A surreal image of a tick looming over a family, symbolizing the threat of Spotted Fever in Uruguay.

Tick Talk: Unmasking the Hidden Threat of Spotted Fever in Uruguay

Jordan Keane in Health & Wellness December 2025 • 4 min read.

"Are aggressive ticks spreading a dangerous disease you should know about?"

For years, a disease called spotted fever in Uruguay was blamed on Rickettsia conorii, with diagnoses made through blood tests. However, a more recent discovery revealed Rickettsia parkeri in ticks that bite humans, turning the spotlight onto a different culprit. While R. conorii's usual vector, the Rhipicephalus sanguineus tick, hadn't been studied for carrying rickettsiae in Uruguay, a closer look was needed.

To solve the mystery, researchers collected 180 R. sanguineus ticks from dogs and 245 Amblyomma triste ticks from plants in three areas of southern Uruguay where spotted fever is common. They then screened these ticks for spotted fever group (SFG) rickettsiae to see which species were carrying the disease.

The results pointed to Amblyomma triste as the key player in transmitting R. parkeri. This article will explore these findings, explain what they mean for the risk of spotted fever in Uruguay, and what you need to know to protect yourself and your family.

Is Your Family at Risk? How Aggressive Ticks Spread Spotted Fever

A surreal image of a tick looming over a family, symbolizing the threat of Spotted Fever in Uruguay.

The study used a technique called PCR to look for the DNA of rickettsiae in the ticks. Surprisingly, none of the R. sanguineus ticks carried any rickettsial DNA. However, in two of the three locations, A. triste ticks were found to be carrying a rickettsial organism, with infection rates ranging from 11.8% to 37.5% in the positive pools.

When the DNA from these ticks was analyzed, it matched Rickettsia parkeri. This discovery, combined with the fact that A. triste ticks are known to aggressively bite humans, reinforces the idea that A. triste is a major vector for human infections caused by R. parkeri in Uruguay. Here's why this is important:

Misdiagnosis No More: Early diagnoses often pointed to R. conorii, but this research highlights the need to consider R. parkeri in spotted fever cases in Uruguay.
Aggressive Biters: A. triste ticks are particularly aggressive towards humans, increasing the chances of transmission.
Endemic Areas: The study focused on specific locations known for spotted fever, indicating a localized risk within southern Uruguay.

It's essential to understand that while R. parkeri has been identified, the presence and impact of other rickettsial species shouldn't be completely ruled out. Continuous monitoring and research are crucial for a comprehensive understanding of tick-borne diseases in the region.

Protecting Yourself and Staying Informed

This research clarifies the role of Amblyomma triste ticks in spreading Rickettsia parkeri in Uruguay, underscoring the need for accurate diagnosis and targeted prevention efforts. Knowing the specific risks associated with R. parkeri, rather than assuming R. conorii as the sole culprit, is the first step in effective management.

To minimize your risk, take these precautions:

<ul> <li>Use Repellent: When spending time outdoors in endemic areas, use insect repellents containing DEET or picaridin.</li> <li>Check for Ticks: After being outdoors, thoroughly check yourself, your children, and your pets for ticks.</li> <li>Protective Clothing: Wear long sleeves and pants when possible.</li> <li>Stay Informed: Keep up-to-date with the latest information on tick-borne diseases in your region.</li> </ul>

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/s0036-46652012000300003, Alternate LINK

Title: Rickettsia Parkeri: A Rickettsial Pathogen Transmitted By Ticks In Endemic Areas For Spotted Fever Rickettsiosis In Southern Uruguay

Subject: Infectious Diseases

Journal: Revista do Instituto de Medicina Tropical de São Paulo

Publisher: FapUNIFESP (SciELO)

Authors: José M. Venzal, Agustín Estrada-Peña, Aránzazu Portillo, Atilio J. Mangold, Oscar Castro, Carlos G. De Souza, María L. Félix, Laura Pérez-Martínez, Sonia Santibánez, José A. Oteo

Published: 2012-06-01

Everything You Need To Know

What is the primary cause of spotted fever in Uruguay, and how does it differ from previous understanding?

Spotted fever in Uruguay was previously attributed to *Rickettsia conorii*, a bacteria spread by the *Rhipicephalus sanguineus* tick. However, recent research revealed that *Rickettsia parkeri*, transmitted by the *Amblyomma triste* tick, is the more significant cause. This is a crucial distinction because it changes how the disease is understood, diagnosed, and treated.

Why is the identification of Amblyomma triste and Rickettsia parkeri significant?

The shift in focus to *Rickettsia parkeri* and its vector, the *Amblyomma triste* tick, is important because of the aggressive biting behavior of this tick species. *Amblyomma triste* ticks are more likely to bite humans, which increases the chance of transmission. The study showed that in specific locations within southern Uruguay, *Amblyomma triste* ticks carried *Rickettsia parkeri*, leading to localized risk.

How did the researchers determine which ticks carried the disease?

PCR (Polymerase Chain Reaction) was used to analyze the DNA of the rickettsiae within the ticks. This method helped researchers identify the presence of *Rickettsia parkeri* in *Amblyomma triste* ticks. The study screened ticks collected from dogs and plants in southern Uruguay to determine which species were carrying the disease. This was a key step in understanding the disease's spread and identifying the primary vector.

What are the implications of misdiagnosing spotted fever in Uruguay?

If *Rickettsia parkeri* is suspected, it means that the medical approach to diagnosis and treatment needs to evolve. The fact that early diagnoses often pointed to *R. conorii* suggests that the medical community may need to consider *R. parkeri* as a potential cause of spotted fever in Uruguay. Misdiagnosis due to assuming *R. conorii* can result in delayed or ineffective treatment, underscoring the need for accurate diagnosis based on the recent findings.

Why is continued research on tick-borne diseases important?

Continuous monitoring and research are essential for a comprehensive understanding of tick-borne diseases. While *Rickettsia parkeri* has been identified as a key player, the presence and impact of other rickettsial species shouldn't be ruled out. Further research can help refine our understanding of the disease and lead to more effective prevention and treatment strategies. Public health officials can use the data to raise awareness and implement measures to reduce exposure to the dangerous ticks.