Facebook data helps secretaries predict Covid waves

You must be used to guiding yourself in the pandemic through data on cases, deaths and hospitalizations for Covid (if not, you should). But there are other ways to observe how the health crisis is progressing. One of them is what people talk about on Facebook.

No, researchers are not reading random comments from your aunt on the social network and seeing how often users post videos of kittens.

The idea is to send a kind of symptom questionnaire to users of the social network, chosen to compose a minimally representative sample.

What is interesting is that, according to the researchers, reports of flu symptoms, that is, compatible with those of Covid, manage to, to a certain extent, capture the developing pandemic situation. And also preview official data, as it takes a few days between a person having symptoms, looking for a test and the result entering the government system.

The explosion of positive responses from December to now stands out, when the ômicron variant began to gain ground in the country.

According to the platform, on November 23, 1.6% of people who responded to the survey were talking about flu-like symptoms. On January 10, it was 7.8%, a growth of 4.8 times.

The last day on the Social Networks and Covid-19 panel, a partnership between Conass (National Council of Health Secretaries) and Vital Strategies, an international public health organization, is January 13 — at that point, the curve had a small decline, with 7.6% of people saying they have symptoms.

On Monday (24), the moving average of Covid cases, according to the consortium of press vehicles, reached 150,236 infections per day, on the seventh record day of the entire pandemic.

According to Carlos Lula, president of Conass, the answers to this questionnaire prevented a “completely blind flight” and helped to guide public managers in December and January, amid the blackout of data from the Ministry of Health, when an explosion in the number of of people pointing out flu symptoms on the dashboard.

“When we noticed that it was at the level of a growth trend, that this curve would in fact be aggressive, we had already gathered the secretaries, already discussed with them and everyone had already started to reprogram their health network”, says Lula.

“Today, what exists in the whole country is people returning to the ICU bed, equipment that was closed for Covid returning to Covid.”

According to Pedro de Paula, executive director of Vital Strategies in Brazil, case data arrive with delays, which vary from location to location, in the Ministry of Health system.

“You realize that the pandemic is moving in a different way with almost a month of delay and, in the Facebook data, although it takes a day to respond, three [dias] to upload [no sistema], you have a week delay and you can anticipate in a week or two, at least, the trends of the dynamics of the pandemic”, he says.

Renato Teixeira, technical consultant at Vital Strategies Brasil, says that the idea of ​​the system was to advance a change in the behavior of the pandemic in the country. “What draws our attention is if this trend was falling and suddenly starts to rise. Then we are on alert”, says Teixeira.

Using the interaction of people on the internet to analyze the pandemic is not unprecedented. Something similar could be seen in simple Google searches.

At a time of rising cases of coronavirus, it is also possible to observe a growth in searches for related subjects. Since the holidays, the search for “Covid symptoms” has increased exponentially, for example.

“They can say: ‘Ah, but extracting data from Facebook is not valid to want to monitor a public policy,'” says Lula. “We managed, even with the blackout of data from the Ministry of Health, to look at the curve of increase in cases since the end of the year”, he counters.

The Social Networks and Covid-19 platform was launched in March 2021, with development since the previous year. And Brazil is not the only place where it is operating.

In the US, information on whether or not mentions of symptoms have grown or not has data even for counties and cities. In Brazil, the maximum granularity is by state (for which there are not always enough answers to be able to compose the local picture, according to the research methodology).

Online questionnaires take eight to ten minutes to complete. There are questions about fever, cough, fatigue, body pain, as well as behavioral questions, about wearing a mask, using public transport and even if you went to an event with more than ten people in the last few days, among many others.

Of course, those chosen daily to respond to the survey are not necessarily representative of the population, considering that only Facebook users (and consequently with internet access) fill out the questionnaire.

The research is also carried out with the support of Facebook’s public health team and researchers from the University of Maryland and Carnegie Mellon University, both in the United States.