Myiasis is infection with a fly larva, usually occurring in tropical and subtropical areas. There are several ways for flies to transmit their larvae to people.
. Some flies deposit their eggs on or near a wound or sore, the larvae that hatch burrow into the skin. Certain species’ larvae will move deeper in the body and cause severe damage.
. Some flies attach their eggs to mosquitoes, other flies or ticks and wait for those insects to bite people. Their larvae then enter these bites.
. One type of fly found in Africa lays its eggs on the ground or on damp cloth such as clothing or bed linens that are hung out to dry. The larvae hatch from the eggs and people get infected by contact with the ground or clothes that have fly larvae attached to them.
In Which Countries Does Myiasis Occur?
Myiasis occurs in tropical and subtropical areas. These can include countries in Central America, South America, Africa, and the Caribbean Islands.
What Are the Signs and Symptoms of Infection with Myiasis?
A lump will develop in tissue as the larva grows. Larvae under the skin may move on occasion. Usually larvae will remain under the skin and not travel throughout the body.
Is Having Myiasis Common?
Myiasis is not common in the United States. Most people in the United States with myiasis got it when they traveled to tropical areas in Africa and South America. People with untreated and open wounds are more likely to get myiasis.
What Should I Do If I Think I Have Myiasis?
Contact your health care provider for proper diagnosis and care.
How Is Myiasis Treated?
The larvae need to be surgically removed by a medical professional. Typically, the wound is cleaned daily after the larvae are removed. Proper hygiene of wounds is very important when treating myiasis. Sometimes medication is given, depending on the type of larva that causes the problem.
This noninvasive approach includes placing petroleum jelly, liquid paraffin, beeswax or heavy oil, or bacon strips over the central punctum and has been used to coax the larvae to emerge spontaneously head-first over the course of several hours, at which time, tweezers (or forceps) aid in the capture. Enlarging the punctum beforehand may make it easier to remove the larvae later as it emerges and is usually needed for botflies. Anecdotal evidence has shown the larvae to emerge within 3-24 hours after application of suffocating material.
These approaches take advantage of the larva's oxygen requirements, encouraging it to exit on its own. However, the covering should not be restrictive (eg, nail polish) because this may asphyxiate the larva without causing it to migrate out of the skin. If the larva does asphyxiate, then surgical removal is necessary.
Surgical removal with local anesthesia
The skin lesion is locally anesthetized with lidocaine and excised surgically followed by primary wound closure. Alternatively, lidocaine can be injected forcibly into the base of the lesion in an attempt to create enough fluid pressure to extrude the larvae out of the punctum. The larvae are anchored deeply to the subcutaneous by anterior hooklets and it is important to remove all parts from the site to prevent a foreign body reaction. Another surgical approach would be to perform a 4- to 5-mm punch excision of the overlying punctum and surrounding skin to gain better access to and visibility of the larva. The larva can then be removed carefully using toothed forceps (experience of B.B. Wilson, MD).
The larva should not be forcibly removed through the central punctum because its tapered shape with rows of spines and hooks prevents simple extrusion.
Furthermore, care should be taken to avoid lacerating the larva because retained larval parts may precipitate foreign body reaction. After removal of the larvae, antiseptic dressings, thorough cleansing, and debridement are indicated, as well as antibiotics if secondary infection is present.
An alternative treatment for all types of myiasis is oral ivermectin or topical ivermectin (1% solution), proven especially helpful with oral and orbital myiasis.
Wound myiasis requires debridement with irrigation to eliminate the larvae from the wound or surgical removal. Application of chloroform, chloroform in light vegetable oil, or ether, with removal of the larvae under local anesthesia, has been advocated for wound myiasis.
Surgical removal is not required unless requested by the patient, as the larvae are naturally sloughed within 5-7 weeks.
How Did I Get Myiasis?
You may have gotten an infection from accidentally ingesting larvae, from having flies lay eggs near an open wound or sore, or through your nose or ears. People can also be bitten by mosquitoes or ticks that harbor larvae. In tropical areas, where the infection is most likely to occur, some flies lay their eggs on drying clothes that are hung outside.
How Can I Prevent Infection with Myiasis?
. Take extra care going to tropical areas and spending a lot of time outside. Cover your skin to limit the area open to bites from flies, mosquitoes, and ticks. Use insect repellant and follow Travelers Health guidelines.
. In areas where myiasis is known to occur, protect yourself by using window screens and mosquito nets.
. In tropical areas, iron any clothes that were put on the line to dry.
Should I Be Concerned About Spreading Infection to The Rest of My Household?
No. Myiasis is not spread from person to person. The only way to get myiasis is through flies, ticks, and mosquitoes.
About Iranian Surgery
Iranian surgery is an online medical tourism platform where you can find the best doctors and surgeons in Iran. The price of Myiasis treatment in Iran can vary according to each individual’s case and will be determined by an in-person assessment with the doctor.
For more information about the cost of Myiasis treatment in Iran and to schedule an appointment in advance, you can contact Iranian Surgery consultants via WhatsApp number 0098 901 929 0946. This service is completely free.