Scientists from the University of São Paulo (USP) identified two cases of infection with the sabiá virus (Sabv) in the interior of the state, while analyzing possible samples of yellow fever, in 2019. Both patients died as a result of complications caused by the infectious agent – which causes a type of hemorrhagic fever and was not identified in Brazil for 20 years.
Published in scientific journal Travel Medicine and Infectious Disease, the study that points to the resurgence of the sabiá virus was led by the Instituto de Medicina Tropical (IMT) and Hospital das Clínicas (HC), both from the USP School of Medicine (FMUSP). “The patients presented hepatitis, bleeding, neurological alterations and died”, say the authors.
“We did this study during the yellow fever epidemic [em 2019]. So, in cases where we were not able to make the diagnosis, we went after other viruses”, details doctor Ana Catharina Nastri, from Hospital das Clínicas, for the USP Journal. “To our surprise, we found these two cases to be extremely rare,” she adds.
There are currently no other known Sabv cases known to exist. “We did not find subsequent infections when we used serological and molecular tests to assess close contacts,” the authors note. In addition, other possible infections have not been documented in recent months.
What do we know about the sabiá virus?
So far, science has described some types of mammarenavirus in South America, but the sabiá virus is characteristic of Brazil. “Some of these viruses have the most well-known viral cycle, while our thrush virus has very little data”, says Dr Nastri. For example, “we still don’t know what its reservoir is in nature, the form of transmission, and whether there would be infection through human-to-human contact”, she points out.
Until then, Sabv cases were identified in Cotia, in 1990, and in the municipality of Espírito Santo do Pinhal, in 1999. In common, the two cases occurred in the rural area of the state of São Paulo and led to the death of patients as a result of of hemorrhagic fever.
The other two previous infections occurred in laboratory workers who most likely became infected with the virus while handling the samples. In this case, the two technicians survived.
Why is the infectious agent given this name?
It is worth explaining that the infectious agent has nothing to do with the thrush. In green, the virus only received that name because the first case was identified in the Sabiá neighborhood, in the city of Cotia. In the history of science, associations of this kind sometimes take place.
Two new cases of the lethal virus in Brazil
Now, the two new cases of the lethal virus were also identified in the interior of São Paulo – in the cities of Assis and Sorocaba –, after suspicion of a serious case of yellow fever. “The clinical part is very similar to what we had seen before [nas infecções dos anos 1990]and between the two new cases, the manifestation was also very similar”, comments Nastri.
Next, check which signs and symptoms were identified in at least one of the patients:
- Muscle and abdominal pain;
- High fever;
- Renal insufficiency.
- Neurological dysfunctions;
- Respiratory failure.
In both cases, it was possible to identify a significant impairment of the liver and organs associated with the production of defense cells, which may facilitate the emergence of secondary infections. This fact makes the initial diagnosis even more difficult and compromises the individual’s chance of recovery.