Acute brucellosis may present with symptoms such as [7]:

• Fever with chills and rigors 
• Anorexia 
• Headache
• Abdominal pain
• Muscular pain
• Fatigue and weakness
• Arthralgia
• Excessive sweating 
• Swollen lymph nodes 
• Hepatosplenomegaly with abdominal tenderness 
• Ocular findings such as uveitis, choroiditis, keratoconjunctivitis, etc.
• Cutaneous lesions such as erythema nodosum, maculopapular rashes, etc.

Fever is typically undulant, i.e it comes, reaches a high peak particularly in the afternoon or evening and then goes away for a while. When fever breaks, the patient may experience cold sweats and chills. After a few hours, fever spikes again. The associating symptoms may or may not persist.

Workup consists of a detailed history and physical examination.

Laboratory tests

• Complete blood count
• Liver function tests
• Culture
• Serology is unreliable. A four-fold rise in titre of agglutinating antibody, which detects IgM antibody, may be diagnostic but cross reactions are common [8]. 
• Arthrocentesis: In patients with joint involvement to rule out septic arthritis. 
• CSF culture: In patients with CNS involvement.
• PCR 
• Bone marrow biopsy
• Urinalysis

Imaging

Imaging studies are conducted if systemic manifestations are present. They may include:

• Chest X-ray if respiratory system seems to be involved. 
• Spinal X-ray to examine vertebral involvement.
• Radionuclide scintography [9]
• CT scan
• Echocardiography to rule out endocarditis

Test Results

Test results are enough to form a definitive diagnosis and treatment needs to be started immediately. An empiric antibody trial may be started if test results are awaited.

Antibiotics are the primary treatment. The most common and most efficacious of used agents include:

• Streptomycin
• Doxycycline 
• Gentamycin
• Rifampin
• Cotrimoxazole
• Ciprofloxacin

Of the currently existing alternative regimens, only the combination of doxycycline with gentamycin can be considered therapeutically adequate and cost-effective, the latter factor being a major obstacle in using quinolones for brucellosis [10].

Even though initial symptoms may appear to be debilitating, brucellosis has an excellent prognosis. With appropriate treatment for a few weeks to months, this disease can be cured with no lasting effects. Relapse may sometimes occur. It should be noted, however, that in patients with comorbidities such as congestive heart failure, prognosis can be negatively affected. Overall, mortality rate in uncomplicated cases is less than 2 to 5%.

Complications

Infection in pregnancy may result in abortion, congenital and neonatal infections, and infections of the delivery team [6]. Other complications include endocarditis, CNS disorders (neurobrucellosis), meningitis, skin lesions, ulcers and eye infections.

The causative agent of brucellosis is an unencapsulated gram negative rod called Brucella. There are three main human pathogens of Brucella, each with their specific animal reservoirs:

• Brucella melitensis (goats and sheep)
• Brucella suis (pigs)
• Brucella abortus (cattle)

Brucella canis (dogs) may also infect humans but it is rare and clinically indistinguishable from B. abortus infection.

Incidence

The reported frequency in USA is 0.04 per 100,000 people [2]. It has been known to cause more than 500,000 infections annually worldwide.

Age

Brucellosis can occur at any age but it is more common in young adults. Infection among children is generally more benign than in adults with respect to likelihood and severity of complications and response to treatment [3].

Sex

Brucellosis is much more common in males than in females. This predisposition to the male gender is attributed to males being more involved in activities, such a cattle farming, that increase chances of exposure.

The organisms enter the body either by ingestion of contaminated milk products or through skin due to contact in occupational setting such as an abattoir [4]. Once inside, these organisms localise in the reticuloendothelial system, where some of them are phagocytosed by macrophages. Some, however, survive within the cells and remain protected from antibodies.

The host response is granulomatous, with lymphocytes and epitheloid giant cells, which can progress to form focal abscesses [4].  The incubation period is usually one to four weeks; occasionally, it may be as long as several months [5].

Prevention can be possible with pasteurisation of milk, immunisation of animals, and slaughtering of infected animals. There is no human vaccine [4].

Brucellosis is a systemic infection with a broad clinical spectrum, ranging from asymptomatic disease to severe and/or fatal illness [1]. It has many other names such as Crimean Fever, Malta Fever, Undulant Fever, Mediterranean Fever, etc. It comes under the category of zoonotic diseases which refers to the group of diseases caused by organisms associated with animal reservoirs. Brucellosis is the most common zoonotic disease.

Definition

Brucellosis is a systemic infection which has a broad clinical spectrum. It may be asymptomatic to, in some extremely rare cases, fatal. It is also known as undulant fever, Malta fever, Mediterranean fever, etc.

Cause

It is caused by a bacteria called Brucella, which lives in animals like sheep, goats, dogs and pigs. Drinking unpasteurised milk or eating the meat of infected animals may result in this infection.

Symptoms

Symptoms include fever with chills and rigors, fatigue, headache, abdominal pain, muscular pain, sweating and sometimes it may be accompanied with skin rashes, eye infections and CNS disorders.

Treatment

Antibiotics are the treatment of choice and this disease can be completely cured in a few weeks of therapy.

Prevention

Brucellosis is easily preventable. By avoiding the use of unpasteurised milk and other dairy products, and eating the meat only from high quality stores, brucellosis can be prevented.

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2. Maloney GE. Brucellosis. eMedicine. Apr 2009. Retrieved Sept 26 2014.
3. Mantur BG, Amarnath SK, Shinde RS. Review of clinical and laboratory features of human brucellosis. Indian J Med Microbiol 2007; 25:188.
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