Story begins March 27, 2021. The ship “MV Shanddong SA Zhi” leaves Malaysia for a long voyage which will bring her to São Luís (State of Maranhão) in Brazil. Note in passing that São Luis is the only state capital of Brazil that was not founded by the Portuguese and whose name is of French origin.
During its journey, the ship docks on April 21 in Cape Town in South Africa. The 24 crew members arrive in Brazil on May 14. Among them, a 54-year-old Indian has been exhibiting respiratory symptoms suggestive of Covid-19 for ten days. The diagnosis of SARS-CoV-2 infection is quickly confirmed. The patient is hospitalized in intensive care in a private hospital in São Luís. Respiratory samples from the index case are sent to the Evandro Chagas Institute (IEC) in Belém in the State of Pará.
Of the 24 crew members, 15 tested positive for SARS-CoV-2, of which three were symptomatic. All are placed in isolation and are under medical surveillance. Six biological samples, RT-PCR positive for SARS-CoV-2, are sent for genomic sequencing. This makes it possible to identify the virus as belonging to the B.1.617 lineage, known as “Indian”.
This virus belongs more precisely to lineage B.1.617.2, linked to the resumption of the epidemic in India where it was spotted for the first time in October 2020. This variant was newly named “Delta” by the World Organization of health. The WHO has indeed just renamed the variants of SARS-CoV-2 with Greek letters. The idea is to have names “Easy to pronounce and remember”, while avoiding appellations “Stigmatizing and discriminatory”.
Three different lineages (B.1.617.1, B.1.617.2 and B.1.617.3) are in fact grouped together under the generic name of so-called “Indian” variants. B.1.617.2 became Delta and B.1.617.1 Kappa. The B.1.617.3 variant has not been renamed. Only the Delta variant (B.1.617.2) is currently considered to be of concern, the other two having been demoted to the rank of variants of interest, the WHO announced on Tuesday.
The Delta variant (B.1.617.2) exhibits significantly less sensitivity to neutralizing antibodies, developed by convalescent Covid-19 patients or produced after vaccination. It also partially escapes certain monoclonal antibodies for therapeutic purposes. To date, this “Indian” variant has been reported in at least 51 countries.
The protein spike SARS-CoV-2 virus identified in these sailors contains the T19R, L452R, T478K, P681R, D950N mutations. Outraged this genetic signature specific for the B.1.617.2 lineage, the virus harbors 21 additional modifications in this same protein.
Strengthen molecular monitoring
As pointed out by Mirleide Cordeiro dos Santos and his virologist colleagues at the Evandro Chagas Institute, this is the first detection in Brazil of the B.1.617.2 variant, in other words of the “Delta” lineage. According to them, their report is a “Alert to the spread of this variant in South America”.
According to these Brazilian scientists, who reported their results on May 27, 2021 on the virological.com site, the discovery of these import cases shows “The need for continuous surveillance of travelers in order to be able to detect the real-time propagation of new variants of SARS-CoV-2”, carriers of mutations that can make them more transmissible or pathogenic, or even likely to escape the immune system.
Marc Gozlan (Follow me on Twitter, Facebook, LinkedIn)
READ too : Covid-19: lower sensitivity of the Indian variant B.1.167.2 to vaccines and monoclonal antibodies
To know more :
Cordeiro Dos Santos M, Sousa EC Jr, de Almeida Ferreira J, et al. First reported cases of SARS-CoV-2 sub-lineage B.1.617.2 in Brazil: an outbreak in a ship and alert for spread. virological.com. May 26, 2021.
Guagliardo SAJ, Prasad PV, Rodriguez A, et al. Cruise ship travel in the era of COVID-19: A summary of outbreaks and a model of public health interventions. Clin Infect Dis. 2021 May 12:ciab433. doi: 10.1093/cid/ciab433
On the Web :
Tracking SARS-CoV-2 variants (New WHO nomenclature)
READ too : Covid-19: lower sensitivity of the Indian variant B.1.167.2 to vaccines and monoclonal antibodies
Covid-19: what we know and what we do not know about the Indian variant
–
