USP investigates deadly virus that re-emerges in Brazil 20 years later – 06/21/2022

A new study, conducted in collaboration with the Institute of Tropical Medicine (IMT) and Hospital das Clinicas (HC), is from the USP School of Medicine (FMUSP), which included two new cases of SABI virus (SABV) infection. Was diagnosed. In 2019, the Brazilian hemorrhagic fever further deepened the investigation of this agent. Earlier, only four such infections were detected in the country, the last one more than 20 years ago. Both diagnoses were made amid an outbreak of yellow fever in the southeastern part of the country.

“We did this study during the yellow fever epidemic, so in cases where we were unable to diagnose, we tracked other viruses,” said HC-FMUSP, infectious diseases division. Physician Anna Katherina Nastri explains. “Surprisingly, we found these two cases extremely rare.” According to him, advances in pathological anatomy, especially in electron microscopy, have allowed for more in-depth study of the Brazilian memarina virus, or Sibia virus, to determine its clinical manifestations, histopathology and the possibility of hospitalization. I’ve got new information. The findings were published in an article in the journal Travel Medicine and Infectious Diseases in May of this year, in which Dr. Nastri became the first author and under the guidance of Professor Anna S. Leon from the Department of Infectious and Parasitic Diseases at FMUSP. Were

Thrush virus

The name Rogzanak refers to the Sabiá neighborhood, located in the municipality of Cotia in Greater Sao Paulo, where the first victims are suspected to be affected. Although several types of Mammarenavirus have been reported in various South American countries, SABV is characteristic of Brazil. “Some of these viruses have the most well-known viral cycle, while our Thrush virus has very little data,” the doctor said. “We still don’t know what its reserves are in nature, how it is transmitted, and whether human-to-human contact causes infection.”

Prior to the study, only four SABV infections were recorded. Apparently, one of them is located in the city of Cotia, in 1990, and the other, in the city of Esprito Santo do Panhal, in 1999, both located in the countryside of the state of Sao Paulo. In both cases, the infection affected rural workers who died as a result of complications of hemorrhagic fever. The other two infections occurred in laboratory workers who may have been infected while dealing with the virus. Both survived.

“Case A and Case B”

A study conducted at Hospital Das Clinicas found two new cases, called “Case A and Case B”, occurred in the cities of Sorokaba and Assos (inland Sao Paulo), respectively, and both patients were admitted to Hospital Das. Was made Clinics (HC) with diagnostic assumption of severe case of yellow fever. The first was a 52-year-old man who passed through a forest in the city of Eldorado (170 km south of Sao Paulo) and began to experience symptoms such as muscle aches, abdominal pain and dizziness. The next day, he developed conjunctivitis, was treated at a local hospital, and was released. Four days later, he returned to the hospital with a high fever and drowsiness. Yellow fever was suspected and he was taken to Das Das Klinkas Hospital.

Upon admission to the hospital, her medical condition worsened until she was transferred to the Intensive Care Unit (ICU), ten days after the onset of symptoms, significant bleeding, renal failure, With low levels of consciousness and hypotension, he died two days later.

Case B refers to a 63-year-old man from Assis (440 km west of Sao Paulo) who suffered from fever, general malaria, nausea and prostration. The symptoms worsened, and eight days later he was admitted to the HC, which required intubation due to loss of consciousness and shortness of breath. Severe left ventricular dysfunction (severe decrease in pumping function of the heart) led to refractory shock and eventual death 11 days after the onset of symptoms.

What we know and what remains to be done.

To perform the diagnosis, the scientists used metagenomic techniques, which made it possible to identify the still unknown viruses by extracting, copying and finalizing the genetic material of the infectious agent. The material is then compared with other organisms in a bioinformatics database that contains information on pathogens from around the world. By confirming the compatibility of the discovery with other types of mammarenavirus virus found in patients and clinical practice, it was determined that it was SABV.

In an analysis of two fatal infections in the study, researchers identified symptoms similar to those registered in 90s cases. “The medical part is very similar to what we’ve seen before, and between the two new cases, it appears. It was very similar,” says Anna Nastri. In all cases, there was a significant defect in the liver and organs associated with the production of immune cells, which may have facilitated the appearance of a secondary infection, further complicating the initial diagnosis.

As far as the geography of infection is concerned, the four registered cases were a common point of infection found in rural areas. “We speculated, based on another South American mammarenavirus virus, that the person may have been infected by inhalation of viral particles, perhaps from rat feces. But this has not been confirmed, as we have very few cases.” Are stated, “says Anna. The doctor also warns that, of course, since these are rural areas with limited laboratory and diagnostic resources, some cases may have escaped medical examination, leading to a full review of Brazilian hemorrhagic fever. It has become impossible. “We don’t know if there really are any mild cases, like yellow fever, which can range from a serious case to people with no symptoms.”

An important difference of the study from previous reports of the virus is the incidence of hospital transfers. Scientists at IMT and Hospital Das Clinicas did not find any such infection during the search. “This shows that with the usual precautions, such as masks, gloves, goggles and aprons, there was no transmission, and that makes us a little calmer about our virus,” says Anna Nastri. However, she says it is not yet possible to draw any conclusions, as these are only two cases.

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