We just received a message from a reader in a rural area of North Florida. She wrote, “Three people in my household have a skin infestation with white worms. I think it may be screwworms. Do the people need to be separated from others? Is it contagious? How should I treat the house?”
For anyone unfamiliar with these nasty creatures, screwworms are a nickname for the larvae of blowflies. There are two different species: primary screwworms and secondary screwworms. Primary screwworms only feed on living tissue and can cause deep lesions in the skin. Secondary screwworms feed only on dead tissue. If our reader’s housemates are indeed infected with screwworms, then we assume they are primary screwworms because they would be feeding on living tissue.
Primary screwworms are white worms that can be found in wounds, cuts, and sores on the skin. So, how does this happen? Adult females lay eggs only once in their life, and they do so in an open wound. She deposits about 400 eggs, and within hours the eggs hatch and the feeding begins. As the screwworms eat, they eventually begin to eat healthy tissue and can even spread to muscles and the lungs. If the infested site grows, other adult females will also lay their eggs in the area. After a few days of eating, the screwworms will detach from their host and burrow into the ground where they pupate, emerge as adults, and begin the cycle over again. So, as we mentioned, these are nasty specimens!
While screwworms do sometimes attack humans, it isn’t a very common occurrence. In fact it is extremely rare. We can’t confirm that our reader’s housemates ail from screwworms, but regardless, we recommend that our reader get her housemates to the doctor as soon as possible to be checked and/or treated for screwworms. Most treatments involve manually extracting all larvae from the body. As we are not medical professionals, we cannot administer any medical advice beyond recommending them to see a doctor.
In conclusion, a reader reached out to us because she believes her roommates might be suffering from screwworms. We encourage them to see a doctor immediately.