Major Flu Variants and Recent Outbreaks

In recent times, the world has been witness to alarming events involving the transmission of the H5N1 avian influenza subtype among animals, raising concerns about the potential for triggering a human pandemic. 

The gravity of this situation is further underscored by a significant mortality event that occurred, claiming the lives of more than 700 seals along the Caspian Sea coast. 

Understanding the Avian Influenza Virus

Avian influenza, commonly referred to as bird flu, stems from infections caused by avian influenza Type A viruses. Although these viruses predominantly affect birds, there are instances where spillover leads to transmission to mammals, and even rarer occurrences of mammal-to-mammal transmission. 

The H5N1 subtype of avian influenza is of particular concern, as it possesses the capability to infect various mammals, including minks, ferrets, seals, and domestic cats. 

Recent Developments in Avian Influenza

Despite India’s declaration of being free from Avian Influenza (H5N1) in 2019, subsequent outbreaks were reported in 2020 and early 2021. These incidents involved both H5N1 and H5N8 strains affecting poultry in multiple Indian states. 

Recognizing Symptoms and Types

Infections with avian influenza cause flu-like symptoms that can vary from mild to severe. Fever, cough, sore throat, muscular aches, and gastrointestinal disorders such as nausea, diarrhoea, and vomiting are among the symptoms. 

Complications involving the respiratory system, such as difficulty breathing, pneumonia, and acute respiratory distress, may arise in severe instances. 

Classification of Influenza Viruses

Influenza viruses primarily responsible for seasonal epidemic illnesses are categorised into Influenza A and B. Influenza C primarily impacts humans and has also been observed in dogs and pigs. On the other hand, Influenza D is prevalent among cattle. 

The classification of influenza A viruses is based on the Hemagglutinin (HA) and Neuraminidase (NA) proteins found on their surfaces. With approximately 18 HA and 11 NA subtypes, various combinations result in designations like H5N1, H7N2, and H9N6. 

While most influenza subtypes are capable of infecting birds, exceptions like H17N10 and H18N11 found in bats exist.

Influenza Vaccination Advances and the WHO’s Role

The World Health Organisation (WHO) has continually played a key role in influenza prevention. The WHO’s flu vaccine advisory panel released recommendations for the composition of influenza virus vaccines for the 2017-18 influenza season in the northern hemisphere, demonstrating this commitment. 

The substitution of the Michigan strain for the California strain was a noteworthy change in strain selection.

The WHO’s Mandate and Impact

Since its establishment in 1948 as a specialised agency under the United Nations, the World Health Organization (WHO) has emerged as a pivotal player in international health. 

Headquartered in Geneva, Switzerland, the WHO brings together 194 countries, 150 national offices, and six regional offices, forming a robust network dedicated to global well-being.

The launch of the WHO on April 7, 1948, was a watershed moment in the organisation’s history. This historic day is now celebrated annually as World Health Day, a monument to the organisation’s steadfast dedication to maintaining and advancing global public health.

Summary

Recent developments surrounding avian influenza and its potential transmission to humans underscore the importance of continued research and vigilance in understanding and combating emerging infectious diseases. 

The complexities of influenza viruses and their potential to cross species barriers necessitate a collaborative global effort to prevent and manage outbreaks.