SP has higher genetic variation of HIV in children and adolescents

Researchers at the University of São Paulo (USP) and the Federal University of São Paulo (Unifesp) observed greater genetic variability of HIV in children and adolescents than indicated in previous studies with adults. According to the investigators, this suggests that the profile of the epidemic is changing in Brazil, which may have implications both in production and in diagnostics and therapy definition of vaccine development. Blood samples were collected from 51 seropositive born between 1992 and 2009 in the state capital.

According to the project coordinator, Professor Sabri Mohamed Saeed Al Sanabani, Institute of Tropical Medicine, USP, there are two types (1 and 2) virus causing AIDS. Type 2 is mostly restricted to the African continent. Type 1, which prevails in the rest of the world, is divided into several groups, and the main M, N, O and P. Group M, which causes major epidemic known today, in turn, has subtypes. "There is still the recombinant forms, which are the mixture of genetic subtypes of virus," he explained.

Study published in 2011 by the same group of scientists shows that subtype B is the most common in the country. This was attested to the analysis of blood samples from 113 HIV-positive men with a mean age of 31 years and also through the analysis of viral DNA. Over 80% of patients were infected with this virus subtype. The most recent survey made with the age 4-20 years old, on the other hand, showed a prevalence of only 52.4%.

Children and adolescents who participated in the study, coordinated by Professor Regina Succi, were accompanied by the Service Centre of the Department of Pediatric Infectious Diseases Unifesp. In all cases, transmission occurred during pregnancy, childbirth or breastfeeding. Almost 40% of them were infected with subtype BF1 mosaic, a mixture of genetic subtypes B and F1. Other 9.5% had subtype F1.

Al Sanabani highlights that this result was not expected initially. "We thought it was finding a genetic type equal to that of adults. We were surprised with this high diversity," he said. The researcher explains that this genetic variability can be explained by the fact that most mothers are a risk group, with many sexual partners and history of drug use. "These recombination phenomena in the case of children, it reaches 40%, the result of this mixture of viruses. Mothers were infected, probably by more than one virus," he said.

The teacher explains that the greater the diversity of HIV, the harder it is to develop a single vaccine to combat the disease. There is also effects the development of a therapy, since the mutation may cause the virus to acquire resistance to treatment. In addition, there may be failures in disease diagnosis, as the change in genetic codes may lead to the identification of the virus. "We need to know what is circulating in our environment. If HIV has the ability to change or recombine, it may even be another type of AIDS," he warned.

Although the mutation is part of the life cycle of the virus, a very efficient treatment reduces viral load in the patient and reduces risk of transmission. "We are basing our cases in children and adolescents in São Paulo and we know that here is quality treatment available. Needs to be done to get it that way to other regions, not to exacerbate the problem," he argued.

The coordinator reported that a new study is underway to characterize the types of HIV circulating in four states, Pernambuco, Rio de Janeiro, São Paulo and Minas Gerais. "Through high-scale sequencing of the HIV genome, we see the virus from end to end.'s A way to know who is and who is pure recombining" he said.

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