Patient movement maps: Kerala's key weapon against COVID-19
Patient movement maps: Kerala's key weapon against COVID-19

Patient movement maps: Kerala's key weapon against COVID-19

Every time a new case was confirmed, it became routine for the people of the district to wait for the map, to identify who was vulnerable.

On March 10, 60 people were under observation for COVID-19 in Kerala’s Pathanamthitta district. The statistics changed exponentially the very next day. A total of 892 people were under observation by March 11. So what changed in one day? The government had published a route map that showed where patients travelled to and initiated contact tracing.

On March 8, a family of five tested positive in Pathanamthitta district. What got the officials worried was that three members of the family, who had arrived from Italy on February 29, had travelled quite extensively in the district.

In two days, the district administration released a flow chart or route map tracing the places the family visited. The map had the duration of each visit, right from the day they landed at Kochi airport until they were admitted to the hospital on March 6. The flow chart was made public on the evening of March 10, and people were asked to alert officials at the district help desk centre if they had been to the same places at the given time frame.

A route map aims to identify primary and secondary contacts of an infected person and place asymptomatic persons in quarantine and test the samples for symptomatic patients.

The route map of the Italy-returned family, who were on a holiday in Kerala, showed that they had visited banks, bakeries, jewellery stores and had even taken public transport. And to be extra careful, maps factor in thirty minutes to two hours extra after a patient's visit. 

The first map released by Kerala

“As soon as we released the route map on March 10, we received 103 calls that day alone. Over the course of the following six days, we received 60 more calls from people. We were able to identify about 1,000 people who may have come in contact and then placed them in quarantine,” an epidemiologist at the Pathanamthitta help desk centre, told TNM.

The health department officials had earlier said that the family was reluctant to share their travel details. “We suggested the idea of releasing a route map using this thread, without revealing any personal details. When we started receiving calls after the first route map was released, we started releasing the route maps for other cases too, using whatever information we had,” said the epidemiologist.

Identifying high-risk, primary low-risk

The idea of a map or flowchart was then done in every other district that reported COVID-19 cases. Every time a new case was confirmed, it became routine for the people of the district to wait for the map, to identify who was vulnerable.

Allowing the public to self-identify also helped Kerala to place more people under home quarantine.

On April 2, Kerala had 265 COVID-19 cases, and 1,65,934 people were in quarantine (home and hospital included).

On April 15, Maharashtra had 2,916 cases and Tamil Nadu 1,242 COVID-19 cases. Though the number of positive cases are significantly higher, the number of people in quarantine in both these states are much lower.

While 69,738 people are in home quarantine and 5,617 people are in institutional quarantine in Maharashtra, Tamil Nadu has 94,450 people in home quarantine and 1,876 under hospital isolation.

When an Italian tourist tested positive for coronavirus in Kerala on March 13, officials learnt that he had been staying in Thiruvananthapuram’s Varkala for 15 days.

The same day, the team of medical officers swung into action to identify the high-risk contacts, conducted telephone interviews and collected the list of the Italian’s co-passengers onboard Vistara UK 897 from Delhi to Thiruvananthapuram on February 27.

“On March 13, we had 40% of the initial information required to prepare the map. The next day, the field staff started collecting more information and collating the list of places and high-risk contacts. The same evening, we put out the first route map of the Italian tourist. On March 15, we updated the map as we identified more primary and secondary contacts,” said a professor at Kottayam Medical College, who did not wish to be named. The professor was part of the team that prepared the route map.

Incidentally, by March 13, the day the tourist tested positive, 226 people were under observation in Thiruvananthapuram district. On March 14, another 308 people were identified. By March 15, when the map was fully updated, a total of 1,449 people were placed under surveillance in the district.

The route map of the Italian tourist

According to experts who worked in teams that identified contacts, a route map helps in identifying the missing links or contacts. 

“We are normally able to identify high-risk contacts and alert them. What we will not be able to identify are the primary low-risk contacts, which are people who interacted with the patient without knowing their travel history or healthcare workers who looked after them. This is where a map helps,” explained Dr Gayathri, superintendent of Taluk headquarters hospital in Malayinkeezhu, Thiruvananthapuram, who is the in-charge of the district investigation team.

In the case of the Italian tourist, the team was able to identify over 110 contacts, which included 30 high-risk contacts. All his contacts were tested and fortunately all of them tested negative for coronavirus.

The calls

According to Dr Gayathri, help centres receive the maximum number of calls within the first two days of releasing the route map. “These are mostly calls expressing their apprehensions regarding their presence at the same place and within the mentioned duration,” she said.

Additionally, more the number of places the COVID-19 patient travelled and halted at, more is the number of calls; for example, if the patient attended functions with large gatherings, including weddings and funerals, or visited a supermarket, unlike visiting a small store. “We get a lot of calls from the staff and customers of public institutions or organisations that the COVID-19 patient had visited,” she said.

Many people call the COVID-19 helpline (DISHA) at 1056 or the Coronavirus Helplines (set up at the Collectorates) mentioned on the route map. Many others call the doctors at the nearest Public Health Centres, who, in turn, alert the district teams.

“The initial route map may not be correct as the dates may vary. In one case, when dates varied while verifying the details, we had to call the banks and then revise the map. To get more clarity, we verify with CCTV footage,” explained Dr Gayathri.

When are route maps needed?

The route maps were mainly released for COVID-19 patients who came from a foreign country and travelled extensively, without self-quarantining, before being tested positive. There were, of course, some exceptions.

For instance, a Congress leader in Idukki district tested positive for coronavirus on March 26. He had no history of travel to another country or state. He was not tested when he initially went to the hospital with certain symptoms. He continued his work as a public servant and travelled

within the district until the testing guidelines changed and he subsequently tested positive. Fearing that as a public figure he had interacted with several people, including politicians, the district administration released his route map to trace contacts.

According to D Sajith Babu, Collector of Kasaragod district, route maps are not required for every COVID-19 case. “A route map is required only when officials cannot ascertain where the person had gone and how many people he may have come in contact with,” he explained.

Kasaragod district had to released only two route maps out of the 184 positive cases so far in the district. Almost all foreign returnees had either gone directly to the hospital from the airport or been at home.

An exhaustive map was released for a businessman who had returned from Dubai and travelled to various places before going to his hometown.

“The man had over 4,000 contacts and did not disclose his whereabouts before being admitted. Besides, he was not disclosing the correct details. If we had published a route map based on factually incorrect details, it would have created more confusion. We had to verify the details he shared and then map his travel. And that was the only case where we required a route map, although it did not really help us” the Collector explained.

The district teams that TNM spoke to added that most patients who tested positive had only travelled from the airport to their houses, and immediately quarantined themselves.

Interestingly, that is one of the reasons that all districts, except Ernakulam, released a route map. Ernakulam district, which has reported about 25 cases so far, saw its first case on March 9 when a three-year-old child from a family that returned from Italy via Dubai tested positive. The parents also eventually tested positive.

As part of the universal screening at the airport, it was detected that the child had fever. The child was immediately admitted to the Ernakulam Medical College hospital while the parents were placed in the isolation ward. The co-passengers and a few airport staff, too, were placed under observation.

If route map is removed from the equation

“Imagine, Person A went to a supermarket and stood next to an infected person. Person A is unaware of this, not even when he starts running a temperature. The person may then interact with his children and elderly members of the family. But, once the route map is published, Person A will be aware of his contact with an infected person, be alert, inform the health officials and get himself tested,” said the professor, pointing out that a route map is an effective tool in the initial containment of the disease.

According to the epidemiologist in Pathanamthitta, “If we do not get these response calls from members of the public, we will not be able to detect if there is community spread, which happens when the source of the infection cannot be traced. We have managed to trace at least 85% of the primary and secondary contacts through the route map and have been monitoring them daily via the call centre for 28 days.”

Further explaining the importance of the route map, Dr Gayathri said, “COVID-19 is a communicable disease that spreads fast. If it was a disease with a longer incubation period (time between exposure to the virus and showing symptoms), we will gradually trace the contact, call them and treat if required. But in the case of COVID-19, there is an urgent need to identify the high-risk contacts and quarantine them soon.”

The professor noted why it is important to release a route map as part of contact tracing as soon as the first two to three cases are reported. “Once there is an established outbreak, that is, exponential growth in cases, these maps are not useful. Taking precautions, assuming the person may have come in contact with others, is the only way and hence the route map.”

Loading content, please wait...
The News Minute