That’s a theory, but it has some critical flaws. Namely one must wonder why did it not spread via prostitutes, needle sharers and blood transfusions earlier?
I’m not sure which specific time period you’re referring to with “earlier”. If you’re talking about the 1970s, I’d guess it’s because HIV simply hadn’t been introduced to those subpopulations often/early enough to stick. If you’re talking about the early 1980s, well, it looks like HIV did spread, at least among needle sharers and people who had blood transfusions. (I haven’t seen data on prostitutes.) According to this 1985 Science article, 12,932 AIDS sufferers were reported to the CDC by August 30, 1985. 1.5% of them had received blood transfusions within 5 years of diagnosis, and 17% were heterosexuals who’d used IV drugs. (Also, 12% of the homosexual & bisexual men diagnosed were IV drug users.)
It is this phenomena, this quick sudden outbreak in a very specific subgroup, which I find extremely difficult to reconcile with the transmission data. Tops and bottoms tend to specialize so the rate-limiting factor for expansion in the gay community would be closer to the insertive A rate, at around 0.06% vs receptive at 0.5%.
Although I’m sure tops & bottoms “tend to specialize”, I doubt men with dozens of sexual partners are completely picky about which role they play. If men are inconsistent about being the top/bottom, the insertive anal transmission rate is going to be an underestimate. In fact, it’s likely to be an underestimate twice over, because preexisting STIs make transmission more likely, and promiscuous men will have more STIs on average. You’ve also got the handful of IV drug users among these men. If I’d had to bet on where HIV would rear its head first, the bathhouse subculture would’ve been a great choice to put my money on.
Needle sharing is about 10 times more effective, and blood transfusion is around 1,000 times more effective.
But neither of those can have an impact until HIV’s introduced to the subpopulations of needle sharers/blood donors, and even after that, their effect will depend on when HIV reached those subgroups, and how many people in those subgroups start off with HIV.
But all the early cases are in this one specific group, which is not even the highest risk group.
Only if you define “early” as really early: the first reports of IV drug users with AIDS came out in the same year as the first reports of AIDS in gay men. And again, risk isn’t everything. Even if group X has much higher transmission risks than group Y, if the virus reaches group Y first, the earliest infections are likely to emerge in group Y.
I mean, the transmission rates for insertive V and A are about the same,
While the receptive A rate is higher than the receptive V rate.
and there are far more heteros than homos, so it just doesn’t make any sense.
Ease of person-to-person transmission within a subgroup matters more to how quickly a disease spreads through that subgroup than the subgroup’s absolute size.
And don’t tell me the homos are having all the sex—they may be having more individually,
Which increases the ease of transmission.
but not when considering prostitutes and sexually liberated women in the 60′s and 70′s,
Which doesn’t much matter if there’s hardly any HIV among those women to start off with. I’d also guess that the proportion of “sexually liberated women” having as much sex and injecting as much drugs as gay men in the 1970s/1980s bathhouse culture is relatively small.
the fact that heteros have anal as well
As often as promiscuous gay men?
and the 100 to 1 hetero to homo ratio.
See above about subpopulation size.
The overall hetero transmission channel is much much larger, especially after considering needle sharing and transfusions, and yet the disease only appears in the homo subgroup, time and time again. Why?
To extend your own metaphor, the “hetero” channel was wider than the “homo” channel, but the “homo” channel had faster flow. Plus, again, there were gay men who engaged in IV drug use, and if gay men were among the first US citizens exposed to HIV, as is very possible, that would’ve given them a head start.
Ignore for a second all high level conceptions about HIV.
Not sure what that means specifically.
Don’t privilege the orthodox HIV hypothesis,
It’s the hypothesis favoured by the medical establishment and the scientific mainstream on the basis of evidence that is at least circumstantial, and at best definitive, which suggests it’s a good starting point. I’m not plucking an arbitrary hypothesis to defend out of thin air.
instead compartmentalize and consider just this evidence concerning transmission rates, and how that evidence should cause one to update from an initial 50⁄50 split between two alternate hypotheses:
HIV spreads primarily horizontally and is novel in homo sapiens
HIV spreads primarily vertically and has been in homo sapiens for a long time
The transmission rates clearly favor 2 - the virus can barely spread sexually, but can spread fairly easily antenatally.
I really disagree with how you’re framing things here. It’s screwy to split horizontal transmission & vertical transmission into separate hypotheses, since both processes are happening right now throughout the human race, and both processes happen at different rates across time & place. I don’t understand why the mode of transmission corresponds to how long HIV’s been circulating in humanity, either.
Mother-child HIV transmission rates per child (without anti-HIV prophylaxis) are generally higher than sexual transmission rates per sex act, sure. But there’re a lot more sexual acts happening than childbirths. So there’s more to the situation than raw transmission rates.
That’s a theory, but it has some critical flaws. Namely one must wonder why did it not spread via prostitutes, needle sharers and blood transfusions earlier?
I’m not sure which specific time period you’re referring to with “earlier”. If you’re talking about the 1970s, I’d guess it’s because HIV simply hadn’t been introduced to those subpopulations often/early enough to stick.
There are several documented cases of early AIDS where we have stored tissue that later tested positive for HIV, such as the gay teenager who died in St Louis in 1969. This poses a serious problem for the standard theories that HIV is transmitted horizontally (unlike any other retroviruses) and presumably came out of Africa. So how did it get into this teenager? You would need some world travelling gay subculture at the time to link the disease to Africa, but not a big enough subculture to create an epidemic. Since only a small portion of men are gay, we should expect that if it came out of Africa the first vectors would have been heterosexual, not homosexual. And as there are several of these strange early cases, it would have had to come over from Africa multiple times, but always only in gay men. This theory is just not salvageable.
Also, consider that the different genetic subtypes are closely associated with particular risk groups—subtype M appears in MSM and IV drug users but not others, which doesn’t make any sense for a horizontally transmitted viral vector. Most of the subtypes are linked to particular geographical regions in Africa, which points to a long history in humans (with M representing a novelty linked to novel behaviour).
Also consider that all other primates have naturally occurring lentivirus family retroviruses very similar to HIV. Consider that the entire family of retroviruses are more symbionts than parasites—humans are ‘infected’ with thousands of different retroviruses, many of which are integrated into our genome, and they have functional roles in gene expression and even the formation of the placenta.
So if all other primates have naturally occurring lentiviruses, why don’t humans? There is a clear evolutionary niche for a lentivirus in mammals, and it seems odd that homo sapiens somehow lost their naturally occurring lentivirus at some point in our evolutionary divergence, only to re-acquire it very recently in the last one hundred years. It just doesn’t make any sense at all.
Retroviruses generally are not horizontally transmittable, and there is no evidence that HIV is an exception. The Padian study in the other thread branch directly shows that HIV is probably not sexually transmittable.
There are several documented cases of early AIDS where we have stored tissue that later tested positive for HIV, such as the gay teenager who died in St Louis in 1969. This poses a serious problem for the standard theories that HIV is transmitted horizontally (unlike any other retroviruses) and presumably came out of Africa.
But most of the earliest confirmed AIDS cases were retracted (David Carr) or have a direct connection to Africa (anonymous Congolese adults & Arvid Noe). It’s only Robert R. (the “gay teenager” you refer to) who didn’t have a direct African connection, but that doesn’t mean there wasn’t one, and such a connection wouldn’t even be necessary with Haiti available as a closer source of HIV.
So how did it get into this teenager? You would need some world travelling gay subculture at the time to link the disease to Africa, but not a big enough subculture to create an epidemic.
This is one teenager. He only had to be unlucky once when having sex with just one infected man.
Since only a small portion of men are gay, we should expect that if it came out of Africa the first vectors would have been heterosexual, not homosexual.
I’m confused. This PNAS paper presents good phylogenetic evidence that the HIV strains causing the North American epidemic came from Haiti, and that Haiti’s HIV came from Africa in the 1960s, which “suggests its arrival in Haiti may have occurred with the return of one of the many Haitian professionals who worked in the newly independent Congo in the 1960s”. So it’s Haitian economic migrants who would’ve been the “first vectors” to carry HIV out of Africa in any real number, and I have no reason to think they were disproportionately homosexual.
And as there are several of these strange early cases,
If by “strange” you mean that all those cases are inexplicable, I disagree.
it would have had to come over from Africa multiple times, but always only in gay men.
Not at all.
Also, consider that the different genetic subtypes are closely associated with particular risk groups—subtype M appears in MSM and IV drug users but not others, which doesn’t make any sense for a horizontally transmitted viral vector.
I’m not an epidemiologist (or a geneticist), but couldn’t that just be a founder effect perpetuated by MSM and IV drug users transmitting HIV much better amongst themselves than they transmit it to everyone else?
Most of the subtypes are linked to particular geographical regions in Africa, which points to a long history in humans (with M representing a novelty linked to novel behaviour).
I’m not seeing why this would be evidence for/against orthodox theories of HIV & AIDS. (And if I were being pedantic, again I’d suggest the relative insularity of MSM and injecting drug users as why subtype M’s linked with them, rather than the novelty of their behaviour as such.)
I’ll pass on commenting on your last three paragraphs, since what I know about retroviruses would fit on the back of a postage stamp. I will try checking Padian et al. again, though.
Looks like I have to split a comment too!
I’m not sure which specific time period you’re referring to with “earlier”. If you’re talking about the 1970s, I’d guess it’s because HIV simply hadn’t been introduced to those subpopulations often/early enough to stick. If you’re talking about the early 1980s, well, it looks like HIV did spread, at least among needle sharers and people who had blood transfusions. (I haven’t seen data on prostitutes.) According to this 1985 Science article, 12,932 AIDS sufferers were reported to the CDC by August 30, 1985. 1.5% of them had received blood transfusions within 5 years of diagnosis, and 17% were heterosexuals who’d used IV drugs. (Also, 12% of the homosexual & bisexual men diagnosed were IV drug users.)
Although I’m sure tops & bottoms “tend to specialize”, I doubt men with dozens of sexual partners are completely picky about which role they play. If men are inconsistent about being the top/bottom, the insertive anal transmission rate is going to be an underestimate. In fact, it’s likely to be an underestimate twice over, because preexisting STIs make transmission more likely, and promiscuous men will have more STIs on average. You’ve also got the handful of IV drug users among these men. If I’d had to bet on where HIV would rear its head first, the bathhouse subculture would’ve been a great choice to put my money on.
But neither of those can have an impact until HIV’s introduced to the subpopulations of needle sharers/blood donors, and even after that, their effect will depend on when HIV reached those subgroups, and how many people in those subgroups start off with HIV.
Only if you define “early” as really early: the first reports of IV drug users with AIDS came out in the same year as the first reports of AIDS in gay men. And again, risk isn’t everything. Even if group X has much higher transmission risks than group Y, if the virus reaches group Y first, the earliest infections are likely to emerge in group Y.
While the receptive A rate is higher than the receptive V rate.
Ease of person-to-person transmission within a subgroup matters more to how quickly a disease spreads through that subgroup than the subgroup’s absolute size.
Which increases the ease of transmission.
Which doesn’t much matter if there’s hardly any HIV among those women to start off with. I’d also guess that the proportion of “sexually liberated women” having as much sex and injecting as much drugs as gay men in the 1970s/1980s bathhouse culture is relatively small.
As often as promiscuous gay men?
See above about subpopulation size.
To extend your own metaphor, the “hetero” channel was wider than the “homo” channel, but the “homo” channel had faster flow. Plus, again, there were gay men who engaged in IV drug use, and if gay men were among the first US citizens exposed to HIV, as is very possible, that would’ve given them a head start.
Not sure what that means specifically.
It’s the hypothesis favoured by the medical establishment and the scientific mainstream on the basis of evidence that is at least circumstantial, and at best definitive, which suggests it’s a good starting point. I’m not plucking an arbitrary hypothesis to defend out of thin air.
I really disagree with how you’re framing things here. It’s screwy to split horizontal transmission & vertical transmission into separate hypotheses, since both processes are happening right now throughout the human race, and both processes happen at different rates across time & place. I don’t understand why the mode of transmission corresponds to how long HIV’s been circulating in humanity, either.
Mother-child HIV transmission rates per child (without anti-HIV prophylaxis) are generally higher than sexual transmission rates per sex act, sure. But there’re a lot more sexual acts happening than childbirths. So there’s more to the situation than raw transmission rates.
There are several documented cases of early AIDS where we have stored tissue that later tested positive for HIV, such as the gay teenager who died in St Louis in 1969. This poses a serious problem for the standard theories that HIV is transmitted horizontally (unlike any other retroviruses) and presumably came out of Africa. So how did it get into this teenager? You would need some world travelling gay subculture at the time to link the disease to Africa, but not a big enough subculture to create an epidemic. Since only a small portion of men are gay, we should expect that if it came out of Africa the first vectors would have been heterosexual, not homosexual. And as there are several of these strange early cases, it would have had to come over from Africa multiple times, but always only in gay men. This theory is just not salvageable.
Also, consider that the different genetic subtypes are closely associated with particular risk groups—subtype M appears in MSM and IV drug users but not others, which doesn’t make any sense for a horizontally transmitted viral vector. Most of the subtypes are linked to particular geographical regions in Africa, which points to a long history in humans (with M representing a novelty linked to novel behaviour).
Also consider that all other primates have naturally occurring lentivirus family retroviruses very similar to HIV. Consider that the entire family of retroviruses are more symbionts than parasites—humans are ‘infected’ with thousands of different retroviruses, many of which are integrated into our genome, and they have functional roles in gene expression and even the formation of the placenta.
So if all other primates have naturally occurring lentiviruses, why don’t humans? There is a clear evolutionary niche for a lentivirus in mammals, and it seems odd that homo sapiens somehow lost their naturally occurring lentivirus at some point in our evolutionary divergence, only to re-acquire it very recently in the last one hundred years. It just doesn’t make any sense at all.
Retroviruses generally are not horizontally transmittable, and there is no evidence that HIV is an exception. The Padian study in the other thread branch directly shows that HIV is probably not sexually transmittable.
But most of the earliest confirmed AIDS cases were retracted (David Carr) or have a direct connection to Africa (anonymous Congolese adults & Arvid Noe). It’s only Robert R. (the “gay teenager” you refer to) who didn’t have a direct African connection, but that doesn’t mean there wasn’t one, and such a connection wouldn’t even be necessary with Haiti available as a closer source of HIV.
This is one teenager. He only had to be unlucky once when having sex with just one infected man.
I’m confused. This PNAS paper presents good phylogenetic evidence that the HIV strains causing the North American epidemic came from Haiti, and that Haiti’s HIV came from Africa in the 1960s, which “suggests its arrival in Haiti may have occurred with the return of one of the many Haitian professionals who worked in the newly independent Congo in the 1960s”. So it’s Haitian economic migrants who would’ve been the “first vectors” to carry HIV out of Africa in any real number, and I have no reason to think they were disproportionately homosexual.
If by “strange” you mean that all those cases are inexplicable, I disagree.
Not at all.
I’m not an epidemiologist (or a geneticist), but couldn’t that just be a founder effect perpetuated by MSM and IV drug users transmitting HIV much better amongst themselves than they transmit it to everyone else?
I’m not seeing why this would be evidence for/against orthodox theories of HIV & AIDS. (And if I were being pedantic, again I’d suggest the relative insularity of MSM and injecting drug users as why subtype M’s linked with them, rather than the novelty of their behaviour as such.)
I’ll pass on commenting on your last three paragraphs, since what I know about retroviruses would fit on the back of a postage stamp. I will try checking Padian et al. again, though.