Screwworms in Humans: How They Affect You, Causes, Prevention, and Treatment

Human Screwworm Infection: Symptoms and Effective Treatment

Reading time : 1 minute, Discovery Chepe Id-724-SAL
Published in 05-28-2025

Images may contain copyright. Illustration of affected skin.

When most people think of parasites, they often imagine something out of a science fiction movie. However, the screwworm is a very real and potentially deadly threat especially in tropical and subtropical regions. The infestation, known medically as *myiasis*, can affect both animals and humans, leading to severe tissue damage if left untreated.

What is the Screwworm?
The screwworm is the larval stage of the *Cochliomyia hominivorax*, a parasitic fly that lays its eggs in open wounds. Once hatched, the larvae commonly referred to as "screwworms" begin feeding on the host's living tissue. Unlike other maggots, these worms don't consume dead flesh; they prefer fresh, living tissue, making them especially dangerous for humans.

Causes of Screwworm Infestation in Humans:
1- Open wounds or skin lesions: These provide the perfect entry point for the screwworm fly to lay eggs.
2- Unsanitary living conditions: Poor hygiene increases the likelihood of exposure.
3- Travel to endemic regions: Areas in Central and South America, Africa, and parts of Asia carry higher risks.
4- Contact with infected animals: Pets and livestock can also carry the parasite.

Causes and Consequences of Screwworms on Human Health

Images may contain copyright. Illustration of affected skin.
How to Recognize an Infestation:
a) Severe pain: The larvae burrow deeper into the tissue, causing intense discomfort.
b) Foul odor: As tissue breaks down, a rotten smell may occur.
c) Moving sensation under the skin: Some people report feeling the worms inside their wound.
d) Visible larvae: In advanced cases, the white or yellowish larvae may be seen in the wound.

Preventive Measures:
1- Cover open wounds: Use sterile bandages when outdoors, especially in endemic zones.
2- Maintain proper hygiene: Clean cuts and abrasions with antiseptics regularly.
3- Avoid fly-infested areas: Use insect repellents and mosquito nets if necessary.
4- Vaccinate pets and livestock: Keeping animals healthy reduces the risk of human transmission.
5- Report outbreaks: Informing health authorities can help control spread.

Treatment Options:
The good news is that with proper medical attention, screwworm infestations are treatable. Here are the most common approaches:

1- Mechanical removal: Doctors may extract the larvae manually using forceps. This must be done carefully to avoid leaving parts of the larva behind.

2- Topical applications: Substances like turpentine oil or chloroform can suffocate the larvae, prompting them to exit the wound. These should only be used under medical supervision.

3- Oral or topical antibiotics: To prevent or treat secondary infections caused by tissue damage.

4- Surgery: In severe cases, debridement or surgery may be necessary to remove necrotic tissue.

Case Studies and Real-Life Impacts:
Although the United States was declared free of screwworm in the 1980s thanks to the Sterile Insect Technique, occasional cases still appear due to international travel. In 2016, a rare outbreak among endangered Key deer in Florida raised public health concerns, reminding authorities that the threat is not entirely eradicated.

Final Thoughts
The idea of a parasite burrowing into human flesh is terrifying, but knowledge is power. By understanding the causes, recognizing the symptoms, and taking basic precautions, the risk of screwworm infestation can be drastically reduced. If you suspect an infection, seek medical help immediately. The earlier it's treated, the better the outcome.

Stay safe, stay clean, and always treat wounds with care even the smallest scratch can open the door to something much more dangerous.