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Infectious Diseases

Drain Fly Infestation



My illness began September 2001 when my stomach popped out and pants did not fit properly. My bowel movements became loose with lots of gas. At the same time, my apartment was infested with drain flies. They were attracted to the cat`s litter box. There were so many flies that you had to wave your hand while you eat to keep them from landing on your food. Within a month I was very sick with bloody diarrhea with mucous and a very bad all over feeling. My dog and cat got bloody diarrhea also. My GI doctor ordered O&P test and stool culture. I was put on Flagyl right away and my pets were put on the same medication by the vet. The animals got better, I did not. My O&P test was negative. The culture showed Staph. I was then placed on antibiotic for 10 days but it did not make a difference in how I felt. I had a stool culture again a few weeks later and it showed Staph again and was placed back on antibiotic which again did not make me feel any better. Colonoscopy in November showed mild chronic inflammation nonspecified and internal hemorrhoids. December I had a laparascopy to remove a bleeding ovarian cyst and lysis of adhesions. In December Blastocystis showed up in my stool and I was put on Flagyl again. I continue to feel sick in varying degrees with my stomach very distended, overall bad feeling, weak, mentally fuzzy. My doctors are leaning towards irritable bowel. My question is this, do you think the fly infestation brought on my illness or was it coincidental? I have had at least 15 O&P tests, all negative except for the Blastocystis in December. Could the flies have given me something other than a parasite? Abdominal CT scan showed diverticulosis, sigmoid colon and internal hemorrhoids, otherwise normal. Small bowel series, normal. Routine blood tests have been normal. However, I have an ANA titer reading of 1:280 and I am being seen by a rheumatologist. He states I do not have all the signs of lupus but he wants to see me every six months.

Thank you for your time.


I do not think that the fly infestation is the cause of your illness. It appears that you have had a thorough evaluation. One long shot to consider is consultation with an infectious disease specialist. Sometimes new ideas can arise that might lead to diagnostic testing that has not been thought of before. I hope this information is of some help. 

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Response by:

Peter D Walzer, MD Peter D Walzer, MD
Professor of Clinical Medicine
College of Medicine
University of Cincinnati