On Sep 17, 2013, at 2:40 PM, Bob Harrison <[log in to unmask]> wrote:



> kashmir virus and nosema N. Were found in 100% of the first samples yet the finding of IAPV Was pushed as the source (at the time) of the problem 



That is a rewrite of history. What the original work actually found was:



> Although KBV was prevalent in both CCD and non-CCD samples (90.2% of all samples), IAPV was, with a single exception, confined to CCD samples, yielding a positive predictive value of 96.1%. We found Nosema spp. by PCR and spore count in both CCD and non-CCD operations. Neither KBV nor N. ceranae contributed significantly to the risk for CCD, nor did they alter the influence of IAPV on CCD.

> 

> We have not proven a causal relationship between any infectious agent and CCD; nonetheless, the prevalence of IAPV sequences in CCD operations, as well as the temporal and geographic overlap of CCD and the importation of IAPV-infected bees, indicate that IAPV is a significant marker for CCD. All of the CCD operations that were sampled used imported bees from Australia or were intermingled with operations that had done so. 



What they said at the time was that both CCD and non-CCD hives had KBV and Nosema C, but the thing that was unique in CCD was IAPV. This DOES NOT mean it causes it, but that it is associated with it. The outbreak of CCD also coincided with the importation of bees from Australia.



Spanish researchers continue to insist that Nosema alone can cause colony collapse (this is not CCD per se). Varroa and the related viruses also cause colonies to collapse, have done from the beginning. 



The only thing unique about the CCD hives that has ever been nailed is IAPV, so far as I know. Ian Lipkin took a lot of flak for claiming to have found the cause of CCD, a claim which he never made. He wrote recently:



> Finding footprints of a microorganism is only the first step in establishing a causative role for that microorganism in a disease. Host factors can have a profound impact on susceptibility to infection and the consequences thereof. Agents that are normally innocuous can have high morbidity and mortality rates in individuals with immunological deficits, whether those deficits are due to genetic mutations, age, malnutrition, [or] a co‐occurring infection.

> 

> The best established criteria for proof of causation were formulated by Loeffler and Koch in the 1880s. Popularly known as Koch’s postulates, these criteria require that an agent be present in every case of the disease, be specific for the disease and be sufficient to reproduce the disease after culture and inoculation into a naive host.



> 

> Although we will continue to see instances in which classical approaches to microorganism hunting, like culture and the pursuit of Koch’s postulates, will succeed, pathogen discovery has evolved from a ‘whodunit’ exercise carried out by solitary investigators to a team effort involving microbiologists, cellular and systems biologists, geographers, mathematicians and other specialists. 



Lipkin, W. Ian (2013) NATURE REVIEWS | MICROBIOLOGY





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