Symptoms of polio, different manifestations in four stages

Babies will be vaccinated after birth. The most common vaccine is the vaccine to prevent polio. Polio is an infectious disease caused by a virus, which is very harmful to children's health. This disease has a certain incubation period, followed by three stages of development.

1. Incubation period

The average duration is 7 to 14 days, with the shortest being 2 to 3 days and the longest being 3 to 5 weeks. There are generally no obvious symptoms during this period and it is a latent case, but it is contagious at the end of this period.

2. There are three stages of development of the disease.

(1) The first stage - the prodromal stage: During this stage, the patient has a low or moderate fever, often accompanied by symptoms such as headache, drowsiness, sweating, and general fatigue and discomfort. They may also experience gastrointestinal symptoms such as loss of appetite, vomiting, diarrhea, or constipation, and even respiratory symptoms such as sore throat, red throat, and mild cough. This period usually lasts 1 to 4 days. Most cases develop to this stage and are of the frustrated type, also known as the lucky type.

(2) The second stage - the pre-paralysis stage: Based on the previous stage, the child's body temperature returns to normal and general symptoms disappear, but after 1 to 3 days the body temperature rises again and is relatively high, usually between 38 and 39°C, and in some children it can be as high as 40°C. At this time, the general symptoms also become more severe. The child is irritable and has headache, vomiting, drowsiness, limb pain and hyperesthesia. There may be myotonia on the back of the neck, and the fontanelle of infants and young children may be tense and full, and the "spinal cord sign" may appear, which is meaningful for diagnosis. This period usually lasts 3 to 5 days, but it can be as short as a few hours or as long as 2 to 3 weeks. During this stage, some cases may still not experience limb paralysis and gradually recover. These are called non-paralysis cases and are also lucky. For another group of children, the condition continues to progress and they enter the paralysis stage.

(3) The third stage - paralysis stage: This stage usually begins on the 3rd to 4th day of the pre-paralysis stage. About 5% of cases enter this stage directly without going through the pre-paralysis stage. Paralysis symptoms often occur when the temperature drops, but some may occur after the fever subsides. It often starts with limb pain and muscle tenderness, followed by sudden paralysis. Paralysis can occur anywhere, but limb paralysis is the most common.

3. Recovery period

During this stage, general symptoms disappear, the fever drops to normal, and paralytic signs no longer progress. This stage usually begins 1 to 2 weeks after the onset of paralysis symptoms. Recovery is faster in the first 6 months, then gradually slows down, and the possibility of recovery becomes increasingly smaller after 2 years.

4. Sequelae

Patients with a disease course of more than 2 years enter the sequelae stage. During this period, various deformities gradually appear, become increasingly severe, and tend to become fixed; at the same time, secondary changes occur in various bones and joints, which aggravate the degree of functional impairment and often bring difficulties to treatment. Therefore, taking positive and effective measures at an early stage is an important part of preventing the occurrence of deformities and reducing the severity of deformities. The causes of deformity are mainly due to the following factors.