B
RUCELLOSIS
By
Dr. Ameer kadhim Hussein
M.B.Ch.B. FICMS (Community Medicine)
I
DENTIFICATION
Brucellosis is a bacterial disease caused by small, gram negative
rod shaped, non motile, non sporing and intracellar coccobacilli of
genus Brucella.
It is a zoonotic disease meaning that it is primarily an infection of
animals but can be transmitted to human.
Different species of Brucella bacteria mostly infect domestic
livestock including:
1. Cattle (
B. abortus
).
2. Sheep and goats (
B. melitensis
).
3. Pigs (
B.suis
).
4. Dogs which can also be infected with (
B. canis
).
5. Brucella ceti and Brucella pinnipedialis
Other names of brucellosis: (Undulant fever, Malta fever and
Mediterranean fever).
RUCELLOSIS
B
G
EOGRAPHICAL
DISTRIBUTION
It is a worldwide infection traditionally associated
with farm workers, veterinarians and persons whose
occupation includes packing of meat or dairy
products.
It affects people of all age groups and of both sexes.
Although there has been great progress in
controlling the disease in many countries, there still
remain regions where the infection persists in
domestic animals and transmission to the human
population frequently occurs.
G
EOGRAPHICAL
DISTRIBUTION
It is an important human disease in many parts of the
world especially in the Mediterranean countries of
Europe, Africa, the Middle East, south and central
Asia and central and south America and Mexico and
yet it is often there are only a few countries in the
world that are officially free of the disease although
cases still occur in people returning from endemic
countries. Significant proportion of brucellosis cases
still remain undiagnosed.
The disease is now rare in most European countries,
North America and Australia.
B
RUCELLOSIS
C
LINICAL
M
ANIFESTATION
Fever, Night sweats, Malaise, Anorexia, Arthralgia, Fatigue, weight
loss and depression. Subclinical has been reported.
Bone and joint involvement are the most frequent complications of
brucellosis occurring in up to 20-60% of cases.
Different syndromes have been reported including sacroiliitis,
spondylitis, peripheral arthritis, osteomyelitis, bursitis and
tenosynovitis.
Brucella sacro-iliitis is especially common. Patients present with
fever and back pain often radiating down the legs (sciatica).
Genito urinary involvement occur in 2% to 20% of cases with
orchitis and epididymitis as a common manifestations
Neuro-brucellosis is less common but more severe (represent 3-
7%). Recovery is usual but disability is often pronounced.
Case fatality rate in untreated cases represent 2% or less usually
from endocarditis. In brucellosis relapse can occur.
M
ODE
OF
TRANSMISSION
Brucellosis is a zoonotic disease transmitted to humans by:
1.
Contact through mucus membranes and breaks in the skin with fluids
from infected animals (including sheep, cattle, goats, pigs, or other
animals) these fluids include blood, urine, vaginal discharges and
aborted fetuses and especially placentas.
2. Ingestion of raw milk and dairy products such as unpasteurized milk
and cheese and ingestion of undercooked meat from infected animals.
3. Airborne transmission has been reported in laboratory and
slaughterhouse workers.
4. Accidenital self inoculation of strain 19, REV-1 and RB 51 brucella
animal vaccines.
5. Person to person transmission is rare, possible sexual transmission
and breast feeding women may transmit infection to their infants.
RUCELLOSIS
B
Reservoir
Cattle, swine, goats and sheep. Dog is regard a reservoir for
B. canis.
Incubation period
Commonly 1-2 months with range of 5 days to 5 months
Period of communicability
Rare person to person transmission but risk may exist for
medical personnel in endemic area expose to contaminated
fomities, tissues or massive bleeding such as obstetric
procedures.
RUCELLOSIS
B
Susceptibility
Severity and duration of clinical illness vary.
Duration of acquired immunity is uncertain.
Diagnosis by the following:
1.Isolation of the infectious agent from blood, bone
marrow or other tissues or discharges.
2. PCR.
3. Serological tests which allow precise diagnosis in
about 95% of cases (including combination of Rose
Bengal and seroaglutination test with coombs-test and
ELISA- test).
CONTROL
OF
ETHODS
M
The most effective method for preventing human brucellosis is
control and eradication of infections in animal reservoirs.
a. Preventive measures :
1.Educate the public especially the tourists about the risks
associated with drinking unpasteurized milk or eating products
made from unpasteurized milk.
2.Educate farmers and workers in slaughter houses and butcher
shops about the nature of disease and risk of handling carcasses
and product from infected animals and importance of appropriate
ventilation.
3.Educate hunters to use protective gloves and clothing when
handling feral swine or potentially infected wildlife such as elk.
CONTROL
OF
ETHODS
M
4. Search for infection among livestock by serological testing and
by ELISA or ring test and eliminate infected animals by segregation
and or slaughtering.
In high prevalence area immunize young goats and sheep with live
attenuated Rev-1 strain of B. melitensis and immunize calves and
adult animals with strain 19 (B. abortus) vaccine.
Since 1996 the strain RB51 of B. abortus has replaced strain 19 for
immunization of cattle against B. abortus. RB51 vaccine was
designed to be less virulent for humans than strain 19 when
accidentally injected.
CONTROL
OF
ETHODS
M
5. Pasteurize milk and dairy products from cows, sheep and
goats. Boiling milk is applied when pasteurization is
impossible. Don’t eat meat from animals that appear ill.
6. Exercise care in handling and disposal of placenta and
discharges and fetuses and disinfect contaminated areas.
(R
EV
-1)
AND
S
TRAIN
19
VACCINES
b. Control of patient , contacts and immediate environment
1. Report to local health authority.
2. Isolation: draining and secretion precautions applied if there
are draining lesions, otherwise none.
3. Concurrent disinfection of purulent discharges.
4. Investigation of contacts and source of infection: Trace
infection to the common or individual source usually infected
domestic goats, swine and cattle or raw milk or dairy products
from cows and goats. Test for suspected animals and remove
reactors.
5. Specific treatment: The treatment of choice is a combination
of doxycycline (200 mg daily) and rifampicin (600-900 mg
daily) or streptomycin (1g daily) for at least 6 weeks.
Methods of control
Epidemic measures
Search for common vehicle of infection usually raw
milk or milk products especially cheese from infected
herd.
Stop production and distribution of product unless
pasteurization is instituted.
International measures:
Control of domestic animals and animal products in
international trade and transport.
Epidemic and international measures
Thank you