Certified in Public Health (CPH) Practice Exam

Why are polio outbreaks hard to control?

1. Because the virus is spread by the fecal-oral route

2. Because the virus crosses the blood-brain barrier

3. Because the virus causes several different kinds of paralysis

4. Because the virus does not cause recognizable symptoms for up to 35 days from infection

The correct answer is: Because the virus does not cause recognizable symptoms for up to 35 days from infection

The difficulty in controlling polio outbreaks is significantly due to the nature of the virus regarding its symptomatology. Polio often does not present any recognizable symptoms for an extended period, potentially up to 35 days after infection. This asymptomatic phase means that infected individuals may unknowingly spread the virus to others without being aware they are contagious. During this asymptomatic period, the virus can be transmitted via the fecal-oral route, which is particularly challenging in areas with inadequate sanitation. This delay in the appearance of symptoms hampers outbreak detection and response efforts, allowing the virus to spread widely before public health interventions are implemented. Furthermore, the absence of immediate symptoms complicates vaccination efforts because there may not be an urgent perception of risk within the community, leading to lower vaccination rates in the absence of visible illness. This characteristic of the virus greatly hinders effective outbreak control strategies and public awareness campaigns.