7.6.1
Possible Future Directions
important waterborne outbreaks throughout the world.
Because most of the microorganisms that are waterborne
Direct Pathogen Monitoring and New Approaches
are spread by the fecal-oral route, their occurrence and
control in wastewaters, animal wastes, recreational waters
The SAB suggests that additional research is required to
and drinking waters are important.  Key in the future to
better understand the limitations of existing microbial
understanding and controlling emerging pathogens is the
water quality indicators, and to develop better pathogen-
application of new tools for monitoring and studying these
specific and new indicator detection methods.  New
microorganisms (Huffman et al. 2003).
methods should be used in surveys of key Areas of Concern
where water quality impairment associated with indicators
Many of these microorganisms are on the “Contaminant
has been identified so that risk-based, science-based
Candidate List” for the U.S. EPA and thus information on
information can be used to assist in restoration efforts.
their occurrence in water is needed (LeChevallier et al.
1999a; 1999b).  Many are transmitted both through
Table 2 describes some of the microorganisms that can be
drinking water and recreational water, including E.coli,
spread through contaminated water.  In the last three
Cryptosporidium, Microsporidia, and all the viruses.
decades, 1970 to 2000, numerous species of bacteria,
While with some of the others the transmission through the
parasites and viruses have been described that have caused
various water routes is uncertain (MAC and Helicobacter).
TABLE 2
Examples of  “Emerging” Waterborne Pathogens of Concern Adapted from Quintero-Betancourt et al. 2003
Pathogen
First described
as waterborne
E.coli 0157:H7
Associated with bloody diarrhea (hemorrhagic colitis) and Hemolytic uremic syndrome
1991
Helicobacter pylori,
Diarrhea, peptic and duodenal ulcer disease, gastric carcinoma
1991
Mycobacterium avium Complex
Diarrhea and respiratory disease
1994
Cryptosporidium
Profuse watery diarrhea (cholera-like), fluid loss, fever and abdominal pain
1984
Cyclospora
Explosive, watery diarrhea, fatigue, anorexia, weight loss, nausea
1994
Microsporidia
Gastrointestinal, pulmonary, nasal, ocular, muscular, cerebral, and systemic infections
1997
Toxoplasma
(Flu-like symptoms). Painful swollen lymph glands in the cervical, supraclavicular, and inguinal
regions. Fever, headache, muscle pain, anemia, lung complications. Fetus at greatest risk
1979
Coxsackievirus
Aseptic meningitis, herpangina, paralysis, exanthema, hand, foot, and mouth disease,
common cold, hepatitis, infantile diarrhea, acute hemorrhagic conjunctivitis
1990
Hepatitis viruses
Fever, nausea, abdominal pain, anorexia and malaise, associated with mild diarrhea,
arthralgias, scleral icterus. Cytologic damage, necrosis and inflammation of the liver (HAV)
1950
Norwalk-like viruses
Diarrhea, vomiting, abdominal pain, cramping, low fever, headache, nausea,
tiredness (malaise), and muscle pain (myalgia)
1968
Rotavirus
Vomiting, abdominal distress, diarrhea, dehydration, fever
1983
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