Contact tracing is essential to break COVID-19 transmission

Individuals must help slow the spread of the virus, while national and community systems must work hand in hand.

Healthcare workers examine a resident during a house-to-house medical campaign as they conduct contact tracing amid the coronavirus disease outbreak in El Salvador [Reuters]

At the beginning of the COVID-19 epidemic, even before it was a pandemic, the World Health Organization (WHO) began advising countries about testing and contact tracing.

While most countries got on board with testing, many in the developed world were less receptive to contact tracing.

Some countries believed they were well organised enough to be able to manage any epidemic. They saw contact tracing – something used successfully to help track and contain outbreaks of Ebola in West Africa and the Democratic Republic of the Congo, and the Plague in Madagascar – as a mechanism only poor countries use.

They were completely wrong.

In its simplest form, contact tracing is about finding and testing all the people who have had “contact” with an infected person. And in doing this, we can more effectively track the spread of a virus and help to contain an outbreak.

The reason we need to do contact tracing is to rapidly detect the secondary cases around an infected person. When we do that, we are able to stop transmission. And by finding these contacts, these new infected cases from the primary person’s contact list, we give each of them more time to survive the disease because they are detected early enough to get the right care.

Contact tracing is not an isolated intervention, however. It fits within the overall context of field epidemiology. We do contact tracing knowing we are already able to do an investigation around every single case.

For our interventions to be successful, we need to link a community-based surveillance system with a centrally-based system in every country. This means we cannot just have a national system. We need a decentralised operation, to make sure that people can analyse information locally and take action to adjust the response on a daily basis.

I worked in the DRC during the world’s second-largest Ebola epidemic which began there in 2018. The DRC is a country plagued by a very poor healthcare system, conflicts involving armed groups, political violence, poverty and poor infrastructure. It was a challenging health intervention.

There were something like 3,000 informal health facilities in the Ebola-affected region. So in doing contact tracing, we had to have a satellite operation with big teams, all working with the community which was also fully involved. At some point, our teams were following up to 300,000 contacts. And if you took the contacts of contacts, there were millions of people to watch and monitor. At a certain point, even the most renowned global experts were completely discouraged, telling us we could not stop the outbreak because it was endemic. But we never gave up.

Despite all the challenges, health workers managed to control the Ebola outbreak. And contact tracing was crucial to identifying cases, finding contacts, and contacts of contacts, and helping to break the chain of transmission.

Many health systems around the world are hospital-based systems. This means that by the time a case reaches a hospital, it is already too late because the patient has contaminated many other people in their community.

For a pandemic like COVID-19, we need an approach accompanied by surveillance and contact tracing. There has to be real risk communication with citizens, and capacity building for communities to get locally organised to protect themselves and protect others. While responding on a national level, governments should also invest in preparedness in areas that are less affected or not affected, and not just focus on the hotspots. This will help prevent the introduction of new flare-ups.

The lessons from other disease outbreaks we have dealt with show us that work has to be done in the community and in hospitals. We need a comprehensive package of real field intervention to be able to stop an outbreak.

Some developed countries, like Germany, started doing contact tracing near the outset, and this helped them identify and monitor potential cases. But many societies that do not have a culture of responding to epidemics are not used to the infrastructure of surveillance and contact tracing. If we look at Europe, for example, before COVID-19 we cannot remember the last time they had an epidemic, apart from perhaps the seasonal flu.

It is also very difficult, in some countries, to mobilise the population and get individuals to do the right thing. It is only when people start seeing so many cases and then they start accepting that they need to wear masks and socially distance.

In not understanding the immediate benefits of things like contact tracing, most developed countries did not put systems in place for it. Eventually, these countries tried to start, but in some cases, they felt it was too late or complex. But it is never too late for any country to adjust such a tactic using the community.

Even when there is no structure in place for a community to get organised, people should be able to self-monitor themselves and their contacts. There are new technologies, the widespread use of mobile phones and even specific applications in some countries. Even in a low-resource setting like the DRC, we are able to use technology that only needs a phone and some data to share information.

Applications themselves are just tools to help us. But we can never replace the human resources needed to do contact tracing. Essentially, we need people who understand the process to interact with the community, with individuals, to ensure the right approach is being used for that setting, to analyse the information the process yields and to ensure quality control.

Everybody will have to go about contact tracing. Because if you give up contact tracing, it means you give up investigation. Without contact tracing, we do not know exactly where we are; we do not have the right data; we do not have the evidence we need to divert the course of the virus.

And importantly, as we get closer to a vaccine, we need to understand where the risks of infection are highest and who the most vulnerable contacts are in each country. We know we will have to wait to get the multiple millions of doses needed to vaccinate everyone. And while that happens, we will need to find and vaccinate those who are most at risk first. Contact tracing is how we find them.

The views expressed in this article are the author’s own and do not necessarily reflect Al Jazeera’s editorial stance.