Test the healthy not just the sick, Israeli scientists urge
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Expert predicts move from national to regional lockdowns

Test the healthy not just the sick, Israeli scientists urge

Calls grow for swabbing to identify so-called silent spreaders, and build coronavirus intelligence to fight the virus in a ‘smart’ manner

A medical worker wearing protective gear takes a swab from an ultra-Orthodox Jewish man for a coronavirus test in Bnei Brak, March 31, 2020. (AP Photo/Ariel Schalit)
A medical worker wearing protective gear takes a swab from an ultra-Orthodox Jewish man for a coronavirus test in Bnei Brak, March 31, 2020. (AP Photo/Ariel Schalit)

As doctors and scientists breathe a sigh of relief at soaring test numbers, there are calls for swabbing to be expanded to seemingly healthy Israelis.

“It’s important, because you really want to identify the asymptomatic people,” said computational biologist Eran Segal, pioneer of an assessment model that is being used to help Israel manage the coronavirus crisis.

He spoke to The Times of Israel on Wednesday as concern was growing internationally about the issue of so-called silent carriers. Robert Redfield, director of the US Centers for Disease Control and Prevention, said on Tuesday: “One of the [pieces of] information that we have pretty much confirmed now is that a significant number of individuals that are infected actually remain asymptomatic.

“That may be as many as 25%. That’s important, because now you have individuals that may not have any symptoms that can contribute to transmission, and we have learned that in fact they do contribute to transmission.”

The Magen David Adom national emergency service drive through test complex in Ashdod on April 1, 2020 (Flash90)

Israel checked more than 7,439 coronavirus tests on Tuesday, putting it roughly on a par with Britain, a country with seven times the population.

It was a big increase for a testing system that had been stuck in the 5,000 to 5,700 range on most days last week, and which has grappled with a range of setbacks, from Mossad bringing incomplete test kits and a temporary suspension in the publishing of results because of data errors.

But while testing is widening, it is still reserved for people with symptoms, and relies on them contacting health services to report them. Even people who have been entering Israel from areas hit hard by the coronavirus pandemic have entered without testing unless they requested a check.

As such, the statistics ignore those who feel ill and fail to register for a test, and silent carriers. To identify these people, Segal, a researcher at the Weizmann Institute of Science, advocates random testing in some parts of the country — mainly areas with high incidence of coronavirus.

“It should happen,” he told The Times of Israel. “This is already something we can begin to think about, and do very quickly.”

Nadav Davidovitch, director of the School of Public Health at Ben Gurion University of the Negev, agrees. “I’m suggesting this kind of testing, and I know that in the Ministry of Health there are such suggestions,” he said.

Illustrative: A doctor checks a medical ventilator control panel while wearing protective clothing at the Samson Assuta Ashdod University Hospital, March 16, 2020. (JACK GUEZ / AFP)

Earlier this week there were unconfirmed reports that the Health Ministry was to conduct random coronavirus tests at supermarket chains, followed quickly by reports that the pilot program was called off over fears that Israelis seeking a COVID-19 test would flock en masse to the stores.

The Ministry of Health didn’t respond to a Times of Israel enquiry on the subject of testing for asymptotic people, and a Magen David Adom spokesman said that his organization has so far only received instructions to test people who feel unwell.

Testing for the general population is expected to yield a large amount of coronavirus “intelligence” that is useful far beyond updating the overall figure of infected people, said Davidovitch. This will be used, he predicted, to fight the virus in a “smart” manner, and move from a national lockdown to regional restrictions.

He elaborated: “Testing doesn’t just tell us how widespread the virus is, but also potentially gives us intelligence that is far more precise in terms of understanding infection levels in specific neighborhoods and areas.”

Israel has actually been deploying health intelligence aimed at this kind of regional information from the early days of the outbreak. Segal said he knew that Bnei Brak would have a spate of cases long before the current spike there.

Bnei Brak, a Tel Aviv suburb with nearly 200,000 residents, has the second most confirmed cases of any Israeli city, though it is the ninth largest in the country by population.

Thanks to a survey he designed, Segal gets early warnings on different parts of Israel and shares it with the Health Ministry so that it can concentrate its treatment and testing operations in the right places.

Eran Segal (Courtesy)

Some 200,000 Israelis have completed his survey, and it has been replicated in 15 other countries. Respondents describe how they are feeling and report whether they have any coronavirus-like symptoms. Based on data he builds a picture of residents’ health in different areas, predicts where outbreaks are likely, and shares results with the Health Ministry.

“A week-and-a-half ago, long before it was in the news that there were lots of cases in Bnei Brak, we saw an increase in symptoms in there,” he told The Times of Israel. “Likewise we saw it in Beersheba and Jerusalem.

“By identifying these regions ahead of time, so we can get there early, we can mitigate outbreaks in particular regions. By getting the best sources in place I think this survey actually saves lives.”

The Magen David Adom national emergency service at a coronavirus testing complex in Bnei Brak on April 1, 2020 (Yossi Zamir/Flash90)

Segal thinks that choosing specific areas of the country and introducing random testing there would be the logical next step for a state that is already making good use of intelligence.

Davidovitch predicted, that testing won’t just expand in the coming days and weeks, but also change, saying that it will come to include serology — the scientific study of serum and other body fluids — which could potentially reveal whether people have had coronavirus, even if they have since recovered. This is potentially important information, as it would help to build accurate statistics, and could inform people who unknowingly had the virus that they may have some disease-fighting antibodies.

“We’re moving towards decentralizing testing, and later adding serology, to see how infection rates are in different parts of Israel,” he said. “We’ll see if there are places that could have more localized quarantine and places that don’t need lockdown.”

Segal agreed, saying: “Regional lockdowns could be a valuable to tool to help us in an exit strategy from the crisis.”

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