According to the study data this is showing that lyme threat; in West largely due to Eastern ticks. Even more surprising is that tick test orders from Californians now edges out tick test requests from traditionally endemic states with smaller populations such as Vermont, New Jersey, Pennsylvania and Connecticut.
The 11-year passive surveillance data reporting by LMZ reveal that most of the Lyme disease bacteria in these western ticks was finding in non-western, non-endemic species. Those tick bites and the Lyme disease were associated with travel to the eastern United States. Our data show that only 2%, or 9 of 430 native ticks; had Lyme there while 25%, or 30 of 119 infecting ticks originating in the East but were plucked off of people in the West.
Lyme threat in west
That means that the threat of Lyme in the West is not from their ticks. Revealing this unexpecting trend is one of the many new; more detailing analyses of little-studied public health endpoints relating to tick-borne illness in the United States that are now possible since Rich; and colleagues establishing the LMZ in 2006. The overall incidence of Lyme disease in the West is 0.2 cases per 100,000 persons per year comparing to 30–80 in the Northeast.
A number of tick surveillance studies have trying to connect tick data with the risk of disease in the West; but traditional tick-collecting methods are not able to link tick information; and diseases they carry directly to the humans who were bitting. This is noteworthy because Ixodes pacificus has long being thought to be the important tick. This is less important to the average person; but it does emphasize that we still don’t understand how Lyme works in the West.
Endemic western ticks
It seems that it is a much more complicated story than we surmising; and much more complicated than in the East, where it’s basically one tick and one bacterium. Finding that 430 endemic western ticks were from three Ixodes species: I. pacificus, I. spinipalpis, and I. angustus while I. scapularis was the most common species among the 119 non-endemic ticks. The researchers used real-time PCR and DNA sequencing to accurately identify each tick sample to the species level.
In the eastern and north-central United States; I. scapularis is the primary vector of several pathogens including Borrelia burgdorferi which causes Lyme disease; Borrelia miyamotoi, Anaplasma phagocytophilum and Babesia microti. In addition to differences in hosts and tick vectors; the species and population of Lyme spirochetes is more diverse in California, the authors point out.