Connect with us

Coronavirus Outbreak

Delta Variant Counted For 60 Per Cent Of Delhi COVID-19 Cases In April: Study

The role of the Delta variant in breakthrough infections – or COVID-19 infections after vaccination – has also been found to be big under the study

Delta Variant Counted For 60 Per Cent Of Delhi COVID-19 Cases In April: Study
Highlights
  • Delta variant is, in fact, 50% more contagious than the Alpha: Study
  • No evidence yet of the role of Delta strain in causing more deaths: Study
  • There are more than 12,200 "Variants of Concern" in the country: Study

New Delhi: The rapid surge in cases during Delhi’s fourth COVID-19 wave was mainly driven by the Delta variant, which likely has immune-evasion properties and counted for 60 per cent of the cases in April, according to a new study. The Delta variant, B.1.617.2, is 50 per cent more transmissible than the Alpha variant, B1.117, first discovered in the UK, say researchers from the National Centre for Disease Control (NCDC) and the CSIR Institute of Genomics and Integrative Biology (IGIB).

Also Read: Delhi Man Turns His Car Into ‘Emergency Response Vehicle’ To Help COVID-19 Patients

Prior infections, high seropositivity and partial vaccination are “insufficient impediments” to the spread of the Delta variant, found the scientists. They traced the factors contributing to the scale and speed of the fourth wave that started in April in Delhi and compared them to the preceding three waves last year.

We find that this surge of SARS-CoV-2 infections in Delhi is best explained by the introduction of a new highly transmissible variant of concern (VOC), B.1.617.2, with likely immune-evasion properties, the researchers noted.

The variant may have led to insufficient neutralising immunity in people, despite high seropositivity, and social behaviour may have augmented the surge by promoting transmission, they added. Neutralising immunity consists of naturally occurring antibodies that play an important role in the immune system.

To determine whether SARS-CoV2 variants may be responsible for the April 2021 outbreak in Delhi, the researchers sequenced and analysed community samples from Delhi from the previous outbreak in November 2020 until May 2021 and related it to effective reproductive number (Rt). The effective reproductive number is the expected number of new infections caused by an infectious individual in a population where some individuals may no longer be susceptible.

The yet-to-be-published paper, posted on the preprint repository MedRxiv on Thursday (June 3), noted that the incidence of the Alpha variant was “minimal” in Delhi in January, rapidly increasing to 20 per cent in February, and 40 per cent in March. However, the rapidly spreading Alpha variant was overtaken in April by the Delta variant, first found in Maharashtra, the authors of the study noted.

The proportion of the Delta variant increased from 5 per cent in February to 10 per cent in March, before overtaking the Alpha variant by April, and accounting for 60 per cent of the sequenced samples, according to the paper. This increase in the proportion of the Delta variant was paralleled by a large increase in the positivity rate, the researchers said. The positivity rate in Delhi had jumped to over 36 per cent by April third week, meaning one in every three samples being tested was found to be positive for COVID-19. On April 20, Delhi saw the highest spike in daily cases since the beginning of the pandemic with 28,395 people testing positive.

While much more remains to be done, three takeaways for now are: Delta (B.1.617.2) is more transmissible than Alpha (B.1.1.7), there seems to be greater immune escape and reinfection, and fully vaccinated breakthroughs were disproportionately due to Delta, said Anurag Agarwal, director, CSIR-IGIB in a tweet.

The researchers also found that breakthrough infections – catching the virus even after vaccination — were disproportionately high because of the Delta variant. However, they are yet to determine whether the variant also leads to increased case fatality ratio (CFR). “Overall, we note that B.1.617.2 is capable of creating very fast-rising outbreaks with vaccination breakthroughs,” the authors wrote in the paper.

We would re-emphasise that prior infections, high seropositivity and partial vaccination are insufficient impediments to its spread, as seen in Delhi, and strong public health response will be needed globally for its containment, they added.

The Delta variant of COVID-19 has now become the dominant VOC in the UK and may also come with an increased risk of hospitalisation, health officials in Britain have said.

Also Read: Delhi Gets First Drive-Through COVID-19 Vaccination Centre At Vegas Mall, Dwarka

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

NDTV – Dettol Banega Swasth India campaign is an extension of the five-year-old Banega Swachh India initiative helmed by Campaign Ambassador Amitabh Bachchan. It aims to spread awareness about critical health issues facing the country. In wake of the current COVID-19 pandemic, the need for WASH (WaterSanitation and Hygiene) is reaffirmed as handwashing is one of the ways to prevent Coronavirus infection and other diseases. The campaign highlights the importance of nutrition and healthcare for women and children to prevent maternal and child mortality, fight malnutrition, stunting, wasting, anaemia and disease prevention through vaccines. Importance of programmes like Public Distribution System (PDS), Mid-day Meal Scheme, POSHAN Abhiyan and the role of Aganwadis and ASHA workers are also covered. Only a Swachh or clean India where toilets are used and open defecation free (ODF) status achieved as part of the Swachh Bharat Abhiyan launched by Prime Minister Narendra Modi in 2014, can eradicate diseases like diahorrea and become a Swasth or healthy India. The campaign will continue to cover issues like air pollutionwaste managementplastic banmanual scavenging and sanitation workers and menstrual hygiene

World

22,95,44,435Cases
19,20,52,504Active
3,27,83,741Recovered
47,08,190Deaths
Coronavirus has spread to 195 countries. The total confirmed cases worldwide are 22,95,44,435 and 47,08,190 have died; 19,20,52,504 are active cases and 3,27,83,741 have recovered as on September 22, 2021 at 3:49 am.

India

3,35,31,498 26,964Cases
3,01,9897,586Active
3,27,83,741 34,167Recovered
4,45,768 383Deaths
In India, there are 3,35,31,498 confirmed cases including 4,45,768 deaths. The number of active cases is 3,01,989 and 3,27,83,741 have recovered as on September 22, 2021 at 2:30 am.

State Details

State Cases Active Recovered Deaths
Maharashtra

65,27,629 3,131

44,269 960

63,44,744 4,021

1,38,616 70

Kerala

45,39,926 15,768

1,61,765 5,813

43,54,264 21,367

23,897 214

Karnataka

29,69,361 818

13,769 617

29,17,944 1,414

37,648 21

Tamil Nadu

26,48,688 1,647

16,993 9

25,96,316 1,619

35,379 19

Andhra Pradesh

20,40,708 1,179

13,905 483

20,12,714 1,651

14,089 11

Uttar Pradesh

17,09,693 13

194 0

16,86,612 13

22,887

West Bengal

15,62,710 537

7,741 69

15,36,291 592

18,678 14

Delhi

14,38,556 39

400 21

14,13,071 18

25,085

Odisha

10,21,216 462

4,844 103

10,08,226 560

8,146 5

Chhattisgarh

10,05,120 26

297 0

9,91,260 26

13,563

Rajasthan

9,54,275 12

99 8

9,45,222 4

8,954

Gujarat

8,25,751 14

133 0

8,15,536 14

10,082

Madhya Pradesh

7,92,410 8

90 6

7,81,803 14

10,517

Haryana

7,70,754 8

328 12

7,60,618 20

9,808

Bihar

7,25,907 6

60 9

7,16,188 15

9,659

Telangana

6,63,906 244

4,938 53

6,55,061 296

3,907 1

Punjab

6,01,359 36

304 3

5,84,554 37

16,501 2

Assam

5,98,864 441

5,081 97

5,87,970 338

5,813 6

Jharkhand

3,48,139 14

65 10

3,42,941 4

5,133

Uttarakhand

3,43,405 12

249 18

3,35,765 29

7,391 1

Jammu And Kashmir

3,28,214 145

1,450 11

3,22,345 154

4,419 2

Himachal Pradesh

2,17,403 263

1,715 99

2,12,033 162

3,655 2

Goa

1,75,690 107

886 76

1,71,507 29

3,297 2

Puducherry

1,25,618 101

922 55

1,22,864 46

1,832

Manipur

1,18,870 197

2,174 9

1,14,861 203

1,835 3

Tripura

83,956 51

353 7

82,794 44

809

Mizoram

82,815 1,355

15,363 223

67,184 1,127

268 5

Meghalaya

79,817 150

1,878 18

76,558 167

1,381 1

Chandigarh

65,195 7

44 3

64,333 4

818

Arunachal Pradesh

54,190 64

413 3

53,504 60

273 1

Sikkim

31,014 43

627 27

30,007 70

380

Nagaland

30,959 52

470 3

29,832 46

657 3

Ladakh

20,743 6

144 6

20,392

207

Dadra And Nagar Haveli

10,670

0 0

10,666

4

Lakshadweep

10,360 1

9 1

10,300

51

Andaman And Nicobar Islands

7,607 7

17 4

7,461 3

129

Coronavirus Outbreak: Full CoverageTesting CentresFAQs

Leaving No One Behind

Mental Health

Environment

Join Us