#RaccoonDog & #SARSCoV2: What's the link? Often when trying to understand emerging viruses, looking at another spillover event provides important insights. #SARSCoV2 & SARSCoV1 (cause of 2002/2003 epidemic) are very similar viruses (same species): SARS1 may hold some clues 1/
Upon investigating the origin of #SARSCoV1, animals sold in wet markets of outbreak regions were tested. Most work was done on civet cats but there were surprising results on raccoon dogs as well: All raccoons dogs tested on markets were SARS1 positive incl. virus isolation 2/
Animals were found in markets in Guangdong and Shenzhen, both regions with early SARSCoV1 spread. Virus was found in throat & rectal swabs & live virus isolated from a fecal sample & animal had antibodies against SARSCoV1. 4/
Kan et al report peak VL >10E6 in civet cats, but unfortunately no VL for raccoon dogs are given. Since virus was isolated & sequenced, VL must have been rather high as well. Sequenced virus was identical to civet cat sequences: Direction of infection could not be determined 5/
A good review on the animal reservoirs of SARSCoV1 is this one : sciencedirect.com/science/articl…, concluding: "Unlike the situation with masked palm civets, very limited research has been conducted to survey wild or farmed raccoon dog." 6/
One wonders why there was not more investigation with a 100% prevalence from randomly selected raccoon dogs at wet markets. For civet cats, surprisingly, the virus was not found in the wild, but only in markets and to a lesser extend in farms, suggesting infection during trade 7/
Conclusion: Raccoon dogs played already a role in SARSCoV1 with high infection rates but were understudied. More recent data on experimental infection with SARSCoV2 is in line with what was found for SARSCoV1: Here virus was found in nose, throat & fecal samples incl isolation 8/
Like for SARSCoV1, animals seroconverted with high antibody titers. ncbi.nlm.nih.gov/pmc/articles/P… No data are given on disease of raccoon dogs with SARSCoV1 in the old studies but for SARSCoV2, there were only subtle clinical signs. 9/
So what else about raccoon dogs? Unlike civets cats which are farmed for food, raccoon dogs are mainly for fur, in very large abundance, specially in northeast China. Fur producers in China own >14 million captive raccoon dogs, that is 99% of the global share of raccoon dogs 10/
actasia.org/wp-content/upl… - this is an interesting report from 2019: "(the industry) is in the process of consolidating its strength through international collaboration, and by adapting its supply of fur in line with new fashions for fur trim" 11/
This means that almost every fluffy fur trim on hoods and caps comes from Chinese raccoon dogs. Interestingly this farming is largely done as household breeding facilities, that decide on own standards (or lack thereof). Many reports on a lack of animal welfare here as well. 12/
In summary, raccoon dogs are shown to be susceptible for SARSCoV1 and SARSCoV2, with many aspects that make them a likely (recent) intermediate host along the trade chain. They were already understudied in SARS1 and one wonders why there are no studies on SARS2 13/
Taken together, the data on SARS1 and experimental data on SARS2 in raccoon dogs are very well in line with the report of the metagenomic findings of raccoon dog DNA and SARSCoV2 RNA intermixed (that will hopefully be released soon as preprint.) 14/
In terms of pandemic prevention, the continuation of farming of known high-risk spillover species like civet cats & raccoon dogs after SARSCoV1 is a massive a global failure. If it goes on after SARSCoV2, any talk about pandemic prevention/preparedness remains nothing but a farce
I recently did a lot of reading on spillover events from before the pandemic for a book that I am currently writing on viruses, bats & their complicated relationship with humans - hopefully released in august. My conclusion: there is a LOT that we can learn from the past events.
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