METHOD: The presence of Entamoeba species was examined in 504 fresh fecal samples, collected randomly from 411 humans and 93 dogs using microscopy and polymerase chain reaction (PCR) amplifying 16 s ribosomal RNA (rRNA). Data was analyzed using appropriate statistical analysis.
RESULTS: The microscopy data showed an overall occurrence of Entamoeba species of 26.3% (108/411) and 36.6% (34/93) in humans and dogs respectively. In humans, the most common species was a single infection of E. dispar (26.5%; 13/49), followed by E. histolytica and E. moshkovskii, (20.4% for each species respectively). Double infection of E. dispar + E. moshkovskii was detected at 10.2%, followed by E. dispar + E. histolytica (8.2%) and E. moshkovskii and E. histolytica (6.1%). 8.2% of the samples had triple infection with all three species. In animals, E. moshkovskii (46.7%) was the most common species detected, followed by E. histolytica, and E. dispar, at 20.0% and 13.3% respectively. Double infection with E. moshkovskii + E. histolytica and a triple infection were found in 2 samples (13.3%) and 1 (6.7%) sample respectively. Risk factor analysis showed that members of the community who used untreated water were more prone to be infected with Entamoeba.
CONCLUSION: This study provides information on the species-specific occurrence of Entamoeba infection, the potential risk factors and their zoonotic potential to humans. This is the first report to describe the molecular occurrence of Entamoeba species in dogs in Malaysia. The presence of pathogenic Entamoeba species implies that dogs could be a reservoir or mechanical host for human amoebiasis. Further studies need to be conducted to better understand the transmission dynamics and public health significance of Entamoeba species in human and animal hosts.