‘Hygiene Hypothesis’: Why Rich Countries Faced More Deaths?

Recently, a study titled ‘Hygiene hypothesis’ has been released pointing out the possible reasons for more COVID-19 related deaths in developed countries as compared to lower-income countries. The main aim of the study was to understand the reasons behind the unexplained greater immunity of lower-income countries as compared to rich nations.

Key Points

• The study was conducted by Indian scientists with the Council of Scientific and Industrial Research (CSIR) Director-General as one of the authors.
• Chennai Mathematical Institute’s Rajeeva Laxman Karandikar and Pune-based National Centre for Cell Sciences’ Bithika Chatterjee are the co-authors of the study.
• Hygiene hypothesis considered data till June 29, 2020. During this time, over 5 lakh deaths were reported and out of this 70% were in high-income countries.
• The study considered various parameters to find out the possible reasons for more deaths in high-income countries. These indicators were- population density, GDP, sanitation and hygiene, human development index rating, demography, and prevalence of autoimmune diseases.
• After considering all the factors, the scientists found that the Hygiene hypothesis can be a possible reason for this.
• As per the ‘Hygiene hypothesis’, people in nations with low sanitation standards get exposed to communicable diseases at an early age and hence develop stronger immunity. This helps them to fight diseases in life. This phenomenon is known as ‘immune training’.
• Contrary to this, people in richer countries have better access to healthcare and have better sanitization standards from the beginning. Hence, their immune systems are unexposed to such dangers and are easily attacked.

As per the study, Covid related deaths are correlated with the prevalence of autoimmune diseases, demography, and sanitation.