Distinguished future physicians welcome toStomp on Step 1 the only free tutorials series that helps you study more efficiently by focusingon the highest yield material. I'm Brian McDaniel and I will be your guide on thisjourney through the Herpes Family of Viruses. This is the 4th tutorial in my playlist coveringmicrobiology and we are going to review genital herpes, cold sores, chickenpox, shingles Mono. This is our first tutorial covering viruses.Unfortunately, with the viruses you have to memorize how many strands the genome is, whetherit is DNA or RNA and if the virus has an envelope. This is perhaps my least favorite thing tolearn for Step 1, but you just have to grit
your teeth and get through it. Some of thequestions on the exam require you to have this info as it will sort of be a 2 part questions.For example, based on the question stem you may know the answer is Herpes Simplex, butwhen you look at the answer choices herpes simplex isn't an option. You will insteadsee something like â€œA double stranded DNA virusâ€�. If you don't know how to translateyour answer into these defining characteristics of the virus you can't get that questionright. So we will be referencing this table as we go through the high yield viruses. Thisobviously isn't exhaustive, but it has the most important examples.
And here is the table listing whether or notthe viruses have a lipid outer layer called an envelope. You can see herpes listed hereas having an envelope. In the general population the term â€œHerpesâ€�is used almost exclusively to describe genital herpes simplex. There are actually 8 membersof the family Herpesviridae (AKA Herpesviruses) and most of them are high yield for the exam.However, we will not discuss all 8 of these viruses in this tutorial. Human Herpesvirus 6(HHV6) and Human Herpesvirus 7 (HHV7) are very low yield for the exam so we will skipthem. We also will hold off on discussing Human Herpesvirus 8 (HHV8 or Kaposi Sarcoma)until a later tutorial that will discuss HIV
AIDs in depth. This family includes some of the most commonand contagious infections in the general population. Over 90% of people have 1 or more herpes infections.However, for a huge majority of the time these infections are not active. After an initialsymptomatic period they have prolonged latent phases where the inactive viruses hide fromthe immune system. In some cases there are sporadic periods of reactivation where thepatient again becomes symptomatic. The symptomatic periods of these infections are usually selflimited,but there is no cure to eliminate the virus or prevent reoccurrences completely. Somepatients don't even know they have the infection
as even the primary infection can be asymptomaticor very mild. The diagnosis of these viruses is usuallymade ally. However, there are tests that can aid in the diagnosis. A Tzanck Test(AKA Tzanck Smear) is a rapid test that can be performed when a herpes virus is suspected.A skin vesicle is broken open and smeared on a slide with a stain. Microscopically ifmultinucleated giant cells with intranuclear inclusions is visible it is a positive results. Here is a picture of what a positive tzancktest looks like. There are 2 types of Herpes Simplex, HSV1 HSV2. HSV1 presents primarily on the lips
or mouth (AKA â€œCold Soresâ€� or OrolabialHerpes) while HSV2 presents primarily on the genitalia. HSV2 is most often an STDwhile HSV1 is mostly spread by saliva. However, there is significant overlap between typesand you can get both viruses via either route and in either area of the body.In both cases Herpes Simplex can be asymptomatic or cause painful fluid filled blisters onthe skin or mucous membrane that can progress to ulcerations. Genital herpes typically hasmultiple lesions while orolabial herpes more commonly has a single lesion. Here is a picture of orolabial herpes andI think you get the point so I'll spare