Dr. Reich reviews the presentation, diagnosis, and treatment of tick-borne illnesses in the St. Louis and surrounding areas as well as the recent measles activity.
Thanks for having me, and I had to sneak in a little bit of a measles discussion as well, uh, in addition to the tick discussion today. Uh, for those I haven't met before, I'm Patrick Reich, one of the PES ID physicians, um, here at WashU, um, and I also do infection prevention. I have no disclosures, although I always share that, um, I present material through my lens as a pediatric ID physician. Um, and I welcome any questions, comments, uh, input from the group as we go. I have the chat open and feel free to come off mute as well. And so the goal of today's talk is to really review uh information about tick bites, general guidance about management of tick bites, um, and then the epidemiology, clinical presentation, etc. of the tick-borne illnesses we see commonly in our area. And then speak a little bit about what has been going on recently with measles, um, and briefly highlight just that there's a broad differential that you guys are thinking about all the time when seeing patients with febrile rash illnesses this time of year. So we are in the thick of things in terms of tick activity. There was a couple of news articles recently in the St. Louis area about tick-related incidents, and I put this picture up just to show that ticks are among us. They can be small, hard to spot, and they're really efficient vectors. So we have, we do see a fair amount of tick-borne illnesses in our area this time of year. So this data shows it's, it's for the Midwest and each different color is a calendar year, but the number of ED visits in the Midwest region um by month for tick bites. And you can see that this green color is our current year and typically this starts, you know, March, but really peaks May through July and then continues to stay around into the, into the early fall in terms of patients presenting for evaluation of of tick bites. And what you can see in the data on the right is that the Midwest is second only to the Northeast in terms of ED visits for tick bites themselves. And then the heat map on the left shows the at least most commonly diagnosed tick-borne illnesses in the US and their distribution. Um, uh, with the Missouri ones we'll go in in more detail, including Eyosis, uh, Rocky Mountain spotted fever, and other spotted fever group Rettsiosis, um, as well as Tularemia, um, being some of the most common tick-borne illnesses we see. In terms of how to prevent tick-borne illnesses, the real best way to prevent them is to prevent tick bites. That's easier said than done, and some of this guidance applies well to certain situations, not well to others, but folks can do things like, you know, wearing repellent. be um containing or non-D containing, you can apply treatments to your clothing, um, you know, making sure you do tick tick checks after being in an area where ticks could be present, um, are, are important ways to really mitigate that risk. And we get asked commonly the best way to remove ticks, and so I just included these infographics from the CDC and the guidance is whether using tweezers or your fingers or what have you, to really just apply slow and steady pressure and lift the ticks. Off the skin, followed by vigorously washing with soap and water afterwards. Importantly, you shouldn't do things like put Vaseline or other topical products on top of the tick. You really should just remove the tick again, either with tweezers or your fingers. The other question we get asked a lot about after tick bites is whether antibiotic prophylaxis is recommended, and the answer to that question depends on where the tick bite occurred. So, um, meaning geographically, not physically on the body. So if you're in a yme endemic region like the upper Midwest or the um New England, Uh, where Lyme disease is common and the tick bite occurred within the past 72 hours, then a single dose of doxycycline prophylaxis is recommended. But if you're in an area where Lyme disease is not endemic, not common, like Missouri and southern Illinois, antibiotic prophylaxis is not recommended. So you just recommend tick removal and local um uh cleaning and wound care and then monitoring for any symptoms, then having a low threshold for consideration of tick-borne illnesses if symptoms develop. In terms of what we see most commonly across the United States, um, you can see the kind of a bar graph on the left over the past few years' worth of data that we have, and then the same information just by number on the right, but you can see far and away across the US Lyme disease is most common. That's not true for our area, but generally speaking. Um, the second most common is anaplasmosis, also something we don't see in our area, but we see some other very similar diagnoses like spotted fever group, Rickettsiosis, Ehrlichiosis, and uleremia, which some are some of the next most common illnesses. Looking more locally, you can see the map on the left with the number of diagnoses of relichiosis, Lyme, tremia, and spotted fever group ettsiosis, um, and then on the right, you can see Saint Louis County data for the last several years. So in Saint Louis County, uh, the most common tick-borne illness, we diagnose this early liuyosis, followed by Rocky Mountain spotted fever slash spotted fever group ettsiosis, which I'll talk a little bit more about in a moment. And we see very little Lyme and anaplasmosis. We do see some tuaremia, but more so in other parts of Missouri, less so in St. Louis proper. And then we'll go through each of these diagnoses individually and talk more specifically about their geographic area in the coming slides. The first one I wanted to talk about is the diagnosis we see most often in our area, which is ehrlichiosis. And importantly, the incubation period is variable, so, uh, symptoms can occur up to 2 weeks after the tick bite. Really, patients present with a very non-specific symptoms that could be consistent with a viral illness like fever, malaise, um, GI symptoms. Um, skin rash is more common in kids than adults, but overall, only a third of people with their leuyosis have a specific skin rash, and it can be polymorphous. There can be associated respiratory symptoms, so, um, uh, this, the presence of respiratory symptoms in a patient who's recently had a tick bite shouldn't necessarily um lead you away from that diagnosis, although there is overlap with respiratory viruses too, right? And some of the hallmarks that we see are some lab findings, most notably leukopenia. You could have a normal white count, but it'd be very unusual to have leukocytosis with herrlichiosis. We can also see low platelet count, elevated transaminasis, and hyponatremia. This can be very severe. The spectrum of diseases is impressive, ranging from pretty mild disease that probably resolves spontaneously, um, to a very severe disease, um, uh, and Ehrlichia can induce HLH, um, so it, it can be really dramatic, and there's this. known associated association with sulfonamide antibiotics, and severe errlichiosis. So we'll hear a patient comes in with severe lichia and had been on Bactrim in the past week for some reason. Um, whereas um and the reason for this association is unknown, but definitely something we see clinically. The distribution of ehrlichiosis cases is similar to most other tick-borne illnesses in terms of time of year. So it's really the late spring peaking in the summer, continuing into the fall, and you can see in this heat map at the bottom left that Missouri is in the top handful of states in terms of ehrlichiosis diagnoses across the country. In terms of where we see it most often in Missouri, you can see that while we see some in the St. Louis area, um, some of these outlying counties and some of the southwestern parts of the state are where we see even more of a concentration in Erlichia diagnosis, but we definitely see a fair amount in our area. And something that I find really interesting about Erlichiosis is that while um older adults are more likely to get errlichiosis for reasons we don't fully understand, um, young children, less than 4 years old, are actually the highest risk group for severe rlichiosis, followed by older aged adults. Um, and the reason for both of these phenomena are, are not understood, but something that we do see clinically. In terms of most recent data in our area, uh, the top is the St. Louis County data for Erlichia cases, uh, with 2025, year to date being in red. You can see we're kind of tracking what we've seen on average over the past five years, and in the bottom you can see that. Number of positive Ehrlichia tests by week within BJC. The most recent weeks at the bottom left in purple, the weeks before that at the bottom right in green. So we have definitely seen Ehrlichia activity in our area, not tons of cases necessarily, but kind of typical for what we would see at this time of year. In terms of diagnosis, so importantly, um, if you're suspicious of errlichiosis, um, empiric initiation of doxycycline is recommended, and there is a phenomenon with both ehrlichiosis and RMSF that delays and initiation of therapy can be associated with worse outcomes. And then if you have access to Ehrlichia PCR testing, that really is the best test. You get the results quickly. The role of uh serology for diagnosis of, of ehrlichiosis is, is, is, is pretty minimal. um, so I would recommend sending PCR testing if you have access to it and consider empiric treatment if you don't have access to PCR testing. And the duration can be as short as 5 days and 3 days after resolution of fever and improvement of symptoms, but some patients are treated for longer, up to 7 to 10 days, just depending on the severity of the illness, duration of symptoms, and clinical response. And sort of, uh, as we talk about ehrlichiosis, there's this group of other similar diagnoses that present clinically in the same way. One of them is anaplasmosis, um, and, uh, actually it used to be called human granulocytic ehrlichiosis, whereas what we now call yosis was called human, uh, monocytic ehrlichiosis. So clinically very similar, different pathogen, and this is Really clustered in New England and the Northern Midwest, but not something we see in the St. Louis area. Otherwise clinically indistinguishable from relichiosis, you can detect it by the same PCR in most labs and would also treat with doxycycline. Then there are at least a couple of viruses that are known to cause very similar presentations to relichiosis in our area, one of them being heartland virus, which was first described over 15 years ago in Missouri and subsequently, there have been cases in other surrounding states. This is Of course an underestimate of underestimate of the true number of cases because you have to get testing through the CDC and we don't always pursue that, right, um, because it's a viral pathogen and the illness typically self resolves with supportive care. Um, so something to at least think about and recognize that if a patient has a clinical phenotype consistent with earlychiosis and isn't responding to doxycycline, this along with um bourbon virus would be another pathogen that you could at least think about, could be causing. the illness and then if the illness was severe and the patient were hospitalized, etc. we might pursue testing through the CDC, but I think in a well appearing patient who's clinically improving, we wouldn't pursue the diagnosis, and I think for the average outpatient, you wouldn't pursue testing through the CBC. And then moving on to the next most common diagnosis, diagnosis group of diagnoses we see that are tick-borne in our area is Rocky Mountain spotted fever and um other associated spotted fever group orque COCs. Um, so, uh, as you guys probably know, um, RMSF also can have a pretty long incubation period like Erlichiosis. The early symptoms are very non-specific like hrlichiosis and have fever, non-specific GI symptoms, malaise, myalgia. The rash is interesting because most people have a rash at some point. But at least half don't in the 1st 3 days of illness. So this could just be a patient who presents with no rash, non-specific symptoms that we think is viral, and then later the rash, rash develops. Um, you can see lab findings with RMSF. Interestingly, we usually don't see as much leukopenia with RMSF. Typically, we'd see a normal white count or um elevated white blood cell count, so that can be a distinguishing hint. And uh we can see similarly hyponatremia, transaminase elevation, severe disease, especially um if a patient is untreated after 5 days, their risk for these complications goes up significantly and we do sometimes see multi-organ failure and, and even death in patients with severe RMSF. And you guys are probably familiar that there's these, this group of other rickett seal pathogens that is closely related to RMSF and is categorized as other spotted fever group Rickettsia species. Sometimes you'll even just see uh RMSF lumped in here and it referred to as a spotted fever group, Rickettsios. Excuse me, the clinical, um, uh, presentation is often similar to RMSF but typically less severe. So could see similar symptoms, but much less likely to see a patient admitted or going to the ICU related to it. Interestingly, we don't usually see, um, um, SRs or or local wounds at the side of the tick bite with RMSF. But you can see it with these other spotted fever group, um, Rickettsial species as as is indicated in the bottom right. And we use the same diagnostic methods for both, uh, which is serology testing, acute in convalescent paired serologies is the gold standard, uh, and then we treat with doxycycline. In terms of where we see these raquette seal infections, you can see at the bottom right that Missouri is um really in this area of darker purple, where we see more cases in Missouri and the surrounding states. We're definitely in the top 5 for this these diagnoses in the US. It's usually late spring, peaks in summer, and goes on into fall. And if you look At the top right, this is the number of cases diagnosed by year, and the main thing that changed in 2020 is the case definition. So it's not that there's less spotted fever group rickett seal infections necessarily across the US, it's just a change in reporting, so no we have to interpret those numbers with that in mind. And then in when you look in Missouri, um, you can see that the Saint Louis area definitely sees some cases of spotted fever group uh rickett seal infections, but there's um a higher concentration in the Southeast and in some of the western counties in the state, uh, that are a bit more rural. What we see in terms of the distribution of ages is similar with RMSF Ezerleuchiosis, that while we definitely see this diagnosis in young kids and young children, um, um, we see um more infections actually in adults and older aged adults. And similar to RMSF young kids, if they do get it, their risk of severe disease and complications is higher um than most adult groups. Similarly, we don't know the reason for this. In terms of diagnosis, I mentioned that serology is really the gold standard. Um, I'll try not to go too far off topic, but making diagnosis by serologist is challenging. I make interpreting serology results because you can get false negative results, you can get false positive results, you can see cross reactivity, and so it, it, it can be difficult to interpret this. Usually what we do is get acute serologies um anticipating that they'll be negative and then that allows us to compare it to uh convalescent serologies in a couple of weeks if needed. And the times when I might pursue that would be if a patient doesn't respond and clinically recover with empiric doxycycline and there's still a question about Rocky Mountain spotted fever, then I might send the convalescent serologies. But unfortunately there's not a great way to diagnose this acutely. Um, and interestingly, because the these rickett seal species and in fact the endothelial cells, they're not freely circulating in the bloodstream. And so a blood PCR like you can do for lichiosis and it's very sensitive interlichiosis is not sensitive for RMSF, which is why we can't rely on PCR testing and we're, we're stuck with serologies and in most cases. Actually just empiric treatment. Um, we use doxycycline here, uh, generally people respond in about 48, 72 hours, and the goal is to start treatment within 5 days as early as possible in the illness, but certainly within 5 days because there's this clear evidence of worse clinical outcomes if initiation of therapy is delayed. The next tick-borne illness is tulloremia, which is kind of a fun diagnosis, um, and this is caused by infection with Franciellatuorensis. The incubation period is also broad, typically, though, um, depending on the exposure source, infection occurs a few days after exposure, and the clinical phenotype is very variable. So the tick-mediated forms of tloremia are ulcero glandular. And glandular forms. So ulcerroglandular is the most common form in adults, and classically the tick bites you and then you develop regional adenopathy in that area and you develop an ulcer or SR at the side of the tick bite. So if the tick's on your head, you might see occipital or um cervical adenopathy. If the tick bites somewhere else, then you'd see a regional adenopathy there. We actually don't usually see this ulcer or um SR site in kids, so we just see the glandular form, where we see regional adenopathy in the area where um the tick bite occurred. And then of course there are these other manifestations of tulloremia that are not tickborne illnesses. So for example, if you drink contaminated water, which is pretty rare, you could get oroprynal disease, if you inhale um contaminated aerosols, you could get the demonic form. The classic story for that is, you know, rabbit, a rabbit has tuilemia, someone runs over the rabbit with their lawnmower, um, Francisellaulorensis gets aerosolized and people are exposed that way. Um, and then this is a pathogen we have to take special care with in the lab and we notify the micro lab personnel if we're ever suspicious of it, because um lab workers can be exposed and develop symptomatic disease in that setting. And then there's a an oculoglandular form which is, you know, conjunctivitis and it's adjacent to adenopathy, and the classic exposure route for there is someone is butchering an animal and then touches their eye and and therefore the Francisella is able to enter that way. Soulloremia is super interesting in the various forms, which really depend on on how the person was exposed. We don't see nearly as many cases of Tularemia in Missouri as we do ehrlichiosis or Rocky Mountain spotted fever, and certainly not too much in the St. Louis area. When you look at the last year for which we have data in Missouri, it's really sort of the southern part of the state that's where we saw the Tulloremia cases. In terms of diagnosis and treatment, so definitive diagnosis is if it grows in culture, we usually don't see that but occasionally do. And then um uh the other way to presumptively diagnose uleremia is with a paired acute and convalescent serologies. And then treatment really depends on the severity of disease, the um the location of disease, um, and, and um how well or unwell the patient is. In textbooks we treat with IV gentamicin, used to say streptomycin, but that's not really available anymore. And then there's some evidence of efficacy of oral ippro and uh doxycycline, very limited data about the efficacy, but it has been used successfully in some patients. So if it's a well appearing child who has adenopathy. And is being managed as an outpatient, you might use something like Cipro, uh, whereas if it's more severe and a patient who's febrile, um, and has significant adenopathies getting admitted, you would probably use IV checked. And then moving on to a diagnosis that is discussed a lot but not seen very often locally is Lyme disease, most commonly caused by Borrelia biorri, but can also rarely be caused by another Borrelia species. Um, the incubation period is usually about a week, if it can be as long as a month after exposure, and then of course there are these late complications that can occur months later like arthritis. We'll see oncoming maps that New England and the Upper Midwest, Great Lakes area are the areas with highest concentration of Lyme disease, and we don't consider Lyme disease endemic in Missouri or southern Illinois. It's certainly not common. There are occasional cases. Um, some of those are travel related, and some of those could be acquired locally, but it's certainly very uncommon and not a diagnosis that um we we really send testing for in a patient who has not traveled outside the St. Louis area. Like these other tickborne illnesses, the peak seasonality is midsummer, where we are now. And this heat map at the top left really shows you the concentration of cases for the year we have um uh the last year we have available data. And then the number of cases is interesting. So, OK, I should say at the bottom right, um, similarly to Rocky Mountain spotted fever, the case definition for Lyme disease changed a couple of years ago, which is why the numbers went up over the last couple of years, not necessarily indicating that there's more Lyme disease, just that we're reporting more based on the case definition. And nationally, there are about 90 cases that meet the reportable case definition, 90,000 cases that meet the reportable case definition across the country. Of those, a very small number is seen in Illinois, and most of those are in northern Illinois and a very, very small number in Missouri. So that just gives you some sense. But this is an underestimate of the number of cases and certainly many more people are treated um on the order of, you know, 4000 to 500,000 patients treated for Lyme disease each year in the US. For Missouri, um, this just again highlights that it's a pretty um infrequent diagnosis made here, um, but could be considered, especially in a patient who's traveled somewhere where Lyme is endemic, which the patients I've seen with Lyme disease had that travel history. And the clinical presentation is variable depending on timing, um, and so the kind of classic presentation is this early localized form where you see an EM rash, which is present in about 80% of cases initially but not present in up to 30%. Uh, you can have non-specific systemic symptoms like fever, malaise, um, myalgia, arthralgia, but that's not present in every patient. You also can see early disseminated disease where there's multiple EM lesions um um present throughout the body, not just one, and similarly you can have these associated non-specific systemic symptoms, but those are not always present. And then these later complications um uh can occur months later. Uh, so Lyme arthritis is something that we've seen and classically it's one joint that, um, um, you know, um, is persistently, uh, inflamed, although not, not. Like an acute uh erythematous, warm, um, septic arthritis or bacterial um arthritis, I think is what we're supposed to say now, um, and, um, it can be a little bit more indolent, a little bit more chronic, um, it's classically one large joint, the knee, for example. You can also see these um uh neurologic complications of Lyme disease and typically these occur in patients who were not treated um when they had early localized or early disseminated Lyme disease and are pretty rare in our area just because Lyme is pretty rare in our area. Importantly, the diagnosis of Lyme disease is nuanced, and so if you have something like joint fluid, uh, you can send a PCR test, and if that's positive, it's definitive, easy to interpret. Um, I don't think that the yield of skin culture is very high, um, uh, and so what we're left with most, in most cases is serology testing. And I think that for the average patient who comes in with non-specific symptoms and a recent tick bite in Missouri or Southern Illinois, Lyme should not be at the top of your differential and not necessarily something you even test for. And then importantly, um, Lyme, uh um uh serology testing is, is two-tiered. So first, there's a very sensitive but non-specific screening test, which is negative, the patient doesn't have Lyme disease and you don't need to pursue it. And if positive, you really need to wait for that confirmatory result to know if the patient has Lyme. Oftentimes when we see patients in ID clinic. They've had a positive screening, um, test, and subsequently, uh, the definitive confirmatory testing for Lyme disease is negative, which means the patient doesn't have Lyme disease, but this can be very difficult for families to understand. And then the treatment of Lyme disease really varies quite a bit depending on the patient population and the extent of disease. Importantly, um, you know, for many forms and kids, we can use amoxicillin. Um, for essentially all forms in pediatrics and adults, you can use doxycycline, including for things like um um Lyme meningitis. There is evidence that you can use doxycycline rather than IV ceftrexone. That might be the only form of meningitis that I've ever entertained oral antibiotics for, um, but something we don't see often, we do see though a lot of concern from families and difficulty in interpreting Lyme serrologies and I would, um, generally have a good reason to send line testing um in a patient because interpretation of the results can be tricky. Something we do see in our area that looks quite a bit like Lyme disease is the southern tick associated rash illness or starry, and the clinical presentation is this EM-like lesion, which you could see with Lyme. Um, some patients have no accompanying symptoms. Some have associated non-specific symptoms like fever, malaise, myalgia, GI symptoms, um, and there's no, uh, specific diagnostic test, and it's not known if you need to treat them, but because there's this clinical overlap with, um, uh, Lyme disease, um, typically patients are treated with either a. Doxicillin or doxycycline, and that's usually the approach I've taken when I see a patient who hasn't traveled here and has this EM-like lesion after a tick bite or a tick was pulled from that area. And I usually recommend it um acknowledging that this is most likely to be starry, that we don't know if there's any long-term complications associated with it, but more erring on the side of caution would typically treat. And then lastly, I don't know how often this comes up in clinic, but I find it to be a fascinating diagnosis. The first time I heard about it, I thought it was made up, but it's real. I pulled all this from the CDC website. So there's this diagnosis called alpha gal syndrome that can occur after a tick bite. And so alpha gal, I forget the, the, the full name of the molecule, uh, but it's found in most mammals, not found in humans, and it also can be found in the saliva of some ticks. And so then there are this subset of people who can have an allergic response after Exposure to alpha gal, which can occur through um tick bites, and in those individuals, they can develop allergic reactions after eating red meat in the future, or exposure to other um animal containing products like gelatin. And so these manifestations can be quite variable, and non-specific allergic symptoms, and so it's at least something to think about um in a patient who has new onset of what appears to be an allergic reaction after eating red meat and had a previous tick bite, because it's definitely something that's described. And then again, please ask questions or make comments as we go, but I will try to use the remaining time to talk a little bit about measles, uh, as this remains a hot topic, and I think something that has to remain on our differential moving forward. As you guys know, measles is not new. Measles occurs all day, every day across the globe, um, and that has not changed, um, you know, in the past several years. What's unique this year is the number of cases in the US. As you can see in the figure on the right, we've had more cases diagnosed this year in the US than in any year in the past 30+ years. And the initial outbreak really was clustered in in West Texas and New Mexico, but there have been outbreaks and clusters, as well as just spontaneous cases occurring in, you know, 40 jurisdictions across the country, including Missouri, over 1300 total cases. Um, importantly, the CDC uh defines an outbreak as 3 or more related cases, so some of these outbreaks are pretty small. Uh, most of the cases are pediatric, which is what we'd expect. Uh, sadly, there have been 3 deaths and the vast majority of cases and, and all the 3 deaths were in unvaccinated individuals. The good news is that um the outbreak certainly centered in in West Texas and New Mexico seems to have slowed. This is the number of new cases by week over time, and you can see that we've gone down from the peak, you know, earlier this late spring, um, but we're still seeing more cases than we would in a typical week, in a typical year, um, and cases have continued to pop up, including in Missouri. So we've now had 7 confirmed cases of measles in Missouri, none in St. Louis proper. We had that exposure event, which you all remember fondly, I'm sure, and we did provide post-exposure prophylaxis to a handful of of infants who were possibly exposed as part of that, but had no no secondary cases diagnosed. There was one earlier on in in the um Branson area, one in southeast Missouri. And then more recently there have been 5 cases in Cedar County. Um, there's been very little information released from the health departments about this, and this is largely because it's occurred in a community that is pretty closed off and um with very low vaccination rates and does not really interact with the health department. And so it was a bit of a challenge to make those diagnoses and the sense is that there were many more cases that weren't confirmed and a couple Of those patients were hospitalized. Um, 4 of the 5 were in one family. The last one that was diagnosed was not in the family, but a contact of that family. And again, the suspicion is that there were more cases associated with this, and these are in pretty recent weeks, end of June, beginning of July. And so I think it just sort of underscores that we remain at risk of seeing patients with measles in our area. And the reason that this is so important is because of how transmissible uh measles is. So on average, one case of measles infects 12 to 18 secondary cases. The fastest on average, and you can see as many as 40 secondary cases from one measles case. Um, importantly, um, if you're not immune, your risk after exposure is quite high, so there's a 90% attack rate after exposure in non-immune individuals. Luckily, or yeah, luckily, fortunately, um, vaccination is really effective. So if you've received two doses of MMR, um, uh, the vaccine efficacy is about 97%, which is great. The symptoms in a um non-immune patient are pretty predictable. So start with really non-specific symptoms like low grade fever, the three Cs, which are cough, charizo, or runny nose, and conjunctivitis. You could see colic spots, um, and then it's really on days 2 to 5 that you start to see this rash, uh, which, uh, as you guys know, classically starts on the face, scalp, head, and then spreads from there. Um, of course, there's a lot of overlap with other diagnoses we see commonly, especially HHV 6, right? Um, and so what we're still using in our area is both compatible symptoms and something that puts the patient at risk, either being unvaccinated or having had um a potential exposure to measles to really raise our suspicion for measles in our area right now. I think that these pictures of the rash, um, are, are very familiar to you guys, and I think if people saw a dramatic rash like this in, in a very light pigmented individual, um, they would recognize it. Um, but importantly, the rash can be variable depending on age, um, immune status, um. A skin pigmentation and so it's important to keep this on your list of things, um, a list of differential, especially in an unvaccinated patient, which includes, you know, essentially all kids less than 12 months of age that we see and any beyond that who have either not been vaccinated or who are immunocompromised and therefore may not have long term immunity. And the other reason we talk about this so much is not only because it's contagious, but because there are complications in a in a sizable proportion of patients. So something like 20% on average get hospitalized, 1 out of 20 get pneumonia, and then about 1 out of 1000 get encephalitis and or die. Um, and the encephalitis can be um dramatic uh with long term disability. So while most patients recover, um, but these do get complications, they can be severe. We continue to recommend routine MMR vaccination for our area, um, uh, which includes the two dose schedule recommended for children. Um, there are these special circumstances for which you could give it, uh, early, like if the patient is going to travel to an area where measles is endemic. Um, and then the recommendations for adults depends a little bit on their age and their prior vaccination status. Generally speaking, if born before 1958, you're considered immune because you likely got measles. Um, if you were vaccinated in the early 1960s, when there were two vaccine products. Including an in inactivated vaccine, which was not as effective, you might need another dose, but most people after 1968 who got one or two MMR vaccines are considered protected and don't need any, any further um doses and don't need serology testing. I think this question came up a lot from families and was discussed a lot in your all's offices, um, whether or not early vaccination should be considered, and unless the local epidemiology changes for measles activity, it's not recommended to give doses early, especially the first dose just because there is evidence of less less robust immune response if the first dose is given early. And then in terms of titers, this came up a lot from adult practitioners and employees, so I just thought I'd mention it. Sending antibody titers for measles is not an effective way to assess immunity. Really, uh, documenting immunization status is best. Um, you could have a negative, uh, tighter and still be still have cellular immunity that provides protection. So, um, and it can be expensive. So I think if someone is unsure if they were ever vaccinated, you can, and they're really interested in getting titers, you could do it if they're detected. I think that provides some reassurance. An alternative approach is, if they don't know they've been vaccinated, just give them a dose of MMR. And if they've been vaccinated, I think providing reassurance that, look, you're vaccinated, and it's a highly effective vaccine with long-term durable immunity, so you don't need to get, um, Um, uh, you don't need to get titers. In terms of the question, the chat about uh prophylactic antibiotics, if a patient presents with a tick bite, so if they're asymptomatic and their tick bite occurred in the St. Louis area, um, you don't need to give antibiotic prophylaxis. But if a patient is within 72 hours of their tick bite and the tick bite occurred in the Lyme endemic area like New England. Um, you know, upper Wisconsin, the upper Midwest, then, uh, you'd give a dose of doxycycline. So really only for those uh bitten in a in a Lyme endemic area. And then I'll just mention briefly something that you guys already know, but I like looking at these numbers. The reason we're seeing measles activity increase and why we have these at-risk populations is because they've been declining vaccination rates, as you guys know very well and face every day. Um, so this is average Missouri kindergarten vaccine coverage data. You can see on the upper left for public schools over the past several years, upper right for private schools over the past several years, and what I have highlighted in the green box are the MMR coverage rates. So you can see in 2019 to 2020, about 95% of kids in public schools had received age appropriate MMR vaccination. That's down to about 91% a couple of years ago. On the right side in private schools, it started lower, about 92%. It's come down even more, 85%, and this is primarily driven by religious and philosophical exemptions, and these are just average numbers, so there are pockets with even lower uh vaccine coverage like Saint Louis City, which has about 75% um um MMR vaccine coverage for kindergartners. So. Um, I think we're gonna continue to see measles moving forward unless this changes and and other vaccine preventable illnesses as well. I think for the sake of time, I will, um, um.
