Brucellosis
[Undulant fever, Malta fever, Mediterranean fever]Objectives
At the end of this lecture you suppose to know the following: - Historical overview Epidemiological occurrence and importance. Agent, reservoir, IP. Identification, diagnosis, interpretation of results. Control and prevention.Historical overview: In 1887 , David Bruce in Animals ** bang’s disease. 1889
The Many Names of BrucellosisHuman Disease Malta Fever Undulant Fever Mediterranean Fever Rock Fever of Gibraltar Gastric Fever
Animal DiseaseBang’s DiseaseEnzootic AbortionEpizootic AbortionSlinking of CalvesRam EpididymitisContagious Abortion
EPIDEMIOLOGY
Occurrence: Most widespread zoonoses, 500,000 new case/y. Does this genuine? In Iraq: ?, in Mosul ?. sex? age? Immunity → uncertain.* Brucella spp.
SourceVirulence
Infective Dose
B. melitensis
Goats, sheep, Cattle, Swine camels
++++
1 – 10 B. suis
Swine, Cattle
+++
1,000 – 10,000 B. abortus
Cattle
++
100,000
B. canis
Dogs
+
1,000,000
Etiologic agents
Reservoirs; ?? IP; 1 week - 4 WKs .occasionally may last for several ms
* Resistance of brucella
For 10 minutes
Phenol 1%For 15 minutes
Direct sunlight
In a few hours
Milk
For several days till?
Fresh cheese
For 3 months
Tap-water
For 57 days
Human urine
For 1 week
Dust
For 6 weeks
Damp soil
For 10 weeks
Animal feces
For 100 days
Yoghurt?
------
Identification:
acute or insidious onset,swinging pyrexia …….profuse sweating , malodorous sweat and peculiar mouth taste.The commonest complications: * Arthritis 20%-60% (causing sacroiliitis, spondylodiscitis * 2%-20%; orchitis and epidedemitis. * Localized suppurative infections. CFR: 2-5% in untreated cases.? Disability is often pronounced
Diagnosis: 1. Clinical suspicion (PUO) 2. Isolation of agent Blood culture urine culture CSF culture BM culture 3. demonstration of AB (most practical but ?): (BAT). Rose-Bengal plate test (screening). (2ME), { chronicity}. Complement fixation test. ELIZA
4. (hepatic biopsy): Histologic evidence of granulomatous hepatitis 5. X Ray.
Period of communicability: No man to man transmission. Mode of transmission: (from ?) Ingestion; raw milk or products, raw vegetables, rarely undercooked meat, Direct contact with tissues or infected animals, discharges.Air- borne infection: inhalation of infected dust, aerosoles Pens, stables, slaughter houses, labs . 4. Accidental inoculation at laboratories and veterinarians by contaminated needles with blood or vaccine (S19 or Rev-1).
9. Method of control:
the control of human brucellosis rests on the elimination of the disease among domestic animals.A- Preventive measures:
Health education of farmers Health education of publicSterilization and pasteurization of milk and its product.Elimination of disease among animals: Searching for infected animals “ring test”.Segregation and Rx till recovery, slaughter, (satisfactory solution) .Vaccination of animals:Human vaccination: living vaccine of B. abortus strain [19-BA vaccine] (severe hypersensitivity, not use or limited use).