This story is a part of the TNM COVID-19 reporting project. To support this project, make a payment here.
Several states in India took on contact tracing on a war footing in the first wave of COVID-19 in 2020. The momentum of the exercise waned as the COVID-19 infections spiralled amid the second wave. With cases gradually declining and new variants of the novel coronavirus being reported, especially the Delta Plus variant, states are back to the exercise of tracing the primary and secondary contacts of all patients, including those whose samples sent for genome sequencing returned positive for the new variant. This time, however, the exercise is more streamlined, and even hectic for some districts.
For example, the Pathanamthitta district of Kerala has reported one case of the latest Delta Plus variant in a ward at the Kadapara panchayat, which has a test positivity rate of 18% (percentage of tested samples that turn positive). The state has reported three cases so far, with two patients in the Palakkad district. According to Dr Sheeja AL, the District Medical Officer (DMO), district health workers in Pathanamthitta have been carrying out contact tracing. However, amid the new Delta Plus variant being detected and due to the ongoing COVID-19 vaccination drive, they had to bring another team on board, the Jagratha Samithi (vigilance committee). The team was initially engaged in surveillance, to check if contacts were adhering to the isolation protocols.
“We roped in the Jagratha Samithi team and gave special training after the new coronavirus variant was detected, since our district health workers, including ASHA workers, are also involved in the vaccination drive. Besides, the contact tracing is a time-consuming exercise,” Dr Sheeja told TNM. Jagratha Samithi comprises Anganwadi workers, volunteers (including college students), Kudumbashree and ASHA workers. This team goes beyond household contacts and traces the external contacts of the COVID-19 patient(s). The team traces the contacts, furnishes their details on a database and Google spreadsheet. Based on this information, the panchayat officials carry out COVID-19 tests for those contacts.
Among the contacts tested, eight family members of the patient with the Delta Plus variant tested positive for coronavirus. “We are seeing more transmission than the severity of the variant in such cases,” said the DMO, who added that Pathanamthitta has earlier detected 52 cases of the Delta variant, one Beta variant (first detected in South Africa) and a few cases with Alpha variant (first seen in the United Kingdom).
When the ongoing second wave of COVID-19 infections hit the country, especially between late March and early June 2021, several districts slowed down the contact tracing process due to the surge in caseload. Once the cases reduced (attributable to the lockdown), a few officials told TNM that they swiftly swung into contact tracing, which has helped them quickly trace COVID-19 patients who are infected with the Delta Plus variant.
— Gaurav Gupta (@BBMPCOMM) June 30, 2021
Here's the Info Graphic summary and Overall zone-wise status of Covid-19 cases in Chennai. #Covid19Chennai #GCC #Chennai #ChennaiCorporation pic.twitter.com/Dhe13Zax5q
— Greater Chennai Corporation (@chennaicorp) June 30, 2021
The Delta Plus has been classified as a variant of concern by the Union Health Ministry. The Delta Plus variant (or AY.1), which was first detected in Europe, is a mutation of the Delta variant, which was first detected in India. It must be noted that viruses mutate as part of a natural process, with some mutations being capable of affecting the level of transmission. India has detected at least 50 cases of Delta Plus variant as on June 29, with Maharashtra reporting the highest and Tamil Nadu recording 10 cases.
In a letter to the Chief Secretaries of seven states on June 25, Union Health Secretary Rajesh Bhushan said that the Delta Plus variant has increased transmissibility, stronger ability to bind to receptors of the lung cells and could potentially reduce monoclonal antibody response. The monoclonal antibody-based (clone of an antibody that targets a specific cell) treatment is being used on COVID-19 patients with mild or moderate symptoms.
Genome sequencing of one randomly selected coronavirus-positive sample takes a minimum of three days. “Somebody is working on it continuously without lunch or dinner break and no sleeping break,” Dr Pavithra Venkatagopalan, a microbiologist and coronavirologist in Chennai. Genome sequencing is a common process to study the evolution of a virus. Since the pandemic began, several countries, including UK, Australia, have been sequencing almost every positive sample. In India, the sample size is insufficient to find patient zero or the patient who has first had the mutation, said Dr Pavithra, who is the lab director at Care Health Diagnostic Lab.
“It takes about a week to 10 days to analyse one sample. Lab technicians have to extract the RNA, amplify the region to be sequenced and analyse the data. It is a technically challenging, time-consuming and expensive process. The low sample size makes finding patient zero practically difficult, besides the fact that some patients would not have even been tested,” she explained.
Senior virologist Dr Shahid Jameel concurred. “Unless the officials find out quickly whether somebody has the Delta Plus variant, it is not practical. By the time the result of the genome sequencing returns after a week or two, contact tracing remains of no value to the person,” he said. Incidentally, Tamil Nadu’s first case of the Delta Plus variant was of a Chennai nurse, who had tested positive on May 4. However, her sample was confirmed positive for the Delta Plus variant only several weeks later. Similarly, the Pathanamathitta case saw the patient testing positive on May 24, weeks before his sample returned positive for the Delta Plus variant.
Dr Shahid and several district officials pointed out that contact tracing helps in finding out the spread or clusters, and containing it immediately. Speaking to TNM, Gagandeep Singh Bedi, the Commissioner of Greater Chennai Corporation, pointed out that there has been supporting and proven evidence to show contact tracing as an effective strategy during a health crisis, such as the Nipah outbreak and Ebola epidemic.
“Unlike other countries, we are not mandated to do genome sequencing, but we are doing the exercise as surveillance. Contact tracing is independent of the variants detected. Irrespective of the variants, our strategy remains the same, even with the Delta Plus variant. The aim is to stop or break the transmission, not the variant of concern,” said the IAS officer, adding that the Chennai Corporation resumed its contact tracing exercise since the COVID-19 cases have reduced in the last three weeks.
Dr M Jagadeesan, City Health Officer (CHO) of Chennai Corporation, as well as D Randeep, Special Commissioner of Health at Bruhat Bengaluru Mahanagara Palike (BBMP), told TNM that their procedural contact tracing has made identifying patients with variants easier.
In the initial stage of the second wave of COVID-19 in Bengaluru, officials found it difficult to visit patients for contact tracing. Contact tracing was limited to four to five primary contacts.
“Now, as the cases have lowered, with 10 to 12 cases per ward, we are able to reach out to at least 10 primary contacts of a COVID-19 patient and five to six secondary contacts within 24 hours of a positive case being reported,” said the BBMP Commissioner.
He, too, pointed out that contact tracing has nothing to do with the variants. “Genome sequencing happens parallelly. We received information about the variant case a week after it was sent for sampling. We then followed a catch-up protocol,” he said. Elucidating, Randeep said that the team is reactivated to pay a second visit to the particular household where the variant has been detected. “This is to recheck if we have covered our tracks, and recheck if we missed any person on the first visit. We check if the patient with the variant visited anybody in the past week, and ask follow-up questions even to secondary contacts,” he said.
All contacts of the 87-year-old patient with the Delta Plus variant in Bengaluru are negative, except one contact, who was asymptomatic and in home isolation. Apart from state-referred samples, BBMP has tied up with another laboratory for genome sequencing, targeting samples from wards with a high test positivity rate. “This is to see if there is a correlation between the variant and the pace at which it spreads,” added Randeep.
Virologist Dr Shahid stressed that every variant can be protected with a mask and vaccine. “If everyone continues to wear masks correctly, people need not worry about being infected with the variants. There is no data that shows the vaccines won't be effective against these variants,” he said.
This story is a part of the TNM COVID-19 reporting project. To support this project, make a payment here.
Watch: All you need to know about the Delta and Delta Plus variants