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Emerging Diseases
Published in Gary S. Moore, Kathleen A. Bell, Living with the Earth, 2018
Gary S. Moore, Kathleen A. Bell
Background: Cryptosporidium is a single-celled microscopic protozoan parasite that belongs to the Class Sporozoa. These organisms are not normally motile and asexually reproduce by multiple fission and sexually by gamete fusion. The resistant form of the parasite is called an oocyst, which is characterized by an outer protective shell that protects the organism against environmental extremes such as heat, cold, dryness, and chemical insult. There are several species of Cryptosporidium, but there is only one pathogenic species, Cryptosporidium parvum. This organism is widely distributed in the intestines of animals and humans, and normally causes infections in humans by the fecal oral route. It is estimated that as few as 30 or even one oocyst(s) may cause infection when swallowed.164 Cryptosporidium is therefore a highly infectious enteric parasite, widely distributed, that is resistant to chlorine and difficult to filter thereby making it a serious threat to water supplies.
Cryptosporidiosis in Ruminants
Published in J. P. Dubey, C. A. Speer, R. Fayer, Cryptosporidiosis of Man and Animals, 2018
Cryptosporidium spp. have direct life cycles, and in calves the life cycle of C. parvum is complete in about 4 d.190 Infection is by the fecal-oral route. The main presenting sign of cryptosporidiosis in calves is diarrhea associated with profuse shedding of infective oocysts (in the order of 106 to 107/g of feces).110,190 At least one large survey of the agents causing diarrhea in neonatal calves684 found a highly significant association between Cryptosporidium sp. infection and diarrhea. Varying degrees of dullness, anorexia, fever, and loss of condition can occur, but monoinfections with C. parvum seldom cause the acute dehydration, collapse, and high mortality experienced in enterotoxigenic Escherichia coli (ETEC-K99+) or rotavirus infections, for example. These observations are in line with experimental transmission studies using oocyst preparations rendered free of live bacteria or viruses by chemical treatment.329,825
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Published in Jamie Bartram, Rachel Baum, Peter A. Coclanis, David M. Gute, David Kay, Stéphanie McFadyen, Katherine Pond, William Robertson, Michael J. Rouse, Routledge Handbook of Water and Health, 2015
Waterborne infectious diseases are caused primarily by pathogenic bacteria, viruses, and protozoa and are associated with the presence of human or animal fecal material, since these microbes are generally transmitted via the “fecal–oral route” (Chapter 2). Of the several dozen known and suspected pathogens transmitted in water, recent evidence suggests that the relative contribution of specific microbes to the burden of disease varies widely by setting and population. Rotavirus, Cryptosporidium, enterotoxigenic Escherichia coli (ETEC), Shigella, Vibrio cholera, and Salmonella are among the most important globally (Kotloff et al. 2013). Although rapid, low-cost, simultaneous methods for detection of multiple pathogens in water is the focus of intense research, current methodological constraints limit our ability to rapidly and accurately identify all pathogens that may be present and determine whether they exist in quantities that pose risks to public health. Because some pathogens have low infectious doses, even as few as a single microbe, even small numbers of pathogens in water may contribute to increased risk of disease. Detecting them directly may therefore require concentration of large volumes of water. So, to assess water safety, we look for the common element that is associated with most of these microbes: human or animal feces, markers of which are more easily detected than specific pathogens.
The perception and expectation of WASH technology services in Pointe-Noire Ville and Tandou-Boma, Republic of Congo through novel conventional-SERVQUAL-AHP model
Published in Urban Water Journal, 2022
Owassa Dza Rebecca Annisha, Zifu Li, Ngomah Madgil Don Stenay Junior, Oscar Omondi Donde
International targets to reduce inadequate WASH coverage were set under the Millennium Development Goals (MDGs, 1990–2015) and now the Sustainable Development Goals (Roche, Bain, and Cumming 2017). The SDGs stress the need for universal access, progressive reduction of inequalities and include hygiene in addition to the provision of water and sanitation services (Weststrate et al. 2019). The provision of adequate and appropriate WASH services plays a key role in the control of infections transmitted through faecal-oral route. Access to adequate water, sanitation and hygiene has the potential to prevent at least 9.1% of the global disease burden and 6.3% of all deaths, and positively contributes to economic wellbeing. While improved water sources reduce diarrhea morbidity by 21%, improved sanitation reduces diarrhea morbidity by 37.5%. Furthermore, the act of washing hands at critical times can reduce cases of infection by as much as 35%. Improvement of drinking-water quality, such as point-of-use disinfection, would lead to a 45% reduction of water related infections (Weststrate et al. 2019; WHO/UNICEF 2019).
Housing conditions and health in Indigenous Australian communities: current status and recent trends
Published in International Journal of Environmental Health Research, 2021
The four selected disease types were (i) shigellosis, (ii) helminthiases, (iii) trachoma, and (iv) acute rheumatic fever. Shigellosis is an intestinal infection that is notifiable in NT and is caused by Shigella bacteria. It is transmitted by the faecal-oral route, and tends to reflect poor hygiene and sanitation conditions. In-depth (albeit occasional) syntheses of enteric disease notifications in NT provide Indigenous-specific shigellosis rates for children between 0 and 4 years (the age group that bears a disproportionately high shigellosis disease burden). Acute rheumatic fever (ARF) has been linked to streptococcal skin infections (McDonald et al. 2004), which in turn are commonly preceded by scabies infestation. ARF is a notifiable disease in NT, and Indigenous-specific rates are reported in tables supplementary to the national health performance framework report (AIHW 2017). A range of helminth infections – hookworm (A. duoedenale), whipworm (T. trichiura), Strongyloides stercoralis, and dwarf tapeworm (H. nana) – have recently been subject to longitudinal assessments in the academic literature (Davies et al. 2013; Crowe et al. 2014; Willcocks et al. 2015; Mayer-Coverdale et al. 2017). All four helminths are transmitted via human faeces and hence indicate inadequate sanitation. Finally, trachoma is an infectious eye disease for which face washing is a key prevention measure. Trachoma has been the subject of a large-scale screening and treatment programme in remote Indigenous communities since 2006, and annual reports present prevalence estimates for Indigenous children 5–9 years at a regional level.
Overview of methodologies for the culturing, recovery and detection of Campylobacter
Published in International Journal of Environmental Health Research, 2023
Marcela Soto-Beltrán, Bertram G. Lee, Bianca A. Amézquita-López, Beatriz Quiñones
Other environmental sources such as untreated water or unpasteurized milk as well as direct contact with feces from farm animals are considered relevant vehicles for campylobacteriosis (Figure 1). Moreover, untreated water has been overlooked as a leading source of Campylobacter. Ground/well water has been more likely to be a risk factor in the dissemination of human infections when compared to municipal surface waters (Hyllestad et al. 2020). In addition, the use of untreated water has been shown to lead to the transmission of Campylobacter in domesticated farm animals during the outdoor grazing period, contributing to the increase of positive samples in the tested animal hosts (Kaakoush et al. 2015). Moreover, C. jejuni outbreaks due to the consumption of unpasteurized milk have increased steadily during the recent years (Mungai et al. 2015), and some of these outbreaks have led to GBS in some patients in the United States (FIOD 2008). Contamination with animal feces or udder infection has been attributed as the source of C. jejuni in milk outbreaks. Infections due to non-food exposure, transmitted by the fecal-oral route, can occur because of contacting animal or human feces and is believed to result in uncommon/sporadic campylobacteriosis (Figure 1). Campylobacteriosis also can occur from travel-related infections associated with the consumption of contaminated food and water in some travel destinations with higher risk in the Americas, Asia, and some European countries (Kaakoush et al. 2015). Travel per se does not contribute to transmission but infected individuals can help disseminate strains with novel antimicrobial or virulent profiles to new and unexposed geographical locations.