Rabies-What is rabies?
Rabies, also known as hydrophobia. Rabies is a zoonotic infectious disease pathogens as the rabies virus is a zoonotic central nervous. Acute infectious disease of rabies through the system. Rabies causes acute encephalitis in mammals and peripheral nerve inflammation, did not receive vaccine in infection, when the nerve is almost inevitable death after onset of symptoms, the usual cause of death are due to central nervous system (brain - spinal cord) damage by the virus, the final died of organ failure caused by autonomic damage.
Rabies - Overview
Rabies mammals, primates, Carnivora, Chiroptera and other animals can become the purpose of rabies patients, such as people, cats, dogs, ferrets, raccoons, skunks, foxes, wolves, bears, bats have horses; and rodents (except beavers outside) very few infections, such as squirrels, chipmunks, rabbits, etc., but to be safe, be bitten by rodents such as mice or rabies vaccine should be injected.
Rabies - etiology:
Rabies vaccine rabies virus RNA-type rhabdovirus, one end of the round convex; end of the concave, shaped like a bullet diameter of 65 ~ 80nm, about 130 ~ 240nm. Virus is easy to sunlight, ultraviolet radiation, formaldehyde, mercuric chloride quaternary ammonium compounds (such as benzalkonium bromide), lipid solvents, 50% to 70% alcohol inactivated, the suspension by 56 ℃ 30 ~ 60 minutes or 100 ℃ 2 分钟 Jimie live. Virus or freeze-dried at -70 ℃ 0 ~ 4 ℃ after the home can remain viable for several years. Infected tissue can be stored in 50% glycerol incoming inspection.
Rabies virus containing five proteins, namely, glycoprotein (G), nucleoprotein (N), dimeric enzyme (L), phosphoprotein (NS) and matrix (M) and so on. The latter two for the small proteins. G can lead to the formation of neutralizing antibodies in vivo can be against virus attacks. N caused by antibodies and not with the force, can detect intracytoplasmic inclusion bodies.
Rabies - Pathogenesis:
Animal experiments show that the majority of rabies, the incubation period and does not appear during the onset of viremia, the incidence of rabies can be divided into three stages.
(A) the local organization from the breeding site of the bite viral invasion, after the wound of the striated muscle spindle receptors at nerve fibers gathered reproduction, later invaded the nearby peripheral nerves. From a local wound to invade peripheral nerves interval is generally less than 3 days, but also that the virus can stay in the invasion at 2 weeks old, or even longer (accounting for most of the incubation period).
(B) the period of the virus invade the central nervous around the nerve axon along concentric spread to the pulp, the hourly rate of about 3mm. Reach the dorsal root ganglia Festival, a large number of virus that is in their breeding, and then invade the central nervous system and spinal cord, cerebellum, etc. mainly affects the brain and neurons.
(C) the period of the virus spread to various organs of the central nervous system from the eccentric to the proliferation of peripheral nerves, invade the tissues and organs, especially in the saliva nucleus, glossopharyngeal nucleus and hypoglossal nucleus damage, there may be fear of the clinical water, breathing difficulties, swallowing difficulties and other symptoms. Saliva secretion, and increased sweating is caused by sympathetic stimulation, vagal ganglia, sympathetic ganglia and cardiac ganglion can cause damage to the patient cardiovascular dysfunction or sudden death.
Rabies - pathology
Congestion of brain and spinal cord of rabies. Microscope, showing diffuse changes in acute transverse myelitis. Nerve cell degeneration, necrosis, perivascular lymphocytes, plasma cells, the formation of blood vessel sleeves phenomenon. Occur within nerve cells characteristic of the Negri body, with a pathological diagnosis. Which appeared in the cytoplasm of nerve cells containing the body, were round or oval, clear boundary, eosinophilic, more common in hippocampal pyramidal cells and pyramidal cells in the brain. The number of cytoplasmic bodies from one to several months, but in the serious parts of the small number of this body.
The main pathological changes of acute diffuse encephalomyelitis, especially with the very site of the bite of the dorsal root ganglion and spinal cord segments, the brain's hippocampus, and medulla oblongata, pons, cerebellum, etc. as the most important, usually without meningeal disease. Brain parenchyma showed congestion, edema and minor bleeding, microscope, non-specific degeneration and inflammatory changes, such as nerve cells, vacuolization, hyaline degeneration and chromatin breakdown, perivascular mononuclear cell infiltration.
These lesions are non-specific, while 80% of patients in the cytoplasm of nerve cells, can be found a specific and a diagnosis of eosinophilic inclusion bodies, as in the base's body (Negribody). Lanes within the base's small round or oval diameter of about 3 ~ 10nm, neat edge, there are one or two seemed to be the nucleus of a small point, the most common in the hippocampus and cerebellar Purkinje cells in the nervous tissue; also The cone cells in the cortex layer of the spinal cord neurons, dorsal horn ganglion cell layer of retinal nerve, sympathetic ganglia, etc. detected. Within the base's body is actually set off the virus, electron microscope, a small body with baculovirus particles.
Salivary gland swelling, soft, clear degeneration of acinar cells, glandular tissue surrounded by mononuclear cell infiltration. And pancreatic acinar epithelium, gastric parietal cells, adrenal medullary cells, renal tubular epithelial cells can be acute degeneration.
Rabies - Rabies features:
Rabies can correctly identify the rabies, rabies is extremely important for the timely elimination. Rabies incidence of disease is generally divided into three phases: pre-behavior change usually only contact with dogs more easy to find talent. As usual, and you become very close to the dog back, or find a place to hide, and some even went very far away, but people usually do not move closer to the dog might become very affectionate with people, lick people close to it body and hands.
At this time the dog's saliva (saliva) already contains a virus, so there is the risk of contagious, sick dogs at this time to moderate fever, Eat or not eat, but also may be biting the soil, the surface blocks, rags and other debris, Dai Li sometimes stare or look empty flutter bite, often encountered stimulate terrified. For 2 days or so early into the exciting period. In the excitement, sick dogs performance was not stable, will stimulate the whole body vibrations encountered, and often attack people or other animals. Usually drooling, tail firmly between legs caught in the two later, bolted down, eye redness, barking mad bite, stiff neck or rotate not working and other symptoms. This period will last 2-3 days, maximum harm on the people; into the paralysis period, the performance of swing into action, scattered hairs, sagging chin, mouth Shenshe, last seen the trunk and limbs, paralysis and other symptoms, ultimately due to respiratory center paralysis or heart failure and death.
Rabies - Epidemiology
Rabies virus of the disease exists in 60 countries, including Southeast Asian countries, the incidence of particularly high. The incidence of domestic 0.4 / 100,000 to 1.58 / one hundred thousand dollars. Were significantly increased. Deaths in the status of legal infectious diseases ranks first or second place.
The mode of transmission is concerned, rabies can be divided into the city, and from non-immune dogs, cats spread; forest type is determined by skunks, foxes, raccoons, mongoose, wolves and bats cause.
Dogs, sick cats and other animals, more saliva containing the virus, the virus through the bite wound was immersed in the body. Mucous membrane is invaded portal, people can be sick because of conjunctival staining liquid animal to sleep, touch the dogs licking the anus and other mucous membranes were acquired infections. In addition, even by stripping sick animal skins, and the incidence of eating infected meat, there are clusters due to inhalation of bat caves in aerosols containing the virus become ill person.
People are generally susceptible to rabies virus, hunters, veterinarians and animal feed are more vulnerable to infection. Rural young people with opportunities for contact and more sick animals, so the incidence were also more. Tropical and subtropical regions are Benbingfasheng any season, spring and summer places in Northeast China is more common.
After people have been bitten by dogs, the average incidence rate of 15% to 20%, after being sick wolf bite is 50% to 60% (refer to those who have not been vaccinated). Disease or with the following factors: ① the bite site, head, face, neck, fingers, etc. The higher incidence; ② degree of trauma, wound deep and big to the high incidence of head and face up to the incidence of deep-injured 80%; ③ local handle the situation quickly and thoroughly cleaned after the bite of those less incidence; ④ clothing thickness, thick winter clothing, infected fewer opportunities; ⑤ Note vaccines, timely, full, full dose of rabies vaccine are The low incidence. Throughout the country report the incidence of injection was 0.15% (0.016% of foreign 0.48%), those who did not note the entire distance of 13.93%.
Rabies - clinical manifestations
Rabies incubation period of varying lengths, mostly in three months or less, an average of 66.9 days of domestic reports. 4 to 10% of patients more than half of the incubation period, 1% more than 1 year, an example of the literature up to 19 years. The length of incubation period and age (children shorter), the wound site (the incidence of head and facial bites earlier, an average of 39 days, the average incubation period of lower extremity bites 90 days), wound depth (deep by a short incubation period), the number of virus and intrusion virulence (toxic and strong by a short incubation period) and other factors, others such as debridement is not complete, trauma, exposure to cold, excessive fatigue, etc., can make the disease occurred earlier.
Rabies - clinical course can be divided into the following three.
(A) the prodromal period or invasion period before the onset of the excited state, most patients have fever, loss of appetite, nausea, headache (mostly in the occipital), fatigue, aches and discomfort, etc., exactly like the "cold"; followed by fear, anxiety, for sound, light, wind, and other more sensitive to pain, and throat tightness. More diagnostic significance of early symptoms of paresthesia and around the wound, there is numbness, itching, pain and formication, etc., which was caused by virus propagation neural stimulation, seen in 80% of cases. Current for 2 to 4 days.
(B) the excited patients gradually into a highly excited state, its outstanding performance as extreme terror, fear of water, afraid of the wind, seizure pharyngeal muscle spasms, difficulty breathing, sweating, salivation, urination and bowel problems, etc.
Fear of water is the specific symptoms of the disease, is caused by pharyngeal muscle spasm, but not necessarily each case are not necessarily in the early stage. Patients typically see the water, heard the sound of water, drinking water, or only mentioned in drinking water, can cause severe throat muscle spasms. Although most patients do not dare to drink thirsty, even after drinking can not swallow. Often accompanied by hoarseness and dehydration.
Wind is also a common symptom of fear, though the breeze can cause pharyngeal muscle spasm. Other stimuli such as light, sound, touch, etc., can lead to the same attack, serious attack, the body can still occur painful convulsions. Due to the presence of respiratory muscle spasm, it can lead to breathing difficulties and cyanosis.
Common sympathetic hyperactivity, manifested as an increase in saliva secretion, sweating, heart rate, blood pressure and body temperature and so on. Due to sphincter dysfunction and urination defecation difficulties were also quite common.
Most patients with a clear mind, though extreme fear and irritability, but rarely intrusive behavior. As the excited state of growth, some patients may suffer from mental disorders, delirium, hallucination, auditory hallucination, collision howling and so on. Disease progressed very quickly, many patients died of respiratory failure in the attack or circulatory failure. Period for 1 to 3 days.
(C) the paralysis period cramps stop, the patient becoming quiet, but there flaccid paralysis, especially in the limbs flaccid paralysis is most common. Ocular, facial muscles and masticatory muscles may also be involved, expressed as strabismus, eye movement disorders, jaw falling, I can not be closed, lack of facial expression and so on.
Patients becoming weak or irregular breathing, and tidal breathing occurs; breakdown pulse, blood pressure, reflex, mydriasis, may be due to respiratory and circulatory failure and rapid death. Before death than patients into a coma. Period for 6 to 18 hours. Throughout the course of rabies not more than 6, and occasionally exceed 10 persons.
In addition to these typical cases, there to a standstill as the main manifestation of the "paralytic" or "quiet type", also known as "dumb rabies" (dumb rabies), about 20%. This type of excitement and fear in patients with non-water phenomenon, with high fever, headache, vomiting, pain at the bite started, followed by limb weakness, abdominal distension, ataxia, muscle paralysis, incontinence, etc., showing transverse myelitis or ascending spinal paralysis and other symptoms. The lesions confined to the spinal cord and medulla oblongata, without involving the brainstem or higher parts of the central nervous system. Duration of up to 10 days due to respiratory muscle paralysis and eventually paralysis and death ball. Vampire bat rabies bite often is caused by this type.
Complications of rabies
May be inappropriate antidiuretic hormone secretion, may be complicated by pneumonia, pneumothorax, mediastinal emphysema, heart rate is not agent, heart failure, venous thrombosis, superior vena cava obstruction, upper gastrointestinal bleeding, acute renal failure.
Rabies - first aid measures
1 animal bites should immediately wash the wound. The key is to wash methods. Because the wound is closed as the valve, as with most, it is necessary to wash the wound broke. Rinse the wound with tap water though a bit against the pain, but we have reluctantly rinse carefully, so as to prevent infection. After washing use a clean gauze to the wound covered, speed to the hospital for treatment.
(2) after animal bites, even the smallest wound, but also the possibility of rabies infection, while infected with tetanus, wounds fester easily. Patients should ask the doctor rabies vaccine and tetanus antitoxin vaccination.
Dog bite dog bites and rabies sub-normal bite (the latter also known as rabies or hydrophobia), the former is no more danger, which is often stored in so mad (or healthy infected dog) rabies virus in saliva, along the bite, wound licking wounds or scratches to invade the nervous system within the brain multiply, causing severe symptoms. In addition to the dog, the infected cat, wolf bites can also occur in this disease. Bitten by infected animals without making the incidence of anti-injecting rate of 10% to 70% or more.
Rabies - a cure
Rabies (a) single-chamber strict isolation, hand care, quiet bed rest to prevent all sound, light, wind stimulation. Large venous catheter line of high nutritional therapy, Cong would be required to wear masks, gowns and gloves. The patient's secretions, excretions and pollutants, must be strictly disinfected. Installed bed rails to prevent seizures in patients injured.
(B) do a good job symptomatic treatment, prevention and treatment of complications
1 the phenomenon of the nervous system should have fear of water to drink fasting to minimize a variety of stimuli. Seizures may be phenytoin, diazepam, etc. Cerebral edema may be dehydrating agent such as mannitol and furosemide, may be invalid lateral drainage.
(2) anti-diuretic hormone pituitary dysfunction should be limited too much water intake, diabetes insipidus were to intravenous rehydration, with the posterior pituitary vasopressin (Pitressin).
3 Respiratory difficulties were to tracheostomy breathing, cyanosis, hypoxia, atelectasis atelectasis by oxygen, artificial respiration, complicated by pneumonia, to physical therapy and anti-bacterial drugs. Pneumothorax were, the implementation of lung recruitment technique. Taken to prevent aspiration pneumonia.
4 most of the cardiovascular system arrhythmia supraventricular, and hypoxemia should be oxygen, and viral myocarditis were handled by myocarditis. To vasoconstrictor agents and hypotension expansion rehydration. Heart failure, water restrictions, the application of Di digoxin and other cardiac stimulant. Arterial or venous thrombosis, venous catheter exchangeable; if the superior vena cava obstruction, should be allocated in addition to intravenous cannulation. Cardiac arrest and resuscitation were implemented.
5 Other anemia blood transfusion, gastrointestinal bleeding blood transfusion, rehydration. Cold mattress with high fever, hypothermia, heat blankets to those in blood volume is too low or too high, should be adjusted promptly.
Rabies - Prevention
In view of the disease of rabies no effective treatment, it should strengthen preventive measures to control the spread of the disease. Vaccination to prevent the onset of a positive value, strict implementation of dog management, can significantly reduce the incidence.
(A) the management of the source of infection to kill all the wild dogs on the need for keeping dogs, police dogs and experimental dogs, should be registered, and preventive vaccination. The sick cats, dogs found and killed immediately, to avoid wounding. Extraordinary dog bite, domestic cats should seek to capture, and isolated for observation for 10 days. Animals are still alive who can be identified as non-rabies quarantine can be lifted. Whichever of the brain tissue of dead animals should be checked, and burned or buried, must not peeling or eating.
(B) early wound treatment wound management is extremely important. Time after people have been bitten by 20% soapy water to fully clean the wound and keep clean. Those who still need to use the catheter wound deeper stretching, continuous perfusion with soapy water for cleaning. If serum for skin test negative, you can into the bottom and around the wound, the wound should not be sutured or bandaged.
(C) vaccination vaccination as follows: ① the wolf, fox and other wild animals that bite are; ② is the incidence of subsequent death (including the observation period) or a missing dog, cat bites are; ③ to have been killed and brain tissue The animal has been bitten by corruption; ④ skin wound is contaminated by the saliva of rabies; ⑤ wound in the head, neck, or large and deep wounds were such as biting animals (refer to non-endemic areas is concerned) and will remain the safety of 5 unharmed, injection can be discontinued; ⑥ medical staff broken skin contamination, etc. for the rabies patients. In recent years, China has found a number of bites and rabies disease death row, while the dog is safe, proven carriers of the virus within the dog's saliva, so endemic areas are bitten by dogs should be vaccinated. Table 11-8 shows the indications of rabies vaccination. Currently the use of rabies vaccine over the world in Table 11-9.
