UKH

It came as a surprise to me that the best way to sanitise your hands against the virus is to use soap and water. My question to anyone here who can speak with authority is does the same apply when it comes to guarding against bacterial infection. As a contact lens user I have once or twice had eye infections and am aware that this can be caused by not having sanitised hands when inserting the lenses. Before inserting lenses I scrub my hands thoroughly with soap and water and I would like to know if this is better or worse than using a so-called anti-bacterial hand wash (which I think doesn’t contain soap). Any advice?

In reply to Rog Wilko:

Not sure about your specific use but I remember being told an NHS worker that washing hands in soap and (preferably) warm water was the best way to protect against MRSA transmission, when that was the primary concern. Also better for the skin than repeat application of aggressive chemicals. The primary reason for using the antibacterial gels, I gather, is convenience and portability.

In reply to Rog Wilko:

I'm not sure if there is any difference in effectiveness between true soap and mild detergents (which is what most shampoos, shower gels and hand washes are).

Both work against viruses by attacking the lipid shell of the virion that protects the viral RNA.

I understand the 20 seconds thing is partly to encourage thorough coverage, and to give adequate contact time for the surfactant to do its job on the lipid shell.

Antibacterial washes often contain an antibacterial agent such as cetrimide.

That's my understanding. Happy to be corrected by those more knowledgeable.

In reply to Rog Wilko:

I don't think anyone recommending that we wash our hands in "soap and water" is differentiating between a traditional bar of soap and a liquid 'hand-wash' soap/detergent/whatever.  I think they're just saying "soap and water" to make it clear that they're talking about actually washing your hands as opposed to using an alcohol gel or the like.

I have no expertise to offer, but from a quick rummage around online I don't think there is any significant difference in efficacy between a bar of soap and squirt of liquid 'hand-wash' from a plastic dispenser.

In reply to Rog Wilko:

Regarding the virus: the advice makes sense, because the outer layer of the virus is made up of fats. So soap and water breaks the thing up.

In reply to Rog Wilko:

I remember hearing many years ago that one popular doctor's aphorism is "a pound of soap is worth a pound of medicine"

I don't know myself of course (and I'm not a doctor), but I always remember that saying

In reply to Rog Wilko:

A doctor who specialises in this told me soap and water which is as warm as you can handle for upto a minute, with alcohol gel after as the icing on the cake, will kill or remove just about anything. Short nails and no jewellery help too, but this shouldn't matter as far as your eyes go. 

In reply to summo:

This could be rubbish but I think the major effect of washing with soap and water is that our skin, no matter how dry it feels, has natural oil which bacteria and viruses adhere to. The soap breaks down the grease and the resulting mixture of soap/grease and bacteria/viruses is rinsed away.

Dave

In reply to Rog Wilko:

Soap or detergent kills a lot of things.  Physical scrubbing and rinsing seems to be the way to get the rest.  I’m not sure about eye infection, maybe an optician will be along soon, I know we have a couple.  

This is interesting and has pictures (I’m a picture person) 

https://www.nytimes.com/2020/03/13/health/soap-coronavirus-handwashing-germ...

In reply to Rog Wilko:

I bought some of this the other day from the “world food” bit of Tesco and it seems to work well.  I have sensitive skin and it hasn’t caused me any issues, but it appears to have quite a few bacteria killing ingredients.  https://www.tesco.com/groceries/en-GB/products/289735673

In reply to Rog Wilko:

And only use antibacterial gels up to 5 times before washing your hands with soap.

In reply to deepsoup:  I believe the action of the alcohol in the alcohol gel similarly destroys the lipid part of the virus.  So not ineffective

In reply to Graeme G:

I've not heard that.  If hands are physically dirty (mud or whatever) then they need to be washed but on physically clean hands you can use alcohol gel to kill the virus when hand washing isn't possible.  

In reply to marsbar:

Worth bearing in mind while those hand gels are effective against coronavirus (thankfully) they’re not effective against some other pathogens like norovirus and cryptosporidium. Proper hand washing also physically removes pathogens in a way that can’t be relied on with hand gels, so is always the better option if it’s available. 

In reply to Rog Wilko:

Advice offered based on a microbiology degree and 15 years working in pharmaceutical sterile processing if that means anything.

Soap and water works in 2 ways: physically removes the virus from your hands through the physical scrubbing and rinsing. Disrupting the lipid coat of the virus so it can no longer function. The temperature of the water has no impact but you are unlikely to wash properly in cold water.

the alcohol gels only have one action to disrupt the virus coat. To do this it must be in contact with each virus particle so again needs applying properly to all surfaces if you have any regular dirt on your hands this will give the virus places to hide and further limit the effectiveness.

in summary both need doing properly to be fully effective, given the choice I'd take soap and water over alcohol, but out and about or in work that requires regular re-sanitisation the alcohol gels are much more user friendly.

In reply to Rog Wilko:

At some stage, at one of the daily briefings, hand washing was described as the “gold standard” and gels second best. This was a scientist not a politician by the way.

In reply to marsbar:

Apparently it eventually becomes a barrier and needs to be washed off.

In reply to wbo2:

No, indeed not.  But I think the number of people in this thread who seem to have assumed the OP was talking about soap -vs- alcohol gel rather than soap -vs- liquid 'hand wash' as I think he was (he's not been back to clarify) could be seen to be reinforcing the point I was trying to make there.

In reply to marsbar:

£1.25 for a bar of soap!
I use Tesco Essentials soap for my hand sanitising which is 15p a bar.  Cheap and cheerful, little or no perfume, etc. and therefore it's kind on the hands.
The anti-bacteria thing is also a bit of a con, all you need is bog standard soap/detergent as their properties of gobbling up fat and thus killing the virus is all that is needed.

In reply to FactorXXX:

I'd imagine the old fashioned soaps that don't contain any moisturisers and leave your skin feeling dry are better at removing the fats and virus from your skin anyway. 

In reply to FactorXXX:

At that time there wasn't much choice, I didn't buy it because it is anti bacterial, but I don't think it is particularly expensive.   I mentioned anti bacterial as the op is talking about eye infections.  

In reply to deepsoup:

You're right, I was considering two factors here: the difference between viruses and bacteria (I'm assuming they're different, but am ignorant) and the relative effectiveness of soap and non-soap based hand washes as I am keen to use the best routine to avoid eye infections which I believe are bacterial in origin. 

In reply to Rog Wilko:

I've been lucky there I think, and never had problems despite some pretty dodgy contact lens hygiene in the past.  It was reading about parasitic amoebae that bucked my ideas up, scary.  Acanthamoebae eat bacteria for breakfast!

In reply to deepsoup:

In point of fact the two episodes I've had were associated with pharyngitis (I think that's how it's spelt) where the GP said that the infection had spread through nasal passages and sinuses into the eye. It was so unpleasant that (i) I now don't use lenses if I have that sort of problem and (ii) I'm a bit paranoid about getting conjunctivitis by transferring infection from my fingers into my eye, hence the OP.

In reply to Rog Wilko:

Surprising viruses that are inactive, having no processes or requirements, only survive a few days, and are destroyed easily by sun or soap.  When tardigrades are fairly indestructible, and it is not completely certain that dinosaurs cannot be reconstructed from their remains. You would think they could remain forever.

Low evolutionary benefit from individual survival time ?

In reply to Rog Wilko:

Hi Roger

I'd say that there are lots of additional factors whose effect will swamp the differential risk of using different soaps for washing your hands. There's certainly evidence that whether or not you wash your hands at all makes a difference to the risk of eye infections from CL wear, but I'd be surprised if there was anything comparing different products, because the total number of infections is low. Theoretically, an anti-bacterial handwash might be better than soap, but I would argue that other factors such as how you dry your hands will turn out to be much more important. As deepsoup says, acanthamoeba is the worry with tapwater, so you want to dry your hands well before using CLs, but preferably not on a towel covered in pathogens! But not many of us have a hot air dryer at home, or use paper towels, so a clean towel is fine (but by the time you've dried your hands with it, I think you've probably undone any additional advantage of using an anti-bac handwash). As for which products are effective at killing acanthamoeba, that would take some looking up (if indeed the research has been done, and reliably). But don't worry, we don't see acanthamoeba infection regularly in practice (I don't expect to ever see it), and those who do get it tend to be swimming in their lenses and leaving them in.

I would simply follow the standard advice of wash and dry your hands, and don't sleep/swim/shower in your lenses. Daily disposables carry less risk than reusable lenses. Since you have or have had some susceptibility to infections, I would add that it's safer not to wear your lenses if your eyes are feeling a bit gritty, as that could mean that the surface layer of the cornea is slightly compromised, which can gives any bacteria or other pathogens a way in to cause trouble. Also make sure that your solution's in date and the lenses have been disinfected overnight (not left in the same solution for some time).

tl;dr

Just wash your hands.

Jon (optom)

In reply to David Riley:

Never mind the acanthamoeba - now I'm fretting about eyeball velociraptors

In reply to Jon Stewart:

Since you wash your face and eyes in tap water.  Probably directly before inserting your lenses.  Why is it a problem touching lenses with tap water on your hands ?

In reply to David Riley:

Fair question - although most people won't wash their eyes in tap water, they'll shut their eyes as they wash their face with soapy water. The danger with tap water is that you introduce microbes from the tap water to the contact lens, where they get into the water-containing matrix of the lens and multiply. It's the interaction of tap water and lens, more than tap water and eye, which is the concern.

In reply to Jon Stewart:

Yes, that seems to be the accepted view.  But I don't find it convincing.

I'm sure everyone thoroughly rinses their eyes with tap water.  How else are you going to get the bits out of the corners ?  If your eyes are full of tap water when you put them in.  It cannot make any difference touching tap water on the lenses.

That is the case with me since my eyes have been abnormally dry all my life.  For people whose eyes water a lot it might be different.

In reply to David Riley:

It's not normal to wash eyes with water.  Eyes are usually moist enough to self clean and then you wash your eyelids and lashes with eyes closed.  Maybe you should see a doctor or optician to see why your eyes are so dry and if you need drops.  

In reply to David Riley:

The tear film is quite complex and useful, and washing it all off with tap water isn't going to be very helpful, regardless of the very small risk of acanthamoeba infection. If your eyes are dry, I'd use a sterile lubricant drop rather than tap water, as that'll do the job the tear film does much better than tap water.

The bits (dead cells and mucus) that collect at the corners can be wiped off the skin rather than washed off the ocular surface itself. The only time I wash an eyeball (with sterile saline) is when there's something toxic on it.

In reply to Jon Stewart:

Hi Jon

Thanks for your detailed response. I think that I'm minimising the risk. I use daily disposables which I hardly ever have in when I shower and I never swim. I've already thought about the hand drying issue by having a dedicated towel for the purpose that I use for about three days and no one else touches. I scrub up thoroughly with soap and a dedicated scrubbing brush. 

Thanks again - I'm feeling more confident.

In reply to Rob Parsons:

Yes. This is a container virus. It has a construction that includes a lipid membrane (fats) that surrounds (contains) the genetic material. Just as it attacks and dismantles other fats and oils, soap dismantles the structure of the lipid membrane. There is then no mechanism for the genetic material to attach to or enter a human cell, so the danger is neutralised. 

A least one WHO hand washing instruction included a handwashing time of 60s which is a lot more than the standard 20s we hear about. That may be designed for a clinical setting but it demonstrates what we're up against. 

Alcohol Based Hand Sanitisers (ABHS) need to be stronger than 60%. Unfortunately, wet hands or applying it in a wet environment dilutes it and makes it ineffective. Also, it may be ineffective against bodily mucous, such as emitted from the nose or mouth. The mucous may contain and protect viruses and can only be broken down effectively with soap.

https://www.theguardian.com/commentisfree/2020/mar/12/science-soap-kills-co...

https://www.independent.co.uk/news/science/coronavirus-soap-wash-hands-covi...