Thursday, March 04, 2010

Where's UCLA Data Showing Surging
HIV Drug-Resistance in SF?

Has a single dire HIV-related prediction forecast by Sally Blower, either while she was at UCSF or at her new scientific home, UCLA, proved true and was the proof offered by independent researchers? After a month of searching for such proof, I can't find it, and I decided to examine an earlier controversial model she concocted for San Francisco's people with AIDS.

Here's the thing that really bugs me about Blower's previous HIV drug resistance math model. Her alarmist prediction in August 2001 said SF would in a few years have a high resistance rate:

Blower’s team estimated that only 3 percent of cases in San Francisco were drug-resistant in 1997. However, by 2005, they predict that 42 percent of all HIV cases will be drug-resistant.

Yet, a report presented last year at a conference on retroviruses found a drop in transmitted resistance. The 2009 study from UCSF researchers found 28 percent resistance rate, much lower by 14 percent than what Blower predicted. A story at The Body about the UCSF research used this headline: Sudden Drop Observed in Transmitted HIV Drug Resistance Among Cohort of Recently Infected San Francisco Patients. From The Body:

What we found is that overall, the transmission of drug-resistant virus seemed to increase from 2003 to 2007, to the point where, in San Francisco in the year 2007, 28 percent of all new cases of HIV were resistant to at least one drug.
What's interesting is that that following year, in 2008, we had a large drop in that resistance. And this is an interesting trend that we're going to look at now to see what led to that drop.

Seems to clear to me, the UCSF experts, who were dealing with actual people not just theoretical modeling, observed a decrease in drug resistance. Yet, a year later, according to the UCLA press release about Blower's new controversial model, one of her colleague alleges a rise in resistance:

"What was very disturbing was we found that some of the drug-resistant strains were increasing," said Smith, now an assistant professor in the department of mathematics and statistics at the University of Ottawa.

If Blower and her colleagues were coming down from their ivory tower, respectfully engaging the local community about their research and the contradictory studies and rates, we could make some educated sense of the confusing studies. Why is Blower's 2001 prediction apparently undercut by the 2009 UCSF research, which is at odds with supposed findings of Blower's 2010 math model? Just one question Blower and colleagues refuse to address.

To get a fuller picture of what is going on with HIV drug resistance here, I've looked at available data from SF DPH about it and there doesn't appear to be any reason for alarm or that the resistance poses "a great and immediate threat to global public health," as Blower claimed in January.

First of all, the latest annual HIV epidemiology report doesn't mention drug resistance a single time. Same omission for the 2007 epi report and also in 2006. These reports, which are quite comprehensive and include a section of PWA use of cocktails, say nothing about resistance.

Second, since thousands of HIV tests are performed annually at the DPH central STD City Clinic, I checked the three most current yearly STD epi reports, which includes tons of data from City Clinic. Well, for 2008, and 2007, and also 2006, the annual STD epi reports omit any HIV drug resistance references.

One place where HIV drug resistance showed up for a few years, was the December monthly STD reports, which presented prelim percentages of drug resistance for at-risk individuals tested _only_ at City Clinic. Let me emphasize these prelim percentages are _not_ for the entire, but, they still serve as a surrogate marker for such resistance.

In the December 2004 monthly STD report, drug resistance at City Clinic was 12% (16 persons). For 2005, the rate jumped to 14% (18 persons), and in 2006 the figure remained stable at 14% (22 persons). Then in the December 2007 edition, this measurement is gone and no explanation is given by DPH for no longer tracking resistance at City Clinic.

If the drug resistance problem is so worrisome, as Blower claims, shouldn't the DPH track resistance data and present it in the annual and monthly reports? Yes, indeed DPH should. How can we reconcile Blower's gloomy "great and immediate threat to global public health" allegation, and the incredible absence of recent or current data on resistance from the healthy department?

In related news from Seattle, published on January 21, 2010, days after Blower's model was published in Science, health officials up there released their latest data on drug resistance. Seattle experts show that testing for resistance among newly diagnosed HIV cases is at 52% completeness, and number of those tested has gone up, the prevalence of resistance across numerous categories remains stable:

Prevalence of high-level antiretroviral drug resistance and HIV-1 subtypes among newly diagnosed HIV cases in King County, by diagnosis year




High-level resistance
2 or 3 classes

If there is increasing drug resistance in either San Francisco or Seattle, I'd like to see the data. All of this data from these two cities demand that Blower and colleague end their ivory tower silence and learn to communicate with folks raising serious questions about their HIV math modeling.

No comments: