Hedgehogs and Tick-Borne Diseases: Urban Reservoir Study Findings
Urban wildlife may play a larger role in tick-borne diseases than previously recognized. A study of European hedgehogs found high rates of infection in ticks, including multiple pathogens within the same tick.
This raises an important question: can urban animals contribute to the spread of Lyme disease and coinfections? Findings suggest that hedgehogs may serve as important reservoirs in urban and suburban environments.
The study, entitled “Melting pot of tick-borne zoonoses,” examined the role of European hedgehogs in maintaining the enzootic cycle of tick-borne pathogens in urban and suburban areas.
European hedgehogs, which are common in urban environments and protected in Belgium, were studied through rehabilitation centers. The number of ticks collected per hedgehog ranged from 1 to 167.
High Rates of Infection and Coinfection
The authors found that 71% of ticks carried at least one pathogen, including Borrelia miyamotoi, Anaplasma phagocytophilum, Rickettsia helvetica, and several Borrelia burgdorferi genospecies such as B. afzelii, B. bavariensis, and B. spielmanii.
“An infection with B. miyamotoi occurred in 20 ticks from five hedgehogs,” according to Jahfari from the National Institute of Public Health and Environment.
Notably, 39% of ticks were infected with more than one pathogen, highlighting the frequency of coinfections in natural settings.
Urban Exposure Risk
The infection rate was higher in ticks collected from hedgehogs than in ticks collected from the environment, suggesting that hedgehogs may actively contribute to transmission cycles.
Hedgehogs are more densely populated in urban parks and gardens than in rural areas, increasing the likelihood that humans may encounter infected ticks during everyday activities.
“Humans are likely to encounter ticks infected with one or several of these pathogens while gardening or recreating in parks,” the authors note.
Implications for Diagnosis and Treatment
The presence of multiple pathogens in a single tick complicates diagnosis and treatment decisions. Coinfections may contribute to more complex or persistent symptoms in patients.
The study did not evaluate Babesia microti, which has been reported in other studies to infect a significant proportion of Lyme disease patients.
This study illustrates a broader principle: patients exposed to ticks in urban and suburban environments may be at risk for multiple infections, not just Lyme disease.
Patients may benefit from evaluation of coinfections, review of Lyme disease symptoms, and awareness of tick bite prevention, even in non-rural settings.
References
- Jahfari S, Ruyts SC, Frazer-Mendelewska E, Jaarsma R, Verheyen K, Sprong H. Melting pot of tick-borne zoonoses. Parasit Vectors. 2017.
- Diuk-Wasser MA, Vannier E, Krause PJ. Coinfection by Ixodes tick-borne pathogens. Trends Parasitol. 2015.
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
