There was a picture in the weekend edition of the Guelph Tribune of a 3-year-old girl with a large python wrapped around her as part of a nature show put on by the Guelph Lake Nature Centre.

While I’m certain I’ll face more wrath from the keep-reptiles-in-schools group that is currently bashing me on the internet (there’s even a Facebook page… at least I’m making an impact!), this brings up a few serious issues. One is the whole idea of putting a python around the neck of a young child. I won’t go there, and in reality the risk of injury is very low. The main issue is, obviously, Salmonella exposure, because of the high rate of Salmonella shedding in reptiles and the high susceptibility of young kids to salmonellosis. A recent paper in Zoonoses and Public Health (Hydeskov et al. 2012) provides more evidence that the concerns about Salmonella exposure in such situations are valid.

  • This study involved the reptile collection at the Copenhagen Zoo. There, the reptile collection consists of two groups: the main group is comprised of animals in the breeding centre, quarantine station and the primary zoo exhibit; the other group is a smaller collection that’s used for education and hands-on teaching. The latter group has direct contact with many people, including kids.
  • Salmonella was isolated from 35% of reptiles overall, with the highest prevalence in snakes (62%).
  • Reptiles from the education group had a significantly higher prevalence than the other reptiles; 64% vs 23%.
  • While these numbers are high, they are presumably an underestimation, since other studies have shown that you will miss a reasonable percentage of positive animals if you only test a  single sample from each individual. So, it’s fair to say that at least 62% of snakes and at least 64% of education-group reptiles were Salmonella positive.

Has the zoo ever been the source of Salmonella in a person? Nothing’s been confirmed; however it’s important to note that in Denmark, official investigation of salmonellosis cases only occurs as part of an outbreak. Since reptile-associated salmonellosis would most likely occur as sporadic cases, not an outbreak, cases might not be identified and reported.

It’s also possible that the zoo hasn’t been a source, because of the short-term nature of contact with the reptiles, contact only by older children and their hygiene practices.

At the Copenhagen Zoo, all reptile contact by kids is supervised, and students are required to wash their hands after touching a reptile. That’s a great approach (as long as compliance is good), and the risks should be low for a short-term supervised activity such as this. High-risk kids, from an age standpoint, aren’t involved since only 7-18 yr old students participate. So, the main group that would be of concern is immunocompromised children, who comprise a small but important subset of participants, and one that may slip by the established control measures since not all immunocompromised kids are readily identifiable. Unless schools know about all high-risk kids (and I’m far from convinced they do) and know that there are things these kids shouldn’t do (e.g. have contact with reptiles), there are still some concerns. Those can be lessened further by ensuring that there is good communication between parents and the school, such that schools are really aware of any high-risk kids. That requires adequate knowledge on the part of the parents and the school, good communication in both directions and trust (since private health information is being disclosed). We have a long way to go to get there, and few people seem interested in starting those discussions.

Back to the Guelph paper photo. This wouldn’t happen at the Copenhagen Zoo, since they apparently don’t let 3-year-olds have contact with reptiles. I wasn’t there so I don’t know what was done in terms of hygiene, but even if this girl washed her hands after, there would still be a good chance that Salmonella was present on her skin or clothing based on how she handled the animal. This nature centre does some excellent work but I worry about the shows they offer for birthday parties. Their advertisement for this, with the "bring your cake and touch a snake" approach, and the picture of another young child with a snake draped around her raises concerns.

Reptile contact isn’t inherently bad. There are just situations when it’s high-risk and should be avoided. Beyond that, if it’s going to be done, it must be done right. Unfortunately, more often than not, that’s not the case.