Four plus signs for brucellosis indicate the presence of brucellosis infection in the subject, but are not indicative of the severity of the infection, and early medical attention and anti-infective treatment is recommended. When brucellosis is examined biochemically, the plus sign indicates the antibody titer used in the tube agglutination test. The plus sign is a direct indication of brucellosis infection, but the number of plus signs does not indicate the severity of the infection or the exact number of bacteria in the body, and needs to be combined with the patient’s own clinical signs, pathology, or a number of biochemistry tests to determine the extent of the infection. After a brucellosis test result shows a plus sign and a positive result, medical treatment should be sought immediately. Brucellosis itself is contagious, so self-isolation and protection are needed immediately after the attack, and appropriate drugs can be selected for treatment under the guidance of the doctor, such as doxycycline combined with streptomycin, and attention is paid to detecting changes in the condition during the treatment. When the subject is positive for brucellosis, he or she should be treated with appropriate drugs and treatment programs under the guidance of a doctor.