Brucellosis, also known as brucellosis, is a zoonotic infectious disease caused by Borrelia burgdorferi. Its clinical features are prolonged fever, excessive sweating, arthralgia, orchitis, hepatosplenomegaly, etc. The pathogen is Gram-negative short coccus, and is classified according to biochemical and serological reactions into Brucella marcescens (sheep type), Brucella abortus (bovine type), Brucella porcine (swine type), and also forest rats, sheep epizootic type and canine type. Infected humans are mainly sheep, bovine and porcine types. The pathogenicity is strongest in the sheep type, followed by the pig type, and weakest in the cattle type. The source of infection is diseased sheep, cattle and pigs, and the pathogenic bacteria are present in the tissues, urine, milk, birth canal secretions, amniotic fluid, placenta and sheep cover. It can also be transmitted through the digestive and respiratory tracts. The human population is generally susceptible and can be repeatedly infected or chronic.
The incidence is high in spring and summer, with a high incidence in pastoral areas. Knowledge of the area visited, occupation, and extent of exposure is helpful for diagnosis.
Clinical manifestations
1.Acute phase
(1) Slow onset. Prominent manifestations are chills, fever and sweating. The fever lasts for 2-3 weeks on average, and reappears in waves after a few days to 2 weeks. The fever pattern is mostly flaccid fever, but it can also be irregular fever. Often due to heavy sweating soaked clothes, and with fever retreat, another prominent feature of the disease.
(2) Arthralgia. Mainly large joints, wandering, a few with joint redness and swelling, or muscle pain.
(3) Lymph nodes and liver and spleen enlargement. Lymph node enlargement is mainly found in the neck and axilla.
(4) Other. Men may have orchitis or epididymitis, women may have ovarian inflammation, and pregnant women may miscarry. Lumbosacral neuropathy, causing sciatica, is also more common.
2.Chronic phase
It can be developed from the acute phase or without acute history. Common symptoms include fatigue, sweating, headache, low-grade fever, depression, irritability, muscle and joint pain.
Laboratory tests
(1) Blood picture: normal or low white blood cell count and relatively increased lymphocytes.
(2) Bacteriological examination: blood, bone marrow and urine can be cultured, and early positive blood and bone marrow cultures can reach 70% to 80%.
(3) Serological examination.
①Serum agglutination test. More than 2 weeks of disease can be positive, the potency of 1:100 or more, twice the potency of the measurement increases exponentially, which helps the diagnosis.
② Complement binding test. A potency of 1:10 or more is positive.
③Anti-human globulin test. A potency >1:80 is considered positive.
④Intradermal test. Inject 0.1ml of brucellactin into the forearm skin, and a local mass of more than 2.5×2.5cm in 24-48 hours is considered positive.
⑤ Fluorescent antibody assay can also be applied.
Treatment principles
1.General treatment
In the acute stage, bed rest, drink more water, eat an easily digestible diet and ensure heat. Give antipyretic and analgesic agents and sedatives if necessary.
2.Pathogenic treatment
Antibacterial drugs are mainly used for patients in the acute stage and chronic relapse. Commonly used drugs are as follows.
(1) Streptomycin and tetracycline combination: streptomycin 1g/day, divided into 2 times intramuscular injection; tetracycline 2g/day, divided into 4 times orally, the course of treatment for 3 weeks.
(2) Combination of cotrimoxazole and streptomycin: the former 2 tablets each time, 3 times/day; the latter dose as above. Duration of treatment is 3 weeks.
3.Treatment of chronic phase
Combination of pathogenic treatment and specific desensitization therapy. The pathogenic treatment is the same as above. Specific desensitization therapy are.
(1) vaccine treatment: the first dose of 250,000 bacteria / day, and then gradually increase the dose, at the end of the course, the vaccine up to 150 million bacteria / day, 10 to 15 days for a course.
(2) hydrolysin and lysozyme treatment: the first dose of both is 1% 1ml/day, gradually increase the dose to 2ml/day, the course of treatment for 10-15 days. Can also be used for patients in the acute stage. Bacterial vaccine, hydrolysin and lysozyme injection after the reaction can occur, mainly chills, fever, sweating, headache, general discomfort, individual heavy also affect breathing, blood pressure.
4.Other
Corticosteroids should be used for severe cases, testicular swelling and pain, severe joint and muscle nerve pain and those with cardiac and cerebral complications. Physiotherapy, such as heat therapy, diathermy, water bath, etc., is also available in the chronic stage.
Prevention
1.Manage the source of infection
Strengthen the management of sick animals and find the affected animals should be isolated in the special pasture. The aborted fetal cover should be buried deeply with quicklime. The sick person should be isolated in time until the symptoms disappear and the blood and urine culture is positive. The patient’s excrement and pollutants should be disinfected.
2. Cut off the transmission route
Dairy, meat and hides from infected areas should be strictly disinfected and sterilized before being shipped out. Protect water sources.
3.Protect susceptible people and animals
Anyone who may be infected with the disease should be vaccinated. At present, M-104 frozen vaccine is mostly used, and the vaccination is done by scratching. In addition, all personnel engaged in livestock industry should do a good job of personal protection. Livestock in grazing areas should also be vaccinated.