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Diagnosis, treatment, and prevention of herpes

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- So we've talked quite a bit about herpes already. The next step would be to understand how do we diagnose herpes? Well commonly what physicians will do is ask the patient about their medical history, recent sexual practices, and other things that may suggest a mode of transmission or some way the patient could have already been infected with herpes. So combined with this history, and the symptoms that they may be exhibiting such as the cold sore either on their lips, that's called herpes labialis or if it's on their genitals that's herpes genitalis. That's usually enough to make the diagnosis. And that's actually what physicians most commonly will do. Beyond that there are a couple of tests that can be used to make the diagnosis. One test that used to be more commonly employed is called the Tzank smear. The Tzank smear, which is named after a famous French dermatologist. So let me draw the French flag here. Let's put in a little red, white, and blue. So this test was first described by a French dermatologist and what they would do is take a swab sample of a cold sore or an ulcer. So here's our sample right there and that sample would be applied onto this slide right here. So let's smear the sample onto the slide right over here and then what you'll see after adding a stain. This could be either a Giemsa stain or a Wright stain, so don't worry about those names, but there's a specific dye that's added to this, so I'll just write up here a dye of some sort is added and what you should see if this patient has herpes are these giant cells. These are supposed to be epithelial cells from the swab of the lip or from the genitals, so that's one giant cell. So I'll write down here we see a couple of giant cells. And there are a few other here. But what's interesting about these cells is that they don't have just one nucleus. There are several of them. So I can count one-ish right there. Maybe here's another one right there. And then there's another one right there. So this cell is multi-nucleated. So we say that we have multi-nucleated and this is suggestive of a diagnosis of herpes, but the problem is this Tzanck smear is suggestive of a couple other things as well, in addition to being positive for HSV1 and HSV2, this can also be found with cytomegalovirus or even with varicella or herpes zoster which is another type of virus altogether which is why this test isn't as commonly done because usually a history and symptoms can be suggestive of herpes by itself. But even beyond that, another test that used to be done is what's referred to as a cytopathic culture. So cytopathic culture. So I think you've heard the term culture before. I'll describe it a little more in detail below here. But the reason why it's called cytopathic is that what we try to do in this test is to take cells or cytes and kill them. So that's why it's a cytopathic culture. Pathic you might recognize from the term pathology which is the study of disease. So we take cells and we give them a disease. So specifically we have this culture right here and we start off with a couple of cells so these are cells that aren't necessarily from the patient but can be from a stalk cell line in a laboratory and to this we add a sample of our patient's blood. So I'll draw the patient's blood right here and I'll label it. And so if we're suspecting that this patient has been infected with herpes I'll draw this triangle or symbol for the herpes simplex virus. What we should see over here is our culture of cells dying off which means that there's something in the patient's blood that' taking over the cells and not allowing them to grow. And so that's a suggestive diagnosis for herpes. But again, this is also something you'll see with a variety of other viruses as well. Alright so let's say we've made our diagnosis. The next step would be treatment. Well for viruses there's a specific class of antibiotics referred to as antivirals that we use on them. But as you remember from the timeline of symptoms that you'll see with herpes, they usually go away in about 10 days, so we don't often give antivirals. These are specifically given to patients that are at high risk for complications of herpes and these folks tend to be immunosuppressed. So we only give antivirals to those that are immunosuppressed. And there are some exceptions to this rule, but this is the general trend and immunosuppressed is sort of an umbrella term for a lot of things. Women that are pregnant are relatively immunosuppressed. So we'll treat them with antivirals if they're positive for herpes sometimes. So in addition to treatment what can we do to prevent the herpes virus from happening in the first place. So prevention, and the mainstay of prevention for all sexually transmitted infections is to block transmission. So going down our list of modes for transmission of herpes we see sex as one of the common ways to do it and so one of the things that we can do during sex is to use a condom. That will help limit direct contact and then additionally for oral sex use of dental dams can also decrease direct contact as well. During childbirth there are two ways that we can limit spread of herpes from an infected mother to a child. One would be to just treat mom with antivirals. And the other is if a pregnant woman has active sores in their genitals, one strategy would be to deliver the baby by C-section because removing the baby through abdominal surgery rather than through a vaginal delivery will decrease their contact with the open sores and thereby block direct contact to decrease their risk of developing neonatal herpes. These last two modes of transmission pertain mostly to healthcare workers in which case use of gloves is a very prudent way to make sure you don't touch an open sore when examining a patient. And another issue that healthcare workers come in contact with is sometimes getting needle stuck when drawing labs from a patient and so safe needle disposal practices will help decrease their risk of a needle stick injury and thereby limit their risk of developing herpetic whitlow as well.