Epidemics were described in classical Ayurvedic literature dating back to centuries before the common era. In Sanskrit, Epidemics were called Janapadodhvamsa - Janapada - large human settlements, Udhvaṃsa - to be affected, to be destroyed. The third chapter in the Vimanasthana of the Carakasaṃhita deals exclusively with this topic raising the important question as to why people of different body constitutions, lifestyle, diet and genetic inhertiance become afflicted with the same disease. The text replies with the answer that Climate, Air, Water and Land can become a common medium through which the same disease can affect a large human settlement.
Today the whole world has come to a standstill due to the outbreak of the COVID-19 pandemic. A glance at classical Ayurvedic texts reveal that Susruta was perhaps the first whistle blower warning us about the possibility of epidemic outbreaks like COVID-19 which primarily affects the respiratory system. Susrutasaṃhita, an ancient text book of surgery in Ayurveda describes illnesses manifesting as epidemics affecting the respiratory system time and again, presenting with the symptoms of fever, cough, breathing difficulty, rhinorrhoea, headache and even anosmia The clinical presentation of such diseases described in the Susrutasaṃhita are strikingly similar to epidemics like SARS, Ebola, MERS, Swine Flu and even COVID-19 exhibiting severe respiratory symptoms. Dalhaṇa, the commentator of this text specifies that causative agent of such diseases enters the human body through the nasal passages. When Dalhaṇa comments on the passage in Susruasaṃhita referring to symptoms of the epidemic manifesting respiratory illnesses that is seen to be caused by airborne transmission, he lists a very interesting symptom - gandhajnana or anosmia Anosmia has been reported in COVID-19 patients. Writes Prof. Claire Hopkins, President of British Rhinological Society, "There is potential that if any adult with anosmia but no other symptoms was asked to self-isolate for seven days, in addition to the current symptom criteria used to trigger quarantine, we might be able to reduce the number of otherwise asymptomatic individuals who continue to act as vectors, not realising the need to self-isolate". Post-viral anosmia is one of the leading causes of loss of sense of smell in adults, accounting for up to 40% cases of anosmia. Viruses that give rise to the common cold are well known to cause post-infectious loss, and over 200 different viruses are known to cause upper respiratory tract infections. Previously described coronaviruses are thought to account for 10-15% cases. It is therefore perhaps no surprise that the novel COVID-19 virus would also cause anosmia in infected patients. There is already good evidence from South Korea, China and Italy that significant numbers of patients with proven COVID-19 infection have developed anosmia/hyposmia. In South Korea, where testing has been more widespread, 30% of patients testing positive have had anosmia as their major presenting symptom in otherwise mild cases. This lends strong support to the assumption that Susrutasaṃhita was referring to viral infections in this context.
The Susrutasaṃhita also describes the modes of contagion - by repeated physical contact (gatrasaṃsparsat), by inhalation (nihsvasat), by eating together (sahabhojanat), by sitting and sleeping together (sahasayyasanat), by contact with clothes, garlands and so on (vastramalyanulepanat) - The importance of social distancing to prevent the spread of epidemic diseases is hinted at in this ancient medical text. Sthanaparityaga or abandoning the places of human activity is mentioned by Susruta as the first and foremost measure in mitigating an epidemic. This reminds us of the stringent measures like lockdown that we have been forced to enforce in the wake of the COVID-19 pandemic. The word quarantine means fourty days in Italian and refers to the practice of isolation to prevent contagion in the middle ages. This practice is said to have been discovered by Avicenna, the Arab Physician. However, such principles in the mitigation of epidemics are found mentioned in classical Ayurvedic texts composed centuries before the common era. Quarantine was also practice in the ancient civilisation of Nepal. nearly a thousand years ago. To contain and prevent the transmission of infectious diseases it was a standard cultural practice for people to self-isolate themselves after travelling to distant places. The Newars of ancient Nepal travelled long distances for trade. As they moved about in far off places and mingled with different types of people, most of them would come back sick with some disease. In order to prevent such diseases from spreading to the community, it was a custom to isolate themselves before returning to their homes. Once they show signs of health, the chief priest would examine them and subject them to a purificatory ritual before sending them to their homes. The self-quarantine routine was an important part of Nepali Culture during the Malla Dynasty and was practiced until the last century.
The word kṛmi in Sanskrit means that which migrates from one location to the other. This term covers pathogenic organisms in general, but also includes microbes. One category of kṛmi is minute, without feet and invisible to the naked eye. The existence of microbes was clearly documented in classical Ayurvedic texts. It is even more interesting to note that these organisms were classified into the natural (sahaja) and pathogenic (vaikarika) . Cakrapaṇi, the commentator of Carakasaṃhita says that the natural organisms and microbes living in the human body have not been counted and this is perhaps a very early allusion to the human microbiome. Modern studies have confirmed that many herbs used in Ayurveda against kṛmis (kṛmighna) have anti viral and anti bacterial activity.
It would be pertinent to ask what medical measures Ayurveda has advised to deal with such epidemic diseases. Interestingly, the Carakasaṃhita says that we will need highly potent medicines to deal with an epidemic and that effort has to be taken to collect and process such medicines before the epidemic scales up. The text advises that as soon as an outbreak is anticipated, people should be administered medicines that enhance their immunity (rasayana) The importance of bolstering one's immune system to survive an epidemic was emphasised in ancient times in Ayurveda.
However, Ayurveda informs us that epidemics are not merely diseases that can be handled just by medical interventions. The texts emphasize that the root cause of an epidemic outbreak is adharma or unsustainable ways of human thought and action that damage the plant and animal life around us, the environment around us and the natural resources available on our planet - From the Ayurvedic point of view, an epidemic comes with a deep message. The message is that we have to mend our ways and find sustainable ways of living and a deeper connection with the Universe. As well as practice compassion to other living forms and even to other human beings and mother earth itself. For this reason, many spiritual practices and compensatory actions are recommended in the Ayurvedic texts for mitigation of the epidemic apart from medical measures. In the aftermath of an epidemic, humans can reflect and introspect and find ways to restore the lost harmony within their own selves, the people and living forms around them and the Universe itself. Caraka also mentions that one should protect onself (guptiratmanah) and relocate to places that are not affected by the disease.