The world is fighting a deadly monster and this is not the first time it is in the grip of such a lethal disease. The question now is whether there is a way to prevent future pandemics such as this Covid-19 one. Can we know in advance which viruses are likely to plague mankind in the future and prevent them? Scientists say with thorough research the world stands a chance to identify its potential attackers early and prepare itself.
The viruses causing deadly diseases, such as Covid-19, are known to have jumped from animals to humans. Scientists, therefore, say the best way to ready ourselves would be to study this process to give us clues into what the future holds. Which animals are carrying the viruses? What triggers the jump?
It is a dangerous job, which means coming into contact with potentially deadly viruses, but there are groups of scientists in Kenya and around the world willing to take this risk and protect mankind: The virus hunters.
In Kenya, the virus hunters are holed up in different labs across the country trying to figure out how to outsmart the pathogens. A group of the scientists tells HealthyNation that Kenyans are placing themselves in the sniper’s scope of these viruses. Kenyans’ appetite for meat, constantly moving into animal habitats increases their interaction with nature.
These diseases, the scientists say, kill through zoonotic transmission. This means they usually live in and affect animals, but jump to humans and kill them too.
SIXTH EBOLA SPECIES
As a virus hunter, virologist Omu Anzala from the University of Nairobi and his colleagues often grab bats, snakes, camels and other animals from wildlife to study whether they harbour any virus that can jump to people. Once they catch the animal, for instance a bat, they take swabs from its mouth and blood samples, which they then take to their labs to check for viruses. To ascertain they have found a new virus, they check against a global database where every known virus is recorded.
One of those viruses, a sixth Ebola virus species - the Bombali ebolavirus— was recently discovered in Kenya’s Taita Hills and Busia in the Angolan free-tailed bat. Prof Anzala and his colleagues from the University of Helsinki in Finland were among the scientists who discovered this virus before it could jump to humans.
While the Bombali ebolavirus has not moved to humankind, Prof Anzala tells HealthyNation it is a matter of “when, not if”. His team wants to be prepared when this happens, so that they can study its transmission mode and plan for measures such as vaccines and prevention.
This is how they are staying ahead of the game: In Busia where the Bombali ebolavirus was found, Prof Anzala and his colleagues are naggingly checking patient records for “unexplained fevers” in the community around where the bats were found in the forest and on the roofs of huts.
This obsession with the viruses is justified. The pathogens have managed to leave a trail of deaths and there are only five families of the viruses: Coronaviridae, Paramyxoviridae, Filoviridae, Flaviviridae and Orthomyxoviridae.
Covid-19, which has infected more than 11 million people and killed more than half a million worldwide since it was first reported in China in late 2019, is also in this group. In Kenya, the coronavirus has infected more than 7,000 people and killed over 160.
Then there is Ebola, which killed 11,323 in Guinea, Liberia and Sierra Leone between 2013 and 2016. Zika, Lassa fever and Severe Acute Respiratory Syndrome (Sars), which have all seen outbreaks in recent years, have also had a grim ripper effect. Apart from the loss of human lives, were economic losses. Ebola cost the world $2.8 billion (Sh298.2 billion) in losses. Other scientists such as Dr Marianne Mureithi, a microbiologist at the University of Nairobi who is also part of this network, have been studying how people’s interactions bring them into contact with these viruses. “For something like Covid-19, it is still not known how it came to people and, therefore, we must be fast and aggressive in our surveillance,” she says.
According to the World Health Organization, Rift Valley Fever, a disease that causes abortions in animals, was reported in sheep in the region in 1931. However, it was not until between November 2006 and March 2007 that the disease moved to people, killing 234 in the northern area. In this case, those that succumbed to the disease may have touched a sick animal or eaten its products.
Salome Bukachi, a professor in medical anthropology at the University of Nairobi, has studied what drives people to handle animals the way they do. In her study of the attitudes of those in Ijara, the epicentre of Rift Valley, the residents told her “they believed that infections in humans occurred as a result of mosquito bites and had little to do with their consumption of meat, milk and blood from infected livestock”.
Whatever the reason for interacting with animals, Eric Fevre, professor of veterinary infectious diseases at International Livestock Research Institute (Ilri) and the University of Liverpool in the UK, has a simple explanation for it.
He runs the urban Zoo Project, a study that seeks to find out how microorganisms land on people’s food systems through interacting with the environment, animals and people.
“When people walk into forests for farming or hunting for food, they are disturbing the ecological balance and the consequence is increasing viral exchanges first from animal to human, then from human to human, sometimes on a pandemic scale,” he says.
The viruses, often sleeping dogs which should be left to lie, are shaken from their natural host and when they come out, they find a new weak host - human beings.
Some of these intrusions into animal habitats are justified. Kenya National Bureau of Statistics recorded that the country’s population stood at 47.6 million in 2019, and these are so many mouths to feed especially with proteins, and so many heads to be housed. So, people are thronging urban centres, where the demand for food and housing is forcing farmers to grow more crops, look for food animals and construct houses. The farming, the constructions and the search for food pushes Kenyans closer to animals and very soon they are going to leave those forests with something deadly, says Prof Fevre.
Sometimes, the intrusions are just pure greed and unchecked power that makes man poor at taking care of natural resources: they are building exotic holiday destinations in the middle of forests or animal paths. Nature fights back directly through human-wildlife conflict or, sometimes, indirectly through these viruses.
People only realise the danger of this interaction when death comes knocking. A 2016 report by the United Nations Environment Program (Unep) estimates that a new zoonosis - a disease that jumps from animals to people - is discovered every four months all over the world.
Due to this uncertainty, of where the next killer disease will come from and which animal will carry it to mankind, the WHO released a list of diseases that are a high risk to the public due to their potential to spark an epidemic and the limited treatment available to combat them. In that list was an ominous “Disease X”, and a year later Covid-19 was the disease.
That it is a matter of time is not the scariest part. In a report published last week by Ilri and Unep on zoonotic diseases and how to break the chain of transmission, researcher Delia Grace and her colleagues mention that four in five of the disease-causing microorganisms are “multi-host”. That means apart from the primary animal that is known to transmit it, say a bat, the pathogens can live in other animals as well.
Take the bat and the dog, for instance. Some dogs survive rabies, which is 99 per cent lethal to mankind. For years, bats have been fingered in some of nature’s deadliest viral killers. They have carried some deadly pathogens like Ebola, Marburg, Hendra and Nipah. However, as they carry the viruses around, the bats rarely, if ever, fall ill.
Sam Kariuki, a professor in microbiology at the Kenya Medical Research Institute (Kemri), says some viruses are able to find other microorganisms and “marry” them to create novel versions of itself in a process called “reassortment”.
In some cases, the result can be a deadlier virus that will not respond to whatever arsenals scientists have for it (say, vaccines). So, just like the biblical demon that finds a clean house and brings seven other demons to possess the house, any person that gets this newly assembled virus may not survive.
It certainly does not make it easier that we have improved our modes of transport. In a presser to journalists, Grace said that normally the virus would just die out because it would claim its victims in a certain location. “Now, because of planes and movement, the diseases move from one population to another very fast,” she said.
Virus hunting is an endeavour that needs money. It is estimated that analysing one tissue sample costs about $50, about Sh5,000. Then there is the equipment needed for these tests and salaries for the staff.
Kenyan researchers, however, lack these kind of funds from the government and have to rely on donor funding.
One such programme that funds the researchers is Predict, run by the United States Agency for International Development (USAid). Predict was started in 2009 after the 2005 H5N1 bird flu scare. Until the cutting of the funding in October 2019, it had cost about $207 million. Predict has trained about 5,000 scientists in 30 Asian and African countries including Kenya and Uganda.
It was mainly to hasten the hunt for zoonoses. Up to 2019, USAid announced that the initiative had collected over 140,000 biological samples from animals and found over 1,000 new viruses, including a new strain of Ebola. Predict’s Global Operations Officer David Wolking said the spillovers, where these diseases move to people, are going to be more common now that people are encroaching animal habitats.