People at risk for mite infestations that may be shed into the urine or stool:
(1) Norwegian scabies
(2) occupational exposure where foraging mite density is high (rice or herb storehouse, other)
Features of significant infestation:
(1) repeated identification of mites in urine or stool samples
(2) presence of clinical findings suggesting an infestation (cystitis, hematuria, mucosal lesions in bladder or rectum)
(3) exclusion of any other explanation for the symptoms or findings
(4) exclusion of accidental environmental contamination
(5) exclusion of intentional contamination
(6) significant immunosuppression or underlying disease that would predispose the patient to an infestation
Ideally the mite should be speciated by an expert, since this can help determine its infectivity for humans.
Cause of false positive samples:
(1) contamination of open specimen containers
(2) environmental contamination
(3) artifact
(4) misidentification of Schistosome eggs
(5) swallowed mite eggs passing into stool
