CSD/B. henselae

Pre-Med & Medical School High School Student Topics
1

<p>High School Life was unable to answer this for me so...</p>

<p>My friends are having a debate. One is saying that preventing Cat Scratch Disease (and B. henselae, the causative agent) in humans is a huge thing in medical society and one says that it isn't. They've been at it for a while. What do you think?</p>

<p>Statistics:
Annual health expenditure on CSD in US alone: 12 million dollars (not including costs of ICU for bacillary angiomatosis/peliosis, Peliosis hepatis)
4-98% of cats (dependent on region) have B. henselae, the causative agent of CSD</p>

<p>CSD is also related with tonsillitis, encephalitis, hepatitis, pneumonia, and other serious diseases (bacillary angiomatosis, peliosis hepatis, etc).</p>

<p>Thanks in advance!</p>

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<p>lol Cat scratch disease? </p>

<p>I don’t think the medical community is wasting much effort on CSD. The disease primarily affects kids and adolescents, who are generally healthy members of the community. It’s usually self-limited with very little long term sequalae. And abx have not really been shown to be much use in healthy hosts. For the most part, you just let them ride out the disease. It’s one of those diseases you learn about for boards and forget about a few days later.</p>

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<p>^Actually, studies have shown that adults are equally as prone to the disease as children. CSD is also a major problem with immunocompromised patients and people, which is why they avoid cats. But thanks!</p>

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<p>By that definition, immunocompromised people should just stay in their room and never leave. They could step on a nail and get pseudomonas osteomyelitis or encounter an immigrant and get disseminated TB. I’ve never heard of immunocompromised people being advised to avoid nails or foreigners. You just have to be careful. Almost any infection is more serious in someone who is immunocompromised. Cat scratch disease is hardly an AIDS defining illness lol</p>

<p>This is a disease that accounts for very little mortality and very few hospitalizations. We already have good detection methods for Bartonella henselae and very good treatments for it. What exactly should the medical community focus its efforts on? Telling people to declaw their damn cats should probably be more effective.</p>

<p>When entering into a discussion about medicine, I think it’s important to know the epidemiology behind what you’re talking about. Have there been case reports of pneumonia or encephalitis caused by CSD? Probably. Disseminated Bartonella disease in an AIDS patient with a 50 CD4 count is not going to stir the medical community up. If tomorrow I raised CSD as a possible cause of pneumonia in my patient, that’ll be good for a laugh from the attending. Students often jump too quickly to the zebras when they hear hoof steps. An understanding of epidemiology would really help them understand the landscape of medicine better.</p>

<p>For example, I never said adults are less susceptible to CSD than kids. But, this will mainly remain a pediatric illness because adults aren’t dumb enough to get a cat scratch them and likely won’t be spending inordinate amounts of time playing with kittens. Hence, if you truly want to decrease the incidence of CSD, do some cat education in the community. Doctors aren’t going to care about this. It’s not a medical issue. It’s a case of parents letting their kids play with dangerous animals.</p>

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<p>You seem to be one of those people that think that they are great enough to choose which diseases should be researched on and shouldn’t. The case is that a stifling number of cats all over the world are bacteremic with B. henselae and will cause harm even if it’s not fatal. (Also, B. henselae causes bacillary angiomatosis and peliosis hepatis, fatal conditions that require fast treatment, in immunocompromised patients)</p>

<p>I only mentioned that CSD has had relations with the different types of serious illnesses, because they exist. There have been multiple clinical evaluations that establish clear relationships between CSD and those diseases (while it is not prevalent). It’s not enough to be a cause but as they are related, it still would be significant to root this out in humans and society. Prevention would mean that less people would have to go to the hospital, etc.</p>

<p>“What exactly should the medical community focus its efforts on? Telling people to declaw their damn cats should probably be more effective.”
REALLY? because declawing all the cats in the world isn’t going to happen. Why don’t you tell patients with the cold not to breathe? Some things are simply not controllable. No doubt you think that the medical community should focus its efforts on diabetes, cancer, AIDS, etc. because they kill. Well, B. henselae kills too. I’m wondering if you are an expert in B. henselae and CSD when you speak with this much of a condescending manner.</p>

<p>You haven’t heard of any advices to immunocompromised patients about nails or foreigners because those threats are negligible. That would be like saying “You don’t want AIDS so don’t have sex.” There are plenty of articles on the web etc. that warn AIDS/HIV/cancer patients against cats and lice (carriers of Bartonella species). There is also a study (published work) that shows that there are more adults that were infected with B. henselae than previously thought. I’ll try to find it and link it.</p>

<p>And I’m sure that you’re so important that you can say what’s important and what’s not. I did ask for opinion but your tone and contempt for the topic is ridiculous. If you’re a doctor, I’m very disappointed. There are plenty of doctors and researchers out there researching B. henselae and trying to solve problems related to it, my friend (HS student) included. It IS a medical issue and doctors DO care about it. I’m sure that it’s a case of parents letting kids play with dangerous animals, because cats are SO dangerous.</p>

<p>If it’s not a medical issue, what is it? No offense, but you’re ridiculous. I’m a high school student so I wouldn’t know as many medical terms or jargon than you. Hell, I don’t even know any specificities that you mention in your above posts. But I really hope that you change the way you think by the time you get to med school and become a doctor. Again, no offense. I’m just ticked off by the way you think that adults “aren’t dumb enough to get a cat scratch on them,” how B. henselae and its manifestation aren’t “a medical issue,” and how “doctors aren’t going to care about this.” Just to clear things up. If you read my OP, I was asking for opinions not just on CSD but all manifestations and implications of B. henselae. (sorry if I didn’t make that clear enough for you)</p>

<p>Thanks for the feedback.</p>

<p>[Answers.com</a> - How many cats are kept as pets in the world](<a href=“Answers - The Most Trusted Place for Answering Life's Questions”>How many cats are kept as pets in the world? - Answers)</p>

<p><a href=“http://www.nytimes.com/1997/12/25/us/national-news-briefs-cats-and-lice-pose-threat-to-aids-patients.html[/url]”>http://www.nytimes.com/1997/12/25/us/national-news-briefs-cats-and-lice-pose-threat-to-aids-patients.html&lt;/a&gt;&lt;/p&gt;

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<p>I find it interesting that you make a post asking for opinions and yet get so defensive. lol </p>

<p>It’s an interesting disease but not one that makes much of a medical impact. Are there people doing research on it? Probably. Is it the most critical research going on in an AIDs patient? No. There are literally dozens of diseases (PCP pneumonia, Kaposi’s sarcoma, cervical cancer, Cryptococcal meningitis, etc.) that are predominantly found in AIDs patients. You don’t extend their life expectancy by trying to cure each disease. You extend it by curing or controlling AIDs. HAART therapy is why AIDs patients live longer today, not avoiding cats. </p>

<p>Again, what exactly do you want the medical community to focus on? When treating a disease, we want a good detection method for it and a good treatment for it. We already have decent detection methods for B. hensalae and we have a multitude of abx with activity against that organism. You can give doxycycline or azithromycin (although azithromycin is awfully expensive to be wasting on a self-limited disease). It’s controversial whether we should even be treating CSD in normal, healthy people.</p>

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<p>I will also say that I’m not a cat lover nor someone with AIDs. For the majority of the medical community, CSD is more trivia than anything.</p>

<p>However, for certain people who are interested in cats or AIDs patients, they may have some interest in the disease. One thing I’ve learned is that professors are very quirky in what they end up researching for their career. They’re academics for a reason. They’re interested in learning about something or answering a question. What they research is not always what is most cost effective or what is most useful. It is simply what is most interesting to them.</p>

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<p>^ and ^^ LOL. That’s not what you said in the first place.</p>

<p>I’m talking about PREVENTING CSD not treating it. Prevention is a completely different thing. I also mentioned that I’m not just talking about CSD but other B. henselae manifestations as well. You seem to think that B. henselae only manifests in “harmless” CSD, which is ridiculous. For example, bacillary angiomatosis was thought to be kaposi’s sarcoma in one patient until biopsies showed otherwise. Thus, there ARE B. henselae manifestations that ARE AIDS defining. And yes, we are trying to cure AIDS. Have we done it yet? No. What are we spending out time doing instead? Trying to prevent it.</p>

<p>Yes, people aren’t avoiding cats, which is more the reason to prevent B. henselae manifestations in humans (through likes of feline vaccines etc).</p>

<p>Wait what did you say was controversial? Are you serious? You’re debating whether to treat infections in people because that infection doesn’t kill? Wow. Just WOW.</p>

<p>“What they research is not always what is most cost effective or what is most useful.”
Here’s what every professor I’ve met has told me, which is including a Nobel laureate that discovered the first oncogene. “We conduct research on our respective fields and subjects because we believe that they are important in the medical field and that further knowledge regarding them will be crucial.” Don’t think you can go around talking about what’s important and what’s not, because apparently, you aren’t a doctor yet.</p>

<p>Why am I so defensive? Because your attitude ****es me off (again, no offense). There are so many snobby “I know what’s important and what’s not” a-holes out there that think that they can determine which subjects are important and which aren’t. If I may, let me say something: You don’t. And you shouldn’t pretend like you should. My friend, who is conducting research on BH, has had her grandmother die due to a B. henselae infection (bacillary angiomatosis). So who are you to say what you’re saying? Again, your behavior preposterous at the least. I’m sorry if I offended you. But again, I really think you should either reconsider being a doctor (even though it’s not really my place to say that) or get your info straight.</p>

<p>Again, thanks for the post.</p>

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<p>Thread: “Hi, I have a question. What do you think? By the way, if you disagree with me, I am going to rant and rave at you in a very insulting manner.”</p>

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<p>^It’s because the poster doesn’t even know what he’s talking about. It’s ridiculous because he’s saying the most extreme (and wrong) things.</p>

<p>and if you notice, I didn’t “rant and rave” at him the first time but after his second post, which is full of the most condescending and untrue statements. So yes, naturally, I had to “rant and rave.”</p>

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<p>You asked for an opinion and I gave you my opinion. The epidemiology of a disease has medical as well as social and economic components. I never said that medically or biologically adults are less susceptible to CSD. But, most of the patients who develop CSD will be kids and adolescents because they are the ones playing with cats the most and for the most part, those patients aren’t going to be immunocompromised or have AIDs. I think you would agree with me that CSD in a healthy person is a very benign disease (if you disagree with this statement, please show me the morbidity and mortality risk in healthy hosts of Bartonella). </p>

<p>The worry is about disseminated disease in AIDs patients. In that case, I honestly and truly believe that education about avoiding cats, about declawing your cats, and de-fleaing your cats is a better and more cost-effective way to lower the incidence of CSD, bacillary angiomatosis, and whatever other sequalae that may result than any medical research we do.</p>

<p>I am not a doctor. I am a student like you. You have a lot of knowledge about CSD but very little knowledge about medical diseases in general and about allocation of medical resources. I’m just trying to put CSD into perspective for you. If I was condescending, I apologize. It’s just I haven’t seen or heard about CSD since my boards and the last place I expected to be talking about it is on CC.</p>

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<p>Also, if it’s you and not your “friend” who’s interested in CSD, just say so in your first post. I would have tempered my comments had I known that you were the one who was defending medical research for CSD. I get that you probably wanted to have some anonymity in hopes of eliciting the most unbiased opinions as possible (although the tone of your first post is anything but unbiased) but if you’re going to do that, you are going to have to deal with very frank and candid opinions. </p>

<p>Your argument is done by painting this picture of horrific CSD disease. Most of the complications you point out only happen in AIDs patients once their CD 4 count is down to 50-100. Once someone’s CD 4 count gets down to that level all bets are off. They can get Strep pneumoniae meningitis from just a sinus infection or an ear infection for example.</p>

<p>The last thing, I think it’s inaccurate to say that AIDs patients are advised to avoid cats because of fears of CSD. They are advised to avoid cats because of fears of toxoplasmosis, which has much more of an impact on the AIDs community than CSD.</p>

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<p>It IS my friend who is interested in CSD. Apparently you didn’t read that my friend does research on henselae. I’m fired up because of your attitude. I read your opinion the first time. I wonder why you had to go and say that csd isn’t a medical issue and that doctors aren’t interested in it. </p>

<p>Why is it biased to state facts? First of all $12m isn’t much. Maybe I should have mentioned that csd isn’t fatal. But isn’t that well known? Your opinion isn’t frank and candid. It’s misrepresented. Apparently, you didn’t know ppl worked on b henselae and that it’s fatal in some ppl. There have been clinical cases where immunocompetent ppl have developed fatal complications of BH. As fir your last comment, please read that ny times article I linked.</p>

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<p>Wow…this thread is more than a little surprising.</p>

<p>As a pediatrician (yes I am a doctor), I actually do see the occasional CSD case. I’ve diagnosed about 4 cases and sent off for titers probably another half dozen. In each case the family is most concerned by the fact that the child has had a fever for a week to ten days, or in some cases even longer. Occasionally they’ll actually be concerned about a palpable lymph node. They usually have been to see their PCP or another urgent care center at least once. </p>

<p>But the important point is that I only begin asking about CSD risk factors when I have a case that just doesn’t make much sense. But in the same breath, this is also the sort of case (depending on age), where I’m also starting to question a bunch of other bizarre things - immunodeficiencies, strange forms of cystic fibrosis, and tick borne illnesses. In fact, if the lymphadenopathy is notable, I’ll probably start entertaining thoughts of lymphoma before I think about CSD…that should tell you something (though it’s mostly due to the fact that I’m a resident and at a tertiary care referral center, so new cancer diagnoses happen much more frequently in our ED than if I were a general pediatrician in private practice). </p>

<p>But the reason why CSD is so far down on the list is a matter of what we call pre-test probability. This is what NCG is getting at with his discussion of epidemiology. In other words, if you put a febrile child in front of me, common things are common, and the likelihood of this patient having CSD is very low. So before I’ve done any tests that are going to push me towards a diagnosis, the pre-test probability directs my clinical decision making. That makes it a more efficient use of my time, the hospital resources, and even the patient’s time to focus on conditions that a) more likely to be responsible and b) represent something more “dangerous”. A child with MRSA pneumonia can require mechanical ventilation and Pediatric Intensive Care Unit management. a patient in septic shock may decompensate and die in the ER, an undiagnosed urinary tract infection may result in pyelonephritis leading to long term kidney damage and possibly chronic dialysis. Drawing Bartonella titers or PCR’s that aren’t going to come back for several days (they only run the Bartonella PCR once a week at my hospital), on every kid with a fever is going to be very, very low yield, and not be worth the time and money.</p>

<p>So when you a have disease that is uncommon to trigger a physician eval (the AAP Red Book says the true incidence is unknown) + even rarer complication rate = lots of physicians not caring. </p>

<p>Does that mean your friend is wrong for working on Bartonella? No, perhaps he’ll find the breakthrough that proves that CSD has a far greater disease burden than expected, that maybe we should be paying more attention to it. Maybe he’ll be the one who links Bartonella exposure to childhood obesity or development of Type 2 Diabetes in adulthood, that’s how medical research works. But on the other hand, he could just as likely spend his whole life working with Bartonella and not find a shred of evidence that affects public health policy here or abroad. So as it stands now, your other friend who feels this isn’t a big deal is much more in line with current medical thinking.</p>

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<p>Not just a low pre-test probability. Even if you “miss” a CSD diagnosis, it’s unlikely to lead to any harm in a kid (the literature I’ve read say there’s limited benefit to treating CSD in immunocompetent individuals). </p>

<p>If a kid shows up with lymph nodes and fever, I’m thinking hand-foot-mouth, Strep, mono, viral URI. Unless there’s an obvious Hx of cat scratches, CSD just doesn’t come up on the differential. </p>

<p>It’s a bigger issue among AIDs patients. But, even with them, I highly doubt too many physicians are asking about cat scratches. It’s a disease with relatively low mortality and morbidity risk right now.</p>

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<p>The key difference is that these children generally show up with an extended history of fever and few if any other symptoms. They don’t have the associated symptoms you’d expect and have gone past the anticipated course of what you’ve listed and even those are self limited. At least with CSD, you can offer antibiotics, which often times is enough to make parents feel better (yes, unfortunately that is often way more important in pediatrics than anything else - just another reason why I’m going into critical care, at least those kids are sicker than snot).</p>

<p>As a further educational point for the medical students: if something is not on your differential, you’re not going to ask the right questions. I’d say that only one case I’ve had did they actually mention a cat scratch. And I, as part of my social history, ALWAYS ask about pets, and even that misses the key info. (2 of 4 cases I’ve treated, the kittens were at a friend’s house).</p>

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<p>I want to ask something. Wouldn’t it be better to get rid of a causative agent of rare but serious complications before there is proof showing that the agent causes more damage than previously thought? I mean, is it necessary for someone to find something about a disease before we find something more detrimental about it? Just wondering.</p>

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<p>How would you propose to get rid of the causative agent?</p>

<p>Somehow figure out to make an entire line of bacteria extinct? Has that every been accomplished in the history of medical science – I’m not sure it’s even possible due to mutation and resistance mechanisms. In the attempt you could take something that is fairly innocuous and end up with “The Stand” or “Resident Evil VII.”</p>

<p>The only infection of any cause I can think of that is for most intent is extinct is Smallpox and one of huge reasons it could be is the lack of a non-human carrier host. Get rid of all the cats and hope the cure isn’t worse than the disease (and I hate cats)? </p>

<p>If you could accomplish such a thing, why not work on something that causes death and disability multiple order of magnitude greater than CSD.</p>

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<p>^The reservoir for B. henselae is in cats. Thus, creating a feline vaccine would cut off the link between the arthropod vector (cat fleas) and humans. That is, of course, assuming that every household/stray cat is vaccinated, which could prove difficult. But it’s a start. It’s not eradicating the bacteria. It’s cutting it off from getting to humans. Also, like I mentioned previously, B. henselae doesn’t only cause CSD but other fatal diseases that are not very proliferate in immunocompetent people (while still possible) but a serious danger to immunocompromised people.</p>

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<p>Blocking the agent and getting rid of it are different things. </p>

<p>Medical and Scientific barriers:
First vaccines are odd things and it’s not always possible to get them to work - would it be a one time or recurring vaccine. There have been many diseases with far more deadly/damaging consequences that have been immune so far to prevention methods including vaccines. </p>

<p>Political, Social, and Financial Barriers:
Even if the vaccine worked (and continued to be effective over time). The cost of vaccinating hundreds of millions of cats nationwide/worldwide to eliminate a spectrum of diseases that cause a relatively tiny amount of mortality/morbidity. Could those research and treatment dollars be far more effectively utilized. Even if the vaccine were 100% effective and free, who/how would the distribution be accomplished.</p>