Researchers at the University of São Paulo (USP) reported that they have deepened an investigation into the Brazillian mammarenavirus, sabiá virus (SABV), which causes Brazilian hemorrhagic fever, after the virus was reported again in Brazil after more than 20 years without a record of cases.
The two most recent diagnoses were recorded in 2019, amid an outbreak of yellow fever in the Southeast region of the country.
The name of the virus is a reference to the Sabiá neighborhood, located in the municipality of Cotia, in Greater São Paulo, where the first victim is suspected to have been infected.
There is still a lot to know about the virus. It is not known, for example, what is its reservoir in nature, the form of transmission, or whether it is possible to have transmission from person to person.
According to preliminary data from the study, one of the transmission hypotheses is the “inhalation of viral particles, perhaps from rodent feces”.
“We inferred, based on the other Mammarenaviruses in South America, that the person is likely to be infected by inhaling viral particles, perhaps from rodent feces. But this has not been proven precisely because we have very few cases described”, said physician Ana Catharina Nastri, from the USP School of Medicine.
Before the start of the study, only four SABV infections had been recorded in Brazil.
Two cases were of rural workers who ended up dying as a result of complications from hemorrhagic fever and another two were of laboratory workers who were probably infected while handling the virus. Both survived.
The cases of rural workers, called “Caso A and Caso B” in the study conducted at Hospital das Clínicas, occurred in the cities of Sorocaba and Assis (in the interior of São Paulo). Patients were admitted to Hospital das Clínicas (HC) with suspected severe case of yellow fever.
The first case, a 52-year-old man, presented with symptoms such as muscle pain, abdominal pain and dizziness. The next day, he developed conjunctivitis, being medicated at a local hospital and then released.
Four days later, he was hospitalized again with a high fever and drowsiness. With suspicion of yellow fever, he was transferred to the Hospital das Clínicas. During hospitalization, his clinical condition worsened and he ended up dying.
The second case was a 63-year-old man, who presented with fever, generalized body pain, nausea, and prostration. Symptoms worsened and eight days later he was admitted to the HC with depressed level of consciousness and respiratory failure requiring intubation. He died 11 days after the onset of symptoms.