The Nigeria Centre for Disease Control (NCDC) says about 55 different lineages of COVID-19 are known to be circulating in Nigeria and they are “changing rapidly”.
The centre made the disclosure in a statement on Friday.
The NCDC noted that the diversity of the virus strains indicates “multiple introductions of the virus” into the country from different parts of the world.
“As at February 14 2021, there are about 55 different lineages of SARS-CoV-2 known to be circulating in Nigeria and they are changing rapidly,” it said.
“The diversity of SARS-CoV-2 strains indicate multiple introductions of the virus into Nigeria from different parts of the world and adds to evidence of community transmission in different states of Nigeria.”
According to the NCDC, all viruses naturally mutate over time, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19).
“Since SARS-CoV-2 was first identified, thousands of mutations have arisen and will continue to do so, allowing new strain lineages of the virus to evolve. The vast majority of mutations will have little impact,” the centre said.
“But every once in a while, a virus mutates in a way that helps it survive and reproduce better than its progenitors. Viruses carrying these mutations can then increase in frequency due to natural selection.
“When mutant viruses have some advantage, they are referred to as ‘variants of concern’. Advantage to the virus conferred by these mutations, which lead to the classification of ‘new variants’ into ‘variants of concern’, can manifest in the following ways: a. faster or more efficient transmission b. increase risk of severe disease or death c. escape immunity from past infection d. escape immunity from vaccination, or e. evade detection by existing tests.”
The NCDC disclosed that a total of 29 cases with the B.1.1.7 strain, which was first described in the UK and shown to be linked to increase in transmissibility, have so far been detected in Nigeria. It described this strain as a ‘variant of concern’.
“These strains were detected from cases in Lagos, FCT, Osun, Oyo, and Kwara and Edo States. All samples with the B.1.1.7 variant strain were collected from patients between November and January 2021,” the centre said.
It further stated that, on February 11, 2021, some recent SARS-CoV-2 genomes were seen to have distinct mutations and characterised as a new variant B.1.525.
As of February 17, 2021, the NCDC said these have been reported from United Kingdom (44), Denmark (35), Nigeria (30), United States of America (12), Canada (5), France (5), Ghana (4), Australia (2), Jordan (2), Singapore (1), Finland (1), Belgium (1), and Spain (1).
“The first detected B.1.525 case in Nigeria was in a sample collected on the 23rd of November from a patient in Lagos State. So far, this has been detected among cases in five states in Nigeria,” the centre said.
“B.1.525 cases have also been reported in other countries in travellers from Nigeria. Currently there is no evidence to indicate that in Nigeria. Therefore B.1.525 is a new strain, but not yet a variant of concern and further analysis is ongoing.”
The NCDC advised Nigerians to continue to adhere to safety guidelines because one way to prevent viruses from mutating is to prevent their transmission.
“The public health measures to control this virus is the same, irrespective the variant. Please continue to avoid close contact with others, wash your hands regularly using soap and running water, wear a mask properly, keep a distance of at least two metres from others,” it added.