Polio is spread through person-to-person contact. When a child is infected with wild poliovirus, the virus enters the body through the mouth and multiplies in the intestine.It is then shed into the environment through the faeces where it can spread rapidly through a community, especially in situations of poor hygiene and sanitation.ost people infected with the poliovirus have no signs of illness and are never aware they have been infected. These symptomless people carry the virus in their intestines and can âsilentlyâ spread the infection to thousands of others before the first case of polio paralysis emerges.
The present progressive tense combines the present indicative of the verb estar (to be) with the present participle of another verb to indicate an action in progress. The present progressive tells what a person is doing right now.
Present Perfect Tense. Present perfect tense describes an action that happened at an indefinite time in the past or that began in the past and continues in the present.This tense is formed by using has / have with the past participle of the verb.ast Perfect Progressive. Past perfect progressive tense describes a past, ongoing action that was completed before some other past action. This tense is formed by using had been and the present perfect of the verb (the verb form ending in-ing).