Monthly Archives: May 2017

Ehrlichiosis may be under-reported in NJ

From the abstract: The lone star tick, Amblyomma americanum, is a vector of Ehrlichia chaffeensis and E. ewingii, causal agents of human ehrlichiosis, and has demonstrated marked geographic expansion in recent years. A. americanum ticks often outnumber the vector of Lyme disease, Ixodes scapularis, where both ticks are sympatric, yet cases of Lyme disease far exceed ehrlichiosis cases. We quantified the risk for ehrlichiosis relative to Lyme disease by using relative tick encounter frequencies and infection rates for these 2 species in Monmouth County, New Jersey, USA. Our calculations predict >1 ehrlichiosis case for every 2 Lyme disease cases, >2 orders of magnitude higher than current case rates (e.g., 2 ehrlichiosis versus 439 Lyme disease cases in 2014). This result implies ehrlichiosis is grossly underreported (or misreported) or that many infections are asymptomatic. We recommend expansion of tickborne disease education in the Northeast United States to include human health risks posed by A. americanum ticks.

Read more here at EID ! NOTE: There is a Continuing Medical Education (CME) credit available (1.00 AMA PRA Category 1 ) upon participation in activity with this article. See the first page of the article for more information.

Reducing ticks by targeting hosts

Ixodes scapularis, taken by James Occi.

Ixodes scapularis, taken by James Occi. This was a photo used for the cover of of the book, “Lyme Disease: Why it’s spreading, how it makes you sick and what to do about it” by Alan Barbour.

From the Abstract: We describe a 2-yr trial to evaluate the ability of SELECT Tick Control System (TCS) host-targeted bait boxes to reduce numbers of host-seeking Ixodes scapularis nymphs in a residential neighborhood. After four successive 9-wk deployments, nymphal and larval I. scapularis infestation prevalence and intensity were significantly reduced on target small mammals. In addition, these deployments resulted in 87.9% and 97.3% control of hostseeking nymphs in treatment sites at 1 yr and 2 yr postintervention, respectively. Installation of a protective metal cover around the SELECT TCS bait boxes eliminated nontarget wildlife damage to bait boxes that resulted in failure of previous bait box types. The results are discussed in the context of the residential environment and future research needs.

Schulze T, R A Jordan, M Williams and M C Dolan 2017 Evaluation of the SELECT tick control system (TCS), a host-targeted bit box, to reduce exposure to Ixodes sxapularis (Acari: Ixodidae) in a Lyme disease endemic area of New Jersey. Journal of Medical Entomology, https://doi.org/10.1093/jme/tjx044