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Outbreak Response

In this lecture, Patrick K Kayembe outlines surveillance activities for an outbreak response. (Step 2.8)
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PATRICK KAYEMBE: Now, I’m going to talk about the Outbreak Response.
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On the slides I’m showing the framework of the Public Health Surveillance Framework. As you can see, we have different columns, named 1 through 6. You see that these represent a key element of health protection that should be in place in order to have an effective surveillance system. So the first column is showing precursors. And from that column, you can see that we have politics, policy, priority, preparation, and payers. This is the precursor. So this should have to be in place to set the policy for the surveillance system. The second column is about perspective. So you to be precise. You have to clarify, so what’s the perspective? Is that a national system?
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Is that at the district level, community level, facility or the lab? So it has to be clarified. And then the third column is about surveillance activities themselves. So you know that these are the 6 core elements to have a surveillance working, so detection of cases, registration of cases, reporting, and confirmation of cases. So we have to confirm ideologically and send some samples to the lab for lab confirmation and then analyze the feedback. The next column would be action and activity. So in here is to investigate outbreak, case management, contact investigation. It might mean to put some of them into quarantine. Investigate all of this to know exactly what’s going on.
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And then the 5th column is if everything is being done correctly, the outcome will be reducing the number of outbreak, and then that would reduce the incidence of disease in the long term so that the population health would be protected. As you can see on this picture, you may refer to this curve as an epidemic curve. So you see at the beginning of the curve, it’s the index case, the first case to come down with the disease. And then we see the number of cases increase and then we have a peak. And after the peak, now the number of cases start decreasing. So you see, you look carefully at the graph, you see the late reporting.
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So the epidemic was reported when cases were at the peak. So when the cases are at the peak, it means there are already a lot of people already being infected. And then when the response is later reported, it leads to the later response. You see that the response has been elicited lately, even exactly when the number of cases starts decreasing as a normal cause of the epidemic. So the action was late and now we have the consequences to see a lot of people dying– a lot of people having viruses. The responses is not going to make it improve the situation, it’s already late because the epidemic is already dying.
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But when you look at the following picture, you see that early reporting leading to early, rapid responses. So we don’t get to the peak anymore. And a lot of people also are prevented from having that disease because of the rapid response. That’s what surveillance should be doing, detecting disease very early so that the response can be rapid to prevent other disease from happening. So I’m going to ask you to pause and go to the link and watch the video. The video is about responding to an outbreak. So while watching the video I want you to pay attention to those two questions. What is an outbreak and why an outbreak should be investigated?
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So an outbreak is occurrence of more cases of disease than expected in a given area, among a specific group of people, of a particular period of time. Outbreak is considered as a public health emergency. It occurs due to the gaps between the real exposure of the disease and the reported one. It indicates surveillance and control failure. Beside [INAUDIBLE] sector, an outbreak also impacts on the sector. If an outbreak occurs, it also can be considered as political and economic emergency, therefore, outbreak requires a rapid action. An investigation should be immediately conducted when an outbreak occurs to reduce or prevent mortality, reduce morbidity, and to design control and preventative measures. Delayed or improper intervention may lead to death.
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An outbreak investigation requires basic medical and public health knowledge, basic concept of epidemiology, sources of specialized information, an example is a reference book and specialists, knowledge of the environment, laboratory testing if needed, and common sense. We have steps to consider when there is an alert that some health condition is happening. So you have to get prepared for the fieldwork. You may have a contingency plan ahead of time, but we have to make it [INAUDIBLE] before getting to the field. Once in the field, we have to establish the existence of an outbreak. This may be looking at the data, seeing how many cases there are. Are there many cases unexpected, for example. So establish the disease into an outbreak.
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And then we need to verify diagnosis. This means that you may even send samples to the lab so they can be tested and confirmed if the agent, the microbe, is there causing that specific disease. Then you have to come up with a case definition to use in the field. That definition has to be very sensitive so that it can detect as many cases as possible. The next step will be to identify cases and collect information. And then once the cases are being collected, we need to collect information on them, so that we can perform descriptive terminology in terms of for who is affected and why they are affected.
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And looking at the data, you have to come up with a hypothesis. So why are people getting the disease? What is the explanation? And then that will be an hypothesis that we need to test. To test this, you have to conduct the research and study, let’s say, a case-control study, to test your hypothesis, if they do explain exactly why people are getting the disease. So you need them to reconcile epidemiology with laboratory and environmental findings. So we have to be looking at many things to understand exactly why the disease is happening and who is getting it and why. And then you have to conduct additional studies as necessary, as I said. And then you have to think of the response.
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But to think of the response, you don’t have to go through our list. So you can, even at the beginning, even when not knowing exactly what’s going on, come up with some measure that people can be observing in order to avoid a disease. So we have to implement and evaluate the response. Is it doing any good? Are you getting good results? You have to evaluate and maybe change the way of thinking as you go along. And then, after the epidemic is gone, the outbreak is under control, you need to put in place a surveillance system.
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You need to initiate and maintain it, so that it will stay in place in order to be monitoring exactly if the situation has been solved. And then you need to communicate the finding. This is very important for a future epidemics. You have to show people what was done, how was it done, so people can learn from this. We went through the steps about the outbreak investigation response. I want you to think about how these steps might look like indicators of polio outbreak, using the example of Syria, from the readings we gave you.
Patrick K Kayembe MD, PhD, MPH School of Pubilc Health, University of Kinshasa, Democratic Republic of the Congo (DRC)

In the lecture, you are invited to pause and watch this video:

This is an additional video, hosted on YouTube.

Now that you have watched this video and the lecture, consider, what are some key differences in surveillance activities when addressing an outbreak vs. a planned response?

Please take a moment to share your thoughts in the discussion.

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