Indian researchers have found that countries with poor hygiene, sanitation and low quality of water supply seem to have had a lower number of deaths due to COVID-19 when compared to richer countries that do better on these parameters.
The researchers also cautioned that their research doesn’t promote poor hygiene conditions but merely hopes to study the varied effects of the same. Dr Shekhar Mande, Director General, Council of Scientific and Industrial Research (CSIR) said that the findings can lead to the exploration of “immune training with possibilities of microbiome therapies.”
The study titled “The mortality due to COVID-19 in different nations is associated with the demographic character of nations and the prevalence of auto-immunity” was conducted by researchers from the National Centre for Cell Sciences (NCCS) and Chennai Mathematical Institute, along with the Council of Scientific and Industrial Research.
The paper has been published in medRxiv, but hasn’t been peer-reviewed yet. This indicates that the research contents have not been evaluated yet and hence shouldn’t be used to guide clinical practice.
They took into consideration all publicly available data for 106 countries, on several parameters like demography, the prevalence of communicable and non-communicable diseases, BCG vaccination status, sanitation parameters etc. They ran multivariate linear regression models and found that incidence of communicable diseases correlated negatively with COVID-19 mortality, while demography, improved hygiene and higher incidence of autoimmune disorders correlated positively with COVID-19 mortality.
Analysis of COVID-19 deaths and sanitation
Mande, who is a co-author of the research paper said, “Per million population (deaths) number appears to be high in countries that are richer and having high GDP and (in) countries with low GDP, less number of people are dying, which is very paradoxical.”
Mande said that the percentage of people above the age of 65 is higher in countries with high GDP. Such people are considered to be at greater risk of being fatally affected by COVID-19. They also found that the prevalence of auto-immune diseases is higher in richer countries.
According to Mande, auto-immune diseases like multiple sclerosis, type 1 diabetes mellitus, psoriasis, rheumatoid arthritis, asthma etc. are prevalent in richer countries since they have very good sanitation facilities like basic drinking water and no open defecation among many others.
“So all these parameters (demography, prevalence of auto-immune diseases and sanitation) combined together account for the fact that countries with higher GDP have higher death per million (due to COVID-19) than countries with lower GDP,” Mande said.
The research noted that poor hygiene and lack of sanitation actually lead to more communicable disease burden in countries with low GDP. Hence, it was reasonable to expect parameters for sanitation and safe drinking water to correlate negatively with COVID-19 deaths.
They were surprised to find a contrary result. Sanitation parameters correlated positively with COVID-19 outcome. “It is, therefore, perplexing to note the positive correlation of sanitation parameters with the COVID-19 CFR,” the study said.