India has faced the worst forms of epidemics in the past. As a nation, we have survived many lethal epidemics, and coronavirus spread is unlikely to match those calamities.
By Pankaj Chaturvedi and Natraj Ramlingam
The present-day Covid-19 pandemic with 10,18,150 cases and 53,251 deaths spread across 199 countries as of April 3, has resulted in unprecedented lockdowns in almost all countries, including India. India has had its fair share of epidemics and pandemics in the past. At this time of lockdowns and pandemic scare, it is prudent for all of us to look into the past pandemics and epidemics for solutions, hope and plan of action towards the current crisis. WHO defines an epidemic 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’. We will look at some of the epidemics involving India in the past.
Little is known regarding the epidemics in ancient India and medieval India. An early text from India by Sushruta Samhita in the 5th century BC describes isolated cases of cholera-like illnesses. Gaspar Correa, a Portuguese historian, described an outbreak of a disease in the spring of 1543 around the Ganges Delta. The local people called the condition “moryxy,” and it reportedly killed victims within 8 hours of developing symptoms and had a fatality rate.
TB has been in India for a thousand years. In Indian literature, there are passages from around 1500 BCE which have mention of tuberculosis. Many Sanskrit manuscripts were discovered dating back to 500 BCE, and these refer to a group of diseases termed ‘Sosha’. These present symptoms like wasting, cough and blood in sputum. The earliest reference concerning plague is from Sushruta in 5 BCE. He described a painful swelling in the axilla with violent fever rapidly terminating in death. The description closely imitates that of bubonic plague.
During early 1900s bubonic plague struck in parts of western India—around 1896, cases were identified and reported in Bombay. Between 1896 and 1914, bubonic plague killed over 8 million people in west India alone. This epidemic saw unprecedented measures by the Bombay presidency to control the spread. The measures provoked resistance, riots, mob attacks on Europeans and even the assassination of British officials. But mortality continued to rise between 1903 and 1907.
The 1918–19 ‘Spanish’ influenza was the most dreadful pandemic in recent past, with mortality estimated up to 50 million. Caused by the H1N1 strain of influenza virus, this pandemic had two waves—first wave in 1918 followed by a severe second wave in early 1919. In terms of mortality, India had an estimated mortality range of 10–20 million and an estimated population loss of 13.8 million. Epidemic spread from Bombay to southern and eastern India. Diminished virulence, decreased velocity of spread led to important epidemiological conclusions. The first conclusion was that the resulting competition among strains of a rapidly evolving virus produces an equilibrium in which the predominant strain is less virulent and slower to travel than the strain that predominated at the onset of the epidemic. Secondly, absolute humidity due to rainfall was also attributed to the curious observations.
Cholera and India have been virtually inseparable for a long time. Starting from the first global pandemic to the seventh pandemic, India has always been either a source or a cesspool for cholera. Endemic belts were located based on these pandemics and were to be found in areas with high population density along rivers and in areas with high rainfall and humidity. The severity of the disease has been attributed to longer viability of El Tor outside the human body, persistent carrier state and spread to cholera naïve areas. During the last decade (1997-2006), there have been 68 outbreaks of cholera across India with an estimated 823 deaths out of 2 lakh affected patients.
Twentieth-century saw one of the severe smallpox epidemics. Between January and May, 1974, over 15,000 people died from smallpox. India reported around 60,000 cases of smallpox to WHO during this time. Eradication of smallpox after its epidemic in the 1970s will always be a crowning achievement for the health sector. The government launched a ‘surveillance–containment’ technique along with vaccination. Every case was found and contained by vaccination of all immediate family members. By 1975, no more new cases were discovered. From March to November 1976, 11 lakh houses were searched for new smallpox cases. By April 1977, India was free of smallpox.
On September 23, 1994, pneumonic plague deaths were reported in Western India. Around 1,061 cases were reported. The migrant workers in these areas unwittingly transmitted the disease to other parts of India. This pattern of spread is termed as relocation diffusion, thus, explaining the presence of plague in far off regions such as Mumbai, Delhi and Calcutta. Treatment in the form of containment and hospitalisation, albeit delayed, led to successful containment of the epidemic.
Nipah Virus (NiV) encephalitis outbreaks have been reported frequently in South East Asia since 1998. From 1998 to 2015, roughly around 600 cases of NiV human infections were reported. India reported two outbreaks of NiV encephalitis in the eastern state of West Bengal, bordering Bangladesh, in 2001 and 2007 with a case fatality rate of 68% during the first outbreak. The recent epidemic in May of 2018, which appeared in Kerala for the first time, resulted in the death of for over 17 people in 7 days.
India has faced the worst forms of epidemics in the past. As a nation, we have survived many lethal epidemics, and coronavirus spread is unlikely to match those calamities. We need to learn a lesson from the current crisis to build a healthy and prosperous nation. Emphasis on handwashing will not only stop coronavirus spread but many other fomite-borne illnesses. Coughing or sneezing in handkerchief will curb the spread of tuberculosis, influenza and other seasonal flu. Social distancing and stoppage of spitting in public places will also stop the spread of TB, H1N1, influenza, etc. Finally, it will prepare society to fight other grave public health problems such as tobacco, alcohol, drugs, road traffic accidents, etc., that kill millions every year.
(Chaturvedi is deputy director, Tata Memorial Center, Mumbai and Ramalingam is fellow, Tata Memorial Hospital)