From UPSC perspective, the following things are important :
Prelims level : Various diseases mentioned and their vaccines
Mains level : Epidemics and their containment
India has witnessed widespread illnesses and virus outbreaks in parts of the country, including the SARS outbreak between 2002 and 2004. However, statistics show that they were nowhere as widespread as the COVID-19 that has now reached almost every part of the country and almost every country in the world.
What is an Epidemic?
- The WHO defines epidemics as “the occurrence in a community or region of cases of an illness, specific health-related behaviour, or other health-related events clearly in excess of normal expectancy.
- The community or region and the period in which the cases occur are specified precisely.
- The number of cases indicating the presence of an epidemic varies according to the agent, size, and type of population exposed, previous experience or lack of exposure to the disease, and time and place of occurrence.
- Epidemics are characterized by the rapid spread of the specific disease across a large number of people within a short period of time.
Epidemics in India
- Many Indian citizens born at the start of the 21st century have not fully witnessed or experienced circumstances surrounding the mass outbreak of epidemics.
- This is not to say however, that as a nation, India is completely unfamiliar with dealing with epidemics and public health crises, some with exceptional success such as:
1915-1926 — Encephalitis lethargica
- Encephalitis lethargica, also known as ‘lethargic encephalitis’ was a type of epidemic encephalitis that spread around the world between 1915 and 1926.
- The disease was characterized by increasing languor, apathy, drowsiness and lethargy and by 1919, had spread across Europe, the US, Canada, Central America and India.
- It was also called encephalitis A and Economo encephalitis or disease.
- Approximately 1.5 million people are believed to have died due to this disease.
1918-1920 — Spanish flu
- This epidemic was a viral infectious disease caused due to a deadly strain of avian influenza.
- The spread of this virus was largely due to World War I which caused mass mobilization of troops whose travels helped spread this infectious disease.
- In India, approximately 10-20 million people died due to the Spanish flu that was brought to the region a century ago, by Indian soldiers who were part of the war.
1961–1975 — Cholera pandemic
- Vibrio cholerae, one type of bacterium, has caused seven cholera pandemics since 1817.
- In 1961, the El Tor strain of the Vibrio cholerae bacterium caused the seventh cholera pandemic when it was identified as having emerged in Makassar, Indonesia.
- In a span of less than five years, the virus spread to other parts of Southeast Asia and South Asia, having reached Bangladesh in 1963 and India in 1964.
1974 — Smallpox epidemic
- According to WHO, smallpox was officially eradicated in 1980. The infectious disease was caused by either of the two virus variants Variola major and Variola minor.
- Although the origins of the disease are unknown, it appears to have existed in the 3rd century BCE.
- This disease has a history of occurring in outbreaks around the world and it is not clear when it was first observed in India. India was free of smallpox by March 1977.
1994 — Plague in Surat
- In September 1994, pneumonic plague hit Surat, causing people to flee the city in large numbers. Rumours and misinformation led to people hoarding essential supplies and widespread panic.
- This mass migration contributed to the spread of the disease to other parts of the country. Within weeks, reports emerged of at least 1,000 cases of patients afflicted with the disease and 50 deaths.
2002-2004 — SARS
- SARS was the first severe and readily transmissible new disease to have emerged in the 21st century.
- In April 2003, India recorded its first case of SARS, severe acute respiratory syndrome, that was traced to Foshan, China.
- Similar to COVID-19, the causative agent of SARS was a type of coronavirus, named SARS CoV that was known for its frequent mutations and spread through close person-to-person contact and through coughing and sneezing by infected people.
2014-2015 — Swine flu outbreak
- In the last few months of 2014, reports emerged of the outbreak of the H1N1 virus, one type of influenza virus, with states like Gujarat, Rajasthan, Delhi, Maharashtra and Telangana being the worst affected.
- By March 2015, according to India’s Health Ministry, approximately 33,000 cases had been reported across the country and 2,000 people had died.
2018 — Nipah virus outbreak
- In May 2018, a viral infection attributed to fruit bats was traced in the state of Kerala, caused by the Nipah virus that had caused illness and deaths.
- The spread of the outbreak remained largely within the state of Kerala, due to efforts by the local government and various community leaders who worked in collaboration to prevent its spread even inside the state.
- Between May and June 2018, at least 17 people died of Nipah virus and by June, the outbreak was declared to have been completely contained.