Relapsing fever

Overview relapsing fever (relapsing fever) is a relapsing fever spirochetes caused by insect-borne acute - disease, clinical features of the cyclical high fever with body pain, hepatosplenomegaly and bleeding tendency, has severe jaundice. According to the media, can be divided into Shat - relapsing fever (epidemic relapsing fever), and splenic mass relapsing fever (local relapsing fever) of two types. Etiology of relapsing fever spirochetes (B.ricurrentis) is reduced body is a spiral or helical borrow's body is (Borrelia). According to the general media insect species classification. Shat - relapsing fever spirochetes only one species, known as relapsing fever spirochetes or door-Bergen spirochetes (B.obermeieri). Tick-borne relapsing fever spirochetes under vector software ticks (ornighodors) naming the type, I can be divided into 10 species. 2 - relapsing fever spirochetes basically the same shape, 10-20μm long, wide 0.3-0.5μm. 4 ~ 30 large spiral without rules at both sharp and lively campaign to transverse proliferation. Gram staining. Wright or Giemsa staining was purple. Training is more difficult, unless required with serum, ascites or rabbit kidney debris in the medium-oxygen conditions can cultivate proliferation. David inoculated mice peritoneal or chicken chorioallantoic membrane reproduction. Cold, but the heat and chemical disinfectants sensitive. Relapsing fever spirochetes wall lipopolysaccharide-free, but endotoxin-like activity. Extreme surface antigen variation. Epidemiology (1) the source of louse-borne relapsing fever-the only source of infection for patients; tick-borne relapsing fever, the main source of infection is rodent, the patient can to the source of infection. (2) transmission of lice spread relapsing fever mass to body lice and head lice of the media. Lice vampire, the spirochete by the louse gastrointestinal tract into the body cavity large population, but not to the salivary glands, some soiled with the discharge milkfish, it ticks and lice bites no infectious feces. When the body was crushed lice, body lice body cavity spiral wound on the skin, or handling contacts eyes, mouth, nasal mucosa of human intrusion. Dual via blood transfusion and transmitted through the placenta. Tick-borne relapsing fever in the media for different types of soft ticks. Ticks can carry life spirochetes. Apart from egg passaged. Ticks it is not only the media, as well as the storage host pathogens. Tick body cavity, feces and saliva contain spirochetes, when a vampire bites it can be transmitted. Can be damaged by the intrusion of human skin. (3) susceptibility crowd of men, women and children were susceptible. After the disease is not lasting immunity. 2 - relapsing fever, no cross-immunity. (4) features pop - relapsing fever ticks widely distributed, and found in all parts of the world. Popular season for the winter and spring. Usually more distributed, by war, famine caused a pandemic, the disease has been eradicated in China; tick-borne relapsing fever confined to the tropical and subtropical regions of the natural foci of disease. Incidence season to August 4 ~ most appearing distributed. Principle and the incidence pathological changes relapsing fever and intermittent episodes of spirochetes and the proliferation of antigenic variation and the immune reaction. Relapsing fever spirochetes penetrated the human body in the blood and viscera of the large population and produce various metabolites caused fever and symptoms of poisoning. Meanwhile, the body gradually produce specific IgM and IgG antibodies, Complement can be activated and phagocytic cells of spirochetes kill dissolved, entered clinical intermittent period. However, in the liver, spleen, brain, bone marrow residues in helix - through antigenic variation antibodies have become resistant to the mutant strain. These spiral-breeding again after a certain amount of blood lead into the second heat (return). So repeatedly until the body to generate sufficient immunity, spirochetes were all killed, to cure diseases. Spiral-produced toxins and metabolites, can destroy red blood cells and cause hemolytic anemia; can damage the capillary endothelial cells, platelets and induced DIC which led to hemorrhagic rash and systemic bleeding tendency. Pathological changes in spleen, liver, kidney, brain and bone marrow-based. Obviously enlarged spleen, scattered infarction and necrosis of small abscess, were observed macrophages and plasma cell infiltration, monocyte-macrophage proliferation. Liver, heart, kidney Visibility congestion, hemorrhage and focal necrosis. Brain edema, hyperemia, a meningeal inflammatory infiltration. Clinical manifestations (1) - - relapsing fever ticks latency 2 ~ 14 days, the average seven-eight days, most of the dramatic onset, began to chills, chills and severe headache, followed by high fever, body temperature 1 to 2 days above 40 ° C, formed MISSED heat, for a few flip-heat or intermittent fever. Severe headaches, body and limb muscle soreness. Some patients have nausea, vomiting, abdominal pain, diarrhea and other symptoms may have eye pain, photophobia, cough, epistaxis, and other symptoms. Face and conjunctival hyperemia, limbs and trunk visible point of hemorrhagic rash, muscle tenderness obvious. Breathing, pulse rate, lung can hear the end of small wetlands rales. More than half of cases of liver enzymes, there will be severe jaundice. Hyperthermia may be mental, neurological symptoms such as the state of unconsciousness, delirium, convulsion and meningeal irritation. Six-seven days later, the temperature dropped, accompanied by sweating may occur even collapse. After the patients consciously weakness and other symptoms, jaundice and hepatosplenomegaly disappeared or faded, for this interim period. After seven-nine days later, another recurrent fever, symptoms recur, and that is the so-called "reversion." Most return to attack symptoms lighter, shorter-range, after a few days cooling also entered the second interim period. An average cycle of about two weeks. Subsequent febrile seizures in a short period of gradual, intermittent phase grows more and finally become self-healing. (2) type of tick-borne relapsing fever latency of 4 ~ 9 days, clinical performance and louse-type similar, but lesser, heat anomalies and relapse more often, up to 5 ~ 6 times. Tick bites were formed purple uplift the inflammatory response, local lymph nodes. Hepatosplenomegaly, jaundice, neurological symptoms than Shat-for-less, but more rashes. Yi complications with bronchial pneumonia. A few cases DIC can occur, occasionally rupture and hemorrhage. In addition, there are otitis media, endocarditis, multiple arthritis. Tick-type relapse cases often late complications such as eye iritis, iridocyclitis and choroidal charge of the central nervous system complications such as meningitis and cranial nerve damage. may have a visual impairment and neurological sequelae such as paralysis.