1

ZOONOTIC DISEASES

Diseases & infections that are naturally transmitted between vertebrate animals and man

2

MODE OF TRANSMISSION

• Direct or direct contact with affected animals or contaminated products.

• Intermediate hosts.

• Vectors (arthropods)

3

Factors Affecting The Occurrence of Zoonoses

• Size and density of animal populations.

• Customs and standards of human society increasing human exposure.

• Prevalence of occupational exposure.

• Environmental factors.

• Inadequate attention to animal health.

4

Impact of Zoonotic Diseases on Man

• Morbidity & overall deterioration of health and reduction of work ability.

• Contribution to human malnutrition.

• Reducing resistance to other diseases.

• Mortality.

5

Socio-Economic Losses

• Loss of millions of human working hours.

• Cost of health care.

• Livestock and animal reduced reproduction.

• Reduced export and loss of foreign exchange.

6

SURVEILLANCE

• Collection of epidemiological information of sufficient accuracy, completeness, distribution and determinants of infection and disease for ACTION.

7

Problems & Constraints Administrative Problems

• Insufficient coordination among national institutions and authorities responsible for VPH.

• Inadequate/Inappropriate legislation for zoonoses control.

• Insufficient budgetary allocations.• Inefficient information system and poor exchange of

information at country and inter-country levels.• Inadequate trained man power.• Insufficient community involvement.• Inadequate inter-country and international

cooperation.

8

Technical Problems

• Inadequate diagnostic facilities.• Inadequate reference laboratories.• Insufficient supply of high quality vaccines for

veterinary and medical services (quality and potency of locally produced vaccines need improvement)

• Limited introduction of appropriate technologies for production and inspection of food, for prevention and control of zoonotic diseases.

9

Educational Obstacles

• Inadequate inclusion of zoonotic disease subjects in the curricula of medical professionals.

• Insufficient availability of learning and training materials.

• Inadequate health education to achieve involvement of communities.

• Weak participation of institutions in design of health education programs and materials

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Brucellosis

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Brucella Bacterial Type In Palestine

• Br. melitensis • Br. abortus• Nearly all of the human brucellosis in Palestine

will be caused by Br. melitensis• Diagnostic test is : - Rose Bengal test - Agglutination - Elisa test

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Source of infection

• 1- Dairy products ( 80% )

• 2- Animal contact ( Farmers, Veterinarians, Abattoir workers, Laboratory technicians) 10%

• 3- Unknown 10%

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Means of Animal to Human Transmission

• Skin & mucous penetration.

• Inhalation

• Ingestion of contaminated dairy products made with non heat treated milk

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Patho Genesis

Brucellosis abortus . Brucellosis meletensis

Opsonized by Normal Human Serum

Phagocytosis Promotion

By PMNs

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Host immunity Acute infection : IgM rises first.The only IG detectable in the first week (s)

Begin dropping off 3 months after onset IgG begin to rise in the second week Remain

elevated for at least 1 year In untreated patient

Decrease to very low level or disappear to months after onset in treated patient

During re infection IgG +++, IgM+++Recently increases IgG+++, IgM+++

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PMNs

Killing Brucellosis abortus

Little ability of killing itracelular

Brucellosis melitensis

For the production of

5 guanoosine monophosphate & adinine

Inhibit degranulation of peroxides- positive granules in PMNs

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Clinical manifestation Severity1. Brucella melitensis 2. Brucella seuis3. Brucella abortus , canis 1/3 with impresive systemic toxicity 2/3 symptom over 1 or more weeks90%sweats,chills,fever, weakness, Common, malaise, headache, anorexia.25-50%weight loss, myalgias, artharlgias,back pain.12-21%lymphadenopathy(cervical inguinal)20-30% splenomegaly.

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ComplicationsLess treated early More treated late 1- Skeletal Arthritis, spondyhtis, osteomyelitis, sacrolitis,………2- NeurologicMeningoencephalitis, myelititis, paresis,depression,

psychosis(2-5%)3- Genitourinary Unilateral epidiolymo- orchitis(2-4%)-(2-10%)Acute

interstizial nephritis or pyelonephritis4- CardioVascularEndocarditis less than 2%The most common cause of death

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5- GastrointestinalHepatomegaly, caseating or non caseating

granuloma ( Brucella abortus ) Hepatitis , abscess- GI discomfort6- SpleenSpleen megaly, abscess formation7- Pulmonary Inhelation or bacterimia ( 15-25 ) cough8- HematologyAnemia ,leucopenia, thrombocytopenia9- Cutaneous ( 5% )Transient & non specific skin lesions.

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Brucella melitensis

1- Resist the bactericidal effect of serum

2- Resist intracellular killing by PMNs

Greater Virulence

Brucellosis not killed by PMNs

Migrate to regional lymph nodes

Blood stream

Localization in the R.E.S

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Uterine exudates 200 days

Water 10-20 days

Street dust/ soil 21 days 10weeks

Vegetable 15 days

Milk & milk product 20-60 days

Feces ( bovine) 120 days

Urine( animal & human) 2-49( 70days)

Frozen tissue for many years

Aborted fetus 75 days

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• Temperature

180 m 55 C

90 m 60C

15 m 65C

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Treatment: 1- Streptomycin

2- Tetracycline

3- Doxycycline

4- Rifampicin

5- Trimethoprim- Sulfa methoxazole

6- Gentamycin

7- Corticosteroids

8- Cephalosporine 3 generation