What is a Hantavirus infection?

Hantaviruses are not new, nor are they transmitted between people, but through rodents in rural areas, and can cause hemorrhagic fever with kidney involvement or cardiopulmonary syndrome, an infection that can be fatal.

The Hantavirus is a type of virus that is transmitted to humans by aerosol droppings of some rodents. They can cause hemorrhagic fever with kidney involvement (FHSR) or a very serious cardiopulmonary syndrome (SCPH) with high mortality, such as that caused by the Andes virus during 2018 and 2019, caused an outbreak with dozens of people affected in Argentina. This week it has caused the death of a person in the Chinese province of Shandong, which has triggered some alarm in the networks due to the population’s fear due to the current coronavirus pandemic. However, we will try to clarify everything we know about this virus to understand why there is no need to be alarmed.

Infections with these viruses, which are distributed throughout Asia, Europe, and North and South America, are probably not always diagnosed because the symptoms they produce can be confused with leptospirosis, dengue, malaria, and other entities, especially in tropical areas.

FHSR occurs in Asia and Europe, with a mortality of less than 1% in mild cases, up to 10-15% in the most severe. In America, Hantaviruses cause SCPH, with a mortality that can reach 50% (or even 80% in some outbreaks), especially if there is no access to adequate treatment means.

Prevalence of hantavirus infections

There are between 16,000 to 100,000 cases a year in China, and in Russia, there are also thousands of patients annually. In Europe, annual cases of the Puumala and Dobrava viruses are estimated at several thousand, although exact figures are not available. Fortunately, SCHP cases in America are fewer in number; Some 3,000 cases have been documented to date, although the number may be higher.

In both cases, after contact with the virus through the feces, saliva, or urine of infected rodents, the virus enters the body through the lungs, from where it spreads to the rest of the body, producing the first phase of general symptoms and high fever, which are not distinguishable from other viral or bacterial infections of different types.

The Andes virus is the only one that can be transmitted from one person to another (thought to be through cough, saliva, urine, and feces, as well as through sexual contact).

To prevent infections, it is essential to control rodent populations in urban areas and prevent them from entering homes in rural areas. There is currently no effective treatment for people infected by a hantavirus. Although in Chile, there is a team investigating the use of monoclonal antibodies for the treatment of SCPH.

Causes of Hantavirus infection

The Hantavirus are RNA viruses belonging to a type called ‘arbovirus, so-called because they are transmitted by rodents (of the English rodent-borne virus ). It is a virus that belongs to group C of Bunyaviridae, which includes other viruses such as Congo and Crimean hemorrhagic fever or Rift Valley fever. The Hantavirus is considered a risk virus biosafety Level 4.

The exact number of Hantavirus species is not known, but it is thought that there are between 20 and 30 different ones. At least a dozen of them are associated with diseases in humans. The first of all those described was the Hantaan virus, isolated in 1978 in Korea from the Han River area. Hence the name of this genus of the virus.

Other viruses of this genus are Seoul (located mainly in China and Korea, such as Hantaan), Dobrava / Belgrade (central and western Europe), Puumala (Scandinavia, Western Europe, Russia), The Sin Nombre Virus (EE .UU. And Canada), the Laguna Negra (Paraguay and Bolivia), the Choclo of Panama, and the Mamore River of Peru. There are also the Black Creek Canal, the New York, and the Bayou in the USA.

How Hantaviruses Are Transmitted to Humans

Although Hantaviruses can secondarily infect many types of mammals, each species of a virus is associated with a specific species of wild rodent, which is its primary natural reservoir. Between 5 and 20% of the rodents associated with each virus are carriers of it. Viruses are distributed around the planet based on the habitats of their associated rodent. For example, viruses that cause hemorrhagic fever with the renal syndrome are carried by voles, except for the Puumala virus, which is associated with the vole.

There is currently great concern about an Andes Hantavirus outbreak in Argentina; this virus can also be found in Brazil and Chile.

The transmission of Hantavirus humans occurs through contact with rodents that either virus. Infected animals shed viruses in urine, feces, or saliva. Transmission of the virus to humans is thought to occur most of the time by producing virus aerosols. This happens mostly inside buildings with rodent infestations and outside workers, such as in fields where rodents may have urinated or defecated.