different Types of Influenza Virus
The type of influenza virus can either be Highly Pathogenic Avian Influenza (HPAI) or Low Pathogenic Avian Influenza (LPAI). H1N1 virus, often mentioned in news, is associated with Swine flu disease.
