Tuesday, May 30, 2017

Zimbabwe's historic anthrax epizootic: new analysis

A paper has been published here and, while in draft form, discussed at length here, which reanalyzes the features of Zimbabwe's anthrax epizootic, which began in 1978 and slowly tailed off after 1980.

The authors include an MD and geography specialists from the University of Nevada, Reno.  The first author, James M. Wilson, MD, has founded a center to investigate and forecast epidemics.  From his bio:
Director, Nevada State Infectious Disease Forecast Station @ the University of Nevada-Reno.This is the first operational infectious disease forecast station in the United States that operates at the state level. 
The group has done a great job collecting information about weather (temperature, rainfall), soils, outbreak locations, possible means of spread, and number of animals and humans affected, as well as the movement of the epidemic over time.  The group has pulled together the detail needed to create maps and tables that convey how the epidemic evolved chronologically.

The authors have [as I believe I did in 1992] put to rest a number of unsupported theories as to the nature of the epidemic, and confirmed that the geographic "hops" anthrax made are not explained by natural occurrences.  The authors confirm that anthrax cases extended to the borders of Zimbabwe, but remained confined within Zimbabwe's boundaries. Adjoining countries experienced no similar epizootic.

The authors agree that the vast majority of human cases were associated with exposure to anthrax-contaminated animals, hides or meat.

Of interest, a number of anonymous commenters were extremely critical of Wilson's paper as it was in progress.  Their arguments were mostly specious, and I would be able to knock each down if it was useful to do so; I did knock down a few, then stopped sparring with anonymous critics.  If the critics were serious, presumably they would have used their names.  What was interesting was the concerted attack on Wilson, some 38 years since the onset of the epizootic, to deny the event could have been due to biological warfare.  Yet there is no other explanation, consistent with the facts, that has ever been put forward.

Wilson's paper also makes clear that the 2015 report on this epizootic, by Stephan P. Velsko from Lawrence Livermore National Laboratory (LLNL), self-published by LLNL, is not worth the paper it is printed on. Velsko ditched the facts and built a house of cards based on his own inferences about the epidemic, providing an example of the extreme lengths a so-called scientific exercise can be taken to turn the scientific method on its head. I criticized his work here.

Wilson reported that I had been living in Zimbabwe at the time of the epizootic.  Actually, I was living in the US.  I travelled to Zimbabwe to study the epizootic in 1992, and did a poster presentation on the epizootic in Nairobi at the International Society for Infectious Diseases in July 1992, making the argument that the many unique features of this epizootic could only be explained as an act of biological warfare.  Margarete Isaakson, a South African infectious disease scientist with likely connections to Project Coast, and an interest in Ebola, screamed at me in Nairobi for daring to present such rubbish. I believe this was because I came too close to her area of expertise.

Nothing has changed since Zimbabwe's tragic epizootic.  Biowarfare is a horrible mode of warfare that has not been eradicated, identifying it is controversial, and developing the scientific tools that allow one to definitively identify when an act of offensive biowarefare has been used, shifts the balance of power from the perpetrators to the investigators and to those who were attacked.  That seems a very fair power shift, but it isn't to everyone's liking. (What makes biological warfare especially attractive is the ability to hide that it actually occurred, and who caused it.) Scientific studies that remove this advantage are, unsurprisingly, being attacked.

The attacks, mostly spurious, that Wilson has received for his paper tell us there are still many people who would keep the whole subject under wraps.

Finally, despite a 2010 paper by Fasanella et al. that flies can transmit anthrax spores in the lab (and several similar earlier papers going back decades have found the same thing), the problem is the flies' failure to transmit enough spores or viable vegetative forms to cause illness in livestock, because on the order of one million spores is required to achieve an infectious dose. It is much more likely that flies could transmit anthrax to rodents, for whom several orders of magnitude fewer organisms are required.  But in nature, they do not seem to do this, either.  So much for the fly theory.

While I am pleased this subject is getting the careful attention it deserves, I wonder why it is getting it now?

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