Waterborne Diseases - Saraniecki

Question 1

Rotavirus

Answer 1

HRV Human Rotavirus
most common cause of severe diarrhea among children
transmission - fecal/oral, contaminated water/foiod, contact with contaminates fomites

Question 2

Norwalk virus

Answer 2

very low infective dose, 10 to 100 PFU
reservoir - humans
transmission: primarily fecal-oral but 3% comes from water

Question 3

Hepatitis A

Answer 3

infectious hepatitis
reservoir: humans and other primates
transmission: fecal/oral, person contact, contaminated food and water (esp mollusks)
vaccine available

Question 4

Pseudomonas aeruginosa

Answer 4

1 of 2 swimmer’s itch
Thermophilic bacteria
common to hot tubs, geotherman pools
UTIs and URIs in immunocompromised
reservoir: water sources and systems, poorly disinfected pools and whirlpools, hospitals

Question 5

Legionella pneumophilia

Answer 5

Legionnaires disease
Pneumonia-like symptoms, 40% fatality
transmission: inhaled droplets ONLY
reservoir - hot tubs, cooling towers, warm ponds, hot water systems
increased risk to smokers, lung disease, immunocompromised

Question 6

Salmonella typhi

Answer 6

typhoid fever aka Enteric Fever
not salmonellosis
500 us cases per year
21 million worldwide, 200k fatal
transmission: contaminated food or water - shellfish from sewage infested waters, raw fruits and veggies fertilized by night soil, slies as mechanical transport
also chronic carriers 5% infected population

Question 7

Salmonella paratyphi

Answer 7

paratyphoid fever
milder version os S. typhi disease

Question 8

Campylobacter jejuni

Answer 8

gastroenteritis
most common US bacterial diarrhea
reservoir - wild and domestic animals, esp poultry cattle puppies and kittens
transmission: undercooked chicken and pork, fecal contaminated food and water
can trigger Guillain Barre syndrome

Question 9

Shigella (sonnei and flexneri)

Answer 9

bacillary dysentery - stools containing blood
450k US cases
small inoculum, 10-200 cfu
reservoir: only humans
transmission: fecal-oral, contaminated food and water, anal sexual contact, flies as mechanical

Question 10

Vibrio cholera

Answer 10

cholera 01 or epidemic cholera
origins of epidemiology
0 to 5 cases US per year
reservoir: mostly humans
transmission: ingestion of food or water contaminated with feces or vomit of infected human, also raw or undercooked contaminated shellfish

Question 11

E. coli O157:H7

Answer 11

shiga toxin-producing E. coli
often grossly bloody diarrhea
can lead to kidney failure
Reservoir: gut of ruminant animals including cattle, goats, sheep, deer, elk, and infected humans
Transmission: raw or undercooked ground beef, alfalfa sprouts, unpasteurized juice and milk, dry cured salami, game meat, lettuce, RWI, petting zoos, raw human sewage, water, cattle wastewater

Question 12

Giardia lamblia

Answer 12

beaver fever
reservoir: humans, beavers, muskrats
transmission: person to person via fecal/oral - institutions and day cares, ingestion of cysts in contaminated water. contaminated food
forms chlorine-resistant cysts
one micron filtration best for removal

Question 13

Cryptosporidium parvum

Answer 13

diarrheal disease, often profuse and watery
reservoir: humans, cattle, cats, dogs
transmission: fecal/oral, waterborne, foodborne
low infective dose 10 to 100 oocysts
highly resistant to chlorine
best removal practice: coagulation, flocculation, sedimentation, then 1 micron filtration
reverse osmosis also effective
fruits and veggies cannot effective be cleaned of this protazoa

Question 14

Naegleria fowleri and PAM

Answer 14

Primary Amoebic Meningoencephalitis
reservoir: ubiquitous in soil and water
transmission: contaminated water via nasal passages, warm corps of engineer lakes, shallow coves, geothermal pools, improperly maintained swimming pools
97% mortality rate

Question 15

Entamoeba histolytica

Answer 15

amoebiasis - amebic dysentery
protozoa, one of many travelers diarrhea
reservoir: humans
transmission: cysts in contaminated food and water, oral-anal, not via acutely ill patients
cysts are chlorine resistant

Question 16

Toxoplasma gonii

Answer 16

endemic to 22% of US population over 12 yo, most people asymptomatic
mild cases: flu like symptoms, swollen lymphs
severe cases: brain and organ damage
reservoir: oocysts in guts of cats and felines, cats eat infected rodents
intermediate hosts - sheep, goats, rodents, swine, cattle, chicken, birds
transmission: food/waterborne - contaminated undercooked pork, lamb, venison, ingestion of contaminated water
zoonotic - ingestion of oocysts found in litter boxes and sandboxes
congenital - transplacental transfer of tachyzoites in blood from newly infected mother to fetus

Question 17

Dracunculus medinensis

Answer 17

guinea-worm infection
occurs only in dry regions of Africa and Asia
reservoir - only humans
transmission - ingestion of larvae from stagnant fresh water
control method - filtration

Question 18

Schistosoma sp

Answer 18

Swimmer’s itch
egg infected migratory fowl feces dropped into lakes and saltwater beach waters
eggs enter snails and develop into larvae
free swimming larvae burrows subdermally and dies
control - eliminate snail host, 10mg/l copper sulfate

Question 19

Schistosoma mansoni

Answer 19

these larvae travel to the blood stream
trematode - blood fluke
snail fever - bilharzia
reservoir: humans - 250 million people infected
migrates to lungs, liver, bladder
water treatment - eliminate the snail host

Question 20

Ascaris lumbricoides

Answer 20

large intestinal roundworm
few or no symptoms
reservoir - humans over 50% prevalence, ascarid eggs in soil
transmission: ingestion of eggs from contaminated soil or uncooked produce