An average of about 21,000 new cases of Brucellosis are reported in the country annually. The disease is a bacterial disease caused by various species of Brucella and mainly infects cattle, goats, sheep, dogs and pigs. Humans generally become infected through direct contact with infected animals, eating or drinking unpasteurized animal products, or inhaling airborne agents. Children, villagers, and people who keep domestic animals are most at risk of infection. Transmission through the fetus is also possible (congenital Brucellosis), and infection in the early stages of pregnancy may cause miscarriage.
Brucellosis is prevalent in all seasons, but is more common in spring and summer, coinciding with the calving and lactation seasons of livestock. The disease is more common in rural areas than in urban areas.
Is Brucellosis fever contagious?
Human-to-human transmission of Brucellosis is very rare and is usually transmitted through contaminated livestock or animal products. However, transmission from mother to fetus during pregnancy, through breast milk, sexual intercourse, and rarely through contaminated blood has been reported.
Is Brucellosis fever fatal?
This infection can often be treated with antibiotics. However, treatment takes several weeks to months. And the infection can come back.
Symptoms of Brucellosis:
o Fever
o Chills
o Excessive sweating
o Weakness
o Fatigue
o Joint, muscle, and back pain
o Loss of appetite
o Headache
Symptoms of Brucellosis may disappear for weeks or months and then return. Some people have long-term Brucellosis, called chronic Brucellosis. They have symptoms for years, even after treatment. Long-term symptoms may include:
o Fatigue
o Recurrent fever
o Endocarditis (inflammation of the lining of the heart chambers)
o Arthritis (inflammation of the joints)
o Spondylitis (arthritis of the bones of the spine)
o Sacroiliitis (arthritis of the joints that connect the spine and pelvis)
Brucellosis in children:
Children usually present to the doctor with symptoms such as prolonged fever, lethargy, pain in the limbs, and sometimes difficulty walking. Joint and bone pain, night sweats, and loss of appetite are common, and the liver and spleen may be enlarged. In children, prompt diagnosis and age-appropriate drug regimens are important to prevent relapse and bone involvement.
Brucellosis in adults:
Symptoms of Brucellosis in adults depend on the severity of the infection and the person's general health. In some cases, the infection may be asymptomatic, but in others, it may be accompanied by more severe symptoms. Symptoms of Brucellosis in women may include menstrual irregularities or pelvic pain, and symptoms of Brucellosis in men include testicular inflammation, among other symptoms.
Symptoms of brucellosis in adults include periodic fever, fatigue and weakness, night sweats, headache, loss of appetite, and symptoms such as cough, shortness of breath, abdominal pain, neurological changes, and digestive disorders. If you have chest pain, shortness of breath, or palpitations, you should be evaluated for heart involvement.
When should you see a doctor?
Brucellosis can be difficult to diagnose, especially in the early stages. In the early stages, it often looks like an illness such as the flu. See your doctor if you are at risk for Brucellosis and have a fever that rises quickly or lasts a long time, or if you have unusual muscle aches or weakness.
Common species of Brucella bacteria that cause Brucellosis fever in Iran:
1. Brucella. melitensis
2. Brucella. canis
Common laboratory tests for Brucellosis:
1. Serology test (Wright, STA, 2ME)
2. PCR test
- Wright test or Standard Tube Agglutination Test (STA)
The Wright tube test (Standard Tube Agglutination Test – STA) is a serological method for diagnosing Brucella infection that measures patient serum antibodies and Brucella antigen.
Coombs' Wright test -
Primarily used to diagnose chronic brucellosis when the Wright test (or standard tubular agglutination test) is negative but symptoms are present. It is also useful in monitoring relapse or evaluating treatment.
2ME or 2-mercaptoethanol test: -
If the Wright test is positive, 2ME is performed as a complementary test to detect active infection and differentiate acute from chronic brucellosis. This test detects immunoglobulin G (IgG). If the titer from this test is high, the test result is declared positive and means that the person has an active infection. Finally, higher titers in endemic areas of the disease are of particular importance and the person should start treatment as soon as possible.
PCR test
This method is performed by examining the DNA of the Brucella bacteria in blood or other body tissues. This test is highly sensitive and can detect even very small amounts of the bacteria. The advantages of PCR include high speed and high accuracy.
The incubation period of this disease:
In many patients, symptoms are mild. Therefore, the diagnosis of Brucellosis fever may not be made. The incubation period of the disease can be very variable and ranges from 1 week to 2 months, but is usually 2 to 4 weeks.
Prevention of Brucellosis:
The most common way of transmitting brucellosis is through the consumption of contaminated milk and dairy products, so changing dietary habits and making food safe is very important; Brucella bacteria are killed by proper heating. The appropriate amount of heat is to boil the milk for 3 to 5 minutes after it reaches the boiling point. Cheese, cream, and yogurt must also be made from pasteurized milk; all people who come into contact with livestock or their products (such as slaughterhouse workers, butchers, livestock farmers, veterinarians, etc.) must use full personal protective equipment. These items include: work clothes, plastic aprons, special shoes, masks, gloves, and eye protection; also, hands should be washed properly with soap and water after contact with a contaminated environment.
Treatment of Brucellosis:
Brucellosis is usually treated with antibiotics prescribed by a doctor.
Complications after treatment:
Some patients experience fatigue, vague muscle and joint pain, or mild night sweats for weeks to months after the infection is treated, which resolves over time. If treatment is incomplete or the person is re-infected, there is a risk of recurrence.
Symptoms such as progressive back pain, neurological symptoms, shortness of breath, or recurrent fever should be evaluated immediately to rule out an underlying infection or new complication. Gradual rehabilitation and return to activity will facilitate recovery of function.
After treatment for Brucellosis, some people continue to experience complications, such as:
- Gastrointestinal complications such as nausea, vomiting, diarrhea, or intestinal disorders
- Allergic reactions such as anaphylaxis (severe allergic reaction), itching and swelling
- Kidney problems such as low urine output, blood in the urine, pain or swelling in the kidney area
- General symptoms such as fatigue, general weakness, headache, increased sensitivity to light, night sweats and lack of concentration
Sources:
https://www.who.int/news-room/fact-sheets/detail/brucellosis
https://my.clevelandclinic.org/health/diseases/17886-brucellosis
https://www.mayoclinic.org/diseases-conditions/brucellosis/symptoms-causes/syc-20351738
https://sbmu.ac.ir