“Doctor Venn, can you help her?”
The old Doctor nodded slowly. “She has just gotten into some bad berries,” the Doctor turned over the palms of the young girl which were stained with red juices.
“Oh.”
“We will need fresh water,” said the Doctor, “and warm blankets.”
“Of course.”
Once she was along, the Doctor fished out a jar. “Very few appreciate you as I do my soft bodied friends.” She opened the jar and carefully and precisely placed three leeches on the body of the patient.
Purifying Leeches
These leeches are carefully raised and kept in special sustaining glass jars until needed for treatment of toxins and diseases. They seem just like any other leech except to the trained eye who will notice that they are exceptional clean.
Sea of Stars RPG Design Journal 