A bacterial infection that spreads from animals to people and causes fever, joint pain, and extreme tiredness (fatigue) is called brucellosis. People often become infected with this infection by eating raw or unpasteurized dairy products. In some cases, a person may become infected from inhaling air droplets that contain the bacteria or direct contact with an infected animal.
In most cases, brucellosis is treated with antibiotics that should be taken for a few weeks to months. However, despite successful treatment, the infection may return.
To reduce the risk or prevent this bacterial infection, you should avoid raw dairy products and take precautions when working with animals or in a laboratory.
Symptoms
The symptoms often appear differently among people. While brucellosis symptoms may appear within several days, some people notice them months after being infected. Check below some brucellosis symptoms:
- Fatigue (extreme tiredness)
- Weakness
- Sweating
- Appetite changes
- Joint, back, or muscle pain
- Headaches
- Chills
- Fever
The symptoms of this infection may come and go even after months. Moreover, some people with a chronic (long-lasting) form of brucellosis may experience symptoms for years even after successful treatment. Check below some symptoms that may last for a long time:
- Recurrent fevers
- Fatigue
- Endocarditis (inflammation of the inner lining of the heart chambers)
- Arthritis (inflammation of the joint)
- Spondylitis (arthritis that affects the spinal bones)
- Sacroiliitis (arthritis of joints that appear where the pelvis and spine connect)
Commonly, it is difficult to diagnose this condition, especially in the early stages, because it causes symptoms similar to other conditions (such as the flu). Thus, if you experience muscle aches, unusual weakness, and a fast-rising or persistent fever, do not hesitate to see a doctor.
Causes
Generally, this bacterial infection negatively affects multiple wild and domestic animals. These include:
- Deer
- Elk
- Bison
- Caribou
- Moose
- Camels
- Dogs
- Pigs
- Sheep
- Goats
- Cattle
Furthermore, there is a form of brucellosis that may negatively affect harbor seals, porpoises, and certain whales. Check below the most common ways that bacteria spread to humans:
- Raw dairy products – The bacterium that causes brucellosis is called Brucella, and it may be in the milk of infected animals. Furthermore, it may spread to people if the infected milk is used in ice cream, butter, and cheeses. However, you may become infected with this bacterium when eating the undercooked meat of infected animals.
- Contaminated air – The Brucella may enter the body through the air. Thus, farmers, hunters, laboratory technicians, and slaughterhouse workers usually get infected with the bacteria.
- Direct contact with blood or other body fluids of infected animals – Blood, semen, or placenta may also contain the bacteria that cause brucellosis. However, normal contact with animals, including touching, brushing, or playing, usually does not cause infection. Furthermore, people with weakened immune systems should avoid handling dogs that are known to be infected with Brucella.
This infection usually does not spread among people, but in some cases, a female has passed the infection to her child during pregnancy or breastfeeding. Rarely, a person may become infected through sexual activity, contaminated blood, or bone marrow transfusions.
Risk Factors
While this bacterial infection occurs rarely in the U.S., it is mostly diagnosed in certain parts of the world. These include Southern Europe (including Portugal, Spain, Turkey, Italy, Greece, and Southern France), Eastern Europe, Mexico, South and Central America, Asia, Africa, the Caribbean, and the Middle East.
Check below some jobs and hobbies that significantly increase the risk of getting brucellosis. Examples include:
- Veterinarians
- Dairy farmers
- Ranchers
- Slaughterhouse workers
- Hunters
- Microbiologists
What Happens if Brucellosis is Left Untreated?
This bacterial infection may negatively affect almost any part of the body, including the heart, liver, central nervous system, reproductive system, and others. Check below some complications that may occur in people with brucellosis:
- Endocarditis (inflammation of the heart chambers’ inner lining) – This complication is considered one of the most serious, and without treatment, it may lead to permanent damage to the heart valves.
- Arthritis – This condition causes joint inflammation that often occurs along with pain, stiffness, and swelling in the joints. It usually affects joints in the knees, hips, ankles, wrists, and spine. Sometimes, this complication may lead to spondylitis or sacroiliitis. Without treatment, these complications may cause permanent damage to the joints in the spine and pelvis.
- Epididymo-orchitis (infection and inflammation of the testicles) – This bacterial infection may negatively affect the epididymis (a tube that links the vas deferens with the testicles). Hence, the infection may spread to the testicles and cause swelling and pain.
- Inflammation and infection of the liver and spleen – This infection may also impact the liver and spleen, causing them to become enlarged.
- Central nervous system infections – These include meningitis (a life-threatening condition that causes inflammation of the membranes that surround the brain and spinal cord) or encephalitis (brain inflammation).
How to Prevent Brucellosis?
The following tips may help reduce the risk or even prevent brucellosis. Examples include:
- Do not consume unpasteurized dairy products – Nowadays, there are a few cases of brucellosis in the U.S. Most of them are associated with dairy products from domestic herds. However, it is recommended to avoid raw dairy products if you travel to other countries.
- Cook meat thoroughly – You should cook the meat until it reaches the internal temperature of 145°F (63 °C). However, ground meat should be cooked at 160°F (71°C) degrees and poultry at 165°F (74°C) degrees.
- Wear gloves – You should wear gloves if you are a veterinarian, farmer, hunter, or slaughterhouse worker because they help prevent getting the bacteria.
- Precautions in high-risk workplaces – These include protective clothing (such as face mask, gloves, and others).
- Domestic animal vaccination – While vaccination has nearly eliminated brucellosis in livestock herds, it may cause some diseases in humans because the vaccine is live. Get medical help if you accidentally sting yourself with a needle used to vaccinate the animal.
Diagnosis
Healthcare professionals usually diagnose this infection by performing certain tests. These include blood tests or bone marrow tests to check for antibodies associated with Brucella. Check below some tests used to check brucellosis complications:
- X-rays – This test is used to identify changes in the joints and bones.
- CT (computerized tomography) or MRI (magnetic resonance imaging) scans – These imaging tests are used to get detailed pictures of different body structures and organs.
- Cerebrospinal fluid culture – This test involves getting a small amount of the fluid that surrounds the brain and spinal cord to check for life-threatening complications such as meningitis and encephalitis.
- Echocardiography – This is a specific test that uses sound waves to make pictures of the heart. It helps check for infection or damage to the heart.
Treatment
The goal of the treatment is to prevent the recurrence of the infection and reduce the risk of complications. Healthcare professionals usually prescribe antibiotics that should be taken for at least 6 weeks or until the symptoms disappear completely. Sometimes, the infection returns and becomes chronic (long-lasting) despite successful treatment.
Frequently Asked Questions
What does Brucella cause in humans?
This is a bacteria that cause infection in humans. This bacterial infection is called brucellosis, and it may cause the following symptoms. For example, fever, joint pain, sweating, and tiredness. Without treatment, brucellosis may cause certain life-threatening complications such as meningitis.
Is brucellosis highly contagious?
No, there are a few cases where the bacteria spread from one person to another. For more details, discuss it with your doctor.
What is another name for brucellosis?
Sometimes, this infection is called Mediterranean fever, undulant fever, Malta fever, Gibraltar fever, Cyprus fever, or Bang’s disease. Ask your healthcare professional if you have any other questions.
