BRUCELLOSIS

Brucellosis is one of the major bacterial occupational zoonostic diseases. It is a severe human and
animal disease with serious economic consequences.

Synonyms
Undulant fever, Malta fever, Mediterranean fever or Bang's disease.

Definition
Brucellosis is a systemic disease with acute or insidious onset caused by different species of Brucella
group of organisms, characterized by intermittent or irregular fever of variable duration, headache
weakness, arthralgia/arthritis, profuse sweating and an enlarged spleen. The disease may last for
several days, months to several years.

Problem Statement
-World The disease is a public health problem worldwide.
-The endemic areas for brucellosis are in Mediterranean zones, Europe, Central Asia, Maxico and
South Africa.
-The disease is endemic in area where cattle, dogs, goats and sheeps are raised in large numbers.
-The disease is now rare in European countries.

India
-Animal brucellosis is prevalent in all the states of India.
-The prevalence of human brucellosis is not known, because many cases go undiagnosed either due
to being inapparent infections or because physicians are unfamiliar with the disease.

Epidemiological Factors
Agent Factors
1.Agent:
-The causative agents are small coccobacilli of the genus Brucella.
-They are gram negative, non-motile, non-spore forming and intracellular bacteria.
-Four species of Brucella infect man, i.e. B. melitensis, B. abortus, B. suis and B. canis.
-B. melitensis is the most virulent species and B. suis is of intermediate virulence and affects mainly
pigs.
-The B. melitensis usually infects goats and sheeps. B.canis infects dogs and B. abortus infects
primarily cattle but infects also man.

2 Reservoir of infection: Of human infection are cattle, sheep, goats, swine, buffaloes, horses and
dogs

3. Source of infection: Infected animal's urine, milk, placenta, uterine and vaginal discharges,
viscera, lymphnodes infected muscle tissues and blood and aborted fetuses.

Host Factors
1.Sex and age: Adult males are predominantly affected.

Occupation: Farmers, shepherds, butchers, veterinarians and laboratory workers are at risk because
of the nature of their occupation which is concerned with handling animals.
Environmental Factors
Poor standard of hygiene in animal sheds, over-crowding of herds, high rainfall, lack of exposure to
sunlight, unhygienic practices in milk and meat production favor spread of brucellosis.

Mode of Transmission
No spread is noted from man-to-man. Transmission is from animals to man through direct contact.
ingestion, inhalation and accidental inoculation.

1. Infected tissues, blood, placenta, urine, vaginal discharges and aborted fetuses cause infection.
through direct contact with abraded skin, mucosa or conjunctiva.

2. Ingestion of raw milk or dairy products (cheese) from infected animals, fresh raw vegetables
infected with animal urine or feces, water contaminated with excreta of infected animals can also
cause infection.

3. Inhalation of dried infected dust from sheep wool or transport used in carrying infected animals or
aerosols from slaughter houses and laboratories can cause brucellosis. 4 Accidental inoculation of
infected animal urine, feces or other infected animal tissue into the abraded skin can also cause
infection.

Incubation Period
1-3 weeks but may be as long as 6 months or more.

Clinical Features
Brucellosis in man can vary from an acute febrile disease to sub acute infection manifested by fever
or chronic low grade disease which may last for several days to months or occasionally years.

Acute Phase
Acute phase has sudden or insidious onset with pyrexia up-to 40"-41°C accompanied with rigors and
sweating, arthralgia/arthritis involving larger joints, eg. hip and knee, low backache, headache and
insomnia, small firm spleenomegaly, hepatomegaly, leucopenia with relative lymphocytosis Disease
is severe and does not show clinical signs, it is the most striking aspect of the clinical picture. Signs
and symptoms acute phase disappear within 2-3 weeks. Treatment with tetracycline, may cause the
symptoms to disappear quickly. The infection, being intracellular, may become subacute with
frequent relapses.
The disease may become chronic and last for a number of years.

Diagnosis
1. Culture of blood, bone-marrow, exudates and biopsy specimens during acute phase of disease to
isolate the organism.
2 Serological tests.

Control of Brucellosis
In the Animals
1. Case finding and slaughter of infected animals: It should be done with full compensation to
farmers whose animals are slaughtered. Case finding is done by mass survey, skin tests.
2. Vaccination: Young animals particularly all heifers (young cow) should be vaccinated with vaccine
of B. abortus strain 19 every year for a period of 7-10 years which may result in elimination of the
disease.
3. Environmental hygiene: Clean environment for animals, should be maintained with sanitary
deposal of urine and feces of animals and education of all those who are occupationally involved

In the Humans
1. Early diagnosis and treatment: Tetracycline is the antibiotic of choice in uncomplicated cases. The
dose is 500 mg 6 hourly for about 3 weeks. Patients with skeletal or other complications are treated
with intramuscular streptomycin 1 g daily in addition to tetracycline.
2. Pasteurization of milk and milk products renders milk safe. If pasteurization is not available, then
milk should be boiled.
3: Protective measures: Persons likely to get infection from infected animals should avoid direct
contact with placenta, aborted animal fetuses, infected animal milk and use protective clothing and
gloves while handling such carcasses, placenta, etc. They should practice high standards of personal
hygiene. Exposed skin areas should be washed and soiled clothing disinfected and washed with soap
and water. Abraded skin area should be covered with dressing.
4. Disease should be notified to the local authority.
5. Isolation: None.
6. Concurrent disinfection of body discharges.
7. Terminal disinfection: None.
8. Investigation of source of infection and its elimination.

Preventive Measures

1 Health education of persons at risk such as farmers, shepherds, milkmen and slaughter house
(abattoir) workers to prevent direct contact with infected animals, products of infected animals and
about the nature of disease.
They should practice high standards of personal hygiene. They should take care in handling and
disposal of placenta, discharges and fetuses from infected animals.
2. Persons at risk as mentioned above should wear protective clothing and gloves while handling
carcasses. Exposed areas of the skin should be washed with soap and water and soiled clothing
changed and disinfected.
3. Pasteurization or boiling of milk should be done to make it safe for human consumption. Milk
products should also be pasteurized.
4. Search for infected animals and their elimination.
5. Meat inspection and inspection of slaughter houses should be done.
6. Human live vaccine of B. abortus strain 19-8 A should be given when available.