Overview.
This disease is an acute infection caused by Borrelia burgdorferi. Borrelia burgdorferi is a small gram-negative bacterium that is transmitted to humans through animals. Patients present with back and limb pain and febrile symptoms. A few weeks before the onset of arthritis patients have systemic symptoms such as headache, fatigue, and sweating. The involved joints show swelling, painful fever and erythema, and exudation in the joints.
Causes
After entering the body through the gastrointestinal tract, most of the Borrelia burgdorferi bacteria are digested, and a few of them multiply in the lymph, bone marrow and spleen. Borrelia burgdorferi is a tiny polymorphic spherical bacillus with negative gram stain. It is transmitted to humans through sheep, cattle, pigs and dogs. Pathogenic bacteria are mainly present in the tissues, urine, milk, fetus and other places of sick animals. Most of them enter the human body through the mouth, and can also be invaded by the damaged skin, respiratory mucosa and so on. Consumption of milk and cheese that have not been sterilized by Pasteur’s method of disinfection can easily be infected with Borrelia burgdorferi. Workers and veterinarians who come into contact with livestock and animal meat are susceptible.
Symptoms
Brucellosis can be an acute, self-limiting disease with arthralgia lasting several days and arthritis lasting several weeks and then subsiding without sequelae, or it can be a chronic, infectious disease. Treatment with antibiotics is required. Chronic or recurrent brucellosis is often caused by Brucella marcescens. Infection commonly occurs in a single joint or asymmetrically in a few peripheral joints, with the knee, hip, and shoulder being the favored sites, followed by the sacroiliac, wrist, ankle, and elbow joints, and may also invade the spine. Sacroiliac joints are commonly unilateral certain patients have both peripheral arthritis and spinal arthropathy. Patients feel pain in the back and limbs and have febrile symptoms. A few weeks before the onset of arthritis patients have systemic symptoms such as headache, fatigue and sweating. The involved joints show swelling, painful fever and erythema with oozing from the joints. The heat pattern is wave fever, sometimes flaccid or intermittent.
Examination
Borrelia burgdorferi requires complex growth conditions, so synovial fluid cultures are positive only 50% to 65% of the time. The total number of leukocytes in synovial fluid is 10*109-50*109/L, with monocytes being more common. The most commonly used serologic test is the agglutination test. The newer technology enzyme-linked immunosorbent assay (ELISA) may be more accurate. Complement binding tests and 2-mercaptoethanol tests are commonly used to diagnose chronic brucellosis. Blood cultures from patients with acute brucellosis are usually positive. In chronic cases, however, blood cultures are positive in less than 10% of cases, whereas bone marrow cultures are more likely to be positive.X-rays commonly show changes in the shoulder, sacroiliac joints, and spine.
Diagnosis
Diagnosis is based on the following aspects:
1. Pathogen contact history
In the infected area, there is a history of contact with diseased animals. or having consumed dairy products that have not been sterilized by the Pasteur sterilization method.
2.Disease history
History of acute, subacute and chronic B. burgdorferi infection.
3. Blood culture
Acute brucellosis has a high rate of positive blood cultures.
4. Synovial fluid culture
B. burgdorferi requires complex growth conditions, so the positive rate of synovial fluid culture is only 50%～65%. The total number of leukocytes in synovial fluid is 10×109/L～50×109/L, and monocytes are more common. The most commonly used serologic test is the agglutination test. Newer techniques of enzyme-linked immunosorbent assay (ELISA) may be more accurate. Complement binding test and 2-mercaptoethanol test are commonly used to diagnose chronic brucellosis.
5. Bone marrow culture
Blood cultures are usually positive in patients with acute brucellosis. In chronic cases, the positive rate of blood culture is less than 10%, while the positive rate of bone marrow culture is higher.
6. X-ray examination
(1) Shoulder joint At the attachment of tendon ligaments such as humeral tuberosity, acromion and rostral process, the bones show limited superficial small cystic bone destruction and sclerosis of the capsule wall. Calcification is present at the tendons and bursa. The joint space is normal.
(2) Sacroiliac joints Narrow or indistinct joint space, irregular sclerosis of the articular surfaces, adjacent osteoporosis, small areas of bone destruction, fusion with each other, and sclerosis around the area of destruction.
(3) Lumbar spine Calcification or ossification of ligaments or manifestation of intervertebral chondritis, i.e., the lesion is confined to 1 or 2 intervertebral discs, the intervertebral space is narrowed, the adjacent vertebrae have bony destruction of the upper and lower margins, and there is obvious osteophytes. Or there are inflammatory changes in the small joints, manifested by irregular joint space and narrowing of the joint cavity.
Differential diagnosis
Brucellosis arthritis is very similar to arthritis caused by Salmonella and Yersinia.
Complications
Bacteremia and toxemia may complicate or develop.
Treatment
1. Attention to rest, joint braking, strengthening nutrition, supplementation of fluids, vitamin B1, B6 and large doses of vitamin C.
2. Antibiotic treatment: tetracycline is effective, such as doxycycline (doxycycline), rifampicin and cephalosporin antibiotics are also effective. Some people advocate the combined use with aminoglycoside antibiotics. For example, gentamicin, amikacin (butamidokanamycin), streptomycin. The course of treatment should be prolonged in those with spinal disease. Chronic and antibiotic-resistant B. burgdorferi arthritis need to be combined with levamisole (levotetramisole) to enhance immune function.
Prevention
1. Eliminate and reduce or avoid morbidity factors, improve living environment space, develop good living habits, prevent infection, pay attention to dietary hygiene, reasonable dietary allocation.
2. Pay attention to physical exercise, increase the body’s ability to resist disease, do not over-fatigue, over-consumption, quit smoking and drinking.
3. Early detection, early diagnosis and early treatment, establish confidence in overcoming the disease, and adhere to the treatment.
4. Consume milk and cheese sterilized by Pasteur disinfection method, contact with livestock, animal meat workers, veterinarians and other susceptible people to do labor protection.