Learn how to prevent hantavirus, a disease caused by wild rodents

Photo: Arquivo / Cidadeverde.com

Hantavirus is an acute viral zoonotic disease, the infection of which appears in humans in Brazil as cardiopulmonary hantavirus syndrome. Only in 2022, as of September, 22 cases of hantavirus were recorded in Brazil, with ten confirmed deaths. A curious case is that of Santa Catarina, who recently introduced a phenomenon known as ratady, characterized by an increase in the number of wild rats in a particular area, resulting in an increase in the population.

This mainly occurs during the flowering of certain species of bamboo (every 10, 20 or more years), known as taquaras. An excessive increase in these animals can cause significant damage, destroy crops, contaminate stored grain, and spread diseases, especially hantavirus, which in the state already recorded eight confirmed cases and four deaths in 2022.

The Department of Health, in partnership with Fucruz and the Department of Health of Paraná, supports the Santa Catarina Department of Health in its environmental epidemiological surveillance measures and the capture of wild rodents. The goal is to properly identify the rodents in question and verify their positivity for hantavirus, provide a better understanding of the wild cycle of hantavirus in the area, and aid in monitoring and prevention, as well as increase the number of professionals trained to handle it. the disease.

Wild rodents known as wood mouse and rice mouse (Akodon sp. and Oligoryzomys sp., respectively) are reservoirs of hantavirus and differ from those often found in urban environments because they are small (the adult male is 25 g) and live near crops, mainly grains.

about the disease

The disease can cause hantavirus cardiopulmonary syndrome (HCPS). It is an acute viral zoonotic disease caused by an RNA virus, belonging to the family Hantaviridae and the genus Orthohantavirus. Human infection occurs mainly by inhalation of aerosols in the form of dust generated by sweeping, consisting of urine, feces and saliva of infected rodents. Other forms of transmission are skin abrasions or rodent bites, and contact of the virus with the mucous membrane of the conjunctiva, mouth or nose by hands contaminated with rodent excreta.

From contact with the virus, about 1 to 5 weeks on average, in the initial stage, the most common symptoms are fever, joint pain, headache, lower back and abdominal pain, nausea, fever and vomiting. When it reaches the cardiopulmonary stage, it is common for a person to have fever, difficulty breathing, rapid breathing, severe heart rate, dry cough, and low blood pressure. At this stage, non-cardiogenic pulmonary edema is also possible, in which the patient develops acute respiratory failure and circulatory shock. Therefore, if you develop signs and symptoms that suggest hantavirus infection, you should seek medical attention as soon as possible.

diagnose

Diagnosis is made by serology in laboratory tests and is available in the public laboratory network. The Ministry of Health provides the necessary supplies for serological tests. The most common method is ELISA-IgM, which identifies specific antibodies against hantavirus in organ fragments. On the other hand, RT-PCR is useful in identifying the virus and its genotype, and is considered a complementary test for research purposes.

Sample collection should be performed soon after the diagnosis is suspected, as IgM antibody appearance occurs concomitantly with the onset of symptoms and remains in the circulation until approximately 60 days after the onset of signs. When it is not possible to establish the diagnosis in a single sample, the collection should be repeated and a second serological examination should be performed only in situations in which the patient shows clinical manifestations strongly compatible with SCPH and if the first sample was collected in the first days of illness.

If necessary, tests are performed for differential diagnosis, in which some signs and symptoms are confused with those of other diseases, such as influenza syndromes, COVID-19, septicemia, leptospirosis, respiratory diseases, atypical pneumonia, dengue fever, hemorrhagic fever of etiology viral..

treatment or treatment

There is no specific treatment. Supportive therapeutic measures, provided on a case-by-case basis by a medical professional, are recommended. Since it is an acute and rapidly developing disease, it is necessary to notify it immediately, and therefore must be reported within 24 hours, to both the municipal and state health departments and the Ministry of Health, through the Department of Health. Health Surveillance (SVS).

Professionals who may be exposed, such as rural workers and health professionals conducting investigations for the potential site of infection, should use personal protective equipment, such as a pff3 mask, glove, apron, and goggles. Prevention of hantavirus disease is based on the use of measures that prevent human contact with wild rodents and their excreta (faeces, urine, saliva).

Control measures should include measures such as, for example, clearing the land around the home, appropriate disposal of existing debris, keeping food stored in closed rodent-resistant containers, as well as other measures that prevent interaction between humans and wild rodents, in places where it is known the existence of these animals. Avoid handling rodents, even dead ones. If necessary, it is important to wear rubber gloves and wash your hands immediately afterwards.

For more information, visit the Health A to Z website.

Source: Ministry of Health