The following paragraphs were taken word for word from an article published in the Journal of Clinical Microbiology, Jan 2005 by Microbiologist, J. Clin.

An 11-week-old boy died unexpectedly in January 2002 a few hours after being fed, the final feeding being slower than normal. The baby was healthy and developing normally until his sudden and unexpected death. The death of the infant was classified by the pathologist as SIDS on the basis of the autopsy findings. The autopsy specimens of the child were investigated as a part of a survey on the association of C. botulinum with SIDS in Finland. Serum, feces, and autopsy sections from the intestine and spleen were examined, as was the opened package of the infant’s last meal of corn gruel.

C. botulinum type B was detected by PCR in, and also isolated from, the vacuum cleaner dust. The quantity of spores in the dust was estimated to be 10/kg of examined material.

The other household samples were negative for C. botulinum by TPGY culture and PCR analysis. The C. botulinum type B toxin gene was identified by PCR in two parallel samples of the infant’s intestinal contents, both incubated at 37°C. C. botulinum was isolated from the PCR-positive samples by plating 0.1 ml of TPGY broth on egg yolk agar plates and incubating them under anaerobic conditions at 37°C for 2 days (19). C. botulinum type B was successfully isolated from one of the intestinal specimens. All other autopsy specimens were negative for C. botulinum, and the serum did not contain detectable botulinum toxin.
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Please note: In this case, the botulinum toxin found in household dust and was found to be the most likely cause of the sudden death of baby Thomas. Neither the author of the article or Allfresh claim to have found the absolute cause of SIDS.