Coinfections Acquired from Ixodes Ticks

Abstract

SUMMARY The pathogens that cause Lyme disease (LD), human anaplasmosis, and babesiosis can coexist in Ixodes ticks and cause human coinfections. Although the risk of human coinfection differs by geographic location, the true prevalence of coinfecting pathogens among Ixodes ticks remains largely unknown for the majority of geographic locations. The prevalence of dually infected Ixodes ticks appears highest among ticks from regions of North America and Europe where LD is endemic, with reported prevalences of ≤28%. In North America and Europe, the majority of tick-borne coinfections occur among humans with diagnosed LD. Humans coinfected with LD and babesiosis appear to have more intense, prolonged symptoms than those with LD alone. Coinfected persons can also manifest diverse, influenza-like symptoms, and abnormal laboratory test results are frequently observed. Coinfecting pathogens might alter the efficiency of transmission, cause cooperative or competitive pathogen interactions, and alter disease severity among hosts. No prospective studies to assess the immunologic effects of coinfection among humans have been conducted, but animal models demonstrate that certain coinfections can modulate the immune response. Clinicians should consider the likelihood of coinfection when pursuing laboratory testing or selecting therapy for patients with tick-borne illness.

Correlation between Tick Density and Pathogen Endemicity, New Hampshire

“…Our result that high tick density areas had the highest overall prevalence of pathogens and the highest prevalence of coinfected ticks supports the fi nding of Hamer et al, who reported a signifi cant difference in the rates of pathogen carriage between recently invaded and I. scapularis-endemic areas (1). The rates of infection we found are similar to those found by Swanson et al from 5 other northeastern states (11). According to their metaanalysis, ≈40% (± 13%) of 2,109 adult and nymphal ticks were infected with B. burgdorferi, 21% (± 17%) with A. phagocytophilum, and 9% (± 8%) with either B. microti or B. divergens.…”

A cross-sectional study of small mammals for tick-borne pathogen infection in northern Mongolia

“…was the only tick species identified on animals captured during this study, I. persculcatus ticks were present in these sampled areas suggesting that Borrelia spp. were also likely present in animal reservoirs captured [3]. The most common strains of Borrelia spp.…”

“…Studying the ecology of TBPs and their animal reservoirs is key to our understanding of disease epidemiology. While much is known about TBPs in developed settings [1–3], major gaps of knowledge remain regarding ticks and sylvatic transmission cycles in developing countries. This holds true in Mongolia, where a number of studies documenting tick diseases of clinical relevance have confirmed the presence of TBPs [4–12], but research regarding wild animal reservoirs has been largely neglected.…”

“…Some research conducted in China has identified TBPs in small mammal species along the Mongolian border in the Xinjiang and Inner Mongolia Autonomous Regions [3,13–17]. However, few studies have assessed the prevalence of TBPs in animals, specifically small mammal species, within Mongolia, and the risk factors associated with TBP detection in animal reservoirs remains largely undescribed.…”

Complications of Coinfection with Babesia and Lyme Disease After Splenectomy

“…Coinfection with Babesia and Lyme disease is common. 1 Some suggest that ticks may host multiple infective agents and that this may increase the number of diseases a patient may present with after a tick bite. 2,3 This patient presented with symptoms and signs of 2 diseases.…”