bulking agent samples would be collected on a subsequent research visit to
Kiritimati to investigate the extent of the existence of these organisms in the
environment.
A sample of fresh faeces taken from a composting toilet mal participant household in September
1995
contained a large number ofGiardia lamblia
cysts, as well asT. trichuria
ova. The prevalence ofGiardia
on Kiritimati was also confirmed by health workers and visiting medical practitioners. There was no evidence ofGiardia
cysts in the compost sample taken from the toilet trial household where the fresh sample was collected (No.12)
whichindicates that the composting process provided effective removal of this protozoan parasite. This was confirmed from analysis of samples from subsequent visits.
Giardia lamblia
is an intestinal protozoa flagellate that lives in the mucus on the surface of cells in the duodenum and sometimes in the small intestine. Infection of the small intestine with this protozoa can cause the disease giardiasis. Symptoms are often absent, but the disease can cause foul smelling stools, flatulence, diarrhoea, abdominal cramps, fatigue, nausea and vomiting and in extreme cases, malabsorption36. Many waterborneoutbreaks of giardiasis have been recorded in areas where water supplies have received filtration and chlorination. Good domestic hygiene, clean water and efficient excreta management systems constitute effective preventive measures (Markell and Marietta
1981: 55-57;
Craun1978: 145;
Faechem et al.
1983: 349).
Based on the findings and advice of the microbiologist from the Richmond Pathology Service, samples were collected during the April
1996 research
visit to Kiritimati, to try and establish where the organismsVibrio
alginolyticus
andShewanella
were originating. Water samples were collected from thetank
at household No.1 in Ronton, from wells at five households in
Tabakea and Banana. Tank water was also collected from a household in Banana, and the Banana water gallery. Soil and bulking agent samples were also collected from composting toilet households for this reason. Soil samples were collected from six households.One fresh faecal sample was collected from each composting toilet household so that baseline data relating to pathogens entering the toilets could be gathered37• The samples were collected over a period of
5
days in May1996.
The faecal samples were collected in the plastic FPC tubes that were used for centrifuging and incubating theT.trichiura
ova.All
the tubes contained a small amount of phosphate buffered saline solution to, try and36 Inability to assimilate, particularly substances such as fats, carbohydrates, and vitamin b12- "Sl It canot be asswned that one sample will reveal every pathogen that my be entering the toilet.
maintain some stability until the samples were returned to Australia. All samples were transported in cabin baggage to ensure that stable
temperatures were maintained. Samples were immediately sent to the Richmond Pathology Service microbiologist in Lismore after arrival in Australia.
Unfortunately, the microbiologist advising and assisting the author was unable to conduct microbiological testing on the compost, faecal, water, leaf, and soil samples returned from Kiritimati. After the. samples had been standing in his laboratory cold storage for an extended period, another microbiologist in Lismore, Ms Sandie Safton, was asked to at least inspect faecal samples and the compost for parasites. She was able to detect
Giardia,
dwarf tapeworm and hookworm in some of the samples38• No evidence of parasites were detected in the compost samples other than
T.trichiura
ova. It was concluded that it was essential to obtain funding so that microbiological testing could be properly financed as part of the research on Kiritimati. It was also concluded that the approach to pathogen analysis should be limited strictly to pathogens entering the toilet through human excreta, and to analyse their survival in the compost. While it would have been useful to identify other possible pathogenic contamination from environmental sources such as water, it was beyond the scope and resources of this research project to do so. As noted in section3.4.1
(a), funding was obtained for a further research visit to Kiritimati and for laboratory analysis of samples.3.4.6
(a) Pathogen analysis of faecal and compost samples in1998
Nine of the faecal and twelve compost samples that were collected from composting toilet households during the research visit were analysed. Four samples from the two Australia composting toilets (Pine Valley and White) were also analysed. Details of the method used for collecting compost samples are recorded in section
3.4.5
(a). The faecal samples were collected in small sample jars with screw top lids over six days before departing from Kiritimati. Samples were stored in a refrigerator below4°C
until departure and transported in cabin baggage. On arrival in Australia all the faecal and compost samples were sent directly to the laboratory where they were re stored until analysed.All
analyses were completed within a week of arrival in Australia.38 The discovery of these parasites is mentioned to indicate what research was needed.
Faecal samples were examined microscopically using both saline and iodine stained wet preparations. The samples were then concentrated using the standard medical laboratory procedure of ethyl-acetate sedimentation. The samples were analysed in the laboratories of Sullivan and Nicholaides and Partners in Lismore, NSW by microbiologist Sandie Safton assisted by the author. Table
3.13
lists the results of the analysis of faecal samples.No. 1 No. 2 No. 3 No. 4 No. 8 No. 10 No. 12 No. 13 No. 14
Trichuris trichiura ova
E.coli cysts. Blastocystis hominis. Giardia lamblia cysts
E.coli cysts (mature & immature)
Trichuris trichiura ova, Hookworm ova, stercoralis larvae Entamoeba cysts
Trichuris trichlura ova
Entamoeba coli cysts. Giardia lamblia hominis
Trichuris trichiura ova, Hookworm ova
Trichuris trichiura ova. Hookworm ova
G.lamblia cysts. E.coli cysts. Trichuris trichium ova, Blastocystis hominis
E.coli cysts. Trichuris trichiura ova, hominis
Trichuris trichiura ova T.trichiura ova, Hookworm ova, S.stercoralis larvae
E.coli cysts (mature & immature). Trichuris trichiura ova
Blastocystis hominis. Trichuris trichiura ova
E.coli cysts. G.lamblia cysts. Trichuris trichium ova
Trichuris trichium ova, Hookworm ova, stercoralis larvae
TABLE 3. 13 Analysis of faecal samples collected during 1998 research visit to Kiritimati. Sample numbers refer to the composting toilet household identified in Figure 3.7.
Numerous enteric pathogens and commensal organisms were found in the faecal samples examined. Protozoans
(Blastocystis hominis, Entamoeba coli, and
Giardia lamblia)
and intestinal nematodes(T.trichuria, hookwonn and
Strongyloides stercoralis)
were found in significant numbers.For the culture of the compost samples, a portion of thoroughly mixed composted material was emulsified in sterile saline. A lOul loop39 was used to streak the suspension to selective media for the isolation of enteric pathogens. Culture plates were examined at 24 and
48
hours incubation for the presence of pathogens. Suspect colonies were identified using standard medical laboratory biochemical tests as well as commercially available Microbat 24 and API 20E bacterial systems.Figures
3.27
and 3.28 show these bacterial system kits in operation during the laboratory analysis for this research project.39 A lOul Loop is
a
loop of wire able to hold a particular sized drop of liquid to streak bacteria in theliquid onto the media.
FIGURE 3.27 Testing of compost samples using Microbat 24 bacterial system kit.
FIGURE 3.28 Testing of compost samples using API 20E bacterial systems kit.