(A) causes of morbidity

Many types of this disease pathogens to Coxsackie A group viruses (1 ~ 6,8,10,22), herpes virus, EB virus, see more. When overworked, allergies, temperature mutation, body cold, or some physical, chemical factors, stimulate the body immunity is low, easy to contracting this disease.

Why kids are prone to suffer from acute respiratory infections do?

Children with acute respiratory infections common reasons are:

1. Respiratory insufficiency barrier, such as small children do not vibrissa, stopped coarse foreign matter in the air.

2. Respiratory mucosa tender, vulnerable to a variety of stimuli (cold, irritating gas, etc.) occurs congestion, swelling or inflammation.

3. Respiratory secretions out of resistance to bacteria, viruses, lack of immune substances, can not fully kill the invading pathogens.

4. Airway surface there is a cell with numerous cilia, these cilia like a clean-up brush, like constantly inhaled and adhesion of small particles on the respiratory tract, such as dust, bacteria and other outside cleaning, routed throat cough, but the cilia on the respiratory tract in children such activities are relatively weak, so "self-cleaning" function also relatively poor.

People in life is to continue to breathe in order to sustain life, so every day with the inspiration to enter the respiratory tract bacteria, viruses, harmful gases, dust and so on, innumerable, coupled with the respiratory tract in children less than all the defense function, so it is susceptible to a variety of acute respiratory infections.

(B) the pathogenesis

The virus from the nasopharynx, oral cavity to the respiratory and digestive tract invasive local mucosa, in epithelial cells, as well as the throat or intestinal lymphoid tissue and proliferation of residence. Virus original foci spread through the lymphatic channels to regional lymph nodes, or enter the blood circulation resulting viremia reaches all body organs, triggering a variety of diseases.