BRUCELLOSIS-2

Lecture on Epidemiology – 07-03-2012

L. Makrai

SZIU-FVS, Department of Microbiology and Infectious Diseases

OVINE EPIDIDYMITIS AND ORCHITIS CAUSED BY Brucella ovis

• Occurs in most sheep-raising regions of the world (Australia, New Zealand, North and South America, South Africa, many countries in Europe)

• Infertility, epididymitis, orchitis in rams

• Sporadic abortion in ewes (placentitis)

• Increased perinatal mortality

• B. ovis, only sheep is susceptible

Epidemiology• Introduction into a herd: with matured, infected,

asymptomatic rams

• B. ovis is shed with urine and semen

• Lifelong infection

• Ewe: infected with semen (venereal transmission) several month – get shot of brucella

• ascending infection: epididymis, testicle, accessory genital glands: inflammation, necrosis, oedema, fibrosis, spermatokele

B. ovis (epididymitis and orchitis)

HAJTÓS DR.

Clinical and Pathological findings• incubation period: 5-9 weeks

• skin of scrotum is flushed

• painfull and enlarged epididymis and testicles

• abnormal gait

• unilateral or bilateral testicular atrophy with swelling and hardening of the epididymis

• decreasing quality of semen and sexual activity, reduced fertility in rams

• Chronic lesions: abscesses and necrotic foci in the testicles, uneven surface, calcification

• sporadic abortion in ewes

• increased perinatal mortality

Diagnosis• Epidemiological situation, clinical signs• Palpation of testicles• microscopic and bacteriological examination of semen• serology: - AGID

- CFT- ELISA

PCR (urine, semen, preputial washes)

Differential diagnosis: - Histophilus somni- Actinobacillus seminis- B. melitensis

Treatment: Pointless!

Prevention, Eradication

• Castration of infected rams!

• young, immature rams: separated rearing

• ELISA test 4-6 weeks intervals: removing

seropositive rams

SWINE BRUCELLOSIS• Occurence

– Worldwide in swine-raising regions– It has been eradicated from domesticated pigs in the US,

Canada, European countries and Australia, but it persits in wild and feral swine population.

• Biotype 1-3: worldwide• 2: wild boars in Europe• 4: arctic regions of North America, and Russia• 5: in the former USSR (murine brucellosis)

• Etiology:– B. suis bt. 1-2-3.

• Epidemiology:Introduction into a herd:

- with infected, asymptomatic breeding animals

- vehicles, instruments

- dog, wild boar

• Pathogenesis: like cattle,

• Infection is aquired by ingestion or by coitus• but: orchitis, vertebral osteomyelitis can be seen more

frequently

• Clinical signs: – bacteraemia: gen. asymptomatic– sows: abortion (any gestation period),

stillbirth, neonatal mortality increase,

non-viable or poorly developed piglets,

vaginal discharge for several days

temporary sterility– boars: excreting brucellae in semen (with or without clin.

signs)• Testicular abnormalities: orchitis, sterility• Lameness, incoordination, posterior paralysis: vertebral abscess,

fractures

• Pathology:

– Fetus: odema of fetus and fetal membranes,

small haemorrhages, maceration, mumifiction

– Sows: necrotic foci in uterine wall

– Boars: enlarged testicle, inflammatory necrotic

foci

– Lesions in bones and joints: vertebral body -

deformities

dr. Deim Zoltán felvétele

dr. Deim Zoltán felvétele

dr. Deim Zoltán felvétele

• Diagnosis:

– Isolation of B. suis

– serology: Slide agglutination, tube agglutination, CFT,

ELISA: susceptibility and specificity also low:

only for livestock diagnosis!!!

• Treatment: NO!

• Eradication: Stock exchange!

• Maintain the disease-free status:

– Control of the import of susceptible animals

– Examination of abortion cases in diagnostic institutes

– Serological survey of breeding boars in each 6 month

– Serological examination of 10% of sows in each year

– Keeping wild boars away from swineherds

CANINE BRUCELLOSIS

• Occurence– Worldwide (America, Asia, Africa)– Europe: sporadic, everywhere– Free: New Zealand, Australia

• Susceptibility– B. canis– B. melitensis– B. abortus– B. suis

Epidemiology• Host spectrum

– narrow, dogs and the members of wild Canidae – zoonosis (more, than 40 cases in the literature)

• Infection• oronasal contact, through mucous membranes

(oral cavity, vagina, conjunctiva)

• infective dosis:– p.o.: 106 CFU– conjunctiva: 104 - 105 CFU

• Shedding bacteria:• bitches: vaginal discharge (during oestrus, and mating),

fetus, fetal fluid (1010 CFU/ml)6 weeks after abortion

• males: settle down in the postate and epididymissemen, urine: 103 - 106 CFU/ml

for 2 years

Clinical signs• No characteristic clinical signs, asymptomatic

• Enlargement of lymph nodes

• Pregnant bitches:

– abortion (between 45-60. days),

– reproduction failures (decreased fertility)

– Reduced litter size

– Neonatal mortality

– Most bitches that have aborted subsequently have normal gestations.

• Males: infertility, epididymitis, orchitis, prostatitis

• Scrotal dermatitis (saliva!)

• Dogs with chronic infections are often aspermic.

• rare: discospondylitis (lameness, paresis, paralysis), uveitis

Leland E. Carmichael és Craig E. Greene, 1998

B. canis

Diagnosis• Examination of semen

– p.i. 5. weeks, inflammatory cells, morphological alteration of sperm

• Isolation of B. canis

– from blood: pi 2-4 weeks – for years (5.5 years)

• Serological examination

– Slide aggl., Tube Aggl., AGID, IF, ELISA

– Earliest positive result: pi. 3-12 weeks

Fate of infected animal

Removal of infected animals from the kennel and

from breeding prgrammes.

Castration (neutering) of infected dog and treatment

with antibiotics reduces the risk of transmission.

Treatment

• Combination of – tetracyclines (minocycline) and– aminoglycosides (streptomicin)

• For 4 weeks

or

• Extermination of infected animals!

Prevention• serological examination:

– Breeding dogs: in each 6 month

– Introduction of a new dog into the kennel: two times in 1 month intervals

– Breeding animals 3-4 weeks before mating.

– If a dog leave the kennel: before readmission.

• Do not get dogs from a kennel, where reproductive problems occurs

• No vaccines available!

Brucellosis of other species

• Horse (B. abortus) – arthritis, bursitis and

tendovaginitis, fistolous withers, poll-evil

• Wild ruminants (B. abortus)

• Wild boars (B. suis) – source of B. s. infection

in domestic pigs reared outdoors

• Wild hare (B. suis bt. 2.)

„hazelnut chocolate” spleen (wild hare – Brucellosis (B. suis bt. 2))

dr. Gyuranecz M. felvétele

Brucella suis (chocolate agar, 37°C, 72 hours)

B. suis bt. 4. (arthritis, reindeer)

HUMAN BRUCELLOSISOne of the most fequently seen bacterial zoonosis in the Earth. 500.000 new patient/year!

Human is susceptible: MID50

B. melitensis ++++ (101)

B. abortus +++ (103)

B. suis ++ (105)

B. canis + (106)

B. ceti +

B. pinnipedialis +

Infection:

- ingestion (po): raw -unpasteurized- milk!

and dairy products made from this,

- skin abrasions: during abortion, amniotic fluid, urine

- inhalation (lab infections)

Incidence of human brucellosis

Clinical signs and pathological findings

- incubation period: 5-14 days (3 months)

- undulant fever (fluctuating pyrexia), malaise,

inappetence, fatigue, muscle and joint pains

- drenching sweats (at night)

- bone and joints alterations

(sacroiliitis, spondylitis, arthritis, osteomyelitis)

- swelling of liver and spleen (33%)

- lymph node alterations (10%)

- alteration in urinary and genital tract (glomerulonephritis,

kidney abscess, orchitis, epididymitis) (10%)

- CNS signs (7%)

- endocarditis

(B. canis: can be asymptomatic, just seroconversion)

Treatment of human brucellosis:

Should be administered early in an infection!

– rifampicin

– gentamycin

– trimethoprim-sulfamethoxazole

– doxycycline, minocycline

– ciprofloxacin

– streptomycin

Long-term treatment may be required!

Diagnosis

• Anamnesis!

• Haemoculture

• serology (B. canis Ag!!!), no crossreaction with B. abortus Ag!!!

– Slide agglutination – Tube agglutination– ELISA

• Fals diagnosis:

– Lack of appropriate serological kit (S-R)

– Occurence of the disease is underestimated

Time after the first clinical signs

Slide agglutination titer

2 months 32

3 months 16

8 months 2

Prevention• Veterinarians: examination of abortion cases - use of gloves and other

protective clothing

• Education of owners about the danger of rearing of brucella infected animals

• Consumption of Raw milk should be avoided!

• Laboratory: safety rules must comply!

• The rules of common sense must be observed if we live together with animals!