Just days ago, the Zika virus strain responsible for the outbreaks in Brazil was detected in Africa for the first time. With more than 7,000 suspected cases of Zika in Cape Verde, the World Health Organisation said it was concerned that the latest strain was spreading and was “on the doorstep of Africa”. Our writer sat down with Dr Ahmed Kalebi, CEO of Lancet Laboratories East Africa and a consultant pathologist who spoke on what the outbreak could possibly mean for Kenyans.
We are seeing re-emergence of the Zika virus, many years after its discovery in 1947. What kind of a virus is it?
For a long time zika was relatively unknown. It was discovered in the Zika forest in Uganda. At that time, Yellow Fever was the big thing and researchers were working with animals in the Zika forest trying to understand the disease in the 1940s. They noticed that some monkeys would get a fever for a short time and then disappear. But when they injected the infected blood to rats, it would damage their brains. So the researchers realised this is a Neurotropic virus (one capable of infecting nerve cell) and started looking at it more closely. That was in 1947. Later, the first case was reported in Uganda of someone infected with the zika virus. Samples were taken to CDC (US Centre for Disease Control) who were able to identify and match it to the same virus that was described in 1947.
Some years later, another case was discovered in Polynesia (Pacific region), and later in the Philippines and Americas. But the reality is that most likely, zika is all over in what we call the Sylvatic cycle (occurring in or affecting wild animals).
How does it spread?
It mainly circulates in the wild among monkeys and other animals in the forest, just like Ebola, which is mostly confined in animals like bats and monkeys. What happens is that through human contact with wildlife, you get this cycle that moves from wild to human – the wild cycle - causing transmission. Zika is transmitted by the aedes eagypti mosquito, which bites people during the day.
Do we have the aedes eagypti mosquito in Kenya?
Yes. There are all over. It’s much more common than the malaria-causing mosquito.
How has the current outbreak evolved?
Up until 2007, there were less than 20 cases ever described in humans. Then in 2013 and 2014, there was an outbreak in the Polynesia affecting more than 3,000 people. Even then, there was not so much outcry because people recovered and a few got the Guillain-Barré Syndrome (GBS) which causes nerve damage. Another subsequent outbreak occurred in South America in 2015 starting in some areas of Brazil.
Apparently, via an article I read online, after an epidemiological trace was done, Zika was introduced to Brazil through a team that had gone to the country to participate in a canoing competition. One of them had zika symptoms and mostly likely was responsible for the outbreak. It just takes one person to introduce it to an environment thats fertile for it.
It didn’t look like a big deal when it started, but some months later, a doctor noticed an increase in microcephaly - babies born with shrunken heads. Then he noticed that the peak in the number of such babies, coincided with the peak of Zika in that area. Meanwhile, Zika was spreading north to other areas progressing towards Colombia.
Zika somehow is related to microcephaly and the World Health Organisation took notice and it became a public health emergency of international concern.
Is there now evidence that this virus causes microcephaly?
There’s a Dutch lady who visited Brazil and returned home this year. While she was being routinely checked at 32 weeks of pregnancy, an ultra sound confirmed the baby had severe deformities in the brain and spinal cord.
She decided to abort and her amniotic fluid was tested. They took brain tissue and were able to isolate the Zika virus.
Zika causes not just microcephaly but also other anomalities like the babies growing small.
They are born with propensity to getting things like dementia, schizophrenia, nerve damage and eye damage, only that microcephaly stands out, you can’t ignore it.
Do all infections lead to microcephaly?
No, we have had hundreds of thousands of people infected and hundreds of women pregnant but not all of them having microcephaly. In fact, in Colombia we have not had a single case of microcephaly despite the outbreak of zika.
It is alleged that the virus in Brazil, or the mosquitoes, could have been genetically modified.
In French Polynesia, we didn’t see an increase in microcephaly. So the question is, why are we seeing that in Brazil? People speculate could it be a different strain of zika or a biologically engineered Zika. But they sequenced the entire genome of zika and compared it with to the one in Polynesia and it is exactly the same. So it’s not genetically modified.
Why does it flourish in Brazil?
Because they have the aedes mosquito, a warm environment and over crowding. This means that if someone came with the virus to Kenya tomorrow and introduced it here, the possibility of an outbreak is very high.
You recently speculated that Kenyans may be immune to the virus. How did you conclude this?
In this part of the world, if you check the blood of many people, they have been exposed to Zika before, and so they have the antibodies. They must have been infected and their bodies cleared it. So the theory is that we have an ongoing zika infection but it’s not virulent (doesn’t cause sickness) or is in small quantities and you don’t really get sick.
So that’s protective. People become immune to it. If you go to Kibera, where I come from, you find children eating dirty food on the streets but do not get diarrhoea. But if you get someone from Lavington to do the same thing in Kibera, they will get diarrhoea, yet it’s the same bacteria.
Nobody has been found to have the virus in Kenya, but people have been found to have the antibodies.
Are we able to test for the virus in Kenya?
Upto now, there has been no commercial tests available, across the world. Commercial means as a laboratory, you can go buy it from a manufacturer and start testing it. But now a lot of labs including Lancet, are doing a polymerase chain reaction (PCR) test. It checks the viral genetic material, the RNA. Now it’s just a matter of getting the prima, the right molecule, so we can begin to test for Zika.
The problem is, you have to do it right and validate it, so it takes time. So at the moment it’s only Kemri and Lancet that are doing Zika testing. The test itself takes a day or two.
Do you think we could have a vaccine soon?
It will take at least five years. You know unlike Ebola, zika is almost completely new.
To be very honest, if the outbreak happened in Africa, we might not have gotten all this attention but because it’s in Brazil and the Rio Olympics are coming up in August this year, there is a big fuss.
Is there treatment?
There’s no treatment for zika. The virus can also be transmitted sexually for up to 28-62 days after infection. So use of condoms is advisable if an infection is suspected. If after 14 to 20 days someone has not had any signs, then they are clean. But I’m also not worried because the outbreak is now. By the time we go to Rio it will have planked away. They are also actively controlling and killing mosquitoes to minimise the spread.
What’s your advise to Kenyans on how to stay safe.
Kenya should raise awareness among pregnant women
and those planning to get pregnant, of the complications with the Zika virus and encourage people to protect themselves against mosquito bites and sexual transmission. If they wish to travel to Brazil, they should be on high alert