Wednesday, December 7, 2011

Tiny Ticks can carry a big punch!


When we were kids, one of the "Ditties" that we used to sing was "If you go down in the woods today, you're sure of a big surprise", which I think ended up being about teddy bears. But what got me humming my old nursery rhyme was nothing to do with bears, but ticks! My eye had been caught by an article about a rare new infection, a bacterium called Neoehrlichia mikurensis which was first identified in Japan, and which had now been found to be transmitted by ticks on the other side of the world in Gothenburg Sweden !

I like to go walking in the country north of Perth WA, and at this time of year it is so easy to pick up ticks - kangaroo ticks, and "salt and pepper" ticks - as you walk through the bush or the woods, and there are as many folkloric ways to manage tick bites as there are different species of those pesky arachnids. So any information about reducing risks always attracts me.

Ticks have eight legs and pass through several stages before they reach adulthood - egg, larva, nymph and then the adult. They mainly appear in the spring and summer months and attach themselves to the tips of long grass or bushes before attaching themselves to "passers-by". If that's a human, they then tend to climb up inside the clothing to the warmer areas of the body, such as the head and neck, and then settle down for a feed by burying their snout and head under the skin to suck blood.

Ticks can cause problems by a reaction to their saliva causing

  • local reactions and itching
  • generalized allergic reactions
  • paralysis due to toxic proteins - dogs
  • spread infections such as Lymes disease in the Asia, Europe and North America

This new infection reported in Sweden has only been found in 8 people worldwide since 2004, so it's unlikely to be coming to an "Tick" near you anytime soon, but it is a timely reminder that these seemingly simple "beasties" can cause significant health issues.

Importantly, the Tick will release more saliva if disturbed, which raises questions as to how best to remove them without causing more problems. For those with a known Tick allergy, the best answer is to leave them well alone and get them removed in a Clinic setting where there are appropriate medical supports and adrenaline is available if necessary. As to the best method of removal, unfortunately there is no consensus on this that I am aware of. But you shouldn't squeeze them, try to pull them out or even poison them as this will upset them and make them release more saliva and potentially upset you in the process!

The Australian Society of Clinical Immunology and Allergy have suggested a novel approach and that is to use a freezing spray - such as Aerostart: apparently used for cleaning Carburetors - which instantly freeze dries the insects and kills them before they can release any more saliva. On paper this seems a great idea, but they also warn that:

  • this advice is based on clinical experience of those treating patients with tick allergy
  • this product is not “registered” for such use
  • this product is highly flammable, and thus should not be used near naked flame or when smoking
  • rapid cooling of the skin and thus skin irritation may occur
  • since it is unlikely that formal studies in this area will occur in the near future, such advice is based on a consensus of “expert opinion” rather than derived from results of formal clinical studies.
So be warned!

The best idea is to avoid getting bitten in the first place so:
  • Wear appropriate clothing when outdoors in tick areas including long sleeved shirts, long pants tucked into socks and a wide brimmed hat. Ticks are more easily detected on light coloured clothing.
  • Spray clothes and hats with an insect repellent and wear a repellent that contains DEET or Picaridin.
  • When returning from an area known to have ticks, remove clothing and search for ticks, especially behind the ears, on the back of the head, groin, armpits and back of knees. Be careful where clothes are placed as they may introduce ticks to inside the house. Don't forget to check children and pets
Reference 1
Reference 2
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3 comments:

FancyScrubs said...

How is this new infection different than Lyme? If untreated Lyme can be quite a battle.

Dr Duncan Jefferson said...

It's a different bacteria with different clinical signs: those affected have reduced immunity as well. And you are right , Lymes is a nasty disease.

Mariodacatsmom said...

Good advice. And, I can see tics are a world wide problem that I never realized before. It's so important to check yourself over well after being out in the woods or tall grasses. I wonder why or how Lymes Disease started. I think back to when I was a kid and you just pulled out the tic with a tweezers and never had a problem with a disease. What has changed I wonder!