[MUSIC PLAYING] EMILY GURLEY: As a contact tracer, you'll need to be able to calculate how long a case should isolate and how long a contact should quarantine themselves. It'll be based on your understanding of their infectious period, and it will be an important component of working with cases and contacts to limit the spread of disease. So let's go through some examples, very practical examples, using a calendar to see how this might work. So how long should a case be isolated from others? Well, the short answer is ideally as long as they are infectious. But there is a longer answer. We know that by the time they're diagnosed, they may already be sick, so by the time you're investigating this case, their infectious period has already started, probably at least a few days before. So you'll need to talk to them about isolating themselves for the duration of their infectious period. They'll have to monitor their symptoms each day to help you determine if they're still infectious and if they've recovered. And remember, they'll need to isolate themselves at least 10 days after symptom onset, and you'll have to know that their other symptoms are improving and they haven't had fever for three days. So let's see practically what this will look like. Let's assume that you identify a case, and you call them on May 10th. During the conversation with them, they tell you that they became ill on May 9th. So now you know that they were infectious for two days before they became ill, and they will be infectious for at least 10 days after their onset. So that means May 9th plus 10 days equals May 19th, so you can see here in blue their total infectious period, which started two days before their onset of disease and went all the way through May 19th, which is 10 days after the onset. So we know that the case will be infectious at least through May 19th in this example, but you'll need to have continuing follow up to see when they can stop isolating from others, because you'll need to know when their symptoms resolve without use of medication. So the 19th is the earliest time that they can stop isolating, but just a reminder that you'll need to be following up with them to see if they can really stop isolating on the 19th or not. So on this slide, the days of their infectious period are shown in blue, and we assume that we call the case on May 10th, and you're going to ask them about the contacts they had since May 7th. Those are shown here also in yellow. We assume that after you call them, so from May 10th through May 19th, they're isolating themselves, so they're not going to have any additional contacts. So in your discussion with them on May 10th, you'll need to list out everyone they had contact with since May 7th. Now that you've identified the contacts, you'll need to help them calculate how long they should quarantine. So how long should a contact stay in quarantine or distance themselves from others? The short answer is ideally as long as they could be infectious, which means the 14 days since their last contact with someone who is infectious. So there's a longer answer though. Again, it's 14 days since their last contact, because we know almost everyone who is infected will develop illness within 14 days. However, by the time that you are having a conversation with the contact, their contact with the case may have been days ago, so you'll need to figure out how much time they should quarantine from the time you talk to them. And in other examples, the contact may be ongoing. So for example, if they live with the case, they lived with someone who is infectious. So that will require some additional calculations. It's important to note also that when you're having a conversation with a contact, if they've developed symptoms, they should probably be considered a case, and so then you would talk to them about isolating rather than quarantine. Now, let's think through a specific example. Remember the case we already talked about? Well, let's assume that you're going to call one of their contacts, and you're able to have a conversation with this contact on May 13th. And on the call with this contact, you understand that their last interaction, their last contact with the case was on May 10th. If you'll recall, that's the second day of illness for the case, so they should receive instructions to quarantine for 14 days since their last exposure to their case. If their last exposure was on May 10th, you would add 14 days, and so that would mean that they should quarantine through May 24th. So we already mentioned that if a contact lives with a case, then figuring out their quarantine period could be a bit more difficult, because their quarantine periods going to be longer. So the contact should quarantine themselves immediately and then also for 14 days following recovery of the case, because that would be the last time they had contact with an infectious case. So for some contacts quarantine is going to be longer than 14 days. Let's just see what that would look like on the calendar. Let's assume, same scenario, we call the contact on the 13th of May, and it's the same case, but they live with the case this time. So the person that they live with became ill on the 9th. This is the case we talked about before. Let's also assume that the case will be fully recovered by the 19th. This would be 10 days since their onset of illness. Therefore, if the contact has to quarantine themselves for 14 days after their last infectious contact, then they would need to quarantine through June 2nd, because that would be two weeks after the full recovery of the case that they lived with. So you can see in this example where the contact lives with the case, their quarantine period is going to be almost three weeks long, because they'll have to quarantine themselves while they're still having contact with the case and for two weeks after. [MUSIC PLAYING]
