Overview of Surveillance

PATRICK K.

KAYEMBE: At this point in the section, we are going to discuss overview of surveillance.

Before getting started, I want you to watch the video. And the video is about the polio surveillance system. And then after this video, we’re going to discuss the definition and the objective of surveillance. So, what is the surveillance? According to the literature, surveillance is the systematic collection and the use of epidemiologic information for the planning, implementation, and assessment of disease control. This definition was set forth by the [INAUDIBLE] back in 1968, at the 21st World Assembly. There’s not a common definition. So you might see many definitions. But the most important thing to return here is, the systematic collection and use of epidemiologic information. That’s the most important thing to keep in mind. So, why is surveillance important in polio eradication?

Surveillance is important, because we want to know exactly if polio has been eradicated. So every case of polio must be detected. So, this is a true detection of acute flaccid paralysis in the community. So, and every case should be detected, and investigated, and tested, so we know that this polio or not. What are the objectives of surveillance? Surveillance, it has two objectives– to detect polio viruses wherever it exists, and secondly, to demonstrate the absence of polio virus in places where polio has been eliminated. As you understand, surveillance is at the heart of the drive to protect children against polio. We have two types of surveillance, active and passive. So we’ll discuss the advantage for either one.

And I’ll discuss a little bit, I’ll talk a little bit about how to choose one or the other. So, we have active surveillance is that– the health professionals are really in control. So the ones who detect cases notify investigate. And passive surveillance is just routine reporting of disease cases with information coming from all the reporting sites and health professionals. So, as you know, passive surveillance most of the time is incomplete. And there are delays in sending the data through the system. If one wants to eradicate polio, since polio also requires that a case be detected, and a rapid response be put in place, one might want to choose active surveillance.

That’s the one the more appropriate for polio eradication, since the presence of the cases has to trigger a rapid response. What kind of information should be collected by the surveillance system? So these are the key information that we need as a health professional, to know what’s going on, so that we can plan and respond to what is happening. So the most important information are the following– who gets the disease or health condition. So we’ll be looking at age, looking at gender, looking at profession, looking at social, economic status. So how many people are affected? So we should know the number, and how the number are increasing. So is it doubling? So what’s the doubling time, and things like that?

Where are people are affected? So location, because we have to know exactly the location, if we have to go there and then respond and react to the disease. So the time period is important. That’s why we the question when. And why? Why is looking at factors that makes up people get diseased. An And from this information, then we know exactly what needs to be done as a response.