Crows are hosts for Campylobacter jejuni bacteria in Davis, California — but the significance of this, no one knows

© 2016 Peter Free

Citation — to study

Conor C. Taff, Allison M. Weis, Sarah Wheeler, Mitchell G. Hinton, Bart C. Weimer, Christopher M. Barker, Melissa Jones, Ryane Logsdon, Woutrina A. Smith, Walter M. Boyce, and Andrea K. Townsend, Influence of host ecology and behavior on Campylobacter jejuni prevalence and environmental contamination risk in a synanthropic wild bird, Applied and Environmental Microbiology, DOI: 10.1128/AEM.01456-16 (pre-print online, 03 June 2016)

Citation — to press release

American Society for Microbiology, Crowds of crows spread C. jejuni: Are humans vulnerable?, ScienceDaily (04 June 2016)

Stay away from that bird?

From the abstract:

Campylobacter jejuni [see here] is a foodborne pathogen that often leads to human infections through the consumption of contaminated poultry. Wild birds may play a role in the transmission of C. jejuni by acting as reservoir hosts.

We tested the hypothesis that host social behavior and habitat play a major role in driving transmission risk. C. jejuni infection and host ecology were studied simultaneously in wild American crows (Corvus brachyrhynchos) in Davis, California over three years.

We found that 178 of 337 samples tested were culture-positive (53%), with infection varying by season and host age.

Among adult crows, infection was highest during the winter when migrants return and crows form large communal roosts. Nestlings had the highest risk of infection . . . .

We deployed GPS receivers to quantify habitat use by crows; space use was non-random, with crows preferentially occupying some habitats while avoiding others. This behavior drastically amplified the risk of environmental contamination from feces in specific locations.

© 2016 Conor C. Taff, Allison M. Weis, Sarah Wheeler, Mitchell G. Hinton, Bart C. Weimer, Christopher M. Barker, Melissa Jones, Ryane Logsdon, Woutrina A. Smith, Walter M. Boyce, and Andrea K. Townsend, Influence of host ecology and behavior on Campylobacter jejuni prevalence and environmental contamination risk in a synanthropic wild bird, Applied and Environmental Microbiology, DOI: 10.1128/AEM.01456-16 (pre-print online, 03 June 2016) (at Abstract) (extracts)

Significance —interesting cawing about not much?

From the press release:

Data is lacking on the prevalence of crow-borne strains of C. Jejuni that have the potential either to infect humans, or to easily mutate to infect humans.

Nor is it clear whether Campylobacter sickens crows — another issue which team members are investigating.

“Whether crows represent a major source of domestic animal and, ultimately, human C. jejuni infection remains uncertain, but our study indicates that data on infection prevalence and molecular characteristics of isolates alone will be insufficient for understanding C. jejuni transmission dynamics,” the investigators write.

© 2016 American Society for Microbiology, Crowds of crows spread C. jejuni: Are humans vulnerable?, ScienceDaily (04 June 2016) (extracts)

The moral? — To be safe, don’t eat the crow poop at UC Davis

Saying more than this is probably medically too much. Just yet.