Illustration of hidden tick dangers in a lush environment.

Tick Talk: What You Need to Know About Spotted Fever Risk

Lena Voss in Health & Wellness December 2025 • 4 min read.

"Uncover the environmental factors that increase your risk of contracting Brazilian Spotted Fever, and how to stay safe."

Brazilian Spotted Fever (BSF), a potentially deadly disease caused by the bacterium Rickettsia rickettsii, is a significant public health concern in southeastern Brazil. The disease is transmitted to humans through the bite of infected ticks, primarily the Amblyomma cajennense species. Understanding the environmental factors that contribute to the prevalence of these ticks, and their infection rates, is crucial for effective prevention and control efforts.

A recent study focused on Americana, a municipality in São Paulo, Brazil, known to be endemic for BSF. The research investigated the tick population dynamics and the presence of Rickettsia bacteria in ticks collected from various locations within the area. By analyzing tick species, their seasonal distribution, and infection rates, the study aimed to provide valuable insights into the ecological risks associated with BSF transmission.

This article translates the key findings of this research, making it accessible to a broader audience. We'll explore the types of ticks found, when they are most active, and the implications for public health, empowering you with the knowledge to protect yourself and your family from the dangers of BSF.

Tick Hotspots: Where Are the Risks?

Illustration of hidden tick dangers in a lush environment.

The research team conducted a year-long survey, collecting ticks monthly from six different areas within Americana using dry ice traps. These traps attract ticks by mimicking the carbon dioxide exhalations of potential hosts. Two primary tick species were identified:

The study revealed important insights into the seasonal activity of these tick species:

Both A. cajennense and A. dubitatum larvae were most abundant during the autumn and early winter months (April to July).
Nymphs of both species peaked in late autumn, winter, and early spring (June to October).
A. cajennense adults were most prevalent during the spring and early summer (October to December).
A. dubitatum adults were found in relatively consistent numbers throughout the year.

These findings highlight the importance of taking precautions against tick bites year-round, but especially during peak activity periods. Knowing when different tick stages are most active can help individuals and public health officials target prevention efforts more effectively.

Staying Safe: What You Can Do

This study underscores the importance of understanding the local ecology of tick-borne diseases. The high environmental burden of A. cajennense and A. dubitatum in Americana, sustained by the presence of capybaras, creates an environment where BSF transmission is a persistent risk.

While the study did not find any A. cajennense ticks infected with R. rickettsii, the presence of Rickettsia bellii in A. dubitatum serves as a reminder of the complex interactions between ticks and pathogens. Further research is needed to fully understand the role of different tick species in the transmission cycle of BSF and other rickettsial diseases.

By staying informed about tick activity patterns and taking preventive measures, you can significantly reduce your risk of contracting BSF and other tick-borne illnesses. When venturing into potential tick habitats, remember to wear protective clothing, use insect repellent, and conduct thorough tick checks upon returning home.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1590/s1984-29612013000300008, Alternate LINK

Title: Environmental Infestation And Rickettsial Infection In Ticks In An Area Endemic For Brazilian Spotted Fever

Subject: General Veterinary

Journal: Revista Brasileira de Parasitologia Veterinária

Publisher: FapUNIFESP (SciELO)

Authors: José Brites-Neto, Fernanda Aparecida Nieri-Bastos, Jardel Brasil, Keila Maria Roncato Duarte, Thiago Fernandes Martins, Cecília José Veríssimo, Amália Regina Mar Barbieri, Marcelo Bahia Labruna

Published: 2013-09-01

Everything You Need To Know

What is Brazilian Spotted Fever?

Brazilian Spotted Fever (BSF) is a potentially deadly disease caused by the bacterium *Rickettsia rickettsii*. It's a significant public health concern, particularly in southeastern Brazil. The disease is transmitted to humans through the bite of infected ticks, specifically of the *Amblyomma cajennense* species.

When are ticks most active, and how does this affect the risk of Brazilian Spotted Fever?

The *Amblyomma cajennense* tick is the primary vector of Brazilian Spotted Fever (BSF). Research in Americana, Brazil, revealed that the larvae and nymphs of both *A. cajennense* and *A. dubitatum* were most abundant during autumn and early winter. The adults of *A. cajennense* were most prevalent during spring and early summer. These seasonal variations in tick activity directly impact the risk of BSF transmission, emphasizing the need for year-round precautions, but particularly during peak activity periods.

What types of ticks are found in the area discussed?

The study found that both *Amblyomma cajennense* and *Amblyomma dubitatum* ticks are present in Americana, Brazil. The research used dry ice traps to collect ticks, mimicking the carbon dioxide exhalations of potential hosts. Understanding the presence and distribution of these specific tick species helps in assessing the local risk of Brazilian Spotted Fever (BSF). The presence of capybaras sustains a high environmental burden of these ticks, increasing the risk of BSF transmission.

When is the risk of getting Brazilian Spotted Fever highest?

The risk of contracting Brazilian Spotted Fever (BSF) is highest during the peak activity periods of the ticks. For *Amblyomma cajennense*, this is spring and early summer. For *Amblyomma dubitatum* adults are found throughout the year. Both species' larvae are most abundant during the autumn and early winter. Nymphs of both species are most prevalent in late autumn, winter, and early spring. This knowledge allows individuals to take extra precautions during these times, such as wearing protective clothing and using insect repellent.

How can I protect myself and my family from Brazilian Spotted Fever?

To protect yourself and your family from Brazilian Spotted Fever (BSF), it's important to understand the local ecology of tick-borne diseases. The presence of the *Amblyomma cajennense* and *Amblyomma dubitatum* ticks in the environment means you should take precautions year-round, but especially during their peak activity periods. Knowing that capybaras sustain the tick population helps us understand the risk. It's important to be aware of these factors to protect yourself.