External signs of an infectious disease do not appear immediately after the introduction of the pathogenic microbe into the body, but only after some time. The time from the moment the microorganism is introduced to the manifestation of the disease is called the incubation period. The duration of the incubation period for each infectious disease is different: from several hours to several weeks and even years. The absence of external signs of disease during this period does not mean that nothing happens in the body. On the contrary, at this time there is a fierce struggle between pathogenic microbes and the body.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.