Parasite risks lurk in children's sandboxes
The Canadian Press
Published Tuesday, June 10, 2008 1:12PM EDT
TORONTO - What little kid can resist the appeal of a sandbox, where a shovel, a bucket and an imagination give rise to all manner of make-believe?
The problem is, what looks like a perfect play environment for a young child looks like a toilet to some members of the animal kingdom. Cats, dogs, occasionally even raccoons can treat sandboxes as their very own porta-potty.
If they do, children can end up encountering some pretty unpleasant parasites in a sandbox. And while those parasites are likely rare in a climate like ours - where the annual winter freeze plays a useful role in keeping populations down - simple steps can make them rarer still, experts insist.
"There's certainly no indication that children should not go into sandboxes. These are extremely rare diseases that affect a very, very small number of people in North America every year," says Dr. Scott Weese, a veterinarian and expert in the diseases - called zoonoses - that animals and people can pass to one another.
"But it's the type of thing that even if it's very rare, (if) we can reduce it further, why wouldn't we?"
Kids at the earliest stage of sandbox play are also those going through the phase of childhood where everything, it seems, ends up in the mouth.
If the sand in a sandbox contains animal feces, children could end up inadvertently ingesting eggs of the various types of hookworms that can infect cats, dogs or even raccoons.
"So the concern is a raccoon or a cat or whatever uses the sandbox as a litter box and then while the child's playing it ingests... Parasite eggs are the main concern. And some of those can be pretty nasty," says Weese, a professor and researcher at the Ontario Veterinary College at the University of Guelph.
In some cases, the hookworms will penetrate the skin, causing a condition called cutaneous larva migrans. In 2006 a summer camp in Florida reported an outbreak of cutaneous larva migrans involving 18 campers and four staff members. Cat feces in a sandbox was thought to be the source of the infection.
Cats pose the greatest risk of sandbox contamination, says Dr. Andrew Peregrine, a veterinarian specializing in parasites who also teaches at the Ontario Veterinary College.
That's because of the animals of concern, felines are most likely to use a sandbox as a litter box. And because cats bury their feces, it wouldn't be immediately evident a sandbox might contain more than just sand. As time passes, animal stools will break up, making feces even harder to spot.
"It's thought that about 90 per cent of all the pooping that occurs in sandboxes by cats occurs at night. So a lot of people probably don't know it's happening," Peregrine says.
Dogs would less commonly use a sandbox as a place to poo, but if they did, they wouldn't bother burying it.
Raccoons like to relieve themselves in elevated areas - the crook of a tree, on a deck or into a window well. They tend to repeatedly use an area, creating what biologists call "latrines" or "scats." Raccoons generally wouldn't use a sandbox as a scat, though it's not unknown.
And given that about a third of raccoons are believed to be infected with Baylisascaris - the parasites that cause the raccoon form of hookworms - children should be kept clear of raccoon feces.
"It can be a very serious disease, a devastating disease, if someone does get it," Weese says, adding that neurological damage is common in survivors.
Peregrine notes a Toronto child developed severe encephalitis - inflammation of the brain - caused by baylisascariasis (the disease triggered by baylisascaris) a couple of years ago. The child had eaten dirt contaminated with raccoon droppings.
Eliminating the risk a sandbox will turn into a litter box is pretty simple, experts say.
"Covering the sandbox is the biggest thing. Easiest thing to do. If the cat can't climb in it, it's not going to contaminate it - full stop," says Weese.
Commercially available sandboxes come these days with a fitted cover. Keep the cover on when the kids aren't in it. For homemade sandboxes, a piece of plywood weighed down by a rock works just fine. "All you have to do is keep the animals out. It doesn't have to look pretty," Weese says.
Covering the sandbox also minimizes the risk that pools of water that could form after a rain could serve as a breeding ground for mosquitoes, other biting bugs or moulds.
"We're trying to make the environment inhospitable to everything but a kid, basically," Weese says.
Kids shouldn't eat or drink while in a sandbox and should wash their hands as soon as play is done.
Changing the sand from time to time probably also makes sense - especially if the lid has been left off and there are telltale signs an animal has paid a visit.
"If you see one piece of poop, there might be five others that are buried and smashed up you're never going to find. So if there's obvious contamination I think that would be a good time to change it," Weese says.
While it's important to keep a sandbox free of contaminants, it's also important to remember sandbox play is terrific for young children, says Dr. Perry Sheffield, a pediatrician and research fellow with the Children's Environment Health Center at New York's Mount Sinai School of Medicine.
"I think it's worth acknowledging the potential for creative development, the chance for a child to have control over their environment in terms of the make believe and the power of that," she says.
"As a pediatrician who thinks that enriching environments are important, if you can create a safe sandbox then it's a wonderful place to play."