It is noteworthy that 4 of the 10 H

It is noteworthy that 4 of the 10 H. taichui worm-positive casesin the present study were STE-negative in Kato-Katz fecal exami-nations. This is undoubtedly due to the low egg laying capacity ofHaplorchis worms in humans (Sato et al., 2009a), and there may bea substantial number of false egg negative cases among the actualHaplorchis-infected cases. In our study, the total EPG of the 6 STEpositive cases was 8736, and from them a total of 76167 Haplorchisworms were recovered. Hence, the EPG/worm was estimated as0.11, and EPD (eggs per day)/worm as 22 (assuming that the dailyfecal amount was 200 g). Therefore, recovery of only 1 egg in a Kato-Katz smear indicates infection with a fairly high number of adultflukes. If 1 egg was found on a Kato-Katz smear, the EPG would be24 (the amount of feces per Kato-Katz smear, 41.7 mg) (Chai andLee, 2002), and the EPD would be 4800. Then, the worm burdenin this case could be estimated to be 218 worms (4800 ÷ 22). TheEPD/worm of Haplorchis (in particular, H. taichui) in humans wasreported previously to be 82 based on data from 25 individuals inThailand (Sato et al., 2009a). This was almost a 4-fold higher figurethan ours. However, Sato et al. (2009a) stated that the EPD/wormwas highly variable (14–168) according to the worm burden, beinghigher in low worm burden cases (6000 worms).