Can rabies bite people?

The issue of rabies has always been a concern for everyone, because rabies can be transmitted inadvertently and may take a dormant period of several months before it breaks out, often without everyone knowing. The incubation period of rabies varies, most of the time it will be within a few months or a few years, so after getting rabies, people generally won't bite, but some other symptoms will appear.

The varying lengths of the incubation period for symptoms and signs is one of the characteristics of this disease. Most cases occur within 3 months, 4% to 10% occur more than half a year, and about 1% occur more than 1 year. The longest case recorded in the literature was 10 years. Factors that affect the length of the incubation period include age (shorter in children), wound location (head and face are more susceptible to the disease earlier), wound depth (deeper wounds are more susceptible to the disease earlier), the number of viral invasions and the virulence of the strain, whether formal wound expansion treatment and rabies vaccination were performed after the injury, etc. Other factors such as trauma, cold, and excessive fatigue may also lead to premature onset of the disease. Clinical manifestations can be divided into two types: manic type (encephalitis type) and paralytic type (quiet type), which are divided into the following three stages:

1. The prodromal phase of the two types is similar. Before the excited state appears, most patients have low fever, drowsiness, lack of appetite, and a few have nausea, vomiting, headache (mostly in the occipital region), back pain, general discomfort, etc.; they begin to be sensitive to stimuli such as pain, sound, light, and wind, and have a tightening feeling in the throat. Early symptoms with great diagnostic significance are numbness, itching, tingling, or abnormal sensations such as crawling insects and ants in the healed wound site and nerve pathways, which occur in about 80% of cases. This is caused by viral reproduction stimulating neurons, especially sensory neurons, and the symptoms can last from hours to days. This phase lasts 1 to 2 days and rarely exceeds 4 days.

2. The excitement phase or spasm phase can be divided into two types, and the manifestations of the two types are different.

(1) Manic rabies: the most common type in China, accounting for about 2/3 abroad. The patient gradually enters a state of high excitement, with prominent manifestations of extreme terror and a sense of foreboding of impending disaster. He is also very sensitive to stimuli such as the sound of water, light, and wind, causing paroxysmal pharyngeal muscle spasms, difficulty breathing, etc.

Hydrophobia is a specific symptom of this disease, but it may not occur in every case and does not necessarily appear in the early stages. Typically, drinking water, seeing water, hearing the sound of running water, or just mentioning drinking water can cause severe spasm of the pharyngeal muscles. Therefore, the patient is extremely thirsty but dares not drink, and even if he wants to drink, he cannot swallow it. His mouth is full of drool, which stains the bed or spit everywhere. Due to vocal cord spasm, the patient may have unclear pronunciation, hoarse voice, or even loss of voice.

Fear of wind is also a unique symptom of this disease. Breeze, wind, draft, etc. can all cause pharyngeal muscle spasms. Other factors such as sound, light, touch, etc. can also cause the same attack.

Attacks of pharyngeal muscle spasm cause extreme pain to patients. Not only are they unable to drink water or eat, but they are often accompanied by spasms of the accessory respiratory muscles, leading to difficulty breathing and hypoxia, or even the whole body entering a state of painful convulsions. After each attack, patients remain irritable and restless, and sweat profusely and become dehydrated.

In addition, due to autonomic hyperfunction, patients experience profuse sweating, drooling, body temperature rising to over 38°C, increased heart rate, increased blood pressure, and dilated pupils. The patients look painful and anxious, but are mostly conscious and rarely engage in aggressive behavior. As the state of excitement increases, some patients may experience symptoms such as mental disorders, delirium, hallucinations, auditory hallucinations, collisions and howling. The disease progresses rapidly, and most patients die from respiratory or circulatory failure during an attack. This phase lasts 1 to 3 days.