Specialists discuss contact tracing as a tool to plan action against COVID-19

Researchers from Brazil, Mexico, Nigeria and the US took part in a webinar organized by FAPESP to discuss privacy and data security and how people’s behavior shapes the pandemic

By Maria Fernanda Ziegler  |  Agência FAPESP – With no COVID-19 vaccine available yet and no well-established treatment for the disease, there is a growing consensus among public health experts that “test, track, trace and isolate” strategies, with the associated technologies, are necessary to reduce the transmission of the virus and create conditions for secure economic reopening.

More succinctly called contact tracing, the policy is considered effective for containing any epidemic. Public health authorities aim to slow the spread of infection by tracing the contacts of infected individuals, testing them for infection, isolating those infected, and tracing their contacts in turn.

“Under current conditions, it’s very important to study the views of experts from different parts of the world, especially in order to understand how behavior may shape the progress of this pandemic. This is necessary despite the effort to develop drugs and vaccines for COVID-19, which at best are many months away,” said Luiz Eugênio Mello, FAPESP’s Scientific Director, in his opening remarks to the online seminar “Contact tracing and lockdown easing: effectiveness v. limitations” held on July 1.

In this online seminar, which was the third FAPESP COVID-19 Research Webinar, scientists from Brazil, Mexico, Nigeria and the United States discussed the main challenges to be met in using contact tracing technology.

The participants were told how researchers at the University of São Paulo (USP) in Brazil partnered with the geotracking startup InLoco to map viral transmission hotspots and analyze the effects of social distancing based on location data voluntarily provided by smartphone users.

“We began analyzing people’s movements during Carnival. The cell phone location data clearly showed changes in behavior after stay-at-home orders were issued, as people stopped going to schools, universities, gyms, museums, and so on. The data also enabled us to calculate the stay-at-home percentage required to decelerate the contagion curve so that health services aren’t overwhelmed,” said Helder Nakaya, a professor at USP’s School of Pharmaceutical Sciences.

In another study, Nakaya and his team collaborated with the Institute for Applied Economic Research (IPEA), a Brazilian government think tank, on a time-based study of the transmission of the disease in the state of São Paulo. “The use of these data and other information can facilitate the planning not just of lockdowns but also of easing or reopening strategies,” Nakaya said.

For Leany Lemos, a former planning secretary of the government of the state of Rio Grande do Sul, where she chaired a controlled social distancing program, combating the pandemic requires not only testing and contact tracing (not widely available in Brazil) but also effective communication with all societal groups.

“In March, we introduced six data-driven protocols covering far more than confirmed cases and deaths. We engaged with labor unions and industry associations, as it’s important for everyone to understand the need for stay-at-home or lockdown situations. We also regionalized our action plan, creating 30 health regions in the state according to hospital capacity and numbers of intensive care beds. All this was communicated to the public,” Lemos said.

In Mexico City, researchers observed increased mobility due to two family holidays, Children’s Day on April 30 and Mothers’ Day on May 10. According to Jorge Velasco Hernandez, a researcher at the Institute of Mathematics at the National Autonomous University of Mexico (UNAM), increased mobility on these dates changed the shape of the contagion curve and forced a postponement of the economic reopening plan.

“Everyone knows how important it is to implement social distancing measures or lockdowns in order to reduce mobility and hence transmission of the disease,” Hernandez said. “These two holidays were close together. Children were at home all week, and people went out to buy gifts, take piñatas to the children and visit their mothers. All this significantly altered the expected curve, and economic reopening had to be postponed. These one-off events have to be taken into consideration by governments in their plans.”

In Nigeria, mobility during the pandemic has also been monitored based on location data voluntarily provided by cell phone users. However, according to Iniobong Ekong, Deputy Director for Health Planning, Research and Statistics in the national capital Abuja’s Health and Human Services Secretariat, the need to protect citizens’ privacy hindered the implementation of a contact tracing app to map the transmission of COVID-19 in Nigeria.

“There is a global consensus that contact tracing is crucial to contain the disease, but in Nigeria, we don’t have the wherewithal to test everyone either, and we aren’t able to trace all contacts of infected people, so we developed a strategy that focused on identifying hotspots. However, the tracking and tracing must be done without disrespecting data privacy rules,” Ekong said.

For Pratik Sinha, a physician and researcher at the University of California San Francisco (UCSF) and professor at Washington University in St. Louis, Missouri, big tech companies such as Google and Apple can help provide innovative solutions to the challenges of contact tracing. “The uptake of these apps is hugely important,” he said. “If we don’t have the necessary level of engagement by the public or the infrastructure, we can’t do contact tracing effectively. My question is how can big tech help by supplying innovative solutions and what are the risks to the individuals involved in terms of digital security and privacy.”

All speakers stressed that contact tracing alone does not avoid the need for social distancing. “In technological terms, it’s perfectly possible to track and trace all cases of the disease, but aside from the privacy issues, I believe it’s important not to see these technologies as a means of avoiding social distancing, and they should be used above all as a planning tool,” Nakaya said.

Sinha agreed. “Where we are right now in the pandemic, it’s probably too late for contact tracing to be implemented as a general strategy involving everyone. We don’t have enough tests to screen the entire population. These apps can help us find out which subgroups need to be tested. Meanwhile, we must avoid crowded places,” he said.