COVID-19: Delta variant dominates Odisha, accounts for 98 per cent of sequenced samples

BHUBANESWAR :  The Delta variant of SARS-CoV-2 that triggered the ferocious second wave in the country seems to be firmly dominating Odisha, accounting for nearly 98 per cent (pc) of the samples sequenced in the State this month.

The proportion of cases with Delta, the highly transmissible double mutant strain, has risen from 21 pc in March to 98 pc in July. Its share was 90 pc in June, 82 pc in May and 48 pc in April.

Although it was initially suspected to have been losing transmissibility in the last week of May as the variant was found in only around 40 pc samples sequenced during the period, further analysis revealed the strain was prevalent in 552 samples that month while all other variants were found in only 116 samples.

The variants are distributed across 30 districts, with highest being reported from Khurda, Cuttack, Sundargarh, Nuapada, Puri, Mayurbhanj, Balasore and Jajpur districts. However, no more Delta Plus has been detected after the only case from Deogarh district sequenced in May first week.

The variant of concern (VoC) as flagged by the National Centre for Disease Control (NCDC), was also found in almost same proportion in the neighbouring states of Chhattisgarh, Jharkhand and Bihar.

Sources said of the 1,588 samples sequenced in Chhattisgarh so far, Delta was detected in 866 samples and Alpha in 25. Similarly, the double mutant was found in 141 and Alpha in six among 190 samples from Bihar while Delta was present in 360 and Alpha in 30 out of 683 samples from Jharkhand.

Of the 2,463 samples sequenced in the State so far, as many as 1,328 samples carried the Delta variant (B.1.617.2), 32 Alpha variant (B.1.1.7) and one Delta Plus variant (AY.1). So far 53,320 samples have been sequenced at 28 national laboratories across the country to monitor the genomic variations in the SARS-CoV-2.

While Delta accounted for about 44.5 pc (23,770 samples) and Alpha 9.7 pc (5191), Beta was found in 328 samples and Delta Plus in 50 samples.

"The Delta variant is now the dominant lineage and the vast majority of the new samples being sequenced are of Delta lineage, from all parts of the country. We have to remain prepared and states have to be careful while easing out of restrictions," said a researcher associated with Indian SARS-CoV-2 Genomics Consortium (INSACOG).

Claiming that the number of cases with Delta Plus infection is not increasing faster than Delta, NCDC Director Dr Sujeet Kumar Singh said a detailed analysis will be shared on Thursday.