STOP PRESS: Henry Bauer knows bugger-all about epidemiology, and HATES IT when you correct him on his own blog

FAIRLY STANDARD BIT OF BAUERIAN NONSENSE on HIV Skeptic the other day.

The occasion was the release of the (United States) District of Columbia’s HIV/AIDS Epidemiology Annual Report for 2008 which announced that 15,120 prevalent adult/adolescent cases of HIV infection had been notified up to the end of 2007, giving a prevalence rate in the District of 2.98%. This was an increase from the previous year: only 12,428 cases had been notified up to the end of 2006, for a prevalence rate of 2.49%.

Henry’s gripe was with the way this was reported in the main news media as DC’s HIV prevalence rate “hitting” 3%, as if the change from 2006 to 2007 represented new actual seroconversions occurring in that 12 month period. In fact, much of the apparent rise was the product of a belated but fairly concerted testing campaign to identify previously undiagnosed cases, and also to tighten up the HIV surveillance notification system, which has been basically non-existent until quite recently. Readers from countries such as Canada or Australia might be surprised to note that the 2007 report (compiling data to the end of 2006) was the first ever to try to tally actual HIV diagnoses in the District. Prior to that, HIV prevalence rates were fairly rough estimates based to a large extent on AIDS notification rates, and a figure somewhere around one in twenty has been generally accepted for some years. (DC's AIDS (not just HIV infection) rate in 2006 was 2.0% (2,016.5 per 100,000) according to the CDC estimate.)

This prompts Henry to fume:

Ignorance of the past is exemplified here by the report, from January 2008, that “One in 20 Washington, D.C. residents is HIV-positive” . One in 20 equals 5%. Fifteen months later, the media trumpet the alarming “news” that the rate has “hit” 3%. They should rather have been celebrating the 40% decrease from 5 percent to only 3 percent in not much over a year. With the media, it’s a lack of familiarity with the data and the history of these press releases. With officialdom, it’s that every string must be pulled to remind everyone how serious the situation is and how desperately the pertinent agencies, offices, and workers need continual infusion of funds.

Now media reporting about HIV/AIDS is like media reporting about other important issues: some of it is ignorant, sensationalist crap, and some of it is more intelligent, informed and nuanced (See Craig Timberg’s Washington Post article linked below, as an example of the latter). But here Henry is completely missing the mark: the 5% figure is an estimate of the actual prevalence, the number of people walking round with HIV whether they know it or not, while the 3% figure is a count of actual diagnoses notified up to a particular date. The fact that the count could increase from 2.5 to 3% in a single year indicates that the testing and notification figure is still underestimating the true prevalence, and actually suggests that the 5% estimate may not be all that far from reality. Nationwide, the CDC estimated in 2006 that 21% of HIV cases in the country were as yet undiagnosed, using back calculation methods based on the disease progression at the time of new diagnoses. DC’s unreported HIV figure is almost certainly higher than that, not just because many are still undiagnosed, but also because the name-based notification system is only a couple of years old, and has yet to fully mature.

AIDS IN THE DISTRICT IS SERIOUS BUT NOT CRITICAL according to the Washington Post's Craig Timberg, but it depends on what you call "critical". While it’s an order of magnitude higher than the country as a whole, and is similar to the national prevalence of some sub-Saharan African countries, much of this is an artifact of DC's unique geography in the US. DC is a small (177 km²) densely populated inner urban parcel of land smack bang in the middle of a large metropolis which is itself only one of several in one of the most urbanized regions on the planet. HIV is disproportionately an inner urban phenomenon in most Western countries because that’s where the relevant sexual and drug using networks tend to concentrate. You can’t directly compare DC’s rates with those of whole states or countries that include not only inner urban but also suburban, small town and rural populations.

Furthermore, a slowly rising true prevalence is not all bad news. Prevalence is cumulative incidence minus deaths: and while a rise in prevalence reflects disease transmission and new infections, it is also a function of improved survival: HIV positive populations are increasing, but they’re also getting older – the treatments are working and more people are living with HIV/AIDS rather than dying from it.
Those considerations aside, a three to five per cent seroprevalence is still substantial and concerning even for an inner city district in the first world, and indicates longer term failures in public health, exemplified by the fact that no one knows how many HIV positive cases remain uncounted, even in 2009. You can't have a flexible and targeted respose to prevention if you can't follow trends in new infections because you are still playing catch-up counting the old ones. And if substantial numbers of people have HIV and are unaware of it then they are more likely to infect others, and individuals will often miss the optimum window for commencing treatment.
One issue has been that Congress has obstinately and perversely blocked city funding for needle exchange services until recently - this is an absolutely bedrock-basic public health measure that's been accepted in most comparable parts of the first world for years if not decades. Injecting drug users have sexual partners (and babies) like everyone else. A lack of ready access to clean needles threatens the health not only of IDUs themselves but the community generally. A lack of reliable prevalence and incidence data means that potential threat is hard to track.
One fallacy that arises from dividing people into "risk groups" for infection - gay men, IDUs, high risk heterosexuals - is that it fosters the illusion of separate parallel epidemics in separate groups. In reality, this is not necessarily the case: for example an infant may be perinatally infected by a mother who contracted HIV heterosexually from a partner who contracted it sharing a needle with a male who got it homosexually from another male and so on down the chain of transmission. When you ignore IDUs in your public health efforts to prevent HIV transmission for whatever political reasons, you undermine everything you've been trying to do to prevent heterosexual, homosexual and perinatal transmission as well. Politicians just don't seem to get this.



LIKE MANY CRANK DENIALISTS, Bauer is going off half cocked at mainstream press reports that he hasn’t bothered to understand. This becomes clear in the comments section of his post, which is interesting reading in itself with several different themes, including Michael Geiger’s bizarre psychologising (see my previous post here) and Henry’s ongoing obsessive fascination with the mechanical and microbial integrity of the Gay Male Lower Intestinal Tract (which deserves a RE post in itself). But for now let’s stick to the epidemiology, which was the subject of his header post.

The weirdness begins at comment #2 with “Jonathan” (resistanceisfruitful or RIF) announcing that he is quoting Henry’s nonsense on his own blog on Open Salon. Then a poster called MG18 turns up on RIF’s Salon blog, and makes critical comments about Henry’s understanding of the figures and posts a link to Reckless Endangerment. RIF wrongly assumes MG18 is yours truly Snout, and huffily accuses him/her of stalking him. Fine, says MG18, I’ll do my own post on the subject on Salon and makes a pretty good fist of deconstructing Henry’s nonsense figures.

Meanwhile, in his dial-up-internet-connected kennel in the World's Top City, Snout is relaxing after a hard day at Pharma Shills Inc., and has been indulging in his favorite secret vice of vanity googling. He discovers that his name is being taken, well, in vain, and that he has already been banned from a blog he’s never in fact visited. Curiosity piqued, he checks out the various threads, and reads the following comment, #5, on HIV Skepticism:

Henry Bauer said
Monday, 23 March 2009 at 5:17 pm

Que?
The anonymous blogger [MG18] merely confuses things by mixing numbers of
cases and rates. Whenever rates are cited, it’s the number of HIV+ RELATIVE TO THE NUMBER TESTED. Since rates are cited for 2008 and for 2009, one can legitimately compare those directly. Trying to calculate between rates and numbers can’t be done without considering the numbers who were tested in each case. Everything is consistent with what I wrote, that the “epidemic of HIV” is an epidemic of TESTING. This anonymous blogger is typical of the HIV/AIDS groupies and vigilantes in trying to evade facts by red herrings and obfuscations.

At this point, Snout’s irony meter spins into overdrive, and he cannot resist the temptation to send a post to Henry, despite the unlikelihood it will pass his “moderation”. Surprisingly, it does, and appears as comment #8:

Snout said
Monday, 23 March 2009 at 11:51 pm

“Whenever rates are cited, it’s the number of HIV+ RELATIVE TO THE NUMBER TESTED.”

No it’s not, Henry.

The 3% figure (2.98% to be precise) is the percentage of the entire adult population of DC who
(a) are currently living, and
(b) have been diagnosed with HIV.

In round figures, 15,000 are currently living with an HIV diagnosis out of a
population of a little under half a million. Around 3% in other words.
There is also an unknown number of people who have HIV antibodies (and thus HIV infection according to mainstream science) who have yet to be diagnosed. Some estimates put their numbers at around 10,000. If that is the case, then the total number of people with HIV (diagnosed or undiagnosed) would be 25,000 or around 5% of the half million population of DC.

And Henry’s reply?

Henry Bauer said
Tuesday, 24 March 2009 at 10:28 am

Snout:OK, I should have said, ““Whenever rates are cited, that OUGHT TO BE the number of ‘HIV+’ RELATIVE TO THE NUMBER TESTED.”If one merely takes the number of “HIV+” people DETECTED after testing x% of the population, it isn’t valid to divide tha number by that of 100% of the population to derive a rate, because you don’t know how many “HIV+” people there may be in the (100-x)% of the population that was not tested. If all the tests were carried out among the high-risk groups, then the true rate for the whole population would be lower, for example.The official estimates were given as 5% at the end of 2007 and 3% now. If those were derived by invalid calculations, it would merely be another instance where official HIV/AIDS numbers are not to be trusted, for quite a variety of reasons.The whole population of Washington DC wasn’t tested in 2007, and it wasn’t tested in 2008 or in 2009. The increase reported was an increase in the NUMBERS of HIV+ people detected AMONG THOSE WHO WERE TESTED. So the “epidemic” increase is not in the RATE but in the NUMBERS. It’s an EPIDEMIC OF TESTING — as also in other parts of the world.

(And in Comment #30 he adds): “Please note also in the story you linked to, that the official position ALWAYS is that the “true” numbers and rates are (probably/almost certainly/surely…) greater than what was actually observed.”

It’s hard to know where to start with such a garbled and confused analysis. But never one to shirk a challenge, Snout replies with:

Snout said
Your comment is awaiting moderation.
Thursday, 26 March 2009 at 12:27 am

"The increase reported was an increase in the NUMBERS of HIV+ people detected AMONG THOSE WHO WERE TESTED."

Henry, I think you are getting quite confused here. The number of people known to be HIV+ prior to them testing and getting a new incident diagnosis recorded in 2007 was zero. If you already know you have HIV you don’t usually bother retesting. If you do happen to retest after already having an HIV diagnosis then your extra positive diagnosis isn’t added to the year’s incident diagnoses, because it is already known and recorded.

The prevalence numbers are calculated by adding all the new diagnoses for the year to the previous cumulative tally, minus deaths. The prevalence rate is found by dividing prevalence numbers by the whole population each year. You seem to be implying that the prevalence rate is calculated by dividing the number of positive tests by the total number of tests. This is only true if you are conducting a seroprevalence survey with a truly random sample of the population you are trying to calculate the rate for. That’s not what they’re doing in DC.

Part of where you’re getting confused, I think, is in assuming that HIV positivity following a confirmed diagnosis is a transient phenomenon that changes from year to year, which is why I addressed this misconception very early in “Reckless Endangerment”. People who have a confirmed diagnosis of HIV infection one year don’t become HIV negative in subsequent years. The 15,120 HIV positive DC residents counted at the end of 2007 are all the adults and adolescents first diagnosed not only in 2007, but every year since testing began, minus all the deaths over the years.

"So the “epidemic” increase is not in the RATE but in the NUMBERS. It’s an EPIDEMIC OF TESTING — as also in
other parts of the world.”

The “epidemic” increase from 12,428 in 2006 (2.49% of the adult/adolescent population) to 15,120 in 2007 (2.98% of the adult/adolescent population) is an increase in prevalent cases identified and counted. It almost certainly doesn’t represent a 22% increase in actual infections out there, but is mostly an increase in the proportion of actual infections that have been identified and counted. We don’t know exactly how many people with HIV infection there are in DC. Some estimates have put it as high as 25,000 or 5% of the adult/adolescent population. So far, they’ve found 15,000 or 3%. The number and rate of identified cases is likely increase over the next few years, because if you find two or three thousand previously unknown cases in one year, most of whom are not newly infected that year, then there are almost certainly a lot more to be found.

"Please note also in the story you linked to, that the official position ALWAYS is that the “true” numbers and rates are (probably/almost certainly/surely…) greater than what was actually observed."

True numbers will always be more than actual case counts observed, when there is still a proportion of the population yet to be tested. If you find 15,000 cases after testing say 60% of the population, then the true number of cases in the whole population can’t be less than 15,000. It’s 15,000 plus however many there are in the untested proportion. The true rate of HIV prevalence in DC at the end of 2007 was (15,120 + x)/506,722, where “x” is the number of people with HIV who have not yet been diagnosed.

Needless to say, this comment failed Henry’s moderation criteria. If it had passed, it would have been comment #33.


BY NOW, ASTUTE READERS OF Reckless Endangerment and Henry Bauer’s HIV Skepticism will have realized one of the main reasons I set this blog up.

Henry’s HIV Skepticism was created partly as an author’s blog to promote his 2007 book The Origin Persistence and Failings of HIV/AIDS Theory, and he uses it to try to reach a wider audience for his beliefs about HIV and AIDS which are founded on his own rather eccentric interpretation of HIV/AIDS epidemiology. He also uses it to uncritically repeat many of the standard Canards of AIDS Denialism, and to rail about the generally poor state of modern science, whose principal deficiency has been a failure to recognize Henry's self-evident iconoclastic genius. By some accounts HIV Skepticism has become something of a full time hobby for him in his retirement. Next thing you know he'll be penning furious letters to his congressman.

In truth, Henry’s grasp of HIV epidemiology is ill-informed, confused and hopelessly inept. The reason his “insights” have been largely ignored by the scientific mainstream has nothing to do - as he claims - with self-interested scientific cartels or knowledge monopolies. It’s because his thesis is just plain woeful, and would be a miserable failure if submitted even at undergraduate level in any competent statistics or epidemiology course.

Henry uses “moderation” in his blog to create the illusion that thesis has never been answered, and is, in fact, unanswerable.

Que?