The presence of large Trichuris spp. eggs in human faecal samples is occasionally reported. Such eggs have
been described as variant Trichuris trichiura or Trichuris vulpis eggs. Within the frame of a randomised
controlled trial, faecal samples collected from 115 Bulang individuals from Yunnan, People’s Republic of
China were subjected to the Kato–Katz technique (fresh stool samples) and the FLOTAC and etherconcentration
techniques (sodium acetate–acetic acid–formalin (SAF)-fixed stool samples). Large
Trichuris spp. eggs were noted in faecal samples with a prevalence of 6.1% before and 21.7% after
anthelminthic drug administration. The observed prevalence of standard-sized T. trichiura eggs was
reduced from 93.0% to 87.0% after treatment. Considerably more cases of large Trichuris spp. eggs and
slightly more cases with normal-sized T. trichiura eggs were identified by FLOTAC compared to the etherconcentration
technique. No large Trichuris spp. eggs were observed on the Kato–Katz thick smears.