Detection of Babesia microti and Borrelia burgdorferi in host-seeking Ixodes scapularis (Acari: Ixodidae) in Monmouth County, New Jersey.

The etiological agents that cause human babesiosis (Babesia microti) and Lyme disease (Borrelia burgdorferi) share a common tick vector (Ixodes scapularis Say) and rodent reservoir (Peromyscus leucopus), but because the geographical distribution of babesiosis is more restricted than Lyme disease, it was not considered a nationally notifiable disease until 2011. Although recent studies have shown dramatic increases in the number of cases of babesiosis and expansion of its range, little is known about infection and coinfection prevalence of these pathogens in the primary tick vector. Of the 478 I. scapularis nymphs collected within six Monmouth County, NJ, municipalities between 2004 and 2006, 4.0 and 10.0% were infected with B. microti and B. burgdorferi, respectively, while 2.9% were coinfected. Analysis of the 610 I. scapularis adults collected during the same period yielded an infection prevalence of 8.2% for B. microti and 45.2% for B. burgdorferi, while 6.2% were coinfected. The potential public health importance of these findings is discussed.

Geographical distribution and prevalence of selected Borrelia, Ehrlichia, and Rickettsia infections in Amblyomma americanum (Acari: Ixodidae) in New Jersey.

We used published accounts to describe the known statewide distribution of the lone star tick, Amblyomma americanum, in New Jersey and field surveys to characterize the geographical range of A. americanum and selected A. americanum-transmitted pathogens in Monmouth County, the hypothesized northern limit of the species distribution. Ticks were collected using standardized methods from 50 widely dispersed public access areas within 18 municipalities to produce estimates of relative abundance among sites. Collected A. americanum adults were stored at -80 degrees C until processed for DNA extraction. Individual ticks were subjected to polymerase chain reaction analyses to detect the presence of Ehrlichia chaffeensis, E. ewingii, Rickettsia amblyommii, and Borrelia lonestari. The range of A. americanum was generally limited to the southern half of New Jersey. Within Monmouth County, we collected A. americanum from 9 of 18 municipalities (50%) and 24 (48%) of the surveyed properties. We found at least 1 pathogen at 17 (70.8%) sites located within 6 of 9 municipalities, while all 4 target pathogens were detected in 5 of those 6 (83.3%) municipalities. The geographical distribution of A. americanum and its associated pathogens appeared to be restricted to the southern portion of the county. Possible factors governing the distribution are discussed.

Relative abundance and prevalence of selected Borrelia infections in Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae) from publicly owned lands in Monmouth County, New Jersey.

To evaluate their potential importance in the transmission of ixodid tick-borne borrelioses in Monmouth County, NJ, we collected host-seeking Ixodes scapularis Say and Amblyomma americanum (L.) (Acari: Ixodidae) adults and nymphs to determine relative encounter frequencies and the infection prevalence of selected Borrelia spp. in their respective tick vectors. We also reviewed records of all ticks submitted for identification by the public in Monmouth County during 2001-2005. Relative abundance of the two species varied markedly among sites. Adult encounter frequencies for the two species were similar; however, A. americanum nymphs were encountered 3 times more frequently than I. scapularis nymphs. Of 435 ticks submitted by the public, 50.1 and 38.9% were I. scapularis and A. americanum, respectively. However, during May through August, the peak Lyme disease transmission season in New Jersey, significantly more submitted ticks were A. americanum (55.9%), compared with I. scapularis (34.1%). Polymerase chain reaction analysis of 94 1. scapularis and 103 A. americanum adults yielded infection prevalences of 31.9% for B. burgdorferi and 5.8% for B. lonestari, respectively. Although the infection prevalence of B. burgdorferi in I. scapularis was considerably higher than the infection prevalence of B. lonestari in A. americanum, the higher encounter frequencies for A. americanum compared with I. scapularis observed in this and other studies may result in increased risk of acquiring exposure to A. americanum-transmitted pathogens. The potential public health implications of these results are discussed.