Disease Transmission(40 posts)
Now that i have gone months without any bites after moving from my bug infested apartment, i've been wondering about disease transmission. i know that the common knowledge is that they do not transmit disease, though they can "harbor" it. But how definitive is that knowledge/research? I have read some other speculation that maybe they can spread a whole rack of diseases.
I lived in a building with drug addicts, some of whom may have had hepatitis or HIV, and I am concerned that bugs may have bitten me after biting the addicts. Is this a reasonable concern? What other bedbug version of rocky mountain fever or chagas is just waiting to be discovered?
My general worry is Wolbachia is a potential health threat, but I haven't seen anything conclusive from anywhere about any pathogens introduced from BBs to humans.
While science and medicine both are enhanced by discoveries;to date according to
the reliable health resources we have such as CDC and WHO there has been no case of bed bugs acting as vectors. Hepatitis is one of the diseases on which several studies have been done and to date they have all showed the bed bug negative for transmitting it.
Sometimes unless a threat is known you have to have a don't worry be happy approach.
I know when I studied parasitology I was terrified of sushi for weeks but it passed and
so far so good.
I love sushi but only eat it one or two times a year partially due to the MSG but basically I do not think it wise to eat uncooked fish these days because of the parasite problem. I wonder if the claim that bbs do not spread disease exists partially because of what appears as a lack of knowledge due to the fact that bbs have not been an epidemic for sixty years or more in the U.S. and also that maybe the professionals do not wish to start a scare but every entomologist that I have spoken with and it has been many would not bet their life savings on the statement that they do not spread disease. What will the future bring?
I wish one professional would explain exactly why and how a bb cannot spread disease.
"I wish one professional would explain exactly why and how a bb cannot spread disease." I think that will only happen when we fully understand the mechanism of biting, until then we can only make the most accurate statements possible, in my case that is definatly that I am not aware of any information with regards bed bugs being effective vectors of disease transmission between people.
I think this is partly due to the mechanism of biting and partly due to the fact of the method they use to reproduce. Traumatic insemination is a risky strategy for any organism. If you think of a human adult walking around with the equivilant of a coffee mug sized piece of skin missing from the middle of your back its a fair analogy.
Evolution have forced the bed bug to develop a way of avoiding infection into this wound site. I was told by en entomologist a few years ago that after feeding they will purge the body with some compound (maybe anti-viral and anti-bacterial) to cleanse the system ready for mating. Few bacteria and viruses of major health concern will survive outside of the body for long and I suspect this is a contributing factor as well.
Simple fact is we know the genome of a human being and several other species on this planet but when it comes down to insect research its still not a well funded area of research and although there are many areas that need studying there is a limit to what money is available to fund research.
Maybe a little lobbying to the scientific research funding bodies will result in some answers. I know when I graduated as a molecular biologist in 92 there was little funding in the UK for anything other than HIV research, they do listen to world issues when needed.
Another angle that I wonder about is when a BB gets smashed, would the risk of disease transmission be possible? I used to use a bug light zapper and heard that when the bugs explode, that it greatly increases the risk of diseases. Even with house flies,I cringe at the thought of using a flyswatter anymore, for that very reason. I've been told about ticks, that even touching them can possibly transfer disease.
Hate to add to such a somber and potentially frightening aspect of bedbugs, but I for one cannot understand how ticks, mosquitos, and fleas are capable of transmitting diseases but not bedbugs. Of course, I know absolutely nothing about entomology, but would love to find out why this is the case.
BBs don't conduct pathogens to humans because BBs are really angels, just in a form we didn't expect. They convey a sense of humility to all humans and remind them to turn from their arrogant and conceited ways. And hence, as an agent of good are not really sent to do us harm but only to prod and poke us.
Bed bugs are fully capable of transmitting disease, they just have not done it yet.
As a scientist I refuse to believe that it will never happen. The mechanism exists, but the best guess that we have is that there is something in the saliva that is preventing the transfer of disease.
If this is in fact the limiting factor it is only a matter of time in my humble opinion before a pathogen adapts to, mutates, or circumvents the barrier.
Rasputin wrote: but I for one cannot understand how ticks, mosquitos, and fleas are capable of transmitting diseases but not bedbugs.
Well, all those bugs transmit different diseases. I guess you'd have to consider the unique biology of each insect and of the disease it transfers.
David wrote: "Few bacteria and viruses of major health concern will survive outside of the body for long and I suspect this is a contributing factor as well."
That's a good point. HIV, for example, does not survive long outside the human body, that's one reason why you can't catch it from casual contact. If a healthy BB will feed every four days or so, I think the chance of transmitting those kinds of viruses is pretty low if not nonexistent.
Jerome Goddard did an audio podcast last December for Pest Control Magazine on this subject. I have the podcast on my hard drive, but I have not been able to locate the link. Maybe someone here on the forum has the link. He discusses the possibility of mechanical transmission.
Mechanical transmission could be described as the crawling dirty hypodermic needle theory. The idea is that a virus could reside on the bed bugs mouth parts & be transmitted like a dirty needle stick. Dr. Goddard did a presentation on bed bugs last year in Washington DC. He pointed out that hospitals track disease transmission from accidental needle sticks & have found roughly a 2% transmission rate.
I question whether our public health surveillance systems would be sensitive enough to detect a 2% or lower rate of transmission, if bed bugs were a vector. Only a small percentage of skin specialists were able to identify a bed bug bite from a photo in a recent study.
I think we would be able to detect the correlation if it was a high transmission rate, but what if it was a very low transmission rate like one half of a percent?
Dr. Goddard stated that he does not believe bed bugs play a significant role in disease transmission.
As David Cain said earlier this is "still not a well funded area of research".
I have to agree with Lt Dan's statement "I wonder if the claim that bbs do not spread disease exists partially because of what appears as a lack of knowledge due to the fact that bbs have not been an epidemic for sixty years or more in the U.S."
There have been some limited animal research with chimps and Hepatitis B that was discussed by Dr Goddard. The researchers were unable to transmit Hepatitis B from bed bugs that were fed on Hepatitis B positive blood to the chimps. They also found that the virus did not seem to be able replicate after being consumed by the bed bugs.
Just like not all species of mosquitoes are vectors for Malaria or West Nile Virus, I don't believe that we can completely rule out the possibility of any disease transmission from bed bugs at this time based on the limited research studies that have been performed. The best we can say is that it has not been documented by modern research.
Charles Campbell wrote a paper that claimed that bed bugs spread Smallpox in the early 1900's based on a series of ethically challenged experiments on human beings, but I don't believe that his findings have ever been replicated by any modern researchers. These days Smallpox only exists in a few bio-warfare labs & that research is likely classified.
I have read that up to thirty different diseases have been identified in bed bugs. I am not sure that anyone has extensively studied whether a crushed bed bug or bed bug feces could transmit a disease to an open wound on a human being, which would be another form of mechanical transmission.
Still, I think Dr. Goddard stated it best when he said that bed bugs do not appear to play a significant role in disease transmission for public health.
I went to a bedbug conference and they said that there had been some studies done specifically on bedbugs and hepatitis transmission and they couldn't find any "vectors" yet. That's a good sign since hepatitis is so easily and quickly transmitted. However, a few studies don't prove much. They don't know much about bedbugs since they were nearly totally eradicated from this country by the Fifties and hence haven't been studied. Mosquitoes are known to kill people and they do every year in this country, even in my state of Massachusetts, but we still have the problem of mosquitoes. Bedbugs lag far behind. With mosquitoes they tell people "Don't go out at dusk and in the evening." What are we supposed to tell people with bedbugs? "Don't go to bed?"
I think it's here. (Pest Management Professional, formerly Pest Control magazine)
And for those interested, there's the source for the 70%/30% don't react/react factoid -- okay so now we have to find that paper as the question of what that source was has come up before.
This is a PCT article by Goddard: http://pctonline.com/articles/article.asp?ID=2052&IssueID=74
And another on Medscape (login required):
Has Goddard provided expert witness testimony in bedbug lawsuits? The podcast seems to suggest that. (If yes, I guess there's no need to ask on which side.)
Goddard states in the podcast that in the cases he has seen, the testimony about disease transmission was suppressed by the judge due to the lack of scientific consensus.
Sorry, Doug, I just listened to it in a noisy location but I heard "lawsuits that you have been involved with" implying that he's had a role, whatever the judges' ruling. I note he closes his articles with comments about lawyers. We all like to pick on lawyers, but in this context, those comments are jarring.
But I'll listen to it again.
My long-standing concern with Goddard has been his public dismissal of bedbugs as a public health concern. He is not the type of public health official who will play a useful role in the future, when, as a society, we will need public health officials everywhere to help, to at least take notice and play, not stay in the sidelines.
In that sense, it is disappointing that he is the go-to authority on the question of disease transmission. Not because I want him to be wrong, absolutely not. But because we have seen other public health officials and urban pest experts at least acknowledge that public health surveillance would be a good idea and, more important, actually support the idea that there is a public health interest and that education, monitoring and the sensible tools of epidemiology can make a difference.
Public health has a role to play here, a vital one. If we want to advocate for such a role, it is not to the Goddards in the current landscape that we must look to.
I guess no one took my Wolbachia bait, or they all think I am deluded, and maybe I am, being affected by BBs.
Since the Wolbachia bacteria are in many insects including bedbugs, and since humans can react strongly to Wolbachia, being the cause for example of African River blindness (Onchocerciasis), where is the research into possible Wolbachia human health risks from BBs?
Wolbachia are nasty. They slice into the insects genes and alter the genders of populations to achieve survival. I wonder that some severe human allergic response to BBs are the result of Wolbachia immune response intead, not only BB salival proteins.
There's lot's to do to research BBs as they become as common as mosquitoes, and poassibly as risky to human health.
Thanks for the link.
You are absolutely correct. The moderator uses the term "seen". Dr. Goddard uses the phrase "been involved in" twice. I paraphrased the comment incorrectly.
Hi Doug, no I thank you for suggesting it and for your comments above! I'd never listened to it before, only read his articles.
I just listened to it again and want to make sure to quote correctly. This was the question asked:
"I know you've been an expert witness in several bedbug lawsuits, what are some of the medical issues that you've seen raised in the lawsuits you've been involved in?"
To be honest, I formed my bad impression when I read what he said in a news story in the Mississippi Sun Herald in May (now no longer available online). In that newspaper article, one of those generic 'bedbugs are back' pieces, he was quoted as saying that bites were "no big deal" and also said something like "most of us" will never get bedbugs.
As it is, I have to stand by my cranky take.
I did see your Wolbachia reference but since you and I have batted it around and I'm still scared, I left the fun to those who are stronger. I see you've done more reading.
I'm actually profoundly relieved that we can't get diseases from bedbugs, as far as we know at this point. My issue is only with the larger public policy implications.
Thanks Doug and H'nomo--I blogged those three podcase links from PMP--should appear tomorrow night. All of this is not new but "new to me" and most readers.
If I were an official and my job was to monitor and care for the well being of the people of the city under my jurasdiction than I would be very concerned with the fact that bed bugs have become a growing epidemic that effects the health of people in many ways even though they are not considerd at this time to spread disease.
Should something that greatly effects the mental health and well being be considered a disease?
We know that bed bug infestations places a large financial burden on most people and it effects peoples mental and physical health which also effects their job responsibilities due to the stress and lack of sleep that most people experience. For example someone like a bus driver or train operator who has the responsibility of transporting people, I can imagine that safety can then be an issue.
"If I were an official and my job was to monitor and care for the well being of the people of the city under my jurasdiction..."
Sadly, my first response to this was that I don't think the mayor where I live gives a hoot about my well-being, unless people are dying or becoming seriously ill AND there's a clear reason why.
Now, caring for the bottom line, that's another story.
Jim Goddard is exactly one of the types of folks you need in a true public health
program. Please don't get me wrong here I am not trying to minimize the plague of bed bugs but in an objective true public heath management scenario it is not "THE PLAGUE" (Yersinia pestis), malaria, encephalitis and other arboviruses which have killed millions and which continue to kill. It is not Lyme,Dengue,Tick Borne Rocky Mountain or Yellow fever. Not to mention the many non arbovirus malady's that face us everyday.
Again I am not minimizing just trying to keep a perspective based on actual morbidity, mortality and limited public health resources. Dr. Goddard is on the look out for
things you don't want to think about, read about some of the health issues caused by Katrina and the accompanying resource issues. Check out, although you probably can't, NYCs Plague scenario.
As for the attitude of they are vectors we just don't know it yet, with no disrespect meant this is similar to the attitude that enabled the current level of bed bug infestation. Well since an insecticide has not be proved to be a carcinogen and even though there is no evidence to lead us in the direction that it is, lets ban or limit its use because we can't prove its not.
There have been many studies over the years even some scientifically and morally questionable ones, but the overall facts as we know them are that bed bugs are not vectors. (Politicians on the other hand ..)
And as such will only get so much of the public health budget pie. For those of you misguided folks who wish that bed bugs would become vectors, you get a lump of coal.
Again please don't lynch me for trying to maintain an overall perspective.
1. Because I am not minimizing the suffering, expense our quality of life attributable to bed bugs.
2. Because I feel that many non direct public health personnel and elected officials continue to mishandle the things they need to do.
3. Because the over zealous, misguided anti pesticide campagian have created and continue to create a bigger problem in terms of bed bugs and other urban pest issues.
4. Because I do return fire at a rate of 950 rounds per minute.
Sleep tight and don't let the bed bugs bite.
I do agree with you. In the grand scheme of things, these bugs do disrupt our lives, but they aren't deadly (as far as we know, anyway). Personally, I'm thankful for that. And yes, I know there is always a chance that in the future we will find out otherwise, but we have to go by what we know now, right? The unfortunate side of the bed bug's non-vector status, is they aren't seen as a priority by many folks. Especially, folks who haven't ever experienced just how damaging they can be. People are more afraid of maladies because they see their own risk of mortality in others' suffering. If bedbugs did transmit disease, you can bet your ass there'd be politicians on their soap boxes screaming that we need to do something about them, and you'd see very aggressive tactics from the government. But they don't transmit disease, thankfully, so those who are unaffected are not afraid of them. And sadly, that means those of us who are affected suffer. It would be interesting to see what would happen if say Gracie Mansion (the mayor's abode in NYC) or places akin to that in other cities got bed bugs. I bet you'd see a downright war on bed bugs.
I am not sure anyone is wishing bed bugs would become a vector. (I am sure you'd agree hopelessnomo wasn't.)
Some are speculating it is possible or might happen, it's true some are doing that--which is okay as long as people understand it is a theoretical speculation and not something to start panicking about. I don't like unfounded panicking.
As far as your attitude:
"1. Because I am not minimizing the suffering, expense our quality of life attributable to bed bugs.
2. Because I feel that many non direct public health personnel and elected officials continue to mishandle the things they need to do.
3. Because the over zealous, misguided anti pesticide campagian have created and continue to create a bigger problem in terms of bed bugs and other urban pest issues."
I see that in your posts.
Unfortunately I have heard the wish that bed bugs carry disease stated openly in
public and on a blog far far away from this one. The point they try to make is that then
it will get the attention and funding that bed bugs should get. It is a foolish statement
although all of us at times make foolish statements. I woe the day bed bugs become vectors because it will not translate into an immediate solution but only more misery.I have met Jim Goddard and have spoken with him and find him to be a no nonsense good ol boy who is insightful and direct in a round about way.
Thanks for clarifying that, Winston!
It will be too bad for people if that we find out one day bed bugs do spread disease, than we could say that we should have done something about the bed bug problem much sooner.
I am not saying that diseases that are spread by insects such as the mosquito should not be paid attention to I am saying that we should also better address the bed bug epidemic. NYC government for example is still is not taking well thought out procedures for bed bug control such as a simple thing like a good public awareness campaign to educate all. Maybe we are not dropping dead from bed bugs but bbs are having an impact on our society and it is going to get much worse in the next year or two. People can be continuously bitten so badly and bites can have such a bad affect that it can seem as though that they are slowly being eaten alive. What are the impacts that a bed bug infestation have on our bodies and mind? I believe the impact is serious. What about the elderly? What about the children?
In this day and age we do have the money to invest in our right to have a bed bug free future but our representatives are not doing what we have elected them to do.
Oh and Winston please take into consideration that the world is not like you, an entomologist or some type of bug professional.
Insects are a passion for you and that is OK but we do not share in your passion at least not to your extent.
Although I have met some good people since I have had bbs I would like to get back to my life someday soon, the life I had before bed bugs. Sometimes I think that bug professionals in some way are so very excited by the recent bed bug epidemic. They have gained notoriety and respect from an audience that a short time ago, before bed bugs, never existed for them. That is OK but please do not make this bb epidemic into less than it is. For us it has been a hell and never should have gotten this far out of hand. I do understand that a whole word exists with a whole world of problems but people are suffering because of bed bugs and very little is being done. Maybe some are soaking grant money and stalling. We can land a friggin robot on Mars and roll it's ass around taking pictures of a bunch of rocks and that is OK but some smart person cannot come up with a better idea on how to get rid of bed bugs.
This is like most issues are, all about money.
I personally do not think that bbs transmit disease because don'tcha think that a lot of people would be getting sick already considering the numbers of infestations. Especially children who get bitten and the elderly, people w/limited immune systems.
I say so what that bbs don't transmit disease. Neither does roaches or head lice. Yet, the schools get all in an uproar when a case of headlice is found. Why? That should not be a factor as to whether politicians need to be concerned.
As far as the mayor and Gale Brewer goes, there's some sorta behind the scenes political talk going on that us regular public folks do not see. C'mon. In 2006 there was going to be a bb task force and some laws pushed for reconditioned mattresses, etc. Then, it went blank. I believe something was said, behind closed doors. It happens more than you know.
I've also been reading that this epidemic will get worse "within a year or two". I've been reading this statement from different people for quite awhile now. Even if it did get worse, will people really give a sh.t? What about those Hurricane Katrina people. Days immediately following there were concerts and the such. Now, even though people are STILL suffering from the Hurricane, you do not even hear or read about these people. It was a disaster, yes, but now people just don't give a hoot. I read that they found housing for these people in trailer parks which are caged in and crime is rampant. How dare they treat people like this. Oh yeah, I forgot, they are not dying, it's not a disease, so just live w/it. Just a nuisance. Hmm, sounds familiar?
Will this problem explode, yes I think so. But I feel that it will explode on the "wrong" population, the poor, elderly, disabled. Politicians do not give a darn about "those" people. These people have no money. As a friend recently told me "it needs to hit the right population, the ones with the deep pockets. Then and only then will something be done."
WelcometoFlatbush wrote about the drug addicts and him being afraid of bbs spreading their diseases. Well, what about when bbs bite your cat or dog or bird or guinea pig or the rats in your walls or pigeons in the trees next to your home? What about the bats where people are said to have gotten them from bat bugs? Are these people getting sick. I don't think so.
A. Bedbugs are not known disease vectors.
B. Bedbugs are a public health concern.
Statements A and B are both true.
They are not incompatible. One does not invalidate the other.
I accept that some of you do not agree, but I submit that you are operating under a very narrow construction of the meaning and purpose of public health.
This is what Dr. Goddard has said about bedbugs:
“Bedbugs are not one of the reportable things like pests that are regulated in an eating place. Bedbugs do not carry disease. We deal with pests of health importance, like mosquitoes, ticks, fleas and lice because they carry diseases.”
"But it’s not a big deal. I’ve put them on my arm and let them suck and it doesn’t hurt." (May, 2007)
Compare and contrast with the following:
Clive Boase - urban pest management expert, UK (2001):
"On a broad level, this outbreak raises fundamental questions about pest outbreaks. We know very little about the underlying biological and mathematical mechanisms that within a few years, can push a previously uncommon urban pest into a widespread outbreak. Only by understanding those processes can we hope in the future to forecast outbreaks of urban pests and vectors, and to design evidence-based strategies that will effectively interrupt such outbreaks."
Dr. Stephen Doggett - medical entomologist, Australia (fact sheet, undated):
"[I]n Australia there has been an increase in the number of bed bug infestations of around 5,000% since the year 1999! The Department of Medical Entomology, ICPMR [Institute of Clinical Pathology and Medical Research], has been at the forefront of documenting this phenomena and providing information on the ecology and control of this important public health pest."
Dr. Tim Myles - urban entomologist, Toronto (2003):
"If the resurgence of bed bugs in shelters and other public facilities is not contained, there is the risk of a continuous and escalating growth in the source populations, leading to larger-scale infestations, which will require more frequent and costly control efforts later."
"As the source populations grow, the rate of spread will inevitably increase and bed bugs will start to appear in hotels, apartments, theatres, restaurants, public transit, hospitals and eventually detached single family homes."
I hope everyone has a happy and healthy holiday season.
"The health hazard of a pest infestation may arise through it being a direct parasite (e.g. bedbugs feeding on human blood), a disease vector (e.g. the large number of diseases transmitted by rats), a hygiene hazard (e.g. cockroaches and houseflies that carry harmful micro-organisms quickly among food sources) or the source of an allergen (e.g. house dust mite droppings)."
And, as previously noted:
I met Dr. Goddard after his presentation in Washington DC last year. He struck me as a very sincere scientist & I respect his opinions.
I simply question whether mechanical transmission at a low rate would be detected by our current public health surveillance systems.
Many doctors do not recognize a bed bug bite when they see one. How can we rely on reports from doctors that often misdiagnose bed bug bites to alert public health
authorities of a suspected case of biological or mechanical transmission?
I seriously doubt that there is a high transmission rate of disease or we would likely spot the correlation, but what if the rate is similar to dirty needle sticks of about 2% or less (Dr Goddard's stat from his presentation)? Do you believe that our health surveillance systems are sensitive enough to rule out an occasional transmission?
I am not an entomologist, just a former paramedic with a master’s degree that was trained to be skeptical about "accepted facts".
I, in fact, do not wish to see bed bugs become identified as a vector. I feed lab bred bed bugs that we use to train Bed Bug Dogs on my body and I previously experienced a light infestation in my home that took eight weeks to eradicate.
I have merely pointed out that if bed bugs were to be identified as a vector we would suddenly see a lot more interest & funding from the government. A simple fact that Dr. Goddard discussed during his presentation.
I value your opinion & solicit your views on the current state of mechanical transmission research. Do you really believe that the limited studies that have been published can be relied upon to completely exclude any possibility of disease transmission in human beings?
The best research published so far is an animal study that was performed on three chimpanzees with the Hepatitis B Virus. My training suggests that this is pretty limited research on which to base an expolated conclusion that no disease transmission is possible in human beings.
Would you take a drug that had only been tested in one experiment on three chimpanzees without any human trials? We can't perform experiments like Dr. Campbell did in the early 1900’s, for obvious reasons.
I think I follow Dr. Goddard's statements about disease transmission & bed bugs.
To wit, “Transmission of human disease agents by bed bugs is controversial. Since the insects repeatedly suck blood from humans and live a relatively long time, conceivably they might ingest a disease organism and later transmit it. A scientist named George Burton in the 1960s reported that bed bugs have been suspected in the transmission of 41 human diseases, however, finding a blood-sucking insect infected with a pathogen doesn’t mean it is a competent vector of that agent or even a vector at all. There are many factors involved in whether or not an insect can transmit disease agents.”
And Dr. Goddard’s conclusion, “Whether or not bed bugs transmit human disease agents remains a point of contention. Attorneys representing plaintiffs bitten by the bugs in hotel rooms often firmly state that the risk is real and that their clients must be compensated. However, until evidence proves otherwise, I think current data can be best summarized like this: Even though bed bugs have been found naturally infected with many disease agents, they have never been proven to transmit even one.”
Any civil case that awarded damages on the basis of possible disease transmission based on the current research would certainly be overturned on appeal for good reasons. Facts in a trial need to meet a test regarding reasonable scientific certainty, but I still question whether the evidence exists to conclusively rule such a possibility out.
I look forward to hearing your views on this subject.
Doug, Well put. Fortunately to date bed bugs have not shown to be active vectors despite numerous studies although serious modern studies are lacking and this is what a part of this discussion is about. How to allocate limited funds. While arboviruses can be deadly serious; they usually require a chain of events to allow for transmission. Obviously if an organism is piercing the skin and sucking blood there is a basis for concern. As far as mechanical transmission such as "dirty needles" who knows and what if any the percent is, insignificant unless of course your in it. And I would concur that the current numbers of ER and doctors visits would miss detection at the outset.While certain mosquitoes transmit malaria they do not transmit AIDS. One reason is that the AIDS virus is not hardy outside of controlled environments (thank goodness). Ticks which transmit Lyme do so after several hours of feeding. Hepatitis would be easier and thats why several studies go there but so far fortunately nothing. These are some of the natural checks and balances in nature perhaps. To quote a friend of mine who is an infectious disease research physician" if they were transmitting anything serious or in numbers we would know" helpful but in trying to maintain a scientific outlook not a total answer. Although he also has stated "sometimes clusters happen" and they do. A big problem with the disease factor is that it would totally cloud the legal arena which I might point out has already clouded the issue.Bed bugs are problematic enough, and having dealt with them since 1998 in the Northeast US after not seeing any since 1970 I don't think the bureaucrat's would deal any differently if they were vectors except to be more ineptly and politically expediently overwhelmed. Although many significant changes in human history were preceded by some sort of catastrophe or plaque let's hope bed bugs are not it.
Interesting to note though of the folks I know who like yourself who for good reason have chosen to become volunteers and not victims they all do prefer the nymphs they have raised or starved adults who are not filled with someone else's blood.
Believe me I am one of the people who desperately hope that BBs do not transmit disease! It does seem that HIV transmission is really not something to worry about at all, apparently it only lasts a few hours in a BB and for a start it would be highly atypical behavior for a BB to feed on a second host within a couple of hours right?
However, hepatitis B is another matter since it apparently lasts for weeks within a BB! Is that 1991 chimpanzee study really the very best example we have that BBs do not transmit hepatitis B?? I certainly hope not!
Winston you mentioned both "numerous studies" and "serious modern studies are lacking" in your last post, would you (or anyone else) perhaps be able to elaborate further? I am really hoping that there are some more encouraging studies than the chimpanzee one - even that one concludes by saying that "while mechanical transmission of HBV is most unlikely after a 10-13-day interval between feedings in bedbugs and tampans, it is still possible that mechanical transmission between humans might occur during interrupted feeds". I mean, a large number of BB exposures occur in hotels, and isn't it quite possible that a previous guest had hepatitis B, was bitten, and then the same bedbug bit the next guest well within 10 days?
Although bed bugs could theoretically act as a disease vector, as is the case with body lice, which transmit Bartonella quintana (the causal agent of trench fever) among homeless persons, bed bugs have never been shown to transmit disease in vivo. Hepatitis B viral DNA can be detected in bed bugs up to 6 weeks after they feed on infectious blood, but no transmission of hepatitis B infection was found in a chimpanzee model. Transmission of hepatitis C is unlikely, since hepatitis C viral RNA is not detectable in bed bugs after an infectious blood meal. Live HIV can be recovered from bed bugs up to 1 hour after they feed on infected blood, but no epidemiologic evidence for HIV transmission by this route exists.
Between the 1950's and early 1990's, very few homes in the US had bedbugs. Now a growing number of homes are afflicted with them.
If bedbugs were spreading a disease of any kind, an increase in transmission of the disease between family members would have occurred in homes that have bedbugs. But as far as I know, medical statistics do not show that.
Conversely, since the early 1990's homes without bedbugs would not have had a change in familial transmission of disease (unless a change resulted from causes other than bedbugs).
Medical statisticians do not seem to have separated bedbugged homes into a separate group from other homes. So statistical conclusions cannot be reached.
Furthermore, if bedbug presence in homes is not a reportable condition, statistics collected about bedbugs will not be accurate. But even so, their role as a vector (if they are that) would show up if bedbugged homes were treated as a separate group from other homes. (The statistics would be gathered at random. In other words, there should be no bias in the type of home sampled. It would also be useful to collect statistics for subtypes of home, for instance, apartment house or standalone home.)
As well as homes, live-in institutions of other kinds might show a difference in disease occurrence between places that have bedbugs and places that do not have them. Prisons are an example. Live-in schools and colleges are another example.
Apart from statistics, doctors do not seem to have noticed that bedbugs spread disease within families. Doctors are trained to be careful observers of patients, and to put two and two together to reveal association and apparent cause (disease and bedbugs).
Unfortunately, if I'm not mistaken, it still seems as if we are kind of struggling to find some good news other than that rather limited 1991 chimpanzee study? The CDC, Goddard and so on seem fairly confident that, if not impossible, the realistic risk of hepatitis B transmission by BBs is very minimal. Have there been other studies that perhaps we don't know about which help to give them this impression? For instance, following one of the links in the CDC article provided by Winston soon led me to this 1979 study:
Transmission experiments with hepatitis B surface antigen and the common bedbug (Cimex lectularius L).Jupp PG, McElligott SE.
Hepatitis B surface antigen (HBsAg)-positive blood meals were fed to a colony of the common bedbug (Cimex lectularius L) in a series of 5 experiments. Antigen persisted in the bugs for at least 7 1/2 weeks, but was undetectable after 18 weeks. Trans-stadial transmission was demonstrated through one moult only, and transovarial transmission did not occur. Antigen was successfully transmitted by adult bugs into 3 out of 35 canisters of HBsAg-negative blood. Antibody of HBsAg was detected in the serum from a rabbit on which HBsAg-positive adult bugs had fed as well as in the serum of 2 out of 10 guinea-pigs on which HBsAg-positive 4th and 5th nymphal instars had fed. The results as a whole indicate that biological multiplication and biological transmission do not occur in C. lectularius, but mechanical transmission has been demonstrated. This is probably an important means of hepatitis B virus transmission among humans in South Africa.
Statistics may indeed be another avenue of potential research. However, even here there are difficulties. For example, according to Wikipedia, at least 30% of hepatitis B infections cannot be associated with any identifiable risk factor. Could a significant part of this percentage be provided by BB transmission?
Finally, as DougSummersMS stated, there don't appear to have been any experiments on transmission when a BB is crushed over a wound (which I presume would carry a much higher risk of transmission due to the quantity of blood involved when compared to simple feeding) - yet, considering how often a blood stain on a sheet is the first sign of a BB infestation, this appears to be a fairly common occurrence. All quite concerning.
Once more, I sincerely hope there is in fact more positive evidence/rationale that I am missing here, because it is bad enough having BBs without all this as well!
If you take an engorged bed bug and squish it (non science term) to the extent that blood runs out and you drip it into someones open wound your theory is that it could possible mechanically transfer in this case Hep.B. In this scenario the hep b person would most likely effect only him/her self or perhaps someone living with them.
My Observations on Bedbugs.
By CHARLES A. R. CAMPBELL, M. D.
I am posting this again because it has been a while since I had last posted this information. This study has been reviewed with much other data by professionals of our time. One can draw their own conclusions.
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