Brazil recorded 2,058 cases of spotted fever and 695 deaths due to the disease between 2013 and 2022. Data are from the epidemiological bulletin of the Ministry of Health. Only the state of São Paulo concentrated more than 61% of deaths (426) and 35% of cases (722) in the last ten years. The disease is caused by a bacterium of the genus Rickettsia, with the star tick being the main vector.
This week, the Government of São Paulo issued an alert about an outbreak of spotted fever that would have started at Santa Margarida Farm, in Campinas, in the interior of the state. Currently mapped as a risk area, the site hosted two events: Seu Jorge’s concert, with 10,000 participants; and Feijoada do Rosa, with around 3,500 people.
Since last Monday (12), the Adolfo Lutz Institute has already confirmed the death of five people who attended parties on the farm. Pilot Douglas Pereira Costa, 42, and dentist Mariana Giordano, 36, are among the victims.
Infectologist and consultant for the Brazilian Society of Infectious Diseases Tânia Chaves explains the causes that lead the state of São Paulo to lead the number of deaths. In Brazil, there are two types of bacteria that cause the disease, Rickettsia rickettsii and Rickettsia parkeri. The first species is considered more serious and found precisely in the states of the Southeast region and in Pará.
According to the infectologist, the type of biome also has a great impact on the proliferation of star ticks. “São Paulo has the characteristics of the biome, the aspects of vegetation and wild forest that are more conducive to [esses aracnídeos] achieve full evolutionary life”, he explains.
In addition to these factors, the risk of infection for humans is related to interaction with wild animals, such as capybaras and horses, and exposure to risky places, mainly in rural areas, such as activities on a farm, fishing or trailing waterfalls.
Despite being a disease with a high lethality rate, the consultant for the Brazilian Society of Infectious Diseases reinforces that the population does not need to panic in relation to the outbreak in Campinas, but it is necessary to remain alert.
Last year, Brazil registered 190 cases and 50 deaths from Rocky Mountain spotted fever. According to the latest report by the Ministry of Health, this year 54 cases of the disease were confirmed, of which 9 resulted in death. In other words, the numbers are within the expected range.
“The disease has been known in São Paulo since 1929. So, we’ve known about the disease for a long time. Fortunately, she has few outbreaks like the one she has now. In general, it is extremely normal to have cases of Rocky Mountain spotted fever every year, because it is an endemic region”, says Patrícia Thyssen, professor of entomology at the Institute of Biology at Unicamp.
Star tick is not present only in SP
Although proportionally the largest number of cases occur in São Paulo, the star tick, host of the bacteria that causes Rocky Mountain spotted fever, can be found in other regions of Brazil, but especially in the Southeast.
Between 2013 and 2022, the Southeast region recorded 1,262 cases of the disease, 722 in São Paulo, 317 in Minas Gerais, 154 in Rio de Janeiro and 69 in Espírito Santo. That is, on average, six out of ten cases were confirmed in this region of the country in the last ten years.
Patrícia Thyssen reiterates that the climate in the center-south of the country is more favorable to the parasite, as well as the large presence of hosts.
“The star tick, in particular, lives associated with rural regions and near or close to forests and water, in some situations”, he explains. “[Este animal] prefers to suck blood from horses and rodents. For this reason, they are often found in rural areas.”
According to the entomology professor at the Institute of Biology, contact between people and the parasite usually occurs between the months of May and August, a phase in which the animal is in constant search of new hosts.
“We have in the field [entre maio e agosto] a lot of larva, a lot of micuim, a lot of nymph, phases in which the [carrapatos-estrela] they are more voracious. They feed more and are always in the vegetation”, continues the specialist.
How to fight the disease?
For Tânia Chaves, the main disease prevention tool is information. “It is necessary to create a program [governamental] involving all sectors of society, including the health and education network. It has to be clear and objective information, especially about seasonality [da infecção, de maio a agosto]”, suggests.
As the disease has a high lethality, early diagnosis is also essential. As soon as the first symptoms appear, it is important that the patient seeks help in health units for medical evaluation and treatment.
In areas considered at risk, the Ministry of Health also recommends the use of clothing that covers the entire body, preferably light colors. That way, ticks can be seen more easily.
The folder still recommends examining the body frequently, because the faster the ticks are removed, the lower the risk of infection.
What are the symptoms?
The main symptoms, according to the Ministry of Health, are:
• fever;
• severe headache;
• nausea and vomiting.;
• diarrhea and abdominal pain;
• constant muscle pain;
• swelling and redness in the palms of the hands and soles of the feet;
• gangrene in the fingers and ears; It is
• paralysis of the limbs that starts in the legs and goes up to the lungs, causing respiratory arrest.
