What is hydrophobia? What is the fear of water?

Hydrophobia is actually rabies, which is a disease caused by viral infection after being bitten by dogs, cats and other animals. People with rabies will develop hydrophobia, which is fear of water. This is mainly because the rabies virus damages the human nervous system, especially the salivary nerves and glossopharyngeal nerves, which are severely damaged, resulting in hydrophobia. Now let’s explain in detail what hydrophobia and fear of water are.

The fear of water in rabies can be summarized into three mechanisms:

1. Rabies virus is neurotropic: Rabies virus will spread centrifugally from the central nervous system to the peripheral nerves, and then invade various tissues and organs, especially the salivary nerve nuclei, glossopharyngeal nerve nuclei and hypoglossal nerve nuclei. The damage will be particularly serious, and clinically symptoms such as hydrophobia, difficulty breathing, and dysphagia may occur.

2. Increased excitability of the patient: Nerve damage will increase the excitability of the nerves, and the patient will show signs of nerve excitement when hearing or seeing the stimulus.

3. Conditioned reflex: Rabies patients will have difficulty swallowing due to laryngeal spasm. Even if they are thirsty, they cannot drink water smoothly. When they see water or hear the sound of water, they are extremely eager to drink water but cannot, which reflexively causes laryngeal spasm, leading to psychological fear.

After being bitten by an animal carrying the rabies virus, the disease generally does not break out immediately. Instead, there is an incubation period of several months to several years. The length of the incubation period depends on many factors, including the location of the wound, the severity of the injury, the number of viruses invading the human body, and the type of virus. Currently, the longest confirmed incubation period is 6 years.

Hydrophobia is just one of the symptoms of rabies, and different symptoms will appear at different stages of the attack. Early symptoms are not obvious, and are generally low fever, loss of appetite, nausea, headache, general discomfort and mild mental symptoms. In the middle stage, nerve excitability increases significantly, and the patient will experience fear of water, fear of light, difficulty breathing and paroxysmal pharyngeal muscle spasms. In the late stages, the patient will become overly excited and develop symptoms of paralysis, and death is not far away.

The rabies virus has a strong affinity for the nervous system. The course of the disease is particularly short after the onset of the disease. During an attack, the virus has invaded the brain and caused damage to the central nervous system. It only takes 24 hours for the virus to enter the brain and completely destroy the nerves. There is no drug that can eliminate the virus and repair the nerves without damaging the central nervous system within a few days. Therefore, once rabies patients become ill, they are almost 100% dead. Neither Chinese medicine nor Western medicine has an effective method to treat rabies during the attack period.

Symptomatic treatment

(1) People with hydrophobia should abstain from food and drink and try to reduce all kinds of stimulation. Convulsive attacks can be treated with phenytoin, diazepam, etc. Cerebral edema can be treated with dehydrating agents such as mannitol and furosemide. If they are ineffective, lateral ventricular drainage can be performed. (2) Patients with pituitary dysfunction and excessive antidiuretic hormone should limit their water intake. Patients with diabetes insipidus should be given intravenous fluid replacement and vasopressin. (3) Patients with respiratory system difficulty inhaling should be given tracheotomy. Those with cyanosis, hypoxia, or atelectasis should be given oxygen and artificial respiration. Those with pneumonia should be given physical therapy and antibacterial drugs. For patients with pneumothorax, lung re-expansion maneuver was performed. Pay attention to prevent aspiration pneumonia. (4) Most cardiovascular system arrhythmias are supraventricular, and those associated with hypoxemia should be given oxygen. For patients with hypotension, give vasoconstrictors and fluid expanders. Patients with heart failure should limit water intake and use cardiotonic drugs such as digoxin. For patients with arterial or venous thrombosis, the venous catheter can be replaced; if there is superior vena cava obstruction, the venous catheter should be removed. Resuscitation was performed on patients with cardiac arrest. (5) Other patients with anemia should receive blood transfusion, and those with gastrointestinal bleeding should receive blood transfusion or fluid replacement. Those with high fever should use cold mattresses, those with hypothermia should use heated blankets, and those with low or high blood volume should be adjusted in time.