Public Lecture at NYC Health Department under auspices of Mayor Bloomberg. 2pm Thursday 18th March 2010
This City Department of Health public lecture started with some rather complex statistical formulae of how to deal with missing data in studies of the natural history of HIV seroconversions. Michelle Shardell PhD had ‘inherited’ a job on a long term project (ALIVE or AIDS Linked to the Intra-Venous Experience) which started, she said, while she was still in school (1988). It enrolled 3000 HIV negative injectors and ordered twice yearly blood testing to determine ‘natural’ rates of seroconversion.
Professor Shardell described the problems of having reams of data but where much was incomplete and how best to draw the correct conclusions by approximating missing data. She discussed the conflicting possible biases of those who miss blood test appointments, some because they may have been well and busy with life … while others may have been unstable and unhappy, using drugs and alcohol, being unemployed and/or engaging in high-risk behaviours and thus missed their blood test.
We were introduced to a complex set of sigma formulae which were supposed to account for missing periods in otherwise long-term data. It was a little disappointing that we were given virtually no outcome data of the study, some details of which I looked up later on an internet search.
On the other hand, Dr Don Des Jarlais quoted HIV prevalence figures for several American cities, Miami, New Orleans and Washington DC were amongst the worst with near 30% of injectors estimated to be HIV positive. In other cities, I understand, including Tucson, Seattle and St Louis, the figure was much lower, some even as low as 1% amongst injectors. In several major centres, the figure was not available.
The message was emphasised that good research from New York had shown that for injectors who began injecting before 1995 the rates of HIV was substantially higher than for those who started afterwards, in just about every category of risk. New York, unlike the rest of the country, had reasonably good access to opioid maintenance treatments as well other harm reduction services such as needle “exchange”, as it is still quaintly termed here. And it largely functions in the US as just that – ‘exchange’ new for old (imagine if we did that for condoms!). We were reminded that the proportion of dependent individuals currently on opioid maintenance treatment (OMT) was calculated to have risen from 6 to 8 percent in America, showing only a modest improvement over ten years. We were reminded also that “secondary needle exchange” (pass-it-on) was vital to the success of the intervention wherein non-addicts (sometimes called ‘alcoholics’) would make small profits by returning used needles and obtaining clean supplies to be sold/distributed at a later time for money.
Dr Des Jarlais is far too experienced to lecture Americans about foreign findings yet he subtly dropped two pearls into the mix towards the end of his presentation in lower Manhattan. He had discussed and described some of the needle services here in American cities and then told the audience that (‘tiny’) New Zealand had over 600 needle exchanges while there were only about 300 in the whole of America. He alluded to the changes in federal funding for such preventive interventions but pointed out that it will take some years for such policy change to filter down to ‘street level’. In a reference to Australia our speaker also pointed out that most of the few drug injectors who contract HIV do so from sexual exposure rather than from needles (while up to 7000 Americans do so annually from contaminated needles if we are to believe the figures).
The correlation between past genital herpes simplex infection and HIV was reiterated, pointing out the behavioural and physical reasons involved. This was clarified further during question time.
While Don Des Jarlais did not quote the HIV rates in New Zealand I had done so privately with the City Health Department official Lucia Torian before she opened the session - which was delayed slightly due to new and inordinate security introduced (all visitors were photographed and ‘branded’!). She had responded to my comment that a number of countries had avoided the HIV plague, saying that I must be referring to Russia, Ukraine and North Korea where there is still denial of the existence of the epidemic in some circles. I said that in fact I was referring to Hong Kong, Australia and New Zealand. Following another off-hand remark she made, I told her that each time I mentioned this to Americans I was either disbelieved or derided, just as she was doing.
Dr Samuel Friedman acted as discussant and in half an hour elaborated some details of the presentations. He commended Dr Shardell on her study but commented that rather than only seeking views of academic experts the team might do better to include the views of knowledgeable drug users. Such folk are readily available and many have a lot to contribute. On that subject, I once asked Professor Vincent P. Dole his opinion about a new secure medicine container. He said that before giving his views he would rather hear the views of a few drug use patients.
Dr Friedman pointed out the large number of major US states and cities which no longer publish official figures on HIV cases. His personal greatest worry in epidemiology was when data was not being collected so that knowledge of the public health issues could be swept under the carpet.
Further, we were told of a study done by Dr Friedman, Des Jarlais and colleagues which showed that the different modes of transmission depending upon the infected pool involved in a given population. Where the prevalence in injectors was >20% already, some behaviours (eg. needle sharing) were directly correlated with seroconversion. Where rates of HIV were <9% risk behaviours were not statistically associated with seroconversion but rather the predictors reflected whom they injected among. We learned that the New York rate was between 9 and 20%. There was also some discussion of arrest rates, socio-economic areas and seroconversions and some research linking them.
I mentioned to Dr Des Jarlais that Hawai’i appears to have the best organised and most widespread needle availability in the US, some of which I saw on a recent visit. Dr Des Jarlais told me he was aware of that since in fact he was the official evaluator for the State’s harm reduction project! That man is everywhere! I recall that he spoke at one of the first Methadone Conferences in Sydney almost 20 years ago, warning us about the threat of HIV and the means to prevent a second wave in drug users. His advice was timely and his campaign to implement better public health strategies continues unabated. More strength to him - and his colleagues! And thanks to the New York City Health Department for sponsoring these public lectures, and allowing strays like me in.
Comments by Andrew Byrne ..
Clinic web page: http://www.redfernclinic.com/c/
Opera blog: http://www.redfernclinic.com/opera/critique/blog/
New York in spring: http://ajbtravels.blogspot.com/
