Brucellosis, also known as brucellosis, is a systemic infectious disease caused by a bacterium called Brucella that can infect both humans and domestic animals. Why is it called brucellosis? It is because a British military doctor named Bruce first identified the causative agent of the disease, and in his honor, scholars suggested that the disease be named “brucellosis”. Brucella is a Gram-negative short small bacillus, there are 6 species and 19 biotypes, and 15 biotypes have been isolated in our country. Brucella in the natural environment is more viable, in the secretions of sick animals, diarrhea and dead animals in the organs can survive about 4 months, in the food about 2 months. As we said earlier, brucellosis is a zoonotic disease, which means that there must be a sick animal first, and then the sick animal then infects people. The main sources of infection are sheep, cattle, pigs and, to a lesser extent, dogs. Diseased livestock secretions, excretions, flow products and milk contain a large number of germs, the main transmission channels are as follows: 1, through the skin mucous membrane contact infection direct contact with sick animals or their excretions, vaginal secretions, delivery; or in the feeding, milking, shearing, slaughter and processing of skin, hair, meat and other processes without attention to protection. It can be infected by skin micro-wound or conjunctiva; 2. Infected by gastrointestinal tract Eating food and water contaminated by germs or drinking raw milk and eating uncooked meat and offal; 3. Infected by respiratory tract The germs contaminate the environment and form aerosol, respiratory infection can occur. Who should think of brucellosis for fever? The main infected areas in our country are in Inner Mongolia, Northeast, Northwest and other pastoral areas, because these pastoral areas have more chances for people to contact with sick livestock, so the patients are mainly concentrated in these places. However, I also encounter people living in cities or remote suburbs who are not infected in pastoralist areas. For example, there is a young man’s family has a Tibetan mastiff, the Tibetan mastiff eat dead lambs, that does not happen to this sheep with brucella, the result is that people are infected. Another young man, a barbecue seller, was infected while wearing lamb skewers. There was also an old man who had the habit of drinking raw goat’s milk for most of his life, but he didn’t want to be infected. So you can see, sometimes occupation and certain habits can also provide some basis for the doctor’s diagnosis. What are the symptoms? The acute phase of the disease is within 6 months, and the main manifestations are fever, excessive sweating and joint pain. 80% of the cases have a slow onset and often have prodromal symptoms, which are similar to a bad cold. The symptoms include general malaise, fatigue, and reduced appetite for 3 to 5 days. 10 to 27% of patients have an acute onset of the disease, with high fever, chills, excessive sweating, and wandering arthralgia as the main manifestations. The fever is usually preceded by chills and chills. Excessive sweating is one of the prominent symptoms of the disease, with profuse sweating at night or in the early morning when the fever subsides. There are also patients who do not have a high fever or have excessive sweating in the interval between fevers. The sweat has a sour odor. Arthralgia More than half of the patients have arthralgia, which goes hand in hand with fever. The pain is cone-like or dull, and the degree of joint pain does not parallel the pathological changes. The lesions mainly involve large joints, such as the hip, shoulder, and knee, singly or in multiple, asymmetrical, localized redness and swelling. It may also manifest as synovitis, tenosynovitis, and periarticular inflammation. In the acute phase, the pain is mostly wandering, while in the chronic phase, the lesion is fixed and the pain is fixed in certain joints. There is also muscle pain, especially in the lower limb muscles and gluteal muscles, and in severe cases, spastic pain. There can also be genital lesions testicular swelling and pain (one of the characteristic symptoms of the disease). There may be orchitis and epididymitis, and the testicular enlargement is mostly unilateral and may be as large as a goose egg. The enlarged testicle is mostly unilateral and can be as large as a goose egg. Female patients may have ovarian inflammation, tubal inflammation and endometritis, which may cause dysmenorrhea, amenorrhea and miscarriage. Neuralgia, hepatosplenomegaly, lymph node enlargement and soft tissue skin lesions can also be seen. The chronic phase of the disease may last for more than 6 months. It may develop from the acute phase or without a history of acute disease (especially in the bovine form). The organic damage can invade many organs and systems. 1. Bone and muscle system: most common, persistent dull pain in joints, recurrent episodes lasting several years, fixed and persistent mostly in sheep type. There can also be synovitis and spinal lesions. Long-term disease may occur joint ankylosis or contracture. 2. Nervous system: peripheral nerve damage is common, manifested as neuralgia, neuritis, radiculitis and plexus neuritis. Central nervous system damage is less common, and may include meningitis, meningoencephalitis and encephalomyelitis, which may result in headache, meningeal irritation, coma, convulsions and paralysis. 3. Other: genitourinary lesions, myocarditis, bronchitis, interstitial pneumonia, pleurisy, hepatosplenomegaly, etc. may also be present.