Abstract
What’s new, what’s hot, what’s timely? If you don’t have time to search the Internet for the latest developments that might affect your work environment, you just might find some of that information in this Capsule column. Please e-mail any comments, suggestions, or insights to Robert A. Rasmussen at
Recruiting the Public to Safely Perform an Experiment Involving RG2-Rated Pathogens
Campylobacter bacteria are among the most widespread human pathogen infections in the world. The most common campylobacter species, Campylobacter jejuni, causes an estimated 2 million cases of enteric disease in the United States alone. Infection is acquired orally, but foodborne sources account for only ∼50% of infections. Campylobacter infection of domesticated farm animals is also widespread, and these bacterial reservoirs are suspected sources of much of the other half of human campylobacter infections. How zoonotic human campylobacter infections can result without direct animal contact is not clear. To better understand if and how recreational walking may function as a zoonotic pathway, a group in the United Kingdom chose a novel laboratory setting and set of research materials to study a number of epidemiological parameters regarding campylobacter transmission. 1 They conducted a 16-month-long study using recruited citizen scientists to repeatedly ramble over selected 4-km, public-access walking routes through areas with proximity to farmlands where campylobacter may be expected. Half the volunteers took their assigned walks in East Anglia, where cropland dominates, while the other half took their walks in England’s Northwest, a region where livestock farming is common. During each of these walks, oversized fabric boot socks were worn over one of each hiker’s shoes. After each walk, the boot socks were mailed off to a central lab for analysis.
The article includes extensive statistical analyses to show seasonal fluctuations and how temperature and precipitation conditions at the time of walk correlate with campylobacter levels. The data generated showed greater campylobacter levels in the Northwest compared with East Anglia (predictable due to the greater proximity to livestock); also, observed winter peaks of campylobacter levels in both regions were surprising because overall infection rates in the United States peak in late June. However, the article’s content is most notable for the organizing and training of the citizen scientists to safely carry out both “sample” collecting and the triple-packaging and shipping of potentially RG2 pathogen-infected boot socks to the lab for polymerase chain reaction and culture assays. A total of 40 citizen scientists were recruited to walk in groups of 3 over 6 different routes. Before each walk, each volunteer placed a plastic boot cover and then a fabric boot sock over a single shoe. At the completion of a walk, the citizen scientists each put on nitrile gloves, and then boot socks were removed and placed into a suitably sized biohazard bag they had been given. This was placed inside a secondary sealable plastic bag, which was then placed in a plastic-lined envelope specifying it contained a UN3373 Biological Substance and mailed to the lab. It is assumed that no “laboratory”-acquired infections occurred during this project as no mention was made as such. It would have been of interest for the article to cite the known overall incidence of campylobacter infections among regular recreational walkers in England to put their experimental results in context, but the methodology is still a fun read.