April Research Round Up
Lyme disease in a neonate complicated by the Jarisch–Herxheimer reaction
This case report, authored by paediatric specialists from the University of Toronto and Toronto's Hospital for Sick Children (SickKids), documents a case of Lyme disease in a 21-day-old infant who presented with symptoms of disseminated Lyme disease after being bitten on the arm by a blacklegged tick (Ixodes scapularis) that subsequently tested positive for Borrelia burgdorferi, the bacterium that causes Lyme disease.
American dog ticks along their expanding range edge in Ontario, Canada
This study uses passive surveillance data collected between 2010 and 2018 to help determine where American dog ticks (Dermacentor variabilis) populations had their greatest concentrations in Ontario and where they were spreading. During that nine year period, more than 17,000 American dog ticks were collected by public health units, making this tick species the second most common in the province. (With over 22,000 specimens collected during the same time period, blacklegged ticks (Ixodes scapularis) ranked first).
Management and clinical outcomes of Lyme disease in acute care facilities in 2 endemic regions of Quebec, Canada: a multicentre retrospective cohort study
Acknowledging that little is known about how Lyme disease is managed in Canada and what the longterm outcomes are for patients due to a lack of published data, these researchers set out to study 272 patients treated at more than a dozen healthcare facilities in two high-risk regions of Quebec in an attempt to get a handle on the situation.
The N-terminal domain of the Agrobacterium tumefaciens telomere resolvase, TelA, regulates its DNA cleavage and rejoining activities
I won't pretend to understand all of the information in his paper by University of Saskatchewan researchers, but the takeaway is that these scientists have made an important discovery about how certain organisms -- Borrelia burgdorferi among them -- reproduce, something that could ultimately bring medical researchers one step closer to devising treatments aimed at short-circuiting the replication process and ultimately produce a cure for Lyme disease.
Sentinel Surveillance Contributes to Tracking Lyme Disease Spatiotemporal Risk Trends in Southern Quebec, Canada
This study, undertaken by Quebec researchers between 2015 and 2019, focusses on regions of southern Quebec that boast the highest provincial rates of Lyme disease in an effort to determine if a cost-effective approach to monitoring Lyme disease risk in a large territory over many years could be developed. In all, 21 sites located within provincial or regional parks known to have emerging blacklegged tick populations and appropriate forest composition were selected for sampling twice per year.
Pacemaker Explantation in Patients With Lyme Carditis
In cases where Lyme disease was not diagnosed early enough and a pacemaker needed to be implanted in order for a patient's heart to maintain normal atrioventricular (AV) node conduction in the face of Lyme carditis, this paper by Queen's University researchers concludes that the pacemaker can be safely removed following antibiotic treatment so long as the AV node has returned to normal function. Most of the time conduction issues resolve within ten days of treatment although temporary disruptions can last as long as 42 days.
Lyme Disease, Anaplasmosis, and Babesiosis, Atlantic Canada
This research letter penned by federal and provincial public health professionals highlights the small but real risk of Maritime residents contracting the tick-borne parasite Babesia microti from the same ticks that carry Lyme disease and anaplasmosis in the region, setting up a scenario where locals could potentially be infected with multiple tick-borne infections from a single bite.
VlsE, the nexus for antigenic variation of the Lyme disease spirochete, also mediates early bacterial attachment to the host microvasculature under shear force
This paper, a co-operative effort between molecular biologists from several institutions including the University of Calgary, details ongoing efforts to determine whether surface lipoprotein VIsE is adhesin-X, an unknown molecular component that likely works with spirochetal adhesin BBK32 and multifunctional surface protein OspC to assist Lyme bacteria in successfully disseminating throughout the body early in the infectious process by slowing it down upon infiltration of the fast-flowing blood steam and helping it to adhere to blood vessel walls, something that is critical for the bacteria
Behavioural risk factors associated with reported tick exposure in a Lyme disease high incidence region in Canada
Recruiting more than 10,000 randomly selected residents of the Estrie region of Quebec between June and September 2018, researchers used a questionnaire in an effort to determine if there was a connection between human behaviour and tick exposure in this high Lyme risk region. This study found that only roughly a quarter of people they surveyed did tick checks, a third used tick repellants, and just under half showered after outdoor activities.