The electrodisinfection micro-focusing unit. (right) Jane Taylor-Flemons
and the power source for the 20, 000 litre/day electrodisinfection
is one of the most difficult infectious agents to neutralise in
water supplies. It is a parasite that infects by forming a feeder
attachment to the intestinal (gut) cells of its host (eg humans).
Its sporozoites (eggs) hatch from its oocyst (shell) and form this
attachment via a feeder organelle. Only 1-10 Cryptosporidium are
required for infection; exposing the elderly, babies and immuno-compromised
patients to serious risk of illness and even death.
exploration of the large biological and electrodisinfection parameter
landscape included phase-contrast video-microscopy at high magnification
of Cryptosporidium oocysts and sporozoites after electroporation
and boiling treatments. The morphological parameter that exhibited
the most profound change after boiling was the apical-distal (AD)
distance between the apex of the feeder organelle and
the posterior of the sporozoite. Electroporation treatments at 4
kHz (focused field strength ~7.8 x 106 V/m) produced a more pronounced
reduction in the AD distance than that produced by boiling, the
recommended treatment for neutralising drinking water during the
recent Cryptosporidium outbreak in Sydney.
highlights the need of a definitive test of the infectivity potential
of Cryptosporidium for properly evaluating even the more commonly
acceptable disinfection treatments such as boiling.
Coster, Virginia Shepherd,
Jane Taylor-Flemons, Lutz Gaedt,
Leonard Coster and Terry Chilcott