The ectoparasite test detects the presence of rickettsial antibodies in the patient’s serum by performing a nonspecific agglutination reaction with OXl9, OX2, and OXK, which have common bacteriophage antigens with rickettsiae. After the human body is infected by rickettsiae, the corresponding antibodies are gradually produced in the serum, which appear 5 to 12 days after the onset of the disease and basically disappear after several months, and generally the agglutination value is above 1:160 or the potency rises significantly during the course of the disease has diagnostic significance. So, what is the test for a negative test? The following is a diagnostic test for a negative test: 1. The titer (serum dilution multiple) in normal people does not exceed 1:20 2. Increased: epidemic typhus (OX19 positive rate can be 100%); endemic typhus (OX19 part can be 1:200-1:800); tsutsugamushi loyalists, 14% of OXK in the first week after the disease is above 1:80. The fourth week can reach 80%. 3, brucellosis, regression fever patients also have increased titers in the serum. Pregnant women may have slightly increased. Reference value: slide agglutination method: OX2 <1:160OX19 <1:160OXK <1:160 Complement binding test: negative Immunofluorescence staining method: negative External Fever test negative patients should rest in bed, drink more water, eat a liquid or soft food, pay attention to oral hygiene, keep the skin clean. For patients with high fever, antipyretic and analgesic agents can be used. In severe cases, corticosteroids can be given to reduce the toxemia symptoms, and those with heart failure should be put on absolute bed rest and controlled with cardiac drugs and diuretics.