This chapter discusses prevention and control of zoonotic diseases. It describes four common zoonotic diseases in detail: anthrax, brucellosis, toxoplasmosis, and rabies. These diseases are usually transmitted from animals to humans through direct contact, ingestion, inhalation or bites. The chapter outlines symptoms, diagnosis, and treatment for each disease. It emphasizes the importance of public education, vaccination, proper food handling, and sanitation to prevent and control the spread of zoonotic diseases from animals to humans.

1. CHAPTER SEVEN
Prevention and control of
zoonotic diseases

2. Outline
 Instructional Objective
Introduction
Specific description of zoonosis

3. Instructional objective
At the end of this session students will able to
1. List at least four common zoonotic disease
2. Describe the common means transmission
3. Discuss common prevention and control
methods of zoonotic disease
4. Discuss management approaches of
zoonotic disease accordingly

4. Introduction
Zoonosis
Communicable diseases common to man and
animals
Causes significant morbidity and mortality.
For most the diseases, human is a dead end
of the transmission cycle.

5. Introduction cont’d
common types of zoonotic disease
When animals used as a food
Taeniasis
Brucellosis
Trichinellosis or trichinosis
Toxoplasmosis
Animal Bite diseases
Rabies
Direct contact diseases
 Anthrax
Animal reservoir diseases
Leishmaniasis
African Trypanosomiasis

6. Anthrax
An acute bacterial disease primary of grass
eating animals, and occasionally infect human.
In human ,it primary affects skin but very rarely
lower respiratory tract ,oropharynx,
mediastinum or intestinal tract.
Cause
Bacillus anthracis
Reservoir
Animal normally herbivores

7. Anthrax-Mode of transmission
Occupational Hazard of workers who process
 Hides
 Hair
 Bone and bone products

8. Anthrax-Mode of transmission
Coetaneous anthrax
¨ contact with tissue of animals dying of anthrax
¨ Bite of flies that had partially feed on such animal
¨ Contaminated materials.
In halation Anthrax
Inhalation of spores in risky industrial process
Intestinal or oropharyngeal anthrax
Ingestion of contaminated meat

9. Anthrax cont’d
IP
Few hours to seven days, most cases 48 hr.
PC
Transmission from person to person is rare,
but contaminated article remain
communicable for years
Susceptibility and resistance
Uncertain

10. Anthrax-C/M
Cutaneous Anthrax
 95% of the cases
 At first small red maculs appear on exposed areas,
head, neck, face, then to papule that changed to
blackened necrotic centre surrounded by highly
expanding zone of oedema
 Pain less swelling, Extensive oedema, no fever
 Non specific pain full regional L/Adenopathy
 80-90% spontaneous healing with persistent
oedema
 10-20% infection progress & with high fever and
rapid death.

11. Cutaneous Anthrax

12. Anthrax-C/M
Inhalation anthrax
Mild symptom of URTI (early sign)
Acute phase occur after 1-3 days with increasing
fever, dyspnoea, stridor, hypoxia, and hypotension
usually leading to death with in 24 hr.
 High fatality rate

13. Anthrax-C/M
Gastro intestinal anthrax
 Early sign: vomiting , watery& bloody diarrhoea
 Variable fever, abd pain
 sometimes rapid developing ascetics.
Oropharyngeal anthrax
 Fever, sore throat ,Dysphasia
 Painful regional L/Adenophathy
 Primary lesion most often on tonsil
 Respiratory distress

14. Anthrax-Dx
Clinical data
Lab Dx from fluid of vesicle, sputum and stool
Gram stain
Culture

15. Anthrax-RX
Penicillin G 10Mu IV daily
or
TTC 2gm PO daily for two wks
Clean & cover the Cutaneous lesion

16. Prevention & Control of Anthrax
¨ Decontamination of wool and goat’s hair or
others
¨ Improvement of working condition of animal
product
¨ Vaccination of susceptible groups & animals
¨ Treat all exposed animal.
¨ HE

17. Brucellosis (Undulant Fever)
A systemic bacterial disease with acute onset
transmitted to humans from infected animals
Agent
B. melitensis acquired primary from goats,
sheep, and camel
B. abortus from goats
B. suis from pig
B. canis from dogs
They are aerobic gram –ve bacilli, intercellular
parasite
Reservoir
Cattle, goat sheep, dogs

18. Brucellosis cont’d
MT
 contact with tissue, blood, urine, vaginal discharge aborted
foetuses especially placentas
 Ingestion of row milk most commonly
 Ingestion of diary products from infected animal
 Air born infection those working in Abattoirs

19. Brucellosis cont’d
IP
1-3 wks or longer
PC
No evidence from person to person

20. Brucellosis-C/M
Abrupt onset of fever, chills, diaphoresis, head ache,
myalgia, fatigue ,anorexia, joint pain sore throat dry cough
Spinal tenderness
Hepatospleenomegally
Asymmetric poly arthritis (knee, hip shoulder,)
Epididymo orchitis
Skin rash, Cardiac murmur, Pneumonia
Multiple organ involvement

21. Brucellosis cont’d
DX
 Clinical features with history of exposure or contact
 Blood or bone cultures
RX
 Doxy + aminoglycoside for 2wks
 Doxy + refampicin for 4-8 wks
 Bactrim + Refampicin in children <7 years and pregnant
mother for 8-12 wks

22. Prevention & Control Brucellosis
Elimination of disease in domestic animals
HE
Proper disposal system
Animal examination and Rx

23. Toxoplasmosis
Chronic or acute systemic Protozoal disease caused by
Toxoplasma gondii
Reservoir:Cats
MT
Ingestion of cyst in raw &under cooked meat.
Ingestion of Oocyte in food, drink, or from hands
contaminated with faeces of infected cat.
Transpalcental
Organ donation

24. Toxoplasmosis cont’d
IP
10-23 days
PC
Not directly from person to person except
transpalcental

25. Toxoplasmosis-C/m
Acute form
Chills, Fever, head ache, myalgia , fatigue
 lymphadenitis
Maculopapular rash
Encephalomyelitis
Retinochorditis that may leads to blindness
In infected child if transpalcental/ congenital
Hydrocephaly
Convulsion
Motor disturbance

26. Toxoplasmosis cont’d
DX
 C/m
 Cell culture
RX:-
Pyrimethamine 100-200mg PO daily followed by
maintenance dose 25mg PO/d for 4 wks.
Note – Rx indicated in sick immunocompromised case
Folinic acid
Prevention & Control
Eat cooked meat and animal products (60c)

27. Rabies
An acute viral disease of CNS invariably fatal
Affect all animals
Transmitted by infected secretion mainly
saliva.
Agent
Rabies virus (lyssavirus)
Reservoir
Dog, rats

28. Rabies cont’d
PC :Usually 3-7 days before the onset of the disease and
throughout the course of disease.
MT
¨ Transmitted with saliva of infected animal and introduced to
body by bite or scratch
¨ Occasionally inhalation, ingestion and tissue transplantation
but unusual
IP: 3-8wks (40 days)

29. Rabies cont’d
Pathogenesis
A bullet shaped virus which has many strain recovered from
rabid street dog called “street virus”
The virus multiplies in muscle at site of inoculation then
ascends along the nerve to CNS where from it subsequently
spread to all parts of the body via emerging net work of
ANS.
 Entrance to saliva propagates transmission
Infected animal identified as Negri body in 80% cases

30. Rabies cont’d
Classification of animal bite
Class I
 Abraded skin, scratches that bleed
Class II
 Bite any part of the body other than head, neck &fingers
 None ulcerated wounds less than 5 in number
Class III
¨ All cases of bite on finger, hand or neck
¨ Wounds >5 anywhere on the body
¨ Lacerated wounds
¨ All cases bitten by wild animal

31. Rabies -C/M
Prodormal phase
Head ache
Fever
Nausea
Abnormal sensation at site of inoculation
Excitatory phase or Aerophobia
¨ Slight sound and wind excites the victim
¨ Irritability restless, nervousness ,tendency to bite
Paralytic phase (full blown rabies)
Spasm of swallowing muscle leads to drooling of saliva and
fear of water (hydrophobia)
 Delirium
 Convulsion
 Death due to respiratory muscle paralysis

32. Rabies -DX
History of bite by known rabid animal
Nigri bodies

33. Rabies -RX
1. Wound care
Wash the wound with soap and water
Stop bleeding, Cover the wound
Never stitch as it may facilitate the spread
2. TAT
3. Anti Rabies vaccination
5ml S/C (preumbilical area) daily for 14 days
and two booster doses on 14th and 30th days

34. Rabies -RX
Indication for anti rabies vaccination
Bite from known rabid animal or contact with
salve to lesioned tissue
The animal escaped
The animal show clinical pictures after 10 days
observation
The animal died
4.Sadation if necessary

35. Rabies -Prevention and control
Immunize all dogs and cats
Detain & clinically observe for 10 days any unhealthy
appearing dog or cat known to have bitten a person
Post exposure prophylaxis
Keep dogs and cats at home
Destroy stray animals where rabies is endemic
Kill rabid animal.

36. Trichinellosis or Trichinosis
 Trichinosis is a disease caused by intestinal round
worm whose larvae (trichinae) migrates to and become
encapsulated in the muscles
Infectious agent
 Trichinella spiralis, an intestinal nematode
Epidemiology
Occur worldwide, but variable incidence, depending in
part on practices of eating and preparing pork or wild
animal meat.

37. Trichinellosis-cont’d
Reservoir
Swine, dogs, cats, horses, rats and many wild
animals, including fox wolf etc
Mode of transmission
By eating raw or insufficiently cooked flesh of
animals containing viable encysted larvae

38. Trichinellosis-cont’d
I/P
Systemic symptoms usually appear about 8-15
days after ingestion of infected meat.
Susceptibility and resistance
¨ Susceptibility is universal.
¨ Infection results in partial immunity

39. Trichinellosis-Clinical manifestations
 Infection ranges from mild febrile illness to a severe progressive
illness with multiple system involvement.
Fever(low-high grade)
Muscle pain mainly up on movement
oedema and spasm (periorbital and facial|)
photophobia and conjunctivitis
Weakness ; pain on swallowing
Dyspnoea , coughing and hoarseness
subconjuctival, retinal and nail splinter haemorrhage and rashes
Diarrhoea abdominal cramps, nausea and vomiting.

40. Trichinellosis-Clinical manifestations
Inflammatory reactions around larvae that
reach tissues other than muscles may result
in:
¨ Meningitis
¨ Encephalitis
¨ Myocarditis
¨ Bronchopneumonia
¨ Nephritis
¨ Peripheral
¨ Cranial nerve disorders

41. Trichinellosis - Diagnosis
Hx of ingestion of raw or inadequately cooked
pork
Larvae in muscle biopsy
Positive serologic test
Oesinophilia

42. Trichinellosis -Treatment
Hospitalization of the Pt
Mebendazole or Albendazole or
Thiabendazole
High dose of corticosteroids for 1-2 days
followed by lower doses for several days or
weeks. But not for intestinal stage.

43. Trichinellosis-Prevention and control
Educate the public on the need to cook all
fresh pork and pork products and meat from
wild animals
Freezing of pork and its products inactivates
trichinae

44. Summary
1. List at least four common zoonotic disease
2. Describe the common means transmission
3. Discuss common prevention and control
methods of zoonotic disease
4. Discuss management approaches of
zoonotic disease accordingly