return fever
Introduction
Introduction to returning heat Relapsing fever is an acute infectious disease caused by a variety of regenerative hot spirals. Its clinical features are paroxysmal hyperthermia with systemic pain, liver and spleen, severe jaundice and hemorrhage, fever and interval. The period alternates, the cold and heat exchanges return, so it is called returning to heat. According to different media, the disease is divided into two categories, namely, rumored regression fever (epidemic regression fever) and rumored regression fever (local regression fever). basic knowledge The proportion of illness: 0.005% Susceptible people: no specific population Mode of transmission: insect vector transmission Complications: spleen rupture asthma polymorphic erythema iridocyclitis choroiditis meningitis pneumonia otitis media endocarditis
Cause
Return to the cause of fever
(1) Causes of the disease
The regenerative hot spirochete belongs to the genus Borrelia, also known as the genus Borrelia. There are more than ten kinds of genus, various forms are similar, but the immune response is different. According to its media, it is divided into two types: rumor and rumor. The regenerative heat pathogen is B. recurrentis, formerly known as B. obermeieri, and the rumored (local) regenerative heat pathogen is named after the species of the insect media scorpion (ornithodorus). There are more than ten species, and the distribution of cockroaches is strictly regional. Therefore, the return heat caused by it is also strictly regional. The two kinds of spirochetes found in the south and north of China are respectively B. persica and Lars. Borrelia (B.latyschevi) is consistent, B. duttoni in Central Africa, B. persica in Central Asia, B. hermsii in the western United States, etc. The structure is easier to change than the regenerative borreliosis. For example, nine serotypes of Borrelia burgdorferi have been isolated in India. In recent years, due to advances in molecular biology, the sputum spirulina has been further understood, such as amplification. Flagellin gene oligonucleotide Needle detection, the other five species of Borrelia (B. parkeri, B.turicatae, B.crocidurae, B.anserina and B. coriaceae) were obtained, and 5 strains of Borrelia Helicobacter were also obtained. It is 10-20m, 0.3-0.5m wide, and has 4-10 irregular shallow spirals (Fig. 1). It is propagated by transverse splitting. It is sensitive to heat, dryness and various chemical disinfectants, but it is cold resistant. It can survive for 100 days in a coagulated blood clot at 0 °C. Such spirochetes contain both specific antigens and non-specific antigens, and can share partial antigens with other microorganisms. Therefore, the serum of infected animals can have specific complement-binding reaction. It can also positively agglutinate with Proteus OXk strain, but the titer is low, and the spirochete antigen is easy to produce mutation. If the antigenicity of different strains is different, the antigenicity of the isolates will be different in different fever periods of the same patient. .
(two) pathogenesis
The patient's fever and spirochete rapidly multiply in the blood circulation and produce a large number of metabolites. When the pathogen proliferates in the body, the body produces specific antibodies mainly composed of IgM and IgG, including lectin, brakein and lysin. The phagocytosis of effector cells and multinuclear and phagocytic cells destroys the spirochete, and the hyperthermia retreats into the intermittent phase. Some undestroyed persons are concealed in the brain, liver, spleen and bone marrow. By means of the mutation of the antigen, the original antibody can not eliminate the recurrence. The spirochetes, which reproduce after invading the blood circulation, cause recurrence. The antigenic mutation of the recurrent pathogen causes a new immune response, which eventually causes the disease to heal, resulting in anemia, hemorrhage and jaundice due to damage of vascular endothelial cells and platelets and destruction of red blood cells. When the spirochete invades the nervous system and the eye and forms a neuroporosis disease, lymphocytic meningitis and peripheral facial paralysis and ocular disorders can occur.
Pathological changes showed splenomegaly, scattered infarction, necrosis and small abscess, can produce spontaneous rupture, scattered necrosis in the liver, hemorrhage, congestion and turbidity degeneration, kidney edema and congestion, heart There are diffuse myocarditis and interstitial lesions, edema in the brain, and sometimes bleeding.
Prevention
Regression heat prevention
Cutting off the transmission route throughout the epidemic is a key measure to prevent this disease, and controlling the source of infection also needs to be carried out simultaneously. There is currently no effective artificial immunization method for protecting the population.
(1) Patients who manage infectious sources must be hospitalized for isolation and complete extinction. The main source of infection of rumors is rodents, and it is necessary to vigorously carry out anti-mouse, rodent control, anti-mite and mites.
(B) cut off the route of transmission in various ways to kill cockroaches and cockroaches. See section 24, "Popular typhus" for mites. Earthworms are mainly found on the ground, on the roof and on both sides of the road, and can be sprayed regularly.
(3) Protecting susceptible persons is mainly for personal protection. Protective clothing should be worn when smashing, and smear-proof clothing must be worn when working in the field. If necessary, oral doxycycline or tetracycline can be taken to prevent the disease.
Complication
Regression thermal complications Complications spleen rupture asthma polymorphic erythema iridocyclitis choroiditis meningitis pneumonia otitis media endocarditis
Easy to develop bronchial pneumonia, DIC can occur in a few cases, occasionally spleen rupture and hemorrhage, in addition to otitis media, endocarditis, polyarthritis and other miscarriages, ophthalmia, asthma exacerbation and polymorphous erythema.
Patients with sputum-type recurrence often have ocular complications such as iritis, iridocyclitis and choroiditis, and central nervous system complications such as meningitis and cranial nerve damage, and may have sequelae such as visual impairment and nerve palsy.
Rumors return to heat and complicated with pneumonia, otitis media, endocarditis, occasional spleen rupture and massive hemorrhage, rumor return to heat after repeated recurrence, can cause iridocyclitis, meningitis, encephalitis, etc., may have visual impairment And sequelae such as nerve paralysis.
Symptom
Regression to hot symptoms Common symptoms High fever joint pain, fatigue, nausea, dizziness, chills, muscle pain, gum bleeding, nosebleeds
(1) The sputum-type return heat incubation period is 2 to 14 days, with an average of 7 to 8 days. Most of the onset is sudden, starting with chills, chills and severe headaches, followed by high fever, body temperature of more than 40 °C within 1 to 2 days, more The heat is retained, and a small amount is relaxation heat or intermittent heat. The headache is severe, the joints of the limbs and the muscles of the whole body are sore. Some patients have symptoms such as nausea, vomiting, abdominal pain, diarrhea, and may also have symptoms such as eye pain, photophobia, cough, and nasal discharge. Facial and conjunctival congestion, visible hemorrhagic rash on the extremities and trunk, and tenderness of the gastrocnemius. Breathing, pulse rate increase, the bottom of the lungs can smell fine wet rales. More than half of the cases have hepatosplenomegaly, and severe cases may have jaundice. During the high fever period, there may be mental and neurological symptoms such as confusion, paralysis, convulsions and meningeal irritation. After 6 to 7 days, the body temperature plummeted, accompanied by sweating, and even collapse. In the future, the patient is consciously weak and weak, while other symptoms, hepatosplenomegaly and jaundice disappear or disappear, which is intermittent. After 7 to 9 days, the recurrence of high fever and recurrence of symptoms, this is called "return." Most of the symptoms of regressive episodes were mild, and the heat stroke was short. After a few days, the fever subsided into the second interval. A cycle averages about 2 weeks. The fever period of the later episodes is getting shorter, and the interval period is getting longer, and finally tends to heal itself.
(2) The sputum-type regression thermal latency is 4 to 9 days. The clinical manifestations are similar to those of sputum transmission, but they are lighter, the heat type is irregular, and the number of recurrences is more than 5 to 6 times. Most of the bite sites have an inflammatory reaction of purple-red bulge, and local lymph nodes are enlarged. Hepatosplenomegaly, jaundice, and neurological symptoms are less than rumor-type, but more rashes.
Examine
Return to the heat check
1. Pathogen examination Regression of the thermospirulina is generally easy to detect in the peripheral blood of the patient during the febrile period. In the thin blood smear, the Gram stain is negative, and the Wright or Giemsa stain is red or purple. Under the microscope, it can be seen that it can flexibly move forward or backward in a rotating and moving manner, and swing to both sides. The bone marrow smear can also find a spiral body. The medium must contain blood, ascites or kidney tissue, which can proliferate under micro-oxygen conditions, but It is easy to decline, and it is not easy to pass on. Therefore, it is often vaccinated with animals. The rumors can use white mice or chicken embryos, and guinea pigs can be used.
In recent years, in the Ethiopian rural clinic, it has been reported that it is centrifuged with high-quality buffy coat (QBC) technology and detected by fluorescence microscopy. This has been reported in West Africa, because it has been reported In the blood smear of patients with heat, the number of spirochetes is small and it is difficult to confirm the diagnosis. The QBC technique is also used to detect pathogens. It is considered that the sensitivity of this method is significantly improved and recommended.
In patients with neuroporphyra, cerebrospinal fluid pressure and protein can be increased, the number of cells can be increased, and spirochetes can be found, and sometimes urine sedimentary spirochetes can also be positive.
2. Blood and urine routine sputum return to heat patients with elevated white blood cell count during fever, between (10 ~ 20) × 109 / L, intermittent period returned to normal, classification changes are small, the white blood cell count of the rumor is normal Platelets can be reduced, the number of episodes is more obvious, but the clotting time is normal, there are jaundice, blood bilirubin is elevated.
A small amount of protein, cells and casts can be seen in the urine.
3. Serum immunological examination can be detected by immunofluorescent antibody test (IFAT) and Western blotting. If the second titer is increased by 4 times, it is helpful for diagnosis, but due to multiple mutations of antigen, the antibody is caused. The positive rate of titer is not high, and because it has the same antigen as other microorganisms, the serum of a few patients may be positive for Kang's or Fahrenheit reaction. The rumored return heat may agglutinate with Proteus OXk, but the titer is low.
4. Lumbar puncture can be found in the cerebrospinal fluid.
5. Splendid can be found by taking blood or bone marrow smear staining microscopy or dark field examination during fever.
Diagnosis
Regression thermal diagnosis
diagnosis
According to epidemiological data such as the season of the disease and the area, personal hygiene and physical health, the typical heat type with fever and intermittent alternating, severe headache, systemic muscle pain, hepatosplenomegaly and other clinical symptoms, combined with laboratory tests The spirochete is detected in the peripheral blood, and the disease can be diagnosed.
In addition, it is also diagnostic value to check whether there is a spirochete in the patient's clothes or body. Zhong has observed that during the recurrent epidemic, whether in the patient's incubation period, fever period or intermittent period, or critical frequency death stage, the body or clothing, the body cavity of the upper body contains a large number of regenerative hot spirals, Dark field direct microscopy or smear staining is extremely easy to find.
It is rumored that the patient's body temperature curve is irregular, the blood spiral is rare, and the diagnosis is sometimes difficult. The diagnosis method is the same as the diagnostic rumor return heat. In addition, local inflammation of the site of the bedding and corresponding lymphadenopathy, as well as the discovery of rodents and ticks, are also helpful in diagnosis.
Differential diagnosis
The early stage of the disease is easily confused with malaria, typhoid, typhus and leptospirosis, and should be identified.
1. Malaria This disease is more common in the summer and autumn mosquito breeding season, symptoms such as chills and fever and sweating appear periodically, patients have no symptoms in the intermittent period, splenomegaly but no rash, low white blood cells, peripheral blood tablets or Plasmodium can be found in bone marrow smears.
2. The onset of typhoid fever is slow, the body temperature gradually rises, the course of disease lasts for about 4 weeks, and the body temperature drops slowly. The patient often has a relatively slow pulse, the serum fat is positive, and the typhoid bacillus can be isolated from blood, urine and stool.
3. The onset season of typhus is the same as the return heat. The two can even occur in the same patient at the same time, and the incidence is acute. Both have severe headache and liver and splenomegaly, but the rash has more rash and hemorrhagic disease. The course of disease is longer and the serum outside the Fischer reaction is positive.
4. Leptospirosis disease is more common in summer and autumn, patients with jaundice are heavier, bleeding tendency is obvious, and often have gastrocnemius pain and tenderness, serum leptospirosis complement test is positive, and can be blood, urine or cerebrospinal fluid The pathogen is isolated.
In addition, it is rumored that the respiratory symptoms of patients with recurrent fever are more obvious, and attention should be paid to the identification of acute respiratory diseases such as influenza and pneumonia.
