Water-borne Diseases Flashcards
How much of the Earth’s surface is made up of water? How many global zoonotic disease outbreaks are water-borne?
over 2/3 (71%) —> also makes up 2/3 of the body
40%
What 3 important laws in the USA protect water?
- 1947 Insecticide, Fungicide, and Rodenticide Act protects from chemical waste
- 1965 Solid Waste Disposal Act
- 1972 Clean Water Act puts restrictions on pollution discharges into river and streams
How much water loss can result in death?
15% loss from the body
water is life for ALL ORGANISMS
Although water covers 2/3 of the Earth surface, what problem is there for the global population?
2.1 billion people (29%) globally do not have access to safe drinking water since their water is contaminated with infectious, chemical, and physical hazards that cause water-borne illness and death
3.57 million deaths per year
What are the 4 major sources of biological and chemical hazards in water causing water-borne disease?
- aquatic and terrestrial animals - humans, domestic, wildlife
- slaughterhouse discharges
- discharges from farms, industry, and commerce
- floods
What are the main 4 types of water-borne hazards?
- biological from feces
- chemical from agriculture and industries
- nuclear
- physical
What are the 5 types of chemical contaminants of water? What are the major sources?
- DISINFECTANTS - chlorine, chloramines, chlorine dioxide
- DISINFECTANT BYPRODUCTS - bromate, chlorite, haloacetic acid
- ORGANIC (agriculture, industries) - antimicrobials, disinfectants, pesticides, herbicides, fertilizers, petroleum
- INORGANIC (heavy metals from factories) - aluminum, ammonia, arsenic, barium, cadmium, chloramine, chromium, copper, fluoride, lead, nitrates/nitrites, mercury, perchlorate, radium, selenium, silver, uranium
- RADIONUCLIDES - radium, uranium
What are the 8 most common toxic effects of chemical hazards on human health?
- birth defects and reproductive disorders
- cancer
- immune disorders
- kidney dysfunction
- liver dysfunction
- enterocyte destruction
- lung and respiratory disease
- neurotoxic disorders
What are the 2 broad categories of water-borne pathogens?
- environmental (aquatic) pathogens
- enteric (obligate pathogens
What is the life cycle of enteric (obligate) water-borne pathogens like?
water-gut-water
What are the 6 most common aquatic/environmental water-borne pathogens?
- Vibrio spp.
- Legionella spp.
- Pseudomonas aeruginosa
- aquatic Mycobacteria spp.
- Nagleria fowleri
- Schistosomes
What is Nagleria fowleri? Schistosomes?
“brain-eating amoeba”
aquatic trematodes that cause gut and kidney damage
How is Legionella transmitted?
breathing in mist (small water droplets in the air) from contaminated water bodies, like fountains and boats
What are 6 enteric water-borne viruses?
- Adenovirus
- Astrovirus
- Enterovirus
- Norovirus
- Rotavirus A
- Sapovirus
What are 7 enteric water-borne bacteria?
- Campylobacter jejuni, coli
- Clostridium difficile
- E. coli (enteroaggregative, enteropathogenic, enterotoxigenic, Shiga-like)
- Shigella
- Salmonella enterica
- Vibrio parahaemolyticus, cholerae, vulnificus
- Yersinia enterocolitica
What are 5 enteric water-borne protozoa?
- Cryptosporidium
- Cyclospora cayetanesis
- Entamoeba histolytica
- Giardia intestinalis, lamblia, duodenalis
- Toxoplasma gondii
29 water-borne pathogens according to WHO:
What disease do Legionella, Pseudomonas aeruginosa, and Acanthamoeba cause?
attack lungs
attack ear, skin, lung, and kidney
attack the eyes and cause ulcerative keratitis
18 water-borne pathogens known in the USA:
included in a surveillance program
What is the major source of water-borne pathogens? In what 2 ways are they most commonly transmitted?
fecal pollution of water
fecal-oral —> fluid (water-borne) and floods
What most commonly facilitates water-borne disease outbreaks?
floods - dumps both biological and chemical pollutants (runoff, municipal sewage, industrial sewage) into water bodies and houses from a wider geographical area
(can become pandemic)
What 8 vital body parts are affected by water-borne pathogens?
- GIT = diarrhea
- brain
- eye
- ear
- lung
- liver
- kidney
- skin
What do water-borne viruses most commonly attack?
GIT
- Astrovirus
- Coxsackievirus
- Rotavirus
- Norwalk/Calicivirus
What water-borne viruses attack the lung and eye, brain, and liver?
LUNG, EYE - Adenovirus
BRAIN - Echovirus, Enterovirus
LIVER - Hepatitis viruses
What do water-borne bacteria most commonly attack?
GIT
- Arcobacter
- Aeromonas
- Campylobacter
- Helicobacter
- Yersinia enterocolitica
What water-borne bacteria attack the lungs, GIT/kidney, and multiple organs at once?
LUNGS - Legionella, Mycobacterium avium complex
GIT/KIDNEY - E. coli
MULTI-ORGAN - Pseudomonase aeruginosa
What do water-borne protozoa most commonly attack? Which one is unique?
GIT - Cryptosporidium parvum, Cyclospora cayetanesis, Giardia lamblia, Microsporidia, Toxoplasma gondii
Acantamoeba attack the brain and eye
What is characteristic of water-borne viruses?
highly infective and can stay in water for several months
Why is it difficult to keep protozoa out of water?
resistant to chlorine treatment in the water
What are the 6 most common signs of a water-borne disease outbreak?
- diarrhea
- pneumonia
- encephalitis
- otitis
- skin infections
- death
How has the cause of water-borne illnesses varied from time to time?
BEFORE 2006 - mostly protozoal
2013-2014 - legionellosis from aerosolized mist
Out of the 18 water-borne pathogens in the USA, what 5 cause the most common water-borne illnesses?
- Pseudomonas aeruginosa - otits externa, pneumonia
- Staphylococcus aureus - otitis externa
- Norovirus - GIT infection
- non-tuberculous Mycobacteria - pneumonia
- Legionella - pneumonia
What 3 water-borne pathogens cause the most hospitalizations and death?
biofilm-associated pathogens that cause pneumonia
- non-tuberculous Mycobacteria
- Legionella
- Pseudomonas
What bacteria has caused 7 pandemics in human history? What does it cause?
Vibrio - inhabits surface water
cholera - fatal gastroenteritis, wound infections/amputations, septicemia, shock
What are the 2 surveillance approaches of drinking water quality and safety in the USA? Which is preferred?
- surveillance of 18 pathogens and 90 chemical contaminants in water bodies
- total coliform (CEEK) count in 100 mL of water*
- monitoring of 18 pathogens is tedious
What are the regulatory maximum limit (mg/L) of Cryptosporidium, Giardia, Legionella, enteric viruses, total coliform, bromate, chlorine, and lead allowed in 100 mL of water? What happens when the concentration is higher?
- CRYPTOSPORIDIUM = 0
- GIARDIA = 0
- LEGIONELLA = 0
- ENTERIC VIRUSES = 0
- TOTAL COLIFORM = 1
- BROMATE = 0.01
- CHLORINE = 4
- LEAD = 0.015
affects public health and should not be used to drink
What is most commonly used as an indicator for contaminated water?
coliform bacteria count
In what 4 ways can water-borne disease be controlled and prevented?
- wastewater treatment for water purification using coagulation, membrane filtration, sedimentation, and disinfection
- controlling wastes at an animal and human level to control water-borne pathogens
- control transmission through 7 Fs pathway
- control pathogens in humans and animals using vaccines and drugs
What are the 5 barriers used to treat and purify water?
- SCREENING using large pore mesh >6mm to remove large solids like fish, bottles, and logs
- COAGULATION using alum (aluminum salt) or iron sulfate to clump wastes or remove solids or colloids
- SEDIMENTATION/FLOCCULATION to collect and remove clumped wastes
- SCREENING/FILTRATION with a different 0.5-6mm pore side to remove fine solids and 0.1-0.5mm pores as microscreens
- DISINFECTION
What are the 3 options for disinfecting water?
- chemical disinfection using chlorine or ozone (O3) to kill pathogens
- irradiation by UV light to kill pathogens
- ultrafiltration (0.1-0.01 µm) and nanofiltration (0.01-0.001 µm)
Water treatment options while hiking, camping, and traveling:
