Hantavirus: What is it, how is it transmitted and how to treat the disease

THE hantavirus It is a disease caused by a virus transmitted from animals to humans (zoonosis). According to the Ministry of Health, 22 cases of the disease were recorded in the country between January and September 2022, with ten confirmed deaths.

Wild rodents known as wood mouse and rice mouse (of the species Akodon and Oligoryzomys, respectively) are reservoirs of hantavirus. The species differ from those found more frequently in urban environments because they are small and live in the vicinity of plantations, mainly of grain.

A phenomenon known as “ratada”, characterized by the increase in the number of wild rats in a given area, generating overpopulation, was recently observed in the state of Santa Catarina, generating an alert for the risk of transmission of hantavirus.

According to the ministry, this occurs mainly during the flowering of certain species of bamboo, popularly known as taquaras, every 10, 20 or more years. The excessive increase in these animals can cause significant damage, such as the destruction of crops, contamination of stored grains and the spread of diseases, especially hantavirus, which, in the state, has already recorded eight confirmed cases and four deaths in 2022.

The Ministry of Health stated that it supports, in partnership with the Oswaldo Cruz Foundation (Fiocruz) and the Paraná Health Department, the Santa Catarina Health Department in epidemiological surveillance and capture of wild rodents.

The action aims to correctly identify the rodents involved and verify positivity with regard to hantavirus, providing a better understanding of the wild cycle of hantavirus in the region, helping in monitoring and prevention, in addition to increasing the number of professionals trained to deal with the disease.

Know the signs and symptoms, how transmission occurs, how the disease is diagnosed and treated

Symptoms and transmission

Hantavirus is a disease caused by a virus of RNA, belonging to the Hantaviridae family and Orthohantavirus genus.

Human infection occurs mainly by inhalation of aerosols in the form of dust generated in places where there is the presence of urine, feces and saliva of infected rodents. other forms of streaming of the disease are skin lesions or rodent bites and contact of the virus with the eyes, mouth or nose through hands contaminated with fluids shed by the rodents.

From contact with the virus, about 1 to 5 weeks on average, patients can present in the initial phase symptoms such as fever, joint pain, headache, lower back and abdominal pain, nausea, fever and vomiting.

Patients can develop a cardiopulmonary syndrome , with shortness of breath, rapid breathing and heart rate, cough and drop in blood pressure. At this stage, lung swelling is also possible, with risks of acute respiratory failure and circulatory shock.

Faced with signs and symptoms suggestive of hantavirus, the Ministry of Health recommends seeking medical attention.

Hantavirus diagnosis

O diagnosis is done by serology in laboratory tests available in the Unified Health System (SUS). The Ministry of Health provides the necessary kits for serological tests. The most common method detects specific antibodies against hantavirus in organ fragments. Molecular diagnosis (RT-PCR) allows the identification of the virus and its genotype, being considered a complementary test for research purposes.

Sample collection should be performed soon after the diagnosis is suspected, since the appearance of IgM antibodies occurs concomitantly with the onset of symptoms and remains in the circulation for about 60 days.

When in a single sample it is not possible to define the diagnosis, the collection should be repeated and a second serology should be performed only in situations in which the patient presents clinical manifestations strongly compatible with cardiopulmonary syndrome and if the first sample was collected in the first days of the disease.

Differential diagnostic tests can be performed, due to the similar symptoms of hantavirus to those of other diseases such as flu syndromes, Covid-19, septicemia, leptospirosis, respiratory diseases, atypical pneumonia, dengue and hemorrhagic fever of viral diseases.

Disease treatment and prevention

In the absence of specific medication, the treatment is done in a personalized way with the aim of relieving symptoms.

THE prevention of hantavirus disease is based on the use of measures that prevent human contact with wild rodents, in addition to animal feces, urine and saliva.

Control measures include actions such as weeding the land around houses in rural areas, properly disposing of existing debris, keeping food stored in closed, rodent-proof containers, in addition to other measures that prevent interaction with wild rodents.

The ministry recommends avoiding handling rodents, even dead ones. If necessary, wear rubber gloves and wash your hands immediately afterwards.

As it is an acute and rapidly evolving disease, hantavirus disease is of immediate compulsory notification. Cases must be reported within 24 hours to the municipal and state Health Departments and to the Ministry of Health, through the Health Surveillance Department (SVS).