The Ebola outbreak in the Democratic Republic of Congo (DRC) is spreading at an unforeseen scale and pace. Ituri province has recorded the highest number of infections, and two more provinces are affected. Transmission spread to Uganda, but the outbreak there is under control. Though the official case count stands at 695 at the time of writing and 138 deaths have been registered, experts consider this a significant underestimate.

Ebolavirus outbreaks have occurred before, but the strain now causing devastation – Bundibugyo – is effectively a new one. It differs from previous Ebolaviruses in that both belong to different species of the virus. A vaccine exists for the previous form of Ebolavirus, but none for the strain driving the current outbreak. Although the common symptoms are fever, fatigue, muscle pain, headache, and sore throat – followed by vomiting, diarrhoea, rash, and kidney and liver malfunction – the fatality rate of this strain is extremely high: 30–50%.

The World Health Organisation (WHO), assessed the risk level for countries outside Africa as ‘low’.

NWS spoke with the world-renowned scientist Gagandeep Kang, who specialises in virology and microbiology, on several issues concerning the spread of Ebolaviruses. Kang says that countries cannot afford to lower their guard in spite of the WHO’s assessment. She warns that without rigorous airport screening, infected travellers may go undetected.

Among her many achievements, the most notable is the development of an indigenous vaccine for diarrhoea, which was claiming children’s lives globally. She is the first Indian woman elected as a Fellow of the Royal Society, London. Canada's University of Saskatchewan recently awarded her an honorary doctorate, and she has worked with the World Health Organisation (WHO) in various capacities.

The following are edited excerpts of the conversation. Text in brackets are the reporter's own explanations to simplify the responses:

Do you believe that the current outbreak can spread beyond the African continent?

This virus has human-to-human transmission [when one healthy person gets in touch with the skin of an infected person, or touches objects which are contaminated with bodily fluids of an infected person].

However, it does not have a respiratory route of transmission like coronavirus [coronavirus infection got transmitted to other people through respiratory droplets, and therefore, had spread much faster]. So, the current Ebola transmission in that sense can be controlled relatively more easily.

How can international travel influence the spread of this disease to these countries?

It is one thing to limit travel from countries where we have an ongoing ebolavirus outbreak. You know, for sure, that you won’t get cases then.

Another option is to have proper screening at ports [instead of travel restrictions]. Still, one may not show symptoms if the person is screened during the incubation period. [The incubation period of a virus is the duration between when a person gets exposed to the virus and actually develops symptoms, and becomes identifiable as a case].

We know that an infected person will stop shedding Ebola virus and transmitting it to others [in the majority of cases] after twice its incubation period. [This period for this virus is 21 days].

So if one does not show symptoms despite being infected, the case would slip through the cracks during screening, and the person would become sick later [after entering the country].

Yet another concern is that the patient may not have come from one of the countries affected by Ebola, and therefore would not be screened [as most of the airports across the world are screening travellers only from DRC and Uganda]. But the person may have contracted the infection during a prior visit to Uganda and the DRC. Subsequently, if he/she lands in another country not affected by Ebola, and from that country, he/she visits India, let's say. So that person would also not be screened despite having a travel history from DRC or Uganda.

This puts all countries in a really tight spot.

The solution to this is awareness. If people are aware enough, and are honest about their travel history [from DRC or Uganda], they would undergo screening [no matter which country they are coming from].

Even if they are not identified during screening, all countries not affected by Ebola at present [including India] must have proper quarantine and treatment facilities.

But this is a difficult situation. Will Ebola, in this way, not spread to other countries which are assessed at low risk by WHO, and which do not have any Ebola cases?

I would never say that there is no chance of it spreading. But all that a country needs is proper preparation to deal with infected people [whenever they show symptoms and become sick].

As long as there is awareness and ability to test [a suspected case], a country can restrict the size of the outbreak.

What other steps do these countries need to take at present?

Make sure they screen and track incoming travellers from the region. Be prepared with diagnostics specific to this strain of Ebola. Set up barrier nursing [treatment facilities at airports].

After all, this virus is not like coronavirus, where the bulk of cases were asymptomatic.

It is really hard to hide the disease if one has symptoms, and the patient will generally visit a [health] facility when one becomes sick. Such patients require very high levels of supportive care.

It is only supportive care that people infected with Ebola can handle because right now there are no specific treatments [which can also contain the spread of the infection].

Any country should be prepared to have a place where you can specifically look after Ebola patients carefully, because it requires making sure that no other person comes in contact with the infected person.

It is not impossible to do any of these things for these countries.

Does the current outbreak have pandemic potential?

No, unless it mutates quite significantly and changes its route of transmission. Pandemics are all about how patients acquire the infection. Even if the transmission is human-to-human [which is the case with Ebola], the spread of infection can be controlled, as I said before.

So unless there is a significant mutation in the Ebola virus…

By significant mutation, I don't mean a single mutation in the virus. I mean multiple mutations which change the virus’s behaviour completely.

In fact, the chances of it acquiring pandemic potential will increase if the healthcare infrastructure collapses [in many countries], and we forget every lesson that we have learnt about infection control [from previous pandemics].

How did infections rise so rapidly in the DRC and Uganda that it has taken the global health agencies by surprise?

The presence of the government is not very strong [in the affected outbreak areas due to ongoing internal conflicts]. There is a lot of transborder traffic. That is why the outbreak, which started in DRC, has also spread to Uganda.

I think we will see a lot more cases in these areas.

Also, if you remember the 2014 Ebola outbreak, the spread was largely happening in urban areas, and less so in rural areas. Now, we are seeing a higher number of cases in the rural areas. It may seem better because the population density in rural areas is lower than in urban spaces. But the problem is that health facilities are extremely restricted in rural regions.

However, since everyone knows that there's a huge problem, everyone is working together to solve it.

We had Ebola outbreaks in the past too. What explains the huge scale of the outbreak this time?

In the central part of Africa, the medical facilities, particularly the lab facilities, are poor.

We had outbreaks earlier and we had Ebola tests. But this particular strain of Ebola virus, known as Bundibugyo virus [which is causing the outbreak now], is quite different [from previous Ebola viruses]. So the tests which were used in the initial phase of the outbreak could not pick up the Ebola cases. It required genome sequencing [identification of the nature of the virus] to know the exact kind of the current strain [and develop new diagnostic kits thereafter].

The other thing is that this area is endemic [infections which occur regularly] for malaria and other infectious diseases. So when people started dying during this outbreak, it was initially thought that malaria or some other related infections were causing the deaths.

Whatever the count of cases we know even now is an underestimate [because of a lack of new kits at the moment]. So, we will have more detection and more identification of cases.

Some people say that the outbreak would have started earlier than it was declared an emergency by the WHO in May...

People think it probably started more than two months before this declaration. It did not catch attention due to the reasons I mentioned previously.

Are we seeing the peak now [thereby meaning that the cases have reached their peak and the trajectory may start coming down]?

We don't know because these are the areas where it is very difficult to find cases, and not every case will be reported.

People will get sick but many will survive too. They will spread infection. So, tracing contacts of those infected is key here because they might be harbouring infection and, in turn, spreading it to others. The low level of contact tracing, therefore, will make it difficult to control the spread. It remains a big challenge at this moment.