They investigate hantavirus in humans in Chile

Transmitted in our country by “long-tailed” mice, cases of Hantavirus Cardiopulmonary Syndrome (SCPH) are few but are usually serious. A study recently published in The Lancet Infectious Diseases journal, led by academics Marcela Ferrés and Nicole Le Corre from the School of Medicine, reviews clinical aspects and management of the disease.

PUC Communications.- In 1995 the first cases of hantavirus were detected in Chile. He hantavirus cardiopulmonary syndrome (HCPS) It is a viral zoonosis, that is, it is transmitted from animals to humansin this case, by wild rodents. In our case, for the Oligoryzomys longicaudatus or commonly known as mouse with a “long tail” and that transmits the “Andes virus”, the only one that can be passed from person to person.

Hantaviruses cause two serious diseases in humans: hemorrhagic fever with renal syndrome (HFRS), in Europe and Asia, and hantavirus cardiopulmonary syndrome (HCPS), In the americas. In the initial stage, both clinical pictures present similar symptoms, such as fever, headache, and muscle pain, especially in the thighs, hips, and back. However, the viruses associated with the infection in America have the lung and heart as their target organ.

Hemorrhagic fever with renal involvement has been seen especially in some European countries such as Sweden, Finland, Germany and Russia. In Asia, in countries like China and Korea, the symptoms can compromise the kidney, and can cause severe variable and reversible kidney failure.

In Chile, the disease is endemic, with a seasonal presentation in spring-summer, that is, the cases are concentrated during the months of November to March.

How serious are hantavirus illnesses?

Its lethality is variable, depending on the virus. In the American continent there are three viruses that present the highest lethality: the Sin Nombre virus (SNV) from the USA; Andes virus (ANDV) from Chile and southern Argentina; and the Araraquara virus (ARAV) from southern Brazil. In these cases the mortality rate among those affected is 30 to 40%.

In the case of hemorrhagic fevers with renal involvement, the vast majority of those infected present with an asymptomatic infection or with few symptoms. The estimated lethality among those who are diagnosed, because they are admitted to the hospital or undergo confirmatory tests, is less than 1%; except for infections caused by the Dobrava virus from southeastern Europe, which reports a lethality of 10%.

Chilean investigation

“Hantavirus in humans: review of clinical aspects and management”is the name of the article recently published in the scientific journal The Lancet Infectious Diseases. The study was led by academics from the Department of Infectious Diseases and Pediatric Immunology, of the Medicine School, Marcela Ferres and Nicole Cumsand was written in collaboration with leading national and international hantavirus researchers, led by Pablo Vialacademic of the Faculty of Medicine – German Clinic University of Development (CAS-UDD).

The incidence of Hantavirus Cardiopulmonary Syndrome (SCPH) in our country is low, Annual cases range from 30 to 90 in the last 5 years, although they are usually serious. As Marcela Ferrés, head of the Department of Infectious Diseases and Pediatric Immunology at the School of Medicine, explains: “Since the first cases were known, in early recognition, uniform management in intensive care units evaluated whether high-dose corticosteroids had real effect in reducing lethality, but Chilean university researchers in conjunction with ministerial groups ruled out the hypothesis. Subsequently, work was done on the evaluation of the early use of plasma donated by patients convalescent from this disease with encouraging results”.

The academic also details that in 2017 it was decided that, given the suspicion of the diagnosis, patients would be referred to tertiary centers with availability of mechanical ventilation and extracorporeal circulation. “Those affected have better survival when they receive intensive medicine care earlyincluding units with access to ECMO for hantavirus cardiopulmonary syndrome (HCPS) that an ICU can offer them”, affirms the researcher.

At the moment, work is underway to develop an “artificial equivalent of immune plasma”, poly or monoclonal antibodies against the Andes virus (ANDV), to be infused early in the cases and eventually use them, after a safety and efficacy study, in subjects at high risk of developing the infection. These could be the close contacts of the ANDV cases, the only virus that, in addition to contracting it in the environment of the long-tailed mouse, can be acquired from a patient to a contact, such as the caregiver who is very close to their fluids, such as saliva. , in the final phase of virus incubation and the onset of symptomatic disease.

The work team that has participated in the study is made up, from the UC, by the Biochemist and Master in Epidemiology Constanza Martínez-Valdebenito, Carolina Henríquez, Nurse Master in Epidemiology, and Jenniffer Angulo, virologist. The research has been carried out throughout Chile and the virological tests have been carried out at the Medical Research Center and the Level 3 Biosafety laboratory of the School of Medicine. It currently has FONDECYT financing #116197 and #1211825.