Scaling the Covid-19 Dharavi model
By: Vishal Patil
Tags: Dharavi, Covid 19, Automation, Corona, Coronavirus

The success of Dharavi model has demonstrated that proactive handling of covid-19 could yield a much better result than a reactive model which seems to be the case now.

What is special about the Dharavi model?

Dharavi model used non invasive medical devices for quick and early screening of the residents. This helped scale up screening without need for a complete lab tests which are still facing difficulties. Though the screening techniques cannot replace lab tests but are a good complementary tool along with lab tests to control covid spread.

I will be discussing the following topics in the remaining part of the post

Need for screening

Dharavi model

Extension to the Dharavi Model

Technical part of the implementation

Cost per person

Discussion on resources

Need of automation

Is there anything left out?

Why we need screening to handle covid?

Despite the fact that we are testing more patients, the above graph points to the fact that the positivity rate has also increased which is a cause of concern and shows the need for method like screening to complement lab testing.

What is the Dharavi model?

The BMC took special efforts to control spread of covid-19 in Dharavi. The BMC people went door to door asking residents for symptoms like fever. They used thermal scanners to check temperature of the residents and also checked their oxygen levels using oximeters. A healthy person generally has oxygen levels above 95%, so anyone with an oxygen level below 95% was quarantined. [1]

This effort yielded amazing results and the spread of covid-19 was controlled to a great extent. The doubling rate of 18 days in April improved to 43 days in May and slowed down to 108 and 430 days in June and July, respectively. [2] This was despite the fact that the area has people using shared sanitation facilities.

Some businesses were then allowed to open in the area.

Can the Dharavi model be replicated in the entire country?

This has it own set of challenges and a set of people looking to take advantage of the new rules. Though people can look to break the new rules there are ways to use technology and statistics to check such behaviour.

The phobia surrounding covid-19 test/screening needs to be removed and a train of thought saying we should get tested/screened to save the lives of our near and dear ones needs to be propagated.

Extension of the Dharavi model

We need to screen people based on a few parameters that relate to the likelihood of getting infected by covid-19, like:

Frequency of external travel / employment need

Body temperature

Hotspot or containment zone

Any other symptoms like shortness of breath

Category 1:

Daily travel outside of home or a job in the transportation or retail sector

People employed in healthcare related services or at hospitals

Factories and offices

Body temperature indicating fever

People living in and around hotspot or containment zones

People displaying other symptoms related to pneumonia or covid-19

People who fall in this category could be screened twice or thrice a week for their temperature and oxygen levels as they have high risk of acquiring and spreading the virus.

Factories and offices that are open should be mandated to carry out the test for their employees/workers and put data in the systems for better implementation and reducing reliance on government machinery to handle everything. Many thoughtful industrialists might themselves be open to adopt the idea for their own good.

Category 2:

People not satisfying the above criteria of category 1 and having disease, ailment, disorder that could affect recovery after getting infected by Covid-19 like lung disease patients

Family members of people who stay with people belonging to category 1

Senior citizens or age > 55

People belonging to this category could be screened atleast once a week as they have some likelihood of catching covid-19 or their recovery getting affected post covid infection.

Category 3:

People not belonging to category 1 or 2

These people could be screened once in two weeks.

The technical part of the screening model

We can build oximeters very easily. These oximeters need to be connected to a smartphone to store the temperature and oxygen level of a person in the cloud, without someone having to enter the values manually. To reduce the effort of entering the name of a person and maintaining the records, the government/authorities could just make it mandatory to use Aadhar card number or Aadhar virtual ID for this screening. This can reduce the per person screening time to less than 2 minutes, including sanitizing for next persons screening.

Cost per person for screening

A point to note is that a single lab test worth few thousand rupees can be performed only for one person, but oximeters and thermal scanners can be used for many patients. Thus the cost for screening a person also reduces drastically. Few thousand spent per oximeter or thermal scanner can screen thousands of people reducing the cost to less than a rupee, considering only the equipment cost. Add the cost of the technician handling everything and the cost rises to few rupees per person. But mind you, this screening is no alternative to lab test for confirming infection, it only can only complement lab tests and act as a check.

Do we have sufficient resources to carry out this effort?

Lets handle this question in two parts

Do we have sufficient oximeters? Do we have the required manpower?

Do we have required number of oximeters?

As soon as the word of oximeter being used spreads, there are chances of its availability getting affected, may be for artificial price increase by affecting supply on purpose. Instead of banning sales of oximeter, they could be priced at very high rate in retail market and we could get more oximeters for the public use, with the money thus obtained. Anyone wishing to buy an oximeter should be required to pay a premium for it until sufficient oximeters are available publicly. This extra price paid by willing customer could be used to get more oximeters for community use.

The DIY/maker community could be encouraged to make some of the parts, just as they got going into making facial shields or ventilators.

Phased implementation with criteria like spreading rate and positive percentage can help target the appropriate areas to begin such a work.

Do we have the required manpower?

In this task we could fall short of nurses, asha or other ground workers, but technology could come to our rescue in this effort.

With automation we will not need nurses or asha workers to carry out the task and free them for actual work. Any educated person with some training would be able to handle the task. Also some effort will be required to sanitize the devices used after screening of every person.

Though the use of Aadhar might raise privacy concerns, the court and the government could look at a greater good for the society until a solid secure implementation of such a platform is achieved.

The need for automation

Automation combined with IT can increase the rate of screening by reducing the time to enter data or search and categorise it as and when needed. Also ready availability of data to the local, state or national authorities simultaneously can enable appropriate allocation of resources.

Is this model foolproof?

Definitely not. There are many nuances which have not been mentioned.

The biggest being how to avoid spreading when huge swaths of population comes for test daily or weekly or monthly, needs careful planning.

There are many other small things, but they would just increase the length of this post. Thank you!

References:

[1] https://theprint.in/opinion/dharavis-unexpected-covid-success-story-has-lessons-for-delhi-other-crowded-cities/441726/

[2] https://m.timesofindia.com/india/explained-how-mumbais-dharavi-flattened-the-covid-19-curve/amp_articleshow/76910062.cms

Please feel free to suggest improvements, point to mistakes or assumptions via comments, message on Linkedin https://in.linkedin.com/in/vishalpp or Twitter: twitter.com/vishalpp

Though I tried searching for scientific references with regards to SpO2 for early COVID screening, I could only find a wearable based reference on medRxiv, so I had to rely on references from media outlets for the information.