The inactivation of Ascaris suum eggs by short exposure to high temperatures

Abstract Ascaris sp. is the most prominent and resilient helminth of human health importance found in faecal sludge, making Ascaris sp. an ideal index organism for inactivation testing. Heat treatment destroys helminths, allowing for safe handling and possible reuse of sludge. Technology development focuses on rapid heating to minimize equipment size and cost. This study evaluates Ascaris suum eggs' viability with short heating time. Ascaris eggs were placed in a water bath at temperatures from 60 to 80 °C for various exposure times (5 seconds to 4 minutes) and were immediately processed and analysed via light microscopy. For all samples within these temperature and time ranges, less than 10% viable eggs were recovered. For 70, 75 and 80 °C, complete inactivation was observed for exposure time of 5 seconds and above.