Detection ofBorrelia burgdorferi,Ehrlichia chaffeensis, andAnaplasma phagocytophilumin Ticks (Acari: Ixodidae) from a Coastal Region of California

Abstract

A study was conducted in Santa Cruz County to estimate the prevalence and distribution of the agents of Lyme disease, human granulocytic (HGE), and human monocytic (HME) ehrlichiosis in 1,187 adult ixodid ticks collected from eight public-use recreation areas over a 2-yr period. Borrelia burgdorferi, the causative agent of Lyme disease, was detected by a polymerase chain reaction (PCR) in 44 of 776 (5.67%) Ixodes pacificus ticks and in 3 of 58 (5.17%) Dermacentor variabilis ticks. Anaplasma phagocytophilum, the causative agent of HGE, was detected by PCR in 48 (6.19%) I. pacificus ticks and 5 (8.62%) D. variabilis ticks. Ehrlichia chaffeensis, the causative agent of HME, was detected by nested PCR in just five (0.64%) I. pacificus ticks and four (6.9%) D. variabilis ticks. Interestingly, eight (1.03%) I. pacificus ticks were co-infected with B. burgdorferi and A. phagocytophilum, and just one (0.12%) tick was co-infected with B. burgdorferi and E. chaffeensis. Less than 1% of 353 Dermacentor occidentalis ticks showed evidence of infection with any of the agents tested. To our knowledge, this is the first reported identification of A. phagocytophilum and E. chaffeensis in D. occidentalis ticks from California This study represents the first extensive survey of Lyme and the ehrlichial diseases across multiple areas of Santa Cruz County, and suggests that prevalence of B. burgdorferi in Santa Cruz County may be higher than other areas of the state.

The Biological Survey of Canada: A Personal History

“…The low disease incidence is consistent with patterns of human disease reported in the far western states (Bacon et al 2008). As has been reported in other parts of its range Holden et al 2003;Lane et al 2004), the infection rates of B. burgdorferi in host-seeking I. pacificus in British Columbia are very low (Ogden et al 2008c), likely because immature ticks preferentially feed on lizards, which are incompetent hosts (Lane and Quistad 1998;Casher et al 2002). Thus in British Columbia, the risk of human infection with B. burgdorferi is very low, partly because of the widespread but focal nature of the established tick populations and the low prevalence of B. burgdorferi in vector ticks (Ogden et al 2008c).…”

Genetic Variants of Anaplasma phagocytophilum Infecting Dogs in Western Washington State

“…Attempts to detect A. phagocytophilum in other species of ixodid ticks in California have been unsuccessful (2,19 (18). The difference in seasonality between the two areas may be due to the differences in vectors and weather.…”

Coinfection withAnaplasma phagocytophilumAltersBorrelia burgdorferiPopulation Distribution in C3H/HeN Mice

“…However, a wide range of coinfection scenarios exist in nature, and the frequency of their occurrences is unknown. Although ticks may harbor both pathogens, prevalence studies in endemic areas throughout the United States have shown that coinfection rates may be as little as 1 to 6% (6,17) or as high as 26% (3), whereas the rate of ticks singly infected with B. burgdorferi can be up to 40% (6) and the rate of ticks singly infected with A. phagocytophilum can be up to 20% (19). In addition, transmission time, from tick to host, may differ for each pathogen (20).…”