Influenza pandemic
Introduction
An influenza pandemic is an epidemic of an influenza virus that spreads across a large region, either across continents or worldwide, affecting a large number of individuals. Influenza pandemics occur when a new strain of the influenza virus is transmitted to humans from another animal species. Species that can be infected by influenza virus include birds, pigs, and humans.
History
Influenza pandemics have occurred throughout history, with the earliest known pandemic occurring in 1580. Since then, there have been several significant pandemics, including the Spanish Influenza pandemic of 1918, the Asian Influenza pandemic of 1957, the Hong Kong Influenza pandemic of 1968, and the 2009 H1N1 pandemic.
Causes
Influenza pandemics are caused by new influenza A virus subtypes. Influenza A viruses are divided into subtypes based on two proteins on the surface of the virus: the hemagglutinin (H) and the neuraminidase (N). There are 18 different H subtypes and 11 different N subtypes. When a new influenza A virus subtype emerges that can infect people and spread efficiently from person to person, an influenza pandemic can occur.
Symptoms
The symptoms of influenza during a pandemic are similar to the symptoms of seasonal influenza and can include fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills, fatigue, and sometimes diarrhea and vomiting. In some cases, influenza can lead to severe complications such as pneumonia, acute respiratory distress syndrome, and death.
Prevention and Control
Prevention and control of influenza pandemics involve a combination of strategies, including vaccination, antiviral treatment, non-pharmaceutical interventions (such as hand hygiene and respiratory etiquette), and community mitigation measures (such as school closures and social distancing).
Impact
Influenza pandemics can have a significant impact on society, causing widespread illness and death, disrupting daily life, and causing economic loss. The impact of an influenza pandemic can be mitigated through preparedness and response efforts.