The etiological agent of the disease is the bacterium Rickettsia rickettsii, a gram negative bacterium and its vector is the tick Amblyomma sculptum, known as the star tick, which is aggressive to humans. This tick is frequent in animals such as the horse, tapir (Tapirus terrestris) and capybara (Hydrochoerus hydrochaeris).
To better understand this scenario in Brazil, it is necessary to highlight that with the increasing loss of natural habitats, wildlife and human beings are getting closer, and consequently, the flow of parasites and pathogens tends to increase.
Naturally, capybaras are reservoirs for the disease; in addition, they are known as amplifying animals, that is, when bitten by a single infected tick, they spend a period with the bacteria circulating in their body, a period known as rickettsmia. During this time, ticks present on this animal that were not infected become infected.
Considering that these animals host a significant number of ticks, around 2800, the number of vectors that carry the bacteria is expressive. It is important to highlight that after the capybara comes into contact with the bacteria and goes through the infection, it will not become infected again, as it will have antibodies to the antigen Rickettsia rickettsii.
Capybaras find in the urban environment a favorable one, as there is an absence of a natural predator, abundance of food and there is a growing approximation with human beings. With these conditions, added to the animal's ability to generate a large offspring, we increasingly have animals that are not immune to bacteria and susceptible to the period of infection.
These animals are present in anthropized environments in places with water bodies, such as lakes, parks, rivers and even leisure clubs. In addition, its popularity among human beings has grown, being known as an extremely charismatic animal. As a result, people are susceptible to tick bites due to the presence of these animals and the tick in urban environments.
For disease transmission, the tick must be infected and the main symptoms are high fever, headache and muscle pain and the appearance of skin rash characterized as macules. The treatment is effective, and the major problem in Brazil is the fact that the disease is misdiagnosed, as the symptoms are similar to other diseases.
Given the above, do not approach any wild animal and do not feed them! Despite being charismatic, they host several pathogens that can be transmitted to humans.
Also, avoid areas where ticks are present. If you are in a green environment, wear light clothes that cover your arms and legs, inspect your body every 3 hours. If you have been to a likely area of infection and begin to experience symptoms, seek medical attention immediately.
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