Field Notes #12: What Travels Between Wounds and Wights
- Heather McSharry, PhD
- 4 days ago
- 5 min read
What Travels Between Wounds and Wights
On injury as revelation
Field Notes is where I take one idea from the episode—something that feels like a hinge point—and follow it to see what it reveals. If you want the full story, you can read or listen to the episode here.
In the Margins
Before wight became associated with undead creatures in modern fantasy, it simply meant a living being. It's the older meaning I'm borrowing here. Every wound releases information. Some of it travels only millimeters. Some of it travels much farther. But once it begins moving, the living world begins listening.
The moment skin is broken, the chemistry changes. Blood reaches the surface. Immune cells release signaling molecules. Skin bacteria encounter a new environment and start producing different compounds. Moisture, warmth, and damaged tissue combine into an entirely new chemical landscape.
To us, a wound is an injury. To many other organisms, it's a revelation.
Some are drawn to it. Some avoid it. Some arrive to feed. Others to heal. A wound is not just damaged tissue, it's an environment that's suddenly changed.
Communication in nature can be the kinds of intentional messages we're familiar with: a bird's song, a wolf's howl, the scent of a flower attracting a pollinator. But nature also communicates through changes that other organisms have evolved to detect.
Underlined
These are some organisms that have evolved to detect chemical signals from wounds:
Parasitic flies
Species such as New World screwworm use chemical cues released by fresh wounds to locate places where their larvae can develop.
Scavenging flies
Many blow and flesh flies respond to volatile compounds released by damaged tissue, often arriving within minutes or hours of an injury.
Predators
For some predators, changes in an animal's chemical signature—including compounds released from damaged tissue—provide another indication that prey may be vulnerable.
Opportunistic microbes
Some bacteria and fungi are able to detect compounds released by damaged tissue, allowing them to colonize wounds where nutrients have become available.
Though these organisms respond for different reasons, that they respond at all reveals that injury creates an entirely new chemical conversation.
What It Points To
We perceive only the version of the world that our physiology allows.
Outbreak Watch
Updates will only include information verified through credible reporting or official public health sources.
As of mid-morning, July 1, 2026:
The Bundibugyo Ebola outbreak in the Democratic Republic of the Congo remains the largest active outbreak in the world and continues to outpace response efforts.
Current reporting places the outbreak at 1,274 confirmed cases with 360 deaths and 502 individuals hospitalised in isolation. The same operational challenges continue to hamper containment: delayed case detection, incomplete contact tracing, insecurity, limited treatment capacity, and difficulties conducting safe burials. Response agencies continue to emphasize that the outbreak remains a regional concern requiring sustained international support.
Uganda's associated Bundibugyo Ebola outbreak remains comparatively small and appears to be stabilizing. Officials report 20 confirmed cases and two deaths, with no newly reported Ebola cases in more than two weeks. Most cases have been linked to imported infections from the DRC followed by limited local transmission. Health officials continue to describe the Ugandan outbreak as being under control while maintaining intensive surveillance.
International monitoring continues as well. The physician diagnosed with Bundibugyo Ebola after returning to France remains in isolation, while Germany continues to care for the U.S. humanitarian worker who was medically evacuated there in May. Both cases were identified rapidly, and public health officials continue to assess the risk to the broader public in Europe as very low.
The Bundibugyo virus remains especially challenging because no licensed vaccine or specific treatment is currently available.
A second viral hemorrhagic fever is now being monitored in Uganda.
Yesterday, Uganda formally notified the World Health Organization of a Marburg virus disease outbreak in the country's west. WHO has confirmed notification of at least one case, while multiple reporting sources indicate two confirmed cases and describe the outbreak as localized.
Marburg virus is closely related to Ebola and spreads through direct contact with the bodily fluids of infected people. Like Bundibugyo Ebola, there are currently no licensed vaccines available for routine use, although several Marburg vaccine candidates are in advanced stages of development.
Uganda has a strong track record of containing Ebola and Marburg outbreaks, but the appearance of a second filovirus while the country is already responding to imported Ebola cases adds another layer of complexity to regional public health efforts. At this stage, officials emphasize that the Marburg outbreak appears localized.
This will be the final Outbreak Watch update on the MV Hondius Andes hantavirus outbreak unless significant new information emerges.
The outbreak remains unchanged at 13 confirmed cases and three deaths. All U.S. passengers completed their 42-day monitoring period without developing hantavirus disease, and CDC has concluded its response.
While the outbreak resulted in fatalities and an unusually large international public health response, no evidence of sustained person-to-person transmission occurred among monitored U.S. contacts. With monitoring complete and no additional cases identified, this investigation can now be considered closed.
New World screwworm continues to expand in Texas.
USDA has confirmed 29 domestic animal cases across multiple Texas counties. No wildlife cases or wild fly trap detections have been reported, though surveillance in wildlife remains an important challenge because infected wild animals are much more difficult to detect than livestock.
Federal and state agencies continue sterile fly release operations, quarantine enforcement, animal movement controls, surveillance, and treatment efforts aimed at preventing screwworm from becoming reestablished in the United States.
Current Impact: Southern livestock import restrictions remain in place, while sterile fly production and release operations continue to expand in response to the growing outbreak.
Economic Impact: Most current costs continue to stem from surveillance, containment, movement restrictions, inspections, and response operations rather than direct livestock losses.
Potential Impact: The greatest long-term concern remains establishment of screwworm in wildlife populations. If the parasite becomes established beyond domestic livestock, eradication becomes substantially more difficult and the consequences could extend to livestock production, companion animals, wildlife management, interstate animal movement, and international trade.
Postscript
Thank you for subscribing. 🫶
This week, behind the scenes, I’ve been working on an Infectious Dose website redesign, on a platform that should result in fewer glitches. Hopefully.
Meanwhile, Gypsy had strong opinions about interior design this morning. Seconds after I made the bed, she hopped up and settled in. Apparently, she appreciates a well-made bed. Same, Gypsy. Same.
We've been having quite a string of outbreaks recently, and I'm not entirely surprised. We'll have to wait and see if the outbreak situation becomes more urgent than the scheduled episode. If it does, I'll push back next week's military vs microbes.
Until then, don't forget to check out last year's Fourth of July comedy episode...not only does it have great tips for food and firewook safety, it might make you laugh, and it ends with a tribute to the bench scientists whose work rarely gets the spotlight.
Until next week,
— Heather
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