Modes of transmission of XMRV - MRVs

[SA2]

The similarity of MLVs to HIV immediately leads one to think that they are probably transmitted similarly, ie. blood transfusions, sexual transmission from person to person, etc.

However, CFS does not have the epidemiological characteristics of HIV. It seems to be fairly rare across spouses, and if it occurs in families it seems more likely to be among children and perhaps a parent. Also, most of the people with CFS that I know never knew anyone else with the illness before they got it, including myself. In fact, before I got CFS I had never heard of anything about it, and this seems pretty typical (It always amazed me how anyone could think this illness was psychological with large numbers of people coming up with the same set of chronic symptoms - sore throat, swollen lymph nodes, debilitating fatigue, difficulty with sleep, foggy thinking, tinnitus, aching joints, funny heart beats, etc - with a sudden onset and never having communicated with anyone else with those same symptoms).

Anyway, this morning I was thinking, it seems there are so many varieties of MLVs (4 polytropic groups plus one xenotropic XMRV so far), that it would be odd for them to all derive from the same mouse to human transmission some decades or so ago. That coupled with the fact that the polytropic MLVs are infectious both to mice and humans lead me to think: what if MLVs were not transmitted to humans decades ago and then transmitted human to human the way HIV is, but were currently being transmitted primarily from mice to humans much the way the hantavirus is, say from mouse dropping that dry, become dust and are later inhaled by humans, or maybe instead via a mouse to human vector such as fleas.

Such a mode of transmission would help account for the odd epidemiological characteristics. Transmission would often be sporadic, without the usual human to human transmission characteristics. Clustered outbreaks would occur when groups of mice became ill by transmitting to each other and then transmitting it to humans in the community. Members in a family would be more likely to get ill if the household had mice infected with the illness. Once humans are infected, blood transfusions could become a source of secondary transmission.

 

[Stone]

"(It always amazed me how anyone could think this illness was psychological with large numbers of people coming up with the same set of chronic symptoms - sore throat, swollen lymph nodes, debilitating fatigue, difficulty with sleep, foggy thinking, tinnitus, aching joints, funny heart beats, etc - with a sudden onset and never having communicated with anyone else with those same symptoms)." SA2

Yeah, SA, 10 years ago when my doctor (who is a specialist in infectious disease) suggested that my symptoms could be a psychological somatization disorder, I replied, "Wow, that would be amazing! So what do you think the odds are that both my sisters and myself, all three of us, living in different parts of the country, all suddenly came down with the same psychological disorder years apart that manifests in precisely the same somatic complaints? Wow, that WOULD be one for the medical journals, wouldn't it?" He got my point, but just for fun I added, "Doctor, if my mind were able to do all this to my body, I would be able to bend spoons, too."

 

[anciendaze]

There is considerable reason to believe this can be transmitted by blood, including needle-stick accidents with large but unrevealed insurance settlements. There is also reason to believe it can be transmitted through mucus secretions. Some clusters have taken place where transfer of infected blood was highly unlikely.

We also have a possible latency period which might be years. The symptoms which take people to doctors may be due to new or reactivated coinfections, not the gamma retrovirus. The rhesus macaques tested showed no obvious signs of disease even though the virus could be detected in blood.

I'm looking for evidence of an intermediate vector between mice and humans which can also be infected. My candidate is the domestic cat. I'm making several assumptions, which could easily turn out to be wrong. One is that this originates in tropical rodents. These populations can breed year round. Infected rodents need not die off during the winter. They might be more vulnerable to predators, with an important predator also living in human dwellings.

I think one factor in the multiple varieties is the way the virus likely causes subtle immune defects. There appears to be nothing to stop a person infected by one from acquiring multiple related infections.

The epidemiology has been a squandered chance. There were documented outbreaks looking very similar in 1934 and 1956. The outbreaks in the 1980s could have been the point where new technologies were brought to bear on the problem.

I'm afraid the absence of conspicuous outbreaks in recent years is because the infected and vulnerable populations have reached rough equilibrium. Most people without innate immunity have either acquired immunity or been infected. If these viruses are now in 7% of the population, albeit most without symptoms, you encounter someone with the infection every day.

 

[SA2]

I'm afraid the absence of conspicuous outbreaks in recent years is because the infected and vulnerable populations have reached rough equilibrium. Most people without innate immunity have either acquired immunity or been infected. If these viruses are now in 7% of the population, albeit most without symptoms, you encounter someone with the infection every day.

anciendaze

Yea, those thoughts are similar to my previous ideas about transmission. Essentially I thought that CFS was caused by some virus that caused a permanent infection, and that most people were immune to the illness, which is why others I knew never got sick. I thought the illness was easily transmitted and that most everyone either already had the illness, or were permanently immune. A second hypothesis was that the illness required a pair of co-factors (such as a primary virus that actually causes the illness, with another virus, say a flu virus, that opens the doorway).

All or any of the above are of course possible, and not mutually exclusive.

However, as the new research has come in, the latter begin to seem less likely. For one, if CFS transmits though mucus secretions then intimate partners would statistically be more likely to get it first with young children and unrelated individuals getting it more rarely. However, this doesn't seem to be the case, even historically. MLVs seem to be extremely dilute in the blood, and are probably located primarily in some other tissue reservoir such as the lymph nodes, the spleen, the nervous system, etc. This is not true of HIV. This could make casual transmission of MLVs via body fluids difficult. Finally, if MLVs are capable of infecting both mice and humans, and since they originated in mice, then they must have transmitted it to humans at some time, and there may be no reason why that is not continuing and perhaps happens to be the primary source of human infection.

 

[Hope123]

Lots of questions about transmission all right.

My story is a bit more complicated but one odd factor in my background is that I visited Incline Village for business purposes a few weeks before I got sick along with my family. No one else became ill except for me; one difference between them and I was I got bitten by a few mosquitos while attempting a hike while my family didn't go hiking with me. I don't think this will be a common form of transmission (as prior epidemic patterns don't seem to bring up insect vectors specifically) but I sometimes wonder if this will be one form of transmission. Not too hard for me to envision mosqitoes picking up blood from infected mice.

I also don't believe sexual transmission to be the only route if it turns out to be a route as there are children/ young teens, whom I doubt are sexually active, who have this. If they got it via their parents (who might or might not be sick), it may argue for long latency period (or other interacting factors) since some didn't get sick until years later.

Also, on the question of co-infections, the authors of the PNAS editorial are certainly thinking about this in their diagram and essay. I don't know if they have data supporting this or if it's a hunch via HIV infection being affected by co-infections.

 

[Sunshine]

Blowing away the smoke and pointing the mirror at the person who dazzled you.

Seems we may be born with XMRV from infected mom, or get it from a vaccine or a blood transfusion. Unless it's contagious and in the air. Highly unlikely, unless there is a mystery contagious pathogen + XMRV/MULV, e.g. Mycoplasmas. At the end of the day the conspiracy of silence is real, and not a conspiracy theory but fact. There is a reason, (despite costing the US tax payer multi billions of dollars in lost work hours per year) 'CFS' is created out of an already classifiable disease (ME - circa 1969). There is a reason to ignore biomedical research evidence for decades, to deny funding for more research, to give all funding to psychologists (in a non psychiatric disease), and to claim there are cures that pathologically make patients worse (exercise) to 100% guarantee the disease is hidden.

If I recommend chocolate for Type 1 diabetes as a proven treatment NO ONE will believe you that diabetes is linked to raised blood glucose and it makes you worse by eating carbohydrate and food. (If diabetes wasn't fatal without insulin). The diabetic is thus disbelieved and considered 'crazy' in conjuction with psychological 'evidence' of this. That one can 'rehabilitaite' the lying hysterical diabetic back into society with CBT. This only works, if there are no diagnostic tests needs to become a diabetic, to guarantee the majority of people with diabetes never have it, and the underlying cause for diabetes is never found. This is what happened with ME/CFS. We all know this, to our terrible cost.

All this therefore means XMRV/MULV was known and needed to be 'lost' which it was. There is no reason to ignore people who have a disease that 1 in 4 people are house/bed ridden, and some die. There is no reason to ignore a disease that affects CHILDREN and young people that devastates their lives and turn a blind eye. There is no reason to give as an official excuse (CDC) that they cannot afford to fund, understand or acknowledge CAV retrovirus back in 1991 even when the virus is photographed as being real and 'new' in CFS. That finding was silenced and the scientist duly has a car crash and no peep is heard out of her ever again (literally). How convenient.

Not wanting to help people who have the disablity level of someone dying from AIDS or heart failure, people who have thousands of research papers behind their illness label, screams vaccine contamination and/or government involvement. Medics and health linked professionals are highly intelligent people. They are always one step ahead of you, because they know the source. The fact the British put files on ME (via the Medical Research Council) under the official secrets act until 2070, again is dead give away of state involvement of the introduction of XMRV/MULV into the human blood supply. Why does it need to be a secret? Why do all the original ME patients (or disinformant agents involved in ME) need to be dead before the truth is known? Few consider this due to brainwashing and the belief 'good' people exist in the health care profession universally. Guess what, they don't.

If a CDC director ( Doctor Raymond Vonderlehr) can help kill African Americans for an 'experiment' with syphalis (tuskegee experiment) for 40 years , anything is possible with CDC later on in ME/CFS. A tiny private scientific group (WPI) 'found' XMRV and told the world. We were not ever going to find out, CFS was about to be renamed as 'unwellness' by the CDC and entered into the psychiatric novel of DSM-V. WPI need a Nobel Prize for saving millions of lives, they prevented future stealth genocide. If 17 million are infected, how many have died so far, that could have been saved, had it not been for the misdirection of funds and the bogus illness label for ME, 'CFS'? Tens of thousands at least have died over multiple decades world wide, at least.

Why is all the discrimination of slandering patients allowed to be published in journals (pure conjecture and bigoted hate of 'personality types' in CFS), with not a word said by authorities? If people said what they say (people, as in doctors) about people of certain faiths, or certain sexual orientation, or certain illneses/disease they would be (rightly) sacked from their jobs and it would make headline news for weeks. In ME CFS, these haters are not put in jail, but placed at the very top of ME/CFS research and given medals and awards and allowed to control funding and prevent the evolution of scientific knowledge.

THAT answers your questions on the 'Modes of transmission of XMRV/MULV', coupled with the recent 'failed' studies by the CDC and British which when examined where scientifically inacapable of detecting XMRV (Thanks Suzanne Vernon), with the wrong cohort of patients, and involving people who said ME/CFS did not exist alongside refusal to use known positive XMRV samples. What on earth? Anyone with an IQ over double figures is aware the CDC do not want to find XMRV/MULV and the Brits also. We have total media blackout in the UK the day the Alter/Lo paper breaks. Again laughable and obvious why. When an ME patient is locked away and they subsequently die of inflammation of the spinal cord (75% destruction of sensory neurons) the people who abused the ME patients are found 'not guilty' in court for accusing her of being insane. What on earth? If found guily, then that case would show ME is involved with terminal illness and not 'illness beliefs'.

Once 'we' (ME/CFS) are maybe infected from mom to baby transmission, XMRV/MULV's go into the next generations and kids are born with XMRV/MULV's activated in teenage years by adrogens/NF Kappa-b and an incomplete immune system that never got to maturity. The majority of people with classic ME/CFS that become profoundly disabled for life and never recover (literally), are nearly always sick before they are 30, they are exclusively children, teens, or people in their 20's because they are probably born infected, like HIV babies can be. If XMRV doesn't 'turn on' until you're 11, 17, 23, 37 etc this is easily plausible. Again, this suggests kids being born with XMRV/MULV, or vaccinated and a long latency period before activation. A fool can see that. We don't need be-spectacled wiry bearded denialists to 'confirm' anything and waste another 5 years to 'confirm' the SCIENCE paper that could be done in a few months if anyone wanted to. Either you test positive for XMRV/MULV through private testing (denied by the state) or you don't. Again a nitwit can go work this out that the SCIENCE paper is true if ME/CFS patients keep testing positive! There are documented cases of developing ME/CFS directly after school vaccine programmes, such as BCG (Tuberculosis). Whether or not the vaccines are contaminated themselves (how else did XMRV/MULV get in our blood from a MOUSE derived retrovirus that is now human?) or they activate the XMRV/MULV's, or even both...remains to be seen.

I'd hazard a guess the HIV & XMRV/MULV epidemic are running on a similar but apparenltly not identical time line. ME came before HIV. ME was classified in 1969 by the WHO as a brain disease after multiple 'outbreaks'. Not that long later along comes an appaling virus, HIV that kills outright. No one, no qualified doctor for ANY REASON OTHER THAN POLITICAL, would rename a certified brain disease (ME) to 'Chronic Fatigue Syndrome' and reduce the diagnostic criteria to include the world and his dog. No one would state over and over again ME 'does not exist' , whilst existing alive and well to this day as a certified brain disease. It's called lying, literally, lying. Does the state usually employ people who print research papers saying MS doesn't exist, or Lupus? Or that Lupus patients should feel shame for being sick? Someone seriously on a 'mission' would be allowed to say that without a single word of complaint or raised eye brows.

Who would you need to employ to spin a story that ME/CFS is 'not new', that ME was seen 100's of years ago in WAR due to trauma......that Florence Nightingale had it and so such BS (when there is no test, and no evidence, and masses of reasons for chronic exhaustion that can never be proven)? You would need to employ someone who is expert in tracing back 'fatigue' states. That needs to be an epidemeologist in order to create a fairytale, and preferably from the military so you can sew up censored information in papers no one will ever see. *Bingo* This person would need to be a psychiatrist too, to enable public mocking of the ME/CFS patient under the excuse it's only a 'theory' and it's their job to 'guess' on reasons for illness. Soon, no one would care, 20, 30, years later this person would be considered a world oracle on ME/CFS by the state/media, through the destruction of ME as serious neuro immune disease and the introduction of 'CFS'.

That single employee, the dictator. The arrogant rutheless defiant sociopathic influencial powerful dangerous person who hold all the cards is? ..... ....... The people who needs to know, knows full well what the 'Modes of transmission of XMRV - MULV's are, as they were shown decades ago as part of their contract to make sure no one ever found out. You and I will never know.

Either way, the WPI are spectacularly infuriating for the never to be named people who miscalculated the possibility of a WPI appearing out of the desert like a mirage. We have the comical situation of a mini clinic leading world researchers behind them like pied piper whilst the people who smashed pied piper's pipe (now glued together) are reeling in chaos, literally not knowing what to say or do next.

And that, is progress..... albeit progress with a bitter sweet taste of victory. Time, cannot be reversed and our lost time is gone forever and needlessly wasted through us being contained within a programme we had no idea of, will never know what it was for and why we were targeted. All we do know now thanks to the WPI, is we need massive funding for research at a federal level.

Where is it? Shall we wait years and years more for someone to get off their backside and do a replication study with the Lombardi methods? 1 year has nearly passed since the Lombardi paper was made public.

And the band played on.........

'Quote CFSAC meeting 2009'.

''We don't want another and the band played on scenario''.

 

[SickOfSickness]

I had pet gerbils and maybe mice. Also what if you have a cat who hunts and eats a mouse or rat. Though I feel I was infected by mosquitos during international travel to Asia, but it could be pets.

I'm thinking maybe even ticks could spread it? Any given tick could have MLV or Lyme or both?

 

[forgottenstar]

I had pet gerbils and maybe mice. Also what if you have a cat who hunts and eats a mouse or rat. Though I feel I was infected by mosquitos during international travel to Asia, but it could be pets.

I'm thinking maybe even ticks could spread it? Any given tick could have MLV or Lyme or both?

I had cats (and one who was amazing at catching mice, birds and ground hogs), guinea pigs, a hampster and lived by the woods so mosquito bites / tick bites were a normal thing. I would assume its extremely possible I became sick from any of these. My hampster bit me one time, when he was sick & dying. My guinea pigs stayed outside in the summer so Im sure they could have been bit by a number of bugs.

I also knew two people with very severe cases of Lyme disease...one was my science teacher/ mentor.

Or as other people stated, it could easily be from vaccinations. My health has been declining ever since I had an 'unknown' virus when I was 12....

 

[bullybeef]

The UK NHS isn't the most in-depth place for information regarding ME/CFS, but I thought I'd look to see if they had updated their information...they hadn't. But I did notice this:

Causes of chronic fatigue syndrome
The cause of chronic fatigue syndrome (CFS) is unknown. There are several theories.

Some experts think that a viral infection such as glandular fever can trigger the condition. Tiredness is normal after a viral infection, but this does not explain why symptoms persist and get worse.

Contributing factors
The main factors thought to increase the risk of developing CFS are:

inherited genetic susceptibility (it is more common in some families)

viral infections such as glandular fever, which weaken the immune system

See: http://www.nhs.uk/Conditions/Chronic-fatigue-syndrome/Pages/Causes.aspx

I was quite surprised even our own draconian NHS advise ME/CFS is common in family environments. Not to mention, the quoted weakened immune system.

What is even more amazing is this was last update before the XMRV discovery!

 

[omerbasket]

It's an interesting theory.
I think it must be investigated. However, there are things that might direct us in the opposite way:
1) As we know, there are many people who are XMRV positive, yet they feel very well. Therefore, I think that it is very much possible that even if you get infected with XMRV, you might continue to fell well and never develope ME/CFS. This may be caused by a number of things (genes; stress, that perhaps might weaken the immune system and therefore "help" XMRV become pathogenic - as opposed to a virus that is under the control of the immune system; Or perhaps even luck - I'm not a scientist, but isn't it possible that if XMRV enters the human genome in one place, it wouldn't do any harm, and if it enters the human genome at another place it would make the person very sick?), but the bottom line of it is: in order to see if people that live close to a XMRV positive ME/CFS patient are more likely to be XMRV positive - you have to check the percentage of XMRV among these people. I think it is possible that in a family, for example, one person would get infected with XMRV and would develope ME/CFS - and would infect his wife and four kids with XMRV - but none of them will ever have ME/CFS, because it seems that there are healthy people who are XMRV positive. Besides, it's also possible that some of them would develope other diseases, such as prostate cancer, so we wouldn't know that ME/CFS is actually contagious.

I think what needs to be done is to check the percentage of XMRV positive people close to XMRV positive ME/CFS patient. And I think that the best way to check it would be to check spouses of XMRV positive ME/CFS patients - because they wouldn't have the same genes, and they wouldn't (normally) inherit XMRV vertically.

2) I remember Dr. Mikovits saying that according to her research until now it seems (although not completely proven yet) that XMRV might be contagious thruogh saliva, and also that it might be the most contagious human retrovirus we know of.

Anyway, I have to say that although I'm diagnosed with Fibromyalgia and not ME/CFS, and although I was never tested for XMRV (and therefore doesn't know if I'm XMRV positive or negative), I'm very much arfraid of infecting other people with it. It is also very problematic for me when it comes to finding a girlfriend... I'll tell her about that possibility of me being contagious even by saliva, but what would a girl find in a sick and perhaps contagious guy that would make her stay with him?

 

[serenity]

Omer, i know this sounds unrealisitic - but a girl who really loves you wont' care.

 

[LaurelW]

Not to mention the fact that both people in a couple rarely get it. It's more common in parent/child.

 

[SickOfSickness]

Yeah. Spouses sometimes are both infected but maybe it's because they both went camping & got bitten. I bet they would find many of the healthy spouses do test positive. Many more than healthy people who aren't intimate or cohabitating with a positive person. Better if they can prove modes of transmission scientifically and not based on statistics.

 

[LaurelW]

True. I've often wondered if they were both positive, but one spouse remains healthy because they don't have the same genetic predisposition or wimpy immune system that the patient does. The sooner they figure this out, the better.

 

[omerbasket]

Omer, i know this sounds unrealisitic - but a girl who really loves you wont' care.

Thanks for the positivity!

Yeah. Spouses sometimes are both infected but maybe it's because they both went camping & got bitten. I bet they would find many of the healthy spouses do test positive. Many more than healthy people who aren't intimate or cohabitating with a positive person. Better if they can prove modes of transmission scientifically and not based on statistics.

I definitley agree with you - they should find that out by science and not statistics. However, statistics might give them a clue as to what they should check first and what they should check more rigorously.

 

[*GG*]

"Yeah, SA, 10 years ago when my doctor (who is a specialist in infectious disease) suggested that my symptoms could be a psychological somatization disorder, I replied, "Wow, that would be amazing! So what do you think the odds are that both my sisters and myself, all three of us, living in different parts of the country, all suddenly came down with the same psychological disorder years apart that manifests in precisely the same somatic complaints? Wow, that WOULD be one for the medical journals, wouldn't it?" He got my point, but just for fun I added, "Doctor, if my mind were able to do all this to my body, I would be able to bend spoons, too."

Love this Stone! Very witty. I would have the stones to say this to my Dr! They are not Gods. I saw one yesterday, and was dismayed by her questions, she is an infectious disease person at the MGH, $23 for parking! ughh!. I guess I was kind of peeved because I filled out there questionarre, so look at the damn thing instead of asking me the same questions from what I filled out!

So many questions on what kind of tired and pain, hard to explain, many kinds of pain and tired since I became ill 7 years ago, hard to remember it all, have a comprehensive form and I will tell you! The cognitive dysfunction makes it hard to anwer your asinine questions! Sorry just venting, perhaps there is a purpose, but...She didn't have much help to offer, drew 23 vials of blood, perhaps something will come of it. She did mention the XMRV news, but she said unleess they found something, that I should probably just see her in a year or 6 months, depends upon on how things evolve.

 

[oipemowell]

Omerbasket...I know what you mean about dating. This is a HUGE issue for me. What SA2 had to say, which started this thread, made me feel better, however, cuz truly, there isnt a very clear sexual transmission link like with HIV. I feel that Dr. Judy jumped the gun in making us all scared about kissing and safe sex, etc. It just doesnt really pan out at this point. However, I dont want to lie to someone I meet, if I should meet HIM, and I have become very ready to meet HIM, finally.....Hey, I have CFS and it may be due to a retrovirus, but not clear if I can give it to you or not...wanna take a chance? I mean, REALLY, what do you say??? Pretend you havent been on the internet about this? Of course, eventually it will hit the national news and everyone will know and freak out. Ive been bummed about this issue since last October.

So, I think I will just continue to meet guys, and see things the way SA2 has described them. It makes more sense to me. If I could give this to guys with just kissing, there'd be alot more people sick from this illness than there is.

 

[SOC]

So, I think I will just continue to meet guys, and see things the way SA2 has described them. It makes more sense to me. If I could give this to guys with just kissing, there'd be alot more people sick from this illness than there is.

I have to agree with you there. Given the number of ill -- or even the number of infected -- compared to the rest of the population, it's very hard to buy that HGRVs can be transmitted by kissing. It seems completely unreasonable to me to expect people to martyr themselves over such a miniscule possibility. Unprotected sex may be a different issue, but avoiding unprotected sex is reasonable and not too much to ask in this day and age.

No one wants to infect other people. We have to make sincere and concrete efforts not to, imo. But that doesn't mean people with ME/CFS need to live like monks. *grin*

Go out and live your life. Don't donate blood. Don't have unprotected sex. Don't share drinking glasses. Don't share needles. Don't bleed in other people's open wounds if you can possibly avoid it. Don't drink and drive. Don't leave guns where children can get at them. In other words, just live smart.

Best wishes.

 

[Megan]

Epidemiology of HTLV different to HIV

More questions for the mix. I googled HTLV and epidemiology and came up with the couple of references below, which make for very interesting reading.

Of note HTLV affects women at higher rates to men (sound familiar!) Supposedly because it is more easily transmitted from male to female than vic virca, or maybe for hormonal reasons.

One question I have is if HTLV is transmitted via sex, then why are gay men not greatly infected with this virus? This is a puzzle I have been pondering re XMRV? In a nutshell HTLV has the same modes of transmission as HIV but seems to infect different populations. I wonder what an epidemiologist would say?



http://www.nature.com/onc/journal/v24/n39/full/1208968a.html

http://virology-online.com/viruses/HTLV2.htm

Some interesting quotes:

From the first link:

The geographic distribution of the virus has been defined, with Japan, Africa, Caribbean islands and South America emerging as the areas of highest prevalence. The reasons for HTLV-I clustering, such as the high ubiquity in southwestern Japan but low prevalence in neighboring regions of Korea, China and eastern Russia are still unknown.

Data from studies of pregnant women may better reflect prevalence rates of the general population. Prevalence rates for HTLV-I and II were sixfold higher in pregnant women than in blood donors in the United Kingdom

Several individual behaviors and exposures have been associated with HTLV-I seropositivity, corresponding to the known modes of transmission: from mother to child, predominantly through breastfeeding; via sexual intercourse and via parenteral transmission by transfusion of infected cellular blood products or sharing of needles and syringes (Manns et al., 1999). Although the biological mechanism of transmission still needs to be clarified, infected cells seem to be essential for transmission, whether the exposure to the virus is through blood, sexual contact or breastfeeding. HTLV-I endemic areas are in the tropics, infection trends to cluster among families and neighbors and a decline in seroprevalence are observed in subsequent generations of people migrating from endemic to nonendemic areas (Miller et al., 1994). These observations strongly suggest the presence of biological or social cofactors influencing HTLV-I transmission (Maloney et al., 1991).

Screening for anti-HTLV-I antibodies during prenatal care in Japan followed by counselling of seropositive mothers to avoid breastfeeding their infants led to significant lower rates of infection in bottle versus breastfed infants (Hino et al., 1997). Other forms of mother-to-child transmission, such as intrauterine or peri-partum, seem to be less important (Fujino and Nagata, 2000), and may be hindered by HTLV-I-induced apoptosis of placenta cells (Fujino et al., 1999). Transmission through saliva is also possible, since the proviral DNA and anti HTLV-I antibodies are detectable in saliva, but currently there is no clear evidence of transmission through this mode (Fujino and Nagata, 2000).

Intravenous exposure to blood seems to be the most efficient mode of HTLV-I transmission.

In most HTLV-I endemic and even nonendemic areas, HTLV-I seroprevalence rates are strongly age and sex dependent, increasing with age and are higher in females (Kajiyama et al., 1986; Murphy et al., 1991; Mueller et al., 1996). The higher prevalence with age may have several explanations: the accumulation of seroconversions to new HTLV-I infections over the lifetime of the individuals surveyed; an age-cohort effect due to declining in HTLV-I seroprevalence over the past decades; or delayed seroconversion to infection acquired early in life (Blattner et al., 1986; Murphy et al., 1991). The latter explanation is not supported by biological data. Higher prevalence in females may be due to a more efficient male-to-female transmission during sexual intercourse; also, hormonal effects may play a role in female susceptibility (Chavance et al., 1990; Nakashima et al., 1995; Kaplan et al., 1996). The dynamics of HTLV-I infection may differ among countries, and variations in sexual behavior (more frequent use of condoms) or breastfeeding practices (duration, use of wet nurses) could contribute to the heterogeneity in prevalence rates. On the other hand, despite dissimilar absolute prevalence rates in Japan, Jamaica and the USA, these countries show the same pattern of age and sex-specific prevalence (Murphy et al., 1991, 1999; Mueller et al., 1996).

Several studies have reported that indicators of lower socioeconomic status such as education are associated with HTLV-I infection in both endemic and nonendemic areas

From the second link:

Seroepidemiological studies reveal that HTLV-I infection occurs in clusters in certain geographic locations around the world. It is endemic in Southern Japan (15-30%), Caribbean (3-6%), Papua New Guinea and some parts of Africa. HTLV-I appears to be transmitted sexually and through blood. Vertical transmission is thought to play an important role in the maintenance of virus in areas of high endemicity. Transmission through breast milk is implicated as a major route for the maintenance of infection in high prevalence areas. Seroprevalence of HTLV-I increases with age and is twice as high in females than males. In Southern Japan, HTLV-I seroprevalence in persons over 80 years was 50% in females and 30% in males. This gender difference usually emerges after 30 years and probably reflects more efficient transmission from males to females during sexually active years. HTLV- II infection is particularly common in IV drug abusers, and has been found in clusters among certain South American Indians.

 

[alex3619]

On epidemics, an hypothesis

Hi, I think it was anciendaze who suggested that epidemics might not be happening because most of these who are at risk (via genetics or other predisposition) have been infected. I hope so, it means the world has dodged yet another gigantic calamity.

I have another hypothesis however. What if so many are now infected that the sporadic rate weeds out potential epidemics before they happen? What is happening with sporadic reporting of ME, CFS, autism etc? Could it be that, rathing than reaching a limit, it has reached critical mass and epidemics wont happen again, just more and more and more sick people until it finally runs up against a predisposition limit or everyone is infected?

Of course there is also the other hypothesis that epidemics are no longer being reported. I thought I should reiterate it so that everyone can see all the alternatives.

Whichever it is, we needed urgent well funded science several decades ago. We are still waiting. We could be like a horde of lemmings approaching a cliff, spouting a mantra of "there is no cliff, there is no cliff, nobody has seen a cliff", and nobody wants to stop and climb a rock so we can look ahead and see where this is all going.

Demand more research funding now!

Bye
Alex