Zoonoses from Milk and Water

Question 1

classically milk-borne bacteria

Answer 1

Brucella spp.
Coxiella burnettii
Mycobacterium bovis

Question 2

“classic” milkborne pathogens

Answer 2

• Bacteria infect the animal systemically colonize the mammary glands
• Bacteria can be secreted into milk in a chronic fashion, often with minimal symptoms in the animal

Question 3

Modern pasteurization is based on…

Answer 3

Coxiella burnetii

Question 4

Do we pasteurize all milk?

Answer 4

Not quite…

– Farmers on the farm
– Foreign travel
– “Raw milk” movement
– Imported soft cheeses

Question 5

True/False: there can be direct transmission to humans in addition to transmission via milk

Answer 5

True:

• Percutaneous or mucous membrane contact with infectious fluids
• Aerosol exposure

Question 6

Most M. bovis cases occur in…

Answer 6

…countries without pasteurization of milk or control programs in cattle

Question 7

Transmission routes: M. bovis

Answer 7

• Aerosol
• oral exposure (intestinal or cervical lymphadenitis)
• percutaneous exposure (lymphadenopathy of draining LN)

Question 8

M. Bovis: Aerosol transmission to people =

Answer 8

pulmonary TB (culture to differentiate from M. tuberculosis)

Question 9

Control of M. bovis

Answer 9

• Eliminate animal reservoir (test-and-slaughter)

- milk pasteurization

Question 10

True/False: Human infections of Brucella and Coxiella are easy to diagnose

Answer 10

False: difficult to diagnose without good index of suspicion

Question 11

“undulant fever” or “Malta fever”

Answer 11

Brucellosis in humans

- recurring fever, abortions, Pleiomorphic symptoms: neurologic, endocarditis, possibly chronic fatigue

Question 12

“Q fever”

Answer 12

Coxiella burnetii in humans

• abortions, pleiomorphic symptoms
• may present as atypical pneumonia or hepatitis

Question 13

most pathogenic Brucella spp in humans

Answer 13

Brucella melitensis

Question 14

Brucella abortus

Answer 14

pathogenic in humans

worldwide distribution

Question 15

Brucella suis and canis

Answer 15

less pathogenic in humans

Question 16

Brucella transmission

Answer 16

Ingestion
mucous membrane exposure
percutaneous inoculation
(Aborted placenta, fetus, fetal fluids, Unpasteurized milk, blood, urine, semen, feces, and uterine/vaginal secretions, Feed/water contamination)

Question 17

controlling Brucella spp

Answer 17

Eliminate reservoir
monitor swine
reduce public exposure: pasteurization of milk and milk used to make soft cheeses

Question 18

Coxiella burnetii: Q Fever

Answer 18

Used for the basis of pasteurization standards
Infects all dairy species
No eradication program in USA
Pasteurization of milk

Question 19

Transmission of Coxiella burnetii

Answer 19

Extremely infectious via aerosol exposure (percutaneous and mucous membrane)
An issue of environmental contamination (aborted placenta/fetus, milk, feces, water, soil, meat)
Veterinary exposure is most likely from environmental sources on farms

Question 20

Barrier to control (milkborne)

Answer 20

wildlife reservoirs
social costs/veterinary infrastructure
compliance of animal owners

Question 21

Cryptosporidium and Giardia

Answer 21

Protozoan parasites (Cryptosporidium is coccidia‐like; Giardia is flagellated)
transmission via water > food!
Infected animals can contaminate water supplies

Question 22

True/False: both Cryptosporidium and Giardia are diverse

Answer 22

True

Question 23

C. parvum

Answer 23

zoonotic

cattle are reservoir

Question 24

C. hominis

Answer 24

human to human

urban municipal water systems

Question 25

estimated number of people with Giardia

Answer 25

200 million people in Africa, Asia, and Latin America have Giardia but only 50,000 cases reported exact zoonotic capacity of Giardia has been long debated

Question 26

zoonotic types of Giardia

Answer 26

humans infection groups: type A and B - 10-20% cattle is type A - 50% dogs and cats have type A or B

Question 27

True/ False: Cryptospiridiosis in humans is usually severe

Answer 27

False: mild=diarrhea; severe in immunocompromised patients

Question 28

Giardia causes

Answer 28

chronic intestinal infections

Question 29

prevention of Cryptosporidium & Giardia

Answer 29

proper treatment (filtration) of drinking water; wash produce; reduce exposure to recreational water; no diapers in swimming pools!

Question 30

True/False: Leptospirosis is a waterborne disease

Answer 30

True

Question 31

Leptospirosis infects...

Answer 31

kidneys/ excreted in urine

Question 32

how long can animals excrete Leptospirosis in their urine

Answer 32

>1 year

Question 33

Leptospirosis survives best in...

Answer 33

warm freshwater or mud

Question 34

Leptospirosis infection via...

Answer 34

Ingestion of water containing Leptospira Mucous membrane or broken skin contact with water containing Leptospira Contact with animal urine containing Leptospira

Question 35

Clinical Leptospirosis (acute)

Answer 35

Fever, depression, lethargy, +/‐ icterus Headache/malaise/ocular pain in people Acute renal damage or failure

Question 36

Clinical Leptospirosis (chronic)

Answer 36

Large animal abortions, stillbirths, weak offspring | Chronic renal insufficiency

Question 37

control of Leptospirosis

Answer 37

``` reduce reservoir (rodent control) reduce human exposure (clean water, wear gloves when handling urine) ```

Question 38

Trematode life cycle

Answer 38

``` Definitive host = a vertebrate Intermediate host(s) = aquatic Accidental hosts can be infected percutaneously ```

Question 39

Trematodes as zoonosis

Answer 39

Anthroponotic as well as zoonotic species | Disease occurs anywhere with appropriate water conditions and presence of intermediate hosts

Question 40

2nd most important human parasite after malaria

Answer 40

Schistosoma spp.

Question 41

Schistosoma japonicum

Answer 41

zoonotic: have domestic animal reservoirs

Question 42

Control of Schistosomiasis

Answer 42

Avoid swimming in fresh water | Treat reservoir hosts; kill intermediate molluscs

Question 43

Swimmer’s Itch

Answer 43

Caused by skin invasion by the aquatic stage of bird trematodes (Humans cannot be the definitive host) Humans are accidental hosts – can result in skin lesions

Question 44

Fasciola spp. (Cattle Liver Flukes)

Answer 44

Important animal disease Humans can be infected (vegetables contaminated with metacercariae) - Humans are NOT infected via eating liver In some parts of the world it is quite common in humans

Question 45

cause bovine abortion and are zoonotic

Answer 45

Brucella abortus Leptospira spp. Coxiella burnetii Listeria monocytogenes