COVID Contact Tracing

Context: Nations are struggling with for controlling COVID-19 pandemic.

Background: Nine months after the World Health Organization declared COVID-19 a pandemic, few countries are wielding contact-tracing effectively. Contact-tracing is one of the greatest tools that countries should deploy and use effectively to contain the outbreak. But, contact-tracers would again rise to the challenge this year, keeping COVID-19 in check as it swept the globe.

In Detail

Across the world, countries have floundered with this most basic public-health procedure. In England, tracers fail to get in touch with one in eight people who test positive for COVID-19, 18% of those who are reached provide no details for close contacts. In some regions of the southern states of India, more than half of people who test positive provide no details of contacts when asked.

These statistics come not from the first wave of COVID-19, but from November, long after initial lockdowns gave countries time to develop better contact-tracing systems.

The reasons for the failures are complex and systemic. Antiquated technology and underfunded health-care systems have proved ill-equipped to respond. Wealthy nations have struggled to hire enough contact-tracers, marshal them efficiently or make sure that people do self-isolate when infected or that they quarantine when a close contact has the disease.

And overstretched contact-tracers have been met with distrust by people wary both of health authorities and of the technologies being deployed to fight the pandemic. Meanwhile, researchers who are keen to draw lessons from contact-tracing operations are stymied by a dearth of data.

String of failures

The textbook version of contact-tracing starts with someone testing positive for COVID-19 and isolating themselves. A contact-tracer interviews this person to find out who they might have exposed while infected, usually from 48 hours before the positive test, or before symptoms appeared.

Like Close contacts exp those who’ve spent more than 15 minutes close to the infected person are of special interest, but anyone who shared public transport or an office space might qualify. Tracers then call or visit those contacts to tell them they need to quarantine, so that they don’t pass the virus on to more people. The chain of transmission is broken.

But, In reality, failures occur at every stage of this test–trace–isolate sequence. People get COVID-19 and don’t know it, or delay getting tested. Positive results can take days to be confirmed. Not everyone who tests positive isolates when requested, one survey in May found that in the United Kingdom, 61% of people who were self-isolating said they’d left their house in the past day1.

People can’t always be reached for an interview or don’t provide details of their close contacts. And not all contacts are reached, or are willing to comply with quarantine orders.

Finding Contacts

In South Korea, authorities use data-surveillance techniques to get around the problem of people being unwilling to disclose or unable to recall close contacts. A law passed in response to an outbreak of Middle East respiratory syndrome (MERS) in 2015 allows authorities to use data from credit cards, mobile phones and closed-circuit television to trace a person’s movements and identify others they might have exposed to the virus.

Information about cases is published online, an approach that allowed the country to avoid broad lockdowns and worked very well. Still, in March, the Korea Centers for Disease Control issued guidelines limiting the release of ‘excessive’ information, after regional governments published maps of infected people’s routes in too much detail.

Tracers in Vietnam also use extra data such as Facebook or Instagram posts and mobile-phone location data to check a person’s movements against those reported to contact-tracers.

Against the Clock

The WHO’s benchmark for a successful COVID-19 contact-tracing operation is to trace and quarantine 80% of close contacts within 3 days of a case being confirmed, a goal few countries achieve.

But even that’s not quick enough, transmission is too rapid and the virus can spread before symptoms emerge. Some analist suggests that even if all cases isolate and all contacts are found and quarantined within three days, the epidemic will continue to grow.

He says that in a single day, 70% of cases need to isolate and 70% of contacts need to be traced and quarantined for the outbreak to slow, defined as each infected person passing the virus to fewer than one other, on average.

But there are ways that contact-tracers can get ahead of a rapidly spreading outbreak. One is to cast a wider net around each case, so that second-order contacts, ‘contacts of contacts’ are traced and quarantined, in Vietnam, tracers sometimes reached out to third-order contacts if a case was identified late in its infectious cycle.

Conclusion

A handful of places stand out as exemplars of successful contact-tracing, including South Korea, Vietnam, Japan and Taiwan. Many of these have cracked down on COVID-19 early, isolated infected people and their contacts and used personal data such as mobile-phone signals to track obedience.

Not all of those techniques are transferable to countries now struggling to contain massive outbreaks. But they still provide some lessons.

Measures that work include tracing multiple layers of contacts, investigating outbreak clusters and providing people who are advised to quarantine with safe places to do so and with financial compensation.

Technology might help, too: from software that streamlines conventional contact-tracing efforts, to smartphone apps that alert people that they might have been exposed to SARS-CoV-2.

Connecting the Article

Question for Prelims : Which of the following statements is/are correct regarding World Health Organization ?

1. It is a specialized agency of the United Nations.
2. It created an Independent Panel for Pandemic Preparedness and Response to tackel Covid pandemic.

Select the correct answer using code given below:

(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Question for Mains : What is contact tracing for COVID-19? How the digital platform can help in it ? What steps were taken in India in this regard ?