Varied recordings of the corona virus, COVID-19, infection from continents and countries suggest fundamental differences in prevailing conditions and factors at locations to favour or hinder the infectivity of the virus in humans.
This write-up explores possible linkages existing between the pathology of COVID-19 and identified demographic factors in countries currently experiencing the effect of the deadly virus.
COVID-19 is a respiratory disease caused by the corona virus strain, SARS CoV-2, first recorded in Wuhan Province of China in December 2019 and now becoming a pandemic affecting over 170 countries.
The world has record varied effects in terms of infection spread and fatalities across nations. Like all flu viruses, COVID-19 seems to be behaving similar to flu or influenza viruses.
Some of the characteristics identified with COVID-19 virus and similar to influenza viruses include upper and inner respiratory effects, pneumonia inducing effect, high infectivity rates in colder environments, high prevalence among the elderly and people with underlining chronic diseases such as cardiovascular disease, chronic obstructive pulmonary disease, diabetes and hypertension.
Although fatalities have been recorded among all races, age groups, and under different climatic conditions, COVID-19 effect is greatest among people aged 60 years and above, people in colder countries with average temperatures below 20 degree Celsius, and among younger people with one or more of the underlining diseases mentioned above.
Effect of COVID-19 on elderly
Generally, the aging human body tends to have reduced immunity to fight diseases due to lowering efficiency of the cells’ metabolic functions required for growth, maintenance of biochemical or life processes, and repair of damaged tissues caused by internal or external factors.
The aging population is thus confronted with many age related diseases such as hypertension, pulmonary or lung diseases, heart or cardiovascular diseases, type 2 diabetes, and cancer.
These diseases, although can be found in younger people, their prevalence is lower compared with the elderly. Influenza diseases which tend to damage respiratory system of an individual who is infected is severe in the elderly who are likely to have at least one of the underlining diseases.
Older people especially those with chronic pulmonary or lung disease experience severe flu attacks if not properly managed.
The younger people, due to their efficient immune systems to fight diseases and also rarely suffering from any of the underlining diseases experience mild to moderate symptoms when infected with flu or related infectious microorganisms.
Data available from countries affected by the COVID-19 points to overwhelming effect of the disease among the elderly from 60 years and above.
It is also clear from the limited data available that countries with relatively high percentage of the elderly population such as Italy with almost 30% (about a third) of its population above 60 years, as compared to Ghana’s 6.7%, have highest COVID-19 infections and fatalities.
There are also associated risks in such countries where the frail and delicate older persons are kept in nursing homes or support facilities which present conditions for maximum spread of any contagious diseases like COVID-19.
Many European countries including France, UK, Spain, Netherlands, etc and to a lesser extent America and Canada have high aging population compared to nations in the developing world such as Sub-Saharan Africa and Asia which rather have high youthful population and relatively small adult population depicted by a narrow ended pyramid.
This increased population of the elderly in the advanced nations is attributed to 1950-1960 high fertility rate called baby boom after the Second World War in nations mostly affected by the war.
Another factor promoting this high aging population is the drastic reduction in fertility rate in these nations far below the replacement fertility rate of 2.1 children per woman.
Thirdly, the improved health systems in these advanced nations have succeeded in extending life expectancy of the people. In Europe today, life expectancy is 84 and 89 years for male and female respectively.
Another factor, though minor, is the internal migration of Europeans to warmer countries in southern Europe closer to the Mediterranean Sea by people of Scandinavian descent as they age.
This is explained by the elderly dislike for the harsh winters in the northern Europe, and thought to claim lives of the elderly especially through winter flu infections prevalent in such nations.
The weak and fragile elderly people aged 80 years and above have been found to be disproportionately affected by the corona viruses and therefore such class within the population may require extensive care. This must aim at insulating them from getting infected and at the same time providing better supporting systems for those affected.
The youth who tend to have mild symptoms and rather becoming carriers of the virus must be more responsible in their lives to safeguard our older population.
COVID-19 and cold weather
Like common flu, COVID-19, currently, is ravaging in colder countries with outside temperatures below 20 C. Countries such as Italy, Iran, China, Spain and affected States in the USA are either experiencing winter or early spring with temperatures lower than 20 C. Influenza viral infection is enhanced by winter where the cold temperature preserves the viral particles from melting and thus staying longer in the environment.
The cold environment is also drier due to lower humidity to facilitate particle dispersion among the population. Winter is also a time when people stay indoors more often and thus enabling the virus to spread from person to person within the more sociable communities.
The UV component of the sun which kills microbes including viruses is less in the winter. Due to reduced sunshine during winter, vitamin D which is synthesized by the body in the sun, and known to suppress viral infection, becomes unavailable unless diet is supplemented with the vitamin.
Hot climates are thus less affected by winter-inducing flu viruses especially if it is not during rainy seasons of June to October or cold periods of December and January due to the hammattan and cold winds from Europe or Sahara desert.
However, this does not mean that the virus cannot spread at all in hot climates. It can spread in hot environment but at a lower rate and also at a reduced fatality all things being equal.
Also people in hot climates who tend to eat cold foods, and stay in cold air-conditioned spaces are more likely to be affected by flu compared to their counterparts. It is advisable that people tend to eat hot foods and infusions such as tea, coffee and soup more often as the viral effect is suppressed by heat.
COVID-19 and chronic diseases
The scanty data available from countries affected so far show that the few younger people killed by COVID-19, about 90% of them had underlining chronic diseases such as cancer, asthmatic disease, heart disease or diabetes.
As explained earlier, due to high immunity of the young ones to diseases, the corona viral disease is either asymptomatic or cause mild to moderate symptoms. This therefore contributes to over 80% of all infected persons of COVID-19 who may not need any form of treatment at all to recover fully.
Thus young people with other forms of diseases such as asthma, hepatitis, HIV, cardiovascular disease, kidney diseases, and diabetes should be properly managed to avoid the COVID-19 infection as well us supporting those infected to recover fully.
COVID-19 and genetic factors
Although there is no scientifically established genetic background in humans found to be resistant or more susceptible to influenza viruses or the current corona virus COVID-19. However, it is possible that some people may respond differently to the viral infection similar to all other forms of communicable or non communicable diseases.
But what is certain is that, environmental factors significantly play important roles in the modulation of the infectivity of the virus as well as the overall pathology of the disease.
In conclusion, it is inferred from the available data that the COVID-19 infectious disease, behaving like influenza virus, may have varied devastating effects on human populations especially among vulnerable groups of people stratified by demographic factors, environmental conditions, efficiency of existing healthcare systems, and the preparedness of each country or community to deal with the pandemic disease.
The country should therefore consider these factors when planning for any mitigating programmes to safeguard lives of the citizenry.
The author is a biochemist, biotechnologist and Director General of the National Sports Authority (NSA)
BY PROF PETER TWUMASI
