Covid-19 in Bulgaria: Omicron BA.5 lineage still dominant, XAN detected – NCIPD

Bulgaria’s National Centre for Infectious and Parasitic Diseases (NCIPD) said on October 5 that it has completed the sequencing of 94 samples taken from Covid-19 patients in the country, which showed the BA.5 lineage of the Omicron strain and its subvariants remained dominant in the country.

All 94 samples, taken over a period of time ranging from August 24 to September 14 in 13 out of Bulgaria’s 28 districts, displayed evidence of the Omicron variant or one of its lineages.

The BA.5 lineage and its subvariants, which NCIPD collectively referred to as BA.5.x, is the main driver of the most recent coronavirus wave globally. Initially detected in South Africa in January 2022, BA.5 is categorised by the World Health Organisation (WHO) as a variant of concern lineage under monitoring.

The WHO defines a variant of concern lineage under monitoring as a subvariant that shows sign of “transmission advantage” to other lineages and has “additional amino acid changes that are known or suspected to confer the observed change in epidemiology and fitness advantage as compared to other circulating variants.”

BA.5.x was found in 73 cases or 77.7 per cent of the total sample size, compared to 72 per cent of the samples in the previous batch sequenced by NCIPD and announced on September 26.

The remaining samples showed evidence of several other lineages of the Omicron strain – two cases of BA.2.x and 18 cases of the BE.x and BF.x lineages, which are a subvariant of BA.5, NCIPD said.

NCIPD said that it also detected the first case of XAN, a recombinant lineage of BA.2 and BA.5.1 strains. The patient, a 76-year-old woman, recovered from the illness.

(Top photo: Military Medical Academy)

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The Sofia Globe staff

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