Q. I recently visited Belize. I was bitten by what I thought was a mosquito, however after 7 weeks the welt still hasn't gone away. I kept it irrigated with peroxide, and took antibiotics for 10 days. After noticing movement under the skin I had a surgeon friend open the area where we found a worm! My question and one he can't find an answer to is this. I assume I was bitten by a black fly which left larvae, will I develop more worms? Is there a particular antibiotic I should be on?

We left the area open so it could drain, at this time it is clear. I'm just concerned about worms developing elsewhere in the wound, and would the worm we removed have laid eggs that would hatch in the future. The surgeon feels there is nothing to worry about, but I am still very concerned as no one in this area has seem to have seen anything like this before. Can you help?

A. Travel to tropical areas does indeed bring the possibility of exposure to diseases uncommon in the U.S. Infections in Central America known to be carried by insects include malaria, dengue, filariasis, leishmaniasis, onchocercosis, and trypanosomiasis (Chagas disease).

The best possibility to clarify the diagnosis would be to collect the sample from the wound site and have the worm examined by a laboratory with experience in such matters. If local facilities cannot provide this, they are often able to ship such a sample to a reference lab elsewhere in the U.S. Treatment would then be determined by the specific diagnosis.

http://www.who.int/health-topics/idindex.htm

http://www.cdc.gov/ncidod/dpd/parasiticpathways/insects.htm

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