Hydrophobia

Introduction Rabies, or rabies, is an acute viral infection that attacks the central nervous system. All warm-blooded animals, including humans, may be infected. It is mostly obtained by biting animals. It is generally believed that mad dogs with white foam on the mouth bite into the infection. In fact, cats, white raccoons, raccoons, skunks, foxes or bats may also be sick and contagious. Diseased animals often become very savage, and the virus in the saliva enters the next patient from the bite wound. It is extremely rare for rabies to pass from one person to another. Most human patients with rabies will die, and in 1971 there was a case of recovery. In 2004, after the death of a patient who was not diagnosed with rabies in the United States, the viscera was donated and the three people who received the donation died of rabies.

Cause

After infection, not all of the people are infected. About 15-20% of the patients are bitten by the sick dog, and about 50% of the patients are bitten by the sick wolf. The incidence or the length of the incubation period is related to the following factors:

1 The site of the bite. The bite of the head, neck and hand is more common, and the incubation period is shorter; the bite is the opposite in the lower limbs.

2 degree of trauma. The wounds are large and deep, and there are many wounds with more onset and shorter incubation period.

3 local processing situation. After appropriate treatment, the incidence is less and the incubation period is longer.

4 dress thick. The thicker clothes on the bite have less onset and longer incubation period.

5 the application of adrenocortical hormone and mental over-stress (such as fear of rabies), sometimes can induce the disease.

Rabies virus has a strong affinity for the nervous system. After the virus enters the human body, it mainly spreads and spreads along the nervous system. After the virus invades the human body, it first propagates in the skeletal muscles and nerves of the wound. This is called a local small-breeding period. It can be as short as 72 hours and as long as several weeks, months or even longer. The virus invades the nerve endings after a small amount of local reproduction, and advances to the central nervous system at a rate of 3 mm per hour along the peripheral nerves. After reaching the spinal cord, the virus multiplies and spreads throughout the nervous system 24 hours later. Later, the virus spreads along the peripheral nerves to the distal end, and finally reaches many tissues and organs, such as salivary glands, taste buds, cornea, muscles, skin, etc., because the head, face, neck, hands and other parts are rich in nerves, the virus is easy to breed, plus The central nervous system is relatively close, so after the bite is bitten, the incidence is more, and the incubation period is shorter. The more serious the injury, the more likely the disease is. The virus mainly invades the vagus nerve, the glossopharyngeal nucleus and the hypoglossal nucleus in the central nervous system.

These nuclei mainly dominate the swallowing muscles and respiratory muscles. After being invaded by rabies virus, they are in a state of high excitement. When drinking water, they hear the sound of running water, and when they are stimulated by sound, hair and light, they can make swallowing muscles and respiratory muscles. Hemorrhoids occur, causing difficulty in swallowing and breathing. If the virus mainly invades the medulla oblongata and the spinal cord, it does not show sputum clinically, but it is manifested as various paralysis ( type), but it is relatively rare.

an examination

Related inspection

Urine routine blood routine

[clinical manifestations]

The length of the incubation period is not one of the characteristics of this disease. Most occur within 3 months, and 4% to 10% for more than half a year, and about 1% for more than one year. The longest case in the literature is 10 years. The factors affecting the length of the incubation period are age (small children), wound site (early onset of head and face), depth of wound (early onset), number of virus invasions and virulence of strains, and whether they have been formalized after injury. Expanded treatment and vaccination against rabies vaccines. Others such as trauma, cold, overwork, etc. may contribute to early onset.

The clinical manifestations can be divided into two types: manic type (encephalitis type) and paralyzed type (static type), which are divided into the following three stages:

1. The prodromal period of the two types of precursors is similar. Before the emergence of excitement, most patients have low fever, lethargy, loss of appetite, a few have nausea, vomiting, headache (more in the occipital), back pain, general discomfort, etc.; sensitive to pain, sound, light, wind and other stimuli, And there is a tight throat. Early symptoms with significant diagnostic significance are wounds and nerve pathways that have healed, and there are sensations of numbness, itching, stinging or insect crawling, ant walking, etc., which occur in about 80% of cases. This is caused by viral reproduction stimulating neurons, especially sensory neurons, which can last for hours to days. The current period lasts 1 to 2 days, rarely more than 4 days.

2. The excitement period or the flood season can be divided into two types, and the performance of the two types is different.

(1) Manic rabies: the most common in the country, accounting for about 2/3. The patient gradually enters a state of high excitement, which is characterized by extreme horror, a sense of horror in the face of the disaster, and is very sensitive to stimuli such as water, light, and wind, causing episodic pharyngeal spasm and difficulty breathing.

The fear of water is a special symptom of this disease, but not necessarily every case, not necessarily in the early stage. Typical people can cause severe throat muscle spasm when they drink water, see water, smell water, or just mention drinking water. Therefore, the patient is extremely thirsty and does not dare to drink, even if drinking can not swallow, full of mouth drooling, staining the bed or squirting around. Because of the vocal cords, the words are unclear, the voice is hoarse, and even the sound is lost.

Fear of the wind is also a unique symptom of this disease, breeze, hair, wind, and so on can cause pharyngeal muscle spasm. Others such as sound, light, touch, etc. can also cause the same episode.

The onset of pharyngeal tendon makes the patient extremely painful, not only unable to drink water and eat, but also often accompanied by assisted respiratory muscle spasm, resulting in difficulty breathing and hypoxia, or even a systemic painful convulsion. After each episode, the patient is still restless and has A lot of sweating and dehydration.

In addition, due to hyperactivity of the autonomic nervous system, the patient developed excessive sweating, salivation, and elevated body temperature above 38 °C, heart rate increased, blood pressure increased, and pupils enlarged. The patient's expression is painful and anxious, but the mind is mostly clear and there is very little intrusive behavior. As the state of excitement grows, some patients may experience symptoms such as mental disorders, paralysis, auditory hallucinations, and screaming. The course of the disease progresses rapidly, mostly in the onset of death from respiratory failure or circulatory failure. This issue lasts 1 to 3 days.

(2) Paralytic rabies: India and Thailand are more common, accounting for about one-third of the total, and less than 10 reported domestically. There is no excitement in the clinic, no symptoms of phobic water and difficulty in swallowing, but high fever, headache, vomiting, and pain in the bite begin, followed by limb weakness, bloating, ataxia, partial or total muscle spasm, urinary retention or size. Incontinence, etc., showing the performance of transverse myelitis or ascending spinal cord paralysis. In the early stage, the pectoral muscle was slammed with a percussion hammer, and it was seen that it was slammed up and calmed down in a few seconds. In the early stage, muscle edema and hair erection occurred only at the percussion. The course of the disease lasts 4 to 5 days.

3. Two types of rabies in the coma or paralysis period are not easy to distinguish. When the sputum stops, the patient is quiet for a while, and there is fashion that can barely drink water to swallow, and the reaction is weakened or disappeared, and it becomes a flaccid paralysis. Among them, limb soft palate is the most common. Eye muscles, facial and chewing tendons, characterized by strabismus, dysmotility, lower jaw, inability to close, and lack of facial expression. In addition, there are still aphasia, loss of sensation, disappearance of reflexes, dilated pupils, and the like.

In this period, the patient's breathing gradually becomes weak or irregular, and tidal breathing, rapid pulse rate, blood pressure drop, low heart sounds, cold limbs, and rapid death from respiratory and circulatory failure can occur. The patient entered a coma before dying. This issue lasts for 6 to 18 hours.

The entire course of rabies, including the prodromal period, averaged 8 days for manic episodes and 13 days for paralysis.

The lesions of manic rabies are mainly in the brainstem, the cervical nerve or the higher part of the central nervous system. The lesions of paralytic rabies are confined to the spinal cord and the medulla, thus causing differences in clinical symptoms.

In most cases, rabies caused by blood-sucking bats does not show excitement, and there is no pharyngeal spasm and water-sucking phenomenon, and the above-mentioned behavior is the main clinical manifestation.

diagnosis

In the case of episodes, the diagnosis can be preliminarily established according to the past history of rabies or suspected rabies or cat, wolf, fox and other animal bites. If you can understand the bite and the health of the animal, then Diagnosing this disease is more valuable. If it is not certain whether the biting dog or cat is suffering from rabies, the animal should be kept in a cage. If the animal does not develop within 7 to 10 days, the animal can generally be excluded from rabies. Patients with typical clinical symptoms such as excitement, arrogance, fear of water, fear of wind, throat muscle spasm, massive salivation, convulsions, etc., can make a clinical diagnosis of rabies. Pay special attention to the symptoms of "three fears" (fear of water, light, wind), if necessary, use fan wind, water and light test, mad sputum symptoms are not obvious should pay attention to pharyngeal muscle edema and hair erection . Such as prenatal immunological antigen, antibody detection positive, post-mortem brain tissue animal inoculation and neuronal cytoplasmic found in the corpus callosum can be diagnosed.

Differential diagnosis

In some cases, the history of bites is not clear, and early cases are often misdiagnosed as neurosis. Symptoms are not typical after onset, sometimes misdiagnosed as mental illness, tetanus, viral meningitis and leptospirosis. Cases of quiet limb paralysis can be misdiagnosed as polio or Guillain-Barré syndrome. Tetanus patients have a shorter incubation period, mostly 6 to 14 days. Common symptoms are closed jaws, bitter smiles, and systemic muscle spasms last longer, often accompanied by angulation. The rabies muscle spasm is intermittent, mainly in the pharyngeal muscle. Tetanus patients do not have high levels of excitement and fear of water, and active treatment can be cured.

Severe changes in consciousness (coma, etc.), meningeal irritation, cerebrospinal fluid changes, and clinical outcomes may contribute to the identification of neurological diseases such as viral meningitis. Immunological antigens, antibody detection, and virus isolation may provide a positive diagnosis.

Rabies should be differentiated from rabies-like snoring (pseudorabies). This type of patient has a history of being a dog and is more likely to be a history of rabid bite or contact with a diseased animal. Symptoms of rabies occur in a few hours or days, such as a feeling of tightness in the throat, drinking water, and mental excitement. , but not fever, not drooling, not afraid of the wind, or showing drinking water, can not cause throat muscle spasm. Such patients can quickly return to health after being suggested, persuaded, and symptomatic.

Suppurative meningitis: Although there are symptoms such as "angular arch reversal" and neck stiffness, but no paroxysmal spasm, patients have severe headache, high heat jet vomiting, etc., the mind is sometimes unclear, cerebrospinal fluid examination has increased pressure, white blood cells Counting increases, etc.

[clinical manifestations]

The length of the incubation period is not one of the characteristics of this disease. Most occur within 3 months, and 4% to 10% for more than half a year, and about 1% for more than one year. The longest case in the literature is 10 years. The factors affecting the length of the incubation period are age (small children), wound site (early onset of head and face), depth of wound (early onset), number of virus invasions and virulence of strains, and whether they have been formalized after injury. Expanded treatment and vaccination against rabies vaccines. Others such as trauma, cold, overwork, etc. may contribute to early onset.

The clinical manifestations can be divided into two types: manic type (encephalitis type) and paralyzed type (static type), which are divided into the following three stages:

1. The prodromal period of the two types of precursors is similar. Before the emergence of excitement, most patients have low fever, lethargy, loss of appetite, a few have nausea, vomiting, headache (more in the occipital), back pain, general discomfort, etc.; sensitive to pain, sound, light, wind and other stimuli, And there is a tight throat. Early symptoms with significant diagnostic significance are wounds and nerve pathways that have healed, and there are sensations of numbness, itching, stinging or insect crawling, ant walking, etc., which occur in about 80% of cases. This is caused by viral reproduction stimulating neurons, especially sensory neurons, which can last for hours to days. The current period lasts 1 to 2 days, rarely more than 4 days.

2. The excitement period or the flood season can be divided into two types, and the performance of the two types is different.

(1) Manic rabies: the most common in the country, accounting for about 2/3. The patient gradually enters a state of high excitement, which is characterized by extreme horror, a sense of horror in the face of the disaster, and is very sensitive to stimuli such as water, light, and wind, causing episodic pharyngeal spasm and difficulty breathing.

The fear of water is a special symptom of this disease, but not necessarily every case, not necessarily in the early stage. Typical people can cause severe throat muscle spasm when they drink water, see water, smell water, or just mention drinking water. Therefore, the patient is extremely thirsty and does not dare to drink, even if drinking can not swallow, full of mouth drooling, staining the bed or squirting around. Because of the vocal cords, the words are unclear, the voice is hoarse, and even the sound is lost.

Fear of the wind is also a unique symptom of this disease, breeze, hair, wind, and so on can cause pharyngeal muscle spasm. Others such as sound, light, touch, etc. can also cause the same episode.

The onset of pharyngeal tendon makes the patient extremely painful, not only unable to drink water and eat, but also often accompanied by assisted respiratory muscle spasm, resulting in difficulty breathing and hypoxia, or even a systemic painful convulsion. After each episode, the patient is still restless and has A lot of sweating and dehydration.

In addition, due to hyperactivity of the autonomic nervous system, the patient developed excessive sweating, salivation, and elevated body temperature above 38 °C, heart rate increased, blood pressure increased, and pupils enlarged. The patient's expression is painful and anxious, but the mind is mostly clear and there is very little intrusive behavior. As the state of excitement grows, some patients may experience symptoms such as mental disorders, paralysis, auditory hallucinations, and screaming. The course of the disease progresses rapidly, mostly in the onset of death from respiratory failure or circulatory failure. This issue lasts 1 to 3 days.

(2) Paralytic rabies: India and Thailand are more common, accounting for about one-third of the total, and less than 10 reported domestically. There is no excitement in the clinic, no symptoms of phobic water and difficulty in swallowing, but high fever, headache, vomiting, and pain in the bite begin, followed by limb weakness, bloating, ataxia, partial or total muscle spasm, urinary retention or size. Incontinence, etc., showing the performance of transverse myelitis or ascending spinal cord paralysis. In the early stage, the pectoral muscle was slammed with a percussion hammer, and it was seen that it was slammed up and calmed down in a few seconds. In the early stage, muscle edema and hair erection occurred only at the percussion. The course of the disease lasts 4 to 5 days.

3. Two types of rabies in the coma or paralysis period are not easy to distinguish. When the sputum stops, the patient is quiet for a while, and there is fashion that can barely drink water to swallow, and the reaction is weakened or disappeared, and it becomes a flaccid paralysis. Among them, limb soft palate is the most common. Eye muscles, facial and chewing tendons, characterized by strabismus, dysmotility, lower jaw, inability to close, and lack of facial expression. In addition, there are still aphasia, loss of sensation, disappearance of reflexes, dilated pupils, and the like.

In this period, the patient's breathing gradually becomes weak or irregular, and tidal breathing, rapid pulse rate, blood pressure drop, low heart sounds, cold limbs, and rapid death from respiratory and circulatory failure can occur. The patient entered a coma before dying. This issue lasts for 6 to 18 hours.

The entire course of rabies, including the prodromal period, averaged 8 days for manic episodes and 13 days for paralysis.

The lesions of manic rabies are mainly in the brainstem, the cervical nerve or the higher part of the central nervous system. The lesions of paralytic rabies are confined to the spinal cord and the medulla, thus causing differences in clinical symptoms.

In most cases, rabies caused by blood-sucking bats does not show excitement, and there is no pharyngeal spasm and water-sucking phenomenon, and the above-mentioned behavior is the main clinical manifestation.

diagnosis

In the case of episodes, the diagnosis can be preliminarily established according to the past history of rabies or suspected rabies or cat, wolf, fox and other animal bites. If you can understand the bite and the health of the animal, then Diagnosing this disease is more valuable. If it is not certain whether the biting dog or cat is suffering from rabies, the animal should be kept in a cage. If the animal does not develop within 7 to 10 days, the animal can generally be excluded from rabies. Patients with typical clinical symptoms such as excitement, arrogance, fear of water, fear of wind, throat muscle spasm, massive salivation, convulsions, etc., can make a clinical diagnosis of rabies. Pay special attention to the symptoms of "three fears" (fear of water, light, wind), if necessary, use fan wind, water and light test, mad sputum symptoms are not obvious should pay attention to pharyngeal muscle edema and hair erection . Such as prenatal immunological antigen, antibody detection positive, post-mortem brain tissue animal inoculation and neuronal cytoplasmic found in the corpus callosum can be diagnosed.

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