Geographic Distribution of Ticks (Acari: Ixodidae) in Iowa with Emphasis onIxodes scapularisand Their Infection withBorrelia burgdorferi

Abstract

In Iowa, public concern regarding Lyme disease has increased markedly over the last decade. In response to these concerns, a statewide surveillance program was initiated in 1990 based on ticks received by the Department of Entomology at Iowa State University. Ticks were received from health care professionals, state government agencies, and the general public. A total of 5,343 ticks from all 99 Iowa counties were identified during the 12 years of this study. Dermacentor variabilis was the most numerous species, followed by Amblyomma americanum, and Ixodes scapularis. Dermacentor variabilis were distributed statewide, but A. americanum came primarily from southern Iowa counties. Prior to 1996, most I. scapularis came from counties along the Mississippi River. In the last 5 years, I. scapularis have been received from several counties in central and western Iowa and there is molecular evidence of infection with Borrelia burgdorferi in a substantial percentage of ticks. All I. scapularis were tested for the presence of B. burgdorferi. During the 12 years of this study, the presence of B. burgdorferi in I. scapularis varied from a low of zero percent in 1991-1995 to 18% in 1996. On average, fewer than 10% of all ticks examined per year were I. scapularis. In the 2000 tick season, the number of I. scapularis per year increased to 22% of submissions. This species further increased to 36.6% of ticks received in 2002.

A large‐scale spatio‐temporal binomial regression model for estimating seroprevalence trends

“…Several recent studies have recognized increasing risk in traditionally low incidence areas. These areas include Illinois (Herrmann, Dahm, Ruiz, & Brown, 2014), Iowa (Lingren, Rowley, Thompson, & Gilchrist, 2005), North Dakota (Russart, Dougherty, & Vaughan, 2014), Ohio (Wang et al, 2014), and Michigan (Lantos et al, 2017). Significant increases in canine prevalence are also seen in some areas that have not yet reported significant human incidence.…”

Spatial Distribution of Counties in the Continental United States With Records of Occurrence ofAmblyomma americanum(Ixodida: Ixodidae)

“…1 displays several clusters of counties in the south without records of A. americanum within what otherwise appears to be and are probably areas of continuous distribution. Conversely, extensive field surveys and compilations of collection records at the state level (e.g., in Nebraska and Iowa, Bartholomew et al 1995, Lingren et al 2005, Cortinas and Spomer 2013) result in portions of these states appearing as distinct geographic foci for A. americanum . We consider it likely that, had similar efforts been undertaken in neighboring states to the south or east, Nebraska and Iowa would have appeared less like geographic outliers and more like the northern edge of a continuous distribution.…”

Prevalence of Cytauxzoon felis infection in healthy free-roaming cats in north-central Oklahoma and central Iowa

“…In our study, blood samples were collected from relatively young cats, and that might have influenced the results as those cats had experienced less time being exposed to tick vectors. As the geographic distribution and range of A americanum expands northwards, 15 it is important to keep monitoring free-roaming cat populations where cytauxzoonosis has not been considered enzootic.…”