GLOBALLY, viruses have once again become topical since the advent of the coronavirus pandemic that began in late November 2019 and spread rapidly throughout the globe.
The COVID-19 pandemic is surging throughout the world, with new variants emerging.
There is talk about the ‘Fourth Wave’ and the Delta variant.
Will mankind contain it?
Zimbabwe seems to be coping well so far, which brings us to the question: What is a virus?
A virus is a very simple micro-organism capable of replicating and mutating within living cells, producing disease.
The term ‘virus’ also refers to the disease caused by a virus, for example flu virus or coronavirus. Figuratively, it may be used to mean a negative or harmful, persistent influence or a human aberration.
Medical dictionaries further describe viruses as “…any of a group of sub-microscopic entities consisting of a single nucleic acid surrounded by a protein coat and capable of replicating only within the cells of humans, animals and plants.”
Many viruses are pathogenic, meaning they are able to cause or produce disease.
Yet viruses are far from simple.
They can invade the human cells, causing ailments as diverse or benign as a wart (mhopo), as irritating as a cold/Flu (chipfuwo), or as deadly as HIV-AIDS, hanta virus, lassa fever, Ebola fever, measles, smallpox or polio.
Ironically, viruses are bundles of genes – strands of DNA or RNA, the very molecules that carry the blueprints for all life forms, which is what makes them so virulent in their disease form.
In replication, clinical viruses are often altered, reproducing stronger strains; hence the subsequent waves of COVID-19 and the expectant Fourth Wave.
Some scientists in the US predict seven waves before the eradication of COVID-19.
While our immune system has been designed to de-activate viruses with antibodies that prevent infection, most Zimbabweans are still oblivious of the severity and virulence of airborne viruses – from the common cold to COVID-19.
Each strain of virus has its own unique configuration of surface molecules.
These enable viruses to gain entry unto hosts by replicating the membrane of targeted cells.
Biologist Richard Dawkins of Oxford University, England, refers to viruses as ‘rebel human DNA’.
Evidently, scientists speculate that viruses originated as primitive self-replicating molecules that later began to parasitise living cells and infecting living organisms, and sometimes killing the cells they invade, such as is the case with polio virus, which can lead to paralysis.
Viruses have plagued mankind since the beginning of recorded time.
In art and archaeology, an Egyptian bas relief, from 1500 BC, depicts a priest with a shrivelled leg; a tell-tale sign of the aftermath of poliomyelitis virus.
In veterinary archaeology, a 13th Century Arabic manuscript shows an image of a crazed dog with tongue lolling, biting a horrified man; evidence that the rabies virus is also centuries old.
Viruses plague every species of life on the planet.
They infect dogs, cats, cattle, goats, chickens, monkeys and mushrooms.
They mottle the leaves of tobacco plants, blight potatoes and stunt the growth of tomatoes.
Viruses even prey on other bacteria.
Some viruses have changed the course of human history.
For example, following European colonisation of the Americas by Spain and Portugal, the native population of the Americas plummeted over a century and a half by an estimated 80 percent (from an estimated 50 million in 1492 to 8 million in 1650), mostly by outbreaks of Old-World diseases, such as small pox, that were hitherto unknown.
Historians believe some Spanish conquistadores carried the smallpox virus that had long existed in Europe, but was new to the western American hemisphere.
The virus ignited a pandemic that is believed to have killed more than a third of the indigenous First World population.
The cause of such devastating outbreaks remained a mystery for centuries until the early 1700s when the newly-invented light microscope revealed the single-celled organism, now known as ‘bacteria’, which proved to cause such diseases as cholera and plague, notably the Black Death in 1347, a pandemic that spread throughout Europe during the following three years.
The death toll was probably about
35 million people in Europe, about one-third of the population.
Towns were especially hard-hit because of their crowded conditions.
Some viruses, such as the yellow fever virus, are transmitted by vector mosquitoes which cause a condition known as yellow jaundice.
Rats transmit the lethal lassa fever virus, identified in 1969.
This virus is incubated in the urine and faecal deposits of rats in the houses they infest.
The blood and other bodly fluids from victims of lassa fever are highly contagious.
Among human viral diseases, none is more widely spread than the common cold.
To date, at least four different groups of the common cold viruses have been identified – these are adenoviruses, coronaviruses, myxoviruses and rhinoviroses, of which each has many varieties. Over 100 distinct strains of rhinovirus alone have been identified.
The human immune system is the body’s major defence against colds and all other viral diseases.
However, if the immune system fails to identify an unfamiliar strain of virus in time, one succumbs to the illness.
This is normally the case with colds/flu viruses that overwhelm us repeatedly because they exist in such diversity.
Viruses are at the apex of humanitarian and global medical concerns today.
COVID-19 is a viral infection.
Viruses, in this case COVID-19, invade and multiply in our noses and throats.
Oral and nasal secretions may contain thousands of virus particles that can adhere on all surfaces, such as doorknobs, table/counter tops, computers, laptops, mobile phones, utensils, cups, bottles and hands —in fact, anything and everywhere that is touched can support viral survival for hours waiting for a hand to scoop them up or a finger to touch a nose, mouth or eyes which are ideal portals of entry for viruses.
Hence the need for stringent hygiene and cleanliness as well as constantly washing and sanitising hands and surfaces of high contact.
Viruses, by nature, are stealthy, stubborn entities.
They can hibernate in the body and remain on surfaces for long periods before detection. Unseen by the human eye, it is practically impossible to know one is harbouring a virus unless medically tested.
Coughs and sneezes are volitant vectors and carriers for the transmission of air-borne virus infections.
Airborne viruses, such as the nouvelle coronavirus (COVID-19), are particularly lethal and hard to contain.
According to virologist Dr Eckard J. Wimmer of State University of New York at Stonybrook: “When a virulent virus such as COVID-19 emerges, modern air and road travel offers the virus a free ride to anywhere in the world,” hence the need to limit groupings and travel.
Despite promises of cures and vaccinations for viruses such as HIV-AIDS and COVID-19, viruses remain a deadly foe to humanity, capable of killing at deadly speed.
Given we cannot prognosticate on the future of COVID-19 and the numerous strains or waves that may result from this virus, our only hope is to follow and adhere to the UN World Health Organisation’s survival guidelines: Get vaccinated, but also mask up; wash up; sanitise; and keep social/physical distancing.
Zimbabwe now needs to vigilantly adjust to the new normal.
The new normal is a new mode of socialisation; a process requiring renewed social/physical distancing initiations in people culturally accustomed to gathering.
Let us hope that in the face of the increased promotion and activity in tourism and reopening of churches, businesses and sporting activities, under the shadow of COVID-19 and its attendant new variants, we can agree on a comprehensive plan that conscientiously limits gatherings and unnecessary travelling.
Our government is mandated by law to protect its citizens.
As a nation, Zimbabwe still needs to take a cautious approach to civic freedom, despite our diligent vaccination programmes.
Dr Tony M. Monda BSc, DVM, is currently conducting Veterinary Epidemiology, Agronomy and Food Security and Agro-economic research in Zimbabwe. He also holds a PhD and a DBA in Post-Colonial Heritage Studies. E-mail: tonym.MONDA@gmail.com