Brucellosis

Brucellosis (Maltese fever, Gibraltar fever, Mediterranean fever, undulating fever, Bang's disease, Bruce's disease, Melitococcosis, Melitococcus) is a zoonotic infectious disease with a variety of mechanisms of the pathogen transmission characterized by fever, musculoskeletal system damage, nervous system, genital organs.

Brucellosis is caused by Brucella sp. Initially, the symptoms of brucellosis include acute febrile illness with little or no local symptoms. Subsequently, the disease passes into the chronic phase, which is characterized by recurrence of fever, weakness, sweats and undefined pain. Diagnosis of brucellosis is based on a culture test (usually blood). Optimal treatment of brucellosis requires the appointment of two antibiotics - doxycycline or trimethoprim-sulfamethoxazole in combination with streptomycin or rifampin.

ICD-10 codes

• A23. Brucellosis.
  • A23.0. Brucellosis caused by Brucella melitensi.
  • A23.1. Brucellosis caused by Brucella abortus.
  • A23.2. Brucellosis caused by Brucella suis.
  • A23.3. Brucellosis caused by Brucella canis.
  • A23.8. Other forms of brucellosis.
  • A23.9. Brucellosis, unspecified.

What causes brucellosis?

Human brucellosis is caused by brucellae : Brucella abortus (from cattle), B. Melitensis (from sheep and goats) and B. Suis (from domestic pigs). B. Canis (dogs) causes sporadic infections. The most frequent sources of infection are domestic animals and raw dairy products. Brucellosis among elk, bison, horses, American moose, Canadian deer, hares, chickens and desert rats have also been reported.

Brucellosis is affected by direct contact with the secrets or excrement of infected animals, as well as when using raw milk or dairy products containing viable microorganisms. This disease is rarely transmitted from person to person. Brucellosis is more common in rural areas, where brucellosis is a professional disease of workers in meat processing enterprises, veterinarians, farmers, hunters and cattle breeders. Brucellosis is rare in the US, Europe and Canada, but this disease is observed in the Middle East, Mediterranean regions, in Mexico and Central America.

What are the symptoms of brucellosis?

Brucellosis has an incubation period that varies from 5 days to months and on average is 2 weeks. The beginning can be sudden. Thus there are such symptoms of brucellosis as: chills and fever, acute headache, pain in the joints and lower back, general weakness and, in some cases, diarrhea.
 
Brucellosis can proceed gradually, with a slight prodromal frustration, muscle pain, headache and pain in the back and neck. All this is accompanied by an increase in the evening temperature. As the disease progresses, the body temperature rises to 40-41 C, after which it gradually decreases to normal or close to them, which is accompanied by profuse morning sweats. In typical cases, intermittent fever lasts for 1-5 weeks, followed by a 2-14-day remission, when symptoms of brucellosis are poor or absent. In some patients, fever may be unstable. In other patients, the febrile phase is repeated one or more times undulating (undulations), between them there are remissions lasting in months - years.

After the initial febrile phase, anorexia, weight loss, abdominal and joint pain, headache, back pain, weakness, irritability, insomnia, depression and emotional instability may appear. Constipation usually occurs. Appears splenomegaly, and lymph nodes may slightly or moderately increase. Up to 50% of patients have hepatomegaly.

Patients with acute uncomplicated brucellosis usually recover on the 2-3th week of the disease even without treatment. Some patients develop subacute, intermittent or chronic forms of the disease. Complications of brucellosis are rare, but include serious diseases such as subacute bacterial endocarditis, meningitis, encephalitis, neuritis, orchitis, cholecystitis, liver suppuration and osteomyelitis.

How is brucellosis diagnosed?

Brucellosis is diagnosed by sampling blood for culture. The growth of microorganisms can take more than 7 days, so it is necessary to warn the laboratory about suspected brucellosis. Serums corresponding to the acute phase of the disease and recovery should be taken separately with an interval of 3 weeks. A 4-fold increase in silt and a titer of 1/160 and higher in the serum corresponding to the acute phase of the disease are considered diagnostic, especially if there is a history of contact and there are characteristic clinical findings. The number of leukocytes in the acute phase of the disease remains normal or may be reduced. In this case, there is a relative or absolute lymphocytosis.

How is brucellosis treated?

In acute cases of the patient, the load is contraindicated and bed rest is recommended during fever attacks. In cases where antibiotics are prescribed, it is more preferable to prescribe a combination therapy. Doxycycline 100 mg orally 2 times a day for 3-6 weeks in combination with streptomycin 1 g intramuscularly every 12-24 hours for 14 days reduces the frequency of relapses. Children under the age of 8 years are prescribed trimethoprim-sulfamethoxazole in combination with either intramuscular streptomycin or oral rifampin for 4-6 weeks. Acute musculoskeletal pain, especially arising along the spine, may require the appointment of analgesics.

Brucellosis can be prevented if pasteurization of milk is carried out. The vaccine against brucellosis is also used . Cheese, prepared from unpasteurized milk, stored for less than 3 months, can be contaminated. People engaged in animal husbandry or carcasses of animals must wear glasses and rubber gloves, and protect skin damage from contact. In the US and some other countries, programs are needed to detect infection in animals, the destruction of infected animals and vaccination of young seronegative cattle and pigs. Immunity after a human infection lasts an average of 2 years.

What is the prognosis of brucellosis?

Brucellosis has a favorable prognosis. Adequate treatment of brucellosis promotes complete recovery. In acute uncomplicated brucellosis, the clinical symptoms of brucellosis disappear after 2-3 weeks, but treatment should continue for 6 weeks or more. Relapses of the disease occur in 5% of cases. Lethal outcomes are rare. Possible disability as a result of severe lesions of the musculoskeletal system and the central nervous system.