All humans have coronavirus, but… —Professor Olaleye
Professor David Olaleye is a virologist with over 25 years experience in research at the University of Ibadan. In this interview with Sade Oguntola, he expounds the new Coronavirus that is ravaging developed countries, how individuals can be protected from it and why the risk of its spread in tropical regions of the world is reduced.
Why should Coronavirus (2019-nCoV) be an issue for us in Nigeria?
Any disease-causing germ should be of concern to anyone in every part of the world, particularly because of our large population, level of hygiene, and our weak health infrastructure.
In Nigeria, we have a lot of human traffic. Travel today is so fast and rapid in the country. A large number of people come in from different parts of the world and also move out. So a problem in one place is a problem in all the places and so everyone must really be concerned.
Where did Coronavirus come from; any possibility that it was an old virus that mutated or has jumped from an animal to human?
We have many viruses that are similar to the Coronavirus, remember the Severe Acute Respiratory Syndrome (SARS) virus that started also in Asia about 2002. This new Coronavirus is about 80 per cent homologous to SARS.
All animal species, including humans, have different Coronavirus and coronaviruses from other animals infect human regularly. That is why we have emerging and re-emerging virus. So you may end up with an infection from a particular virus from different sources.
There is also the possibility of a virus recombining and then emerging as a new one. A virus can also mutate. Also over a period of time, the virus can change its genome into another form that is slightly different to bypass its’ host immune pressure. That is one of the unique properties of viruses.
When this occurs, the body’s antibodies will not be effective any longer to that virus, even though the cellular arm of the immunity has been initially primed. That is how we come about emerging and newly emerging viruses.
Take, SARS another coronavirus. It becomes infective outside of its host, causing disease in them. Also, consider shrew, a rodent the Yorubas call eku asin, it is a host to a strain of the rabies virus. They go around with this strain of rabies virus but do not develop rabies.
But when they bite other animals, including humans, they transmit the rabies virus to them and so the person or animal beat comes down with rabies.
Many wild animals are host to many organisms. So when man intrudes their environment, man becomes exposed to such a virus. Because man’s immune system is not prepared for it, the man runs into trouble.
It is the same with Lassa fever that is ravaging Nigeria today. Mastomys natalensis, a rodent with long tails and many mammary glands is the reservoir for Lassa fever. It is different from the rats many see running around the house.
Many people cannot differentiate between the two that is why it is important to be careful of all rodents.
Mastomys natalensis lives in the wild. It sheds the virus in its urine and faeces. When the urine dries up, it is aerosolised and can then inhale. Also, if the rodent bites a human, it could pass on the virus too.
This animal also gets dislodged from the wild because of bush burning or when people go hunting. When people spread cassava and other food items on the highway to dry, these rodents also come out looking for food. They also defecate and urinate there, making the food item infected.
When packing the food item, an aerosol is created and the person ends up inhaling the virus with it. The same is with Coronavirus.
Is there any possibility that this new Coronavirus has been transferred from an animal to human?
That has been established in Wuhan City, from the particular market where they sell and buy different species of wild animals. You remember in 2002, when we had the bird flu problem, it started at the live birds’ markets in Nigeria.
Epidemiologists traced the early index case of Coronavirus to someone that visited this market and suggested the virus had jumped from animal to humans. What is left is to determine the exact animal the virus jumped out from.
The other side of it is when people become infected from this animal reservoir; the next major mode of transmission is human to human. Coronavirus is a respiratory virus, so it is not all the reported cases that the affected person had visited the market. They had picked it up from an infected person who they had close contact with.
During its incubation phase, they shed and spread the virus to infect others. So, if the person speaks, sneezes or coughs, the virus is released into the air.
Does it mean that during the incubation period, there would not be any sign or symptom of this infection?
There is always a sign because there will be inflammation of the airway. As such the affected individual may experience things like raise body temperature and sneezing, which many people would assume to due to many things.
It is important not to overlook the fact that when there is an outbreak of a disease, everybody’s level of suspicion should go up and as such people become conscious of what goes on around them.
It is better to go to the hospital once there is a fever or any respiratory problem to rule out the virus rather than wait until a major problem may have developed. Early detection ensures the progression of the disease if confirmed can be arrested and managed effectively.
But a report said that Coronavirus (2019-nCoV) is symptomless in some individuals.
Again, I will not blame those individuals because they are hypersensitive. They may invariably develop symptoms if they have been in contact with somebody that is infected. What is worth doing is to walk to the hospital and have a check done after being in contact with any suspected case of Coronavirus.
Then we must remember that there are also some Coronavirus infect that humans. Some people might also have developed an antibody to other coronaviruses that are cross protecting, limiting the multiplication of this new Coronavirus after they have become exposed.
In such a person, you may isolate the Coronavirus but the person will have no sign or symptoms of the disease.
How about government’s attention to Coronavirus?
A lot of preparation is going on by the government to prevent the new Coronavirus, as it was when there was an outbreak of SARS, Avian flu and pandemic flu.
Coronavirus, like SARS, broke out and spread in Asia and some other parts of the world during their winter period. That says something about the virus; it transmits efficiently in the cold region.
The virus does not really survive long outside its host in the tropical environment, thus giving us little relief to invariably interrupt its spread in the tropical region of the world. Howbeit, this does not mean that we must not prepare very well for it.
Coronavirus has a very thick envelope that is highly susceptible to many cleaning agents, including detergents, toilet soap, bleach, and alcohol-based hand sanitizers. They can easily be killed using these cleaning agents. So, regular handwashing is important.
One can also carry a small bottle of hand sanitiser for regular hand cleaning. These are things that are helpful in our environment where the virus does not survive very well.