A new variant of the Human Immunodeficiency Virus (HIV) is circulating in Brazil today, according to a study by the Federal University of the state of Bahia (northeast) and the Oswaldo Cruz Foundation.
In the publication of the journal Memorias del Instituto Oswaldo Cruz, the researchers reveal that they found four records of the recombinant virus in the country, in the states of Bahia, Rio de Janeiro and Rio Grande do Sul.
So far, no infections with this variant have been reported in other countries.
According to the study, the new variant combines genes from HIV subtypes B and C, which are predominant in the South American giant, which is why it is called a recombinant virus.
“What is striking about the emergence of these recombinant forms is the double infection rate. Individuals are contaminating and recontaminating,” says biologist Joana Paixão Monteiro-Cunha, co-author of the research.
He explains that for variants such as the one described in the study to emerge, two subtypes must be found in the same host organism and reproduce, mixing genetic characteristics of both.
According to Paixão Monteiro-Cunha, recombinant viruses can be unique when found in a single individual who has undergone reinfection, or they can be viable or circulating when they become transmissible versions. This is the case of the newly discovered variant, named CRF146_BC.
The recombinant virus was discovered in 2019, during a population study in which researchers, including Paixão Monteiro-Cunha, analyzed around 200 samples from infected patients treated at the Hospital das Clínicas in Salvador, the capital of Bahia.
After finding the variant, they compared the virus’s genome information with public databases containing HIV genetic sequences.
“We had three other samples in these databases that had exactly the same dynamic structure as the virus found in Bahia,” the researcher recalls.
He points out that none of those identified is the “patient zero” of the variant, the one infected twice by two HIV subtypes that recombined. The four cases are already the result of the transmission of CRF146_BC.
It is not known whether the variant has greater transmission or virulence, that is, whether it progresses more quickly to the phase of the disease, called Acquired Immunodeficiency Syndrome (AIDS).
According to Paixão Monteiro-Cunha, the researchers only had access to the clinical picture of the first case discovered in Bahia and the patient was under treatment with antivirals, with no indication that the recombinant virus is resistant to the drug.
It is estimated that one million people are currently living with HIV in Brazil.
