Occurrence of tick-borne pathogens in questing ticks, ticks from riding horses, and red deer blood in Western Pomerania, Poland.

Overview

• This study investigated the presence and diversity of multiple tick-borne pathogens in ticks collected from recreational areas, ticks feeding on horses, and blood samples from red deer in Western Pomerania, Poland.
• The research highlights significant prevalence and co-occurrence of several pathogens, indicating a considerable risk of multiple infections for humans and animals exposed to ticks in these environments.

Background and Importance

• Tick Species: Ixodes ricinus, a common vector in Europe, transmits various pathogens harmful to humans and animals.
• Increasing Risk Factors: Climate change, urban development converting natural green spaces to recreational areas, and increasing populations of humans and animals (including pets) contribute to higher exposure to tick-borne pathogens (TBPs).
• Research Focus: Identifying prevalence, pathogen diversity, and co-infections in ticks and animal hosts in a specific geographic region provides crucial data for managing public and animal health risks.

Methodology

• Sample Collection:
  • Questing Ixodes ricinus ticks were collected from recreational forested areas (409 samples).
  • Ticks were also collected from horses (135 samples).
  • Blood samples were taken from red deer (42 samples), an important wildlife host species.
• Molecular Analysis: The samples were tested using molecular techniques (likely PCR-based) to detect the presence and type of tick-borne pathogens.

Key Findings: Pathogen Prevalence

• In Questing Ticks:
  • Borrelia afzelii was found in 15% of samples.
  • Borrelia garinii occurred in 14% of samples.
  • Other Borrelia species were detected in 25.2%.
  • Anaplasma phagocytophilum was present in 4.6%.
  • Rickettsia helvetica was found in 11%.
  • Rickettsia raoultii and Rickettsia monacensis had lower prevalence (0.5% and 0.3%, respectively).
• In Blood Samples from Red Deer:
  • Borrelia garinii was detected in 2.4% of samples.
  • Other Borrelia spp. in 4.8% of samples.
  • Anaplasma phagocytophilum in 9.5%.
  • Rickettsia helvetica in 4.8% of samples.

Co-Occurrence of Pathogens (Co-Infections)

• Several dual co-detections were observed, indicating ticks and animals carrying more than one pathogen simultaneously:
  • Borrelia afzelii and Borrelia spp. co-occurring in 8.3% of questing ticks.
  • Rickettsia spp. and Borrelia spp. co-detection at 2.4%.
  • Anaplasma spp. and Borrelia spp. co-occurring in 0.9%.
• Higher-order multiple infections were less frequent but present:
  • One triple co-detection involving Borrelia spp., Anaplasma phagocytophilum, and Rickettsia helvetica was found in questing ticks (0.2%).
  • Two quadruple pathogen combinations, involving either Anaplasma phagocytophilum or Rickettsia helvetica with various Borrelia species, were identified in deer blood (0.3%) and ticks from horses (0.6%).

Implications and Conclusions

• Significant Risk: The high prevalence of multiple TBPs in ticks from recreational areas indicates that humans and animals are at substantial risk of exposure to varied and possibly multiple infections.
• Public and Veterinary Health: Co-infections may complicate diagnosis and treatment outcomes, underscoring the need for awareness and monitoring.
• Ecosystem Interaction: The detection of pathogens in wildlife (red deer) and ticks from horses shows the complex transmission cycles involving wildlife, domestic animals, and humans.
• Recommendations: These findings emphasize the importance of tick control strategies, public education about tick bite prevention, and further research in these habitats to mitigate the risk of tick-borne diseases.