Polio symptoms every parent needs to know!

Children's symptoms after contracting polio vary. The severity of the disease varies. Some cases are relatively mild and the symptoms are very mild, even adults cannot notice them, but some symptoms are more serious and more difficult to treat.

1. Latent infection (asymptomatic type): accounts for 90-95% of all infections. No symptoms appear after infection. The virus reproduces only in the digestive tract, does not produce viremia, and does not penetrate into the central nervous system. However, the virus can be isolated from the pharynx and feces, and specific neutralizing antibodies can be detected in the body. If a susceptible person develops symptoms such as sweating, irritability, hyperesthesia, sore throat, pain in the neck, back and limbs, stiffness, and loss of tendon reflexes after contact with the patient, this disease should be suspected. The prodromal period should be differentiated from general upper respiratory tract infections, influenza, gastroenteritis, etc. Patients in the pre-paralysis stage should be differentiated from various viral encephalitis, purulent meningitis, tuberculous meningitis and epidemic encephalitis B. The incubation period is 3 to 35 days, usually 7 to 14 days. According to the severity of symptoms and the presence or absence of paralysis, it can be divided into latent infection, abortive type, non-paralysis type and paralysis type.

2. Abortive type (mild): accounting for about 4-8% of the virus invading non-neural tissues throughout the body. The clinical symptoms lack specificity and may include: ① upper respiratory tract inflammation symptoms, such as varying degrees of fever, pharyngeal discomfort, pharyngeal congestion and hyperplasia of the posterior pharyngeal wall lymphoid tissue, swollen tonsils, etc.; ② gastrointestinal symptoms, nausea, vomiting, diarrhea or constipation, abdominal discomfort, etc.; ③ flu-like symptoms, joint and muscle aches, etc. The symptoms last for 1 to 3 days and recover on their own.

3. Non-paralytic type: The polio virus invades the central nervous system, and the circulating nerve fibers spread throughout the body. Symptoms of this stage may appear at the beginning of the disease, but most patients may be asymptomatic or have reduced symptoms for 1 to 6 days after the prodromal period, and then enter this stage.

4. Paralysis type: accounts for about 1-2% of the infected people. It is characterized by lesions involving the gray matter of the anterior horn of the spinal cord, brain and cranial nerves on the basis of non-paralysis type clinical manifestations, leading to muscle paralysis.