1.3.4 Helminths
Major helminths causing waterborne infestations are nematodes which include
ascarids, pinworms, hookworms, strongylids, angiostrongylids, capillarids and
guinea worms, flukes which include schistosomes and liver flukes, tapeworms
together with the beef, red meat and fish tapeworms as well as cystic and alveolar
hydatid tapeworms. Improper sanitation and contaminated water facilitate the transmission of these helminths both among animals and humans (Strunz et al. 2014). The
lifecycles of the maximum of these helminths are very established and they can be
easily controlled by breaking these cycles. Recent studies suggest that waterborne
helminth infestations have increased due to global warming and change in the global
rain cycle (Ribas et al. 2017). Temperature and rainfall primarily determine the
seasonal prevalence and human infestations cycle of these helminthes. However,
they are more prevalent in rainy season or areas with heavy rainfall. Contaminated
water used for irrigation, washing ingredients, and drinks are the major sources of
the infestations (Ribas et al. 2017).
1.4 Waterborne Infections and Diseases
1.4.1 Transmission of Waterborne Diseases
The major sources of water-borne diseases are contaminated drinking water supply
systems that contain several contaminants (Fig. 1.2). Unprotected water bodies or
groundwater are often contaminated by human or animal feces or agricultural
effluents. Piped water sources are also contaminated from a variety of pollutants
(Hartemann et al. 1986). Moreover, due to lack of maintenance, supply pipes can
consume chlorine residues, making the decontamination process ineffective. Broken
pipes or crossed connections with sewage pipes also add contaminants into a water
system, creating an efficient pathway for pathogen transmission. Further, during the
power cuts, a negative pressure is created in the supply system which pulls the
contaminants into the water system from the outer environment. Concealed networks
(holes made in existing water pipes by persons) create openings in water pipes that
also allow entry of contaminants into the water system. These microorganisms reach
to human system through the orofecal route (Hatami 2013). There have been
numerous reports on outbreaks of orofecal diseases such as typhoid or cholera.
There are several other ways, where fecal material can reach to the human digestive
system through contaminated food. The microorganisms in feces can spread rapidly
and cause an outbreak in a very short period (Rooney et al. 2004; Pons et al. 2015;
Mari et al. 2019). Some of the most prominent water-borne diseases are listed in
Table 1.2.
1 Microbial Contamination of Drinking Water
7
Major helminths causing waterborne infestations are nematodes which include
ascarids, pinworms, hookworms, strongylids, angiostrongylids, capillarids and
guinea worms, flukes which include schistosomes and liver flukes, tapeworms
together with the beef, red meat and fish tapeworms as well as cystic and alveolar
hydatid tapeworms. Improper sanitation and contaminated water facilitate the transmission of these helminths both among animals and humans (Strunz et al. 2014). The
lifecycles of the maximum of these helminths are very established and they can be
easily controlled by breaking these cycles. Recent studies suggest that waterborne
helminth infestations have increased due to global warming and change in the global
rain cycle (Ribas et al. 2017). Temperature and rainfall primarily determine the
seasonal prevalence and human infestations cycle of these helminthes. However,
they are more prevalent in rainy season or areas with heavy rainfall. Contaminated
water used for irrigation, washing ingredients, and drinks are the major sources of
the infestations (Ribas et al. 2017).
1.4 Waterborne Infections and Diseases
1.4.1 Transmission of Waterborne Diseases
The major sources of water-borne diseases are contaminated drinking water supply
systems that contain several contaminants (Fig. 1.2). Unprotected water bodies or
groundwater are often contaminated by human or animal feces or agricultural
effluents. Piped water sources are also contaminated from a variety of pollutants
(Hartemann et al. 1986). Moreover, due to lack of maintenance, supply pipes can
consume chlorine residues, making the decontamination process ineffective. Broken
pipes or crossed connections with sewage pipes also add contaminants into a water
system, creating an efficient pathway for pathogen transmission. Further, during the
power cuts, a negative pressure is created in the supply system which pulls the
contaminants into the water system from the outer environment. Concealed networks
(holes made in existing water pipes by persons) create openings in water pipes that
also allow entry of contaminants into the water system. These microorganisms reach
to human system through the orofecal route (Hatami 2013). There have been
numerous reports on outbreaks of orofecal diseases such as typhoid or cholera.
There are several other ways, where fecal material can reach to the human digestive
system through contaminated food. The microorganisms in feces can spread rapidly
and cause an outbreak in a very short period (Rooney et al. 2004; Pons et al. 2015;
Mari et al. 2019). Some of the most prominent water-borne diseases are listed in
Table 1.2.
1 Microbial Contamination of Drinking Water
7