Investigation of an Outbreak of Amoebiasis in a Rehabilitation Institution for Mental Patients in Taichung City

Min-Tsung Lin

2009 Vol.25 NO.11

Correspondence Author： Min-Tsung Lin

Abstract：

On May 29, 2008, a hospital in Taichung reported a suspected case of Entamoeba histolytica who was a resident in a rehabilitation institution for mental disorder patients. On June 6, this case was confirmed as amoebiasis. Fecal samples from 105 residents and workers on the same floor (4th floor) were collected. Both enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) were used to test for E. histolytica. The results showed that 15 of the 105 people were ELISA-positive. Eight of the 15 ELISA-positives were also PCR-positive. All positive cases were residents. Workers were not infected. 9.8% (9 /92) of the residents on the 4th floor were infected. This investigation used ELISA to screen possible cases, which was at least 48 hours faster than the method of microscopy and without the bias related to a person’s skill of microscopy. The results proved that ELISA is the best tool to screen mass cases in the initial stage of investigation. Moreover, E. histolytica testing must be executed before a resident admitted to a rehabilitation institution and included in residents’ annual health examination in order to find asymptomatic cases early and prevent outbreak of amoebiasis in a crowded organization.
Keywords: Amoebiasis, enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), stool microscopy