Hand Sanitizers and Viruses

As public health officials struggle to contain a series of viral outbreaks, many people are reaching for bottles of hand sanitisers at winter period.

 

Studies show that alcohol based sanitisers,
particularly those with 60% ethanol or more, can reduce microbial counts on contaminated hands and reduce the spread of some strains of the flu.

But against norovirus, the severe gastrointestinal illness gripping many parts of the world, they may be useless.

 

Some viruses like influenza, are coated in lipids, “envelopes” that alcohol can rupture.

But non-enveloped viruses, like norovirus are generally not affected.

Bleach is effective against norovirus and can be used to decontaminate counter tops and surfaces. And for people, the best strategies may be washing with plain old soap and water.

 

In 2011, the Centres for Disease Control and prevention studied 91 long term care facilities. During the winter of 2006-07, they identified 73 outbreaks, 29 of which are confirmed to be norovirus.

 

The facilities where staff members used alcohol-based sanitisers were six times more likely to have an outbreak of norovirus than the facilities where the staff preferred using soap and water.

The CDC says that as a means of preventing norovirus infection, alcohol-based sanitisers can be used “in addition” to hand washing, never as a substitute.

 

Hand sanitisers can reduce the spread of some viruses, like the flu. But against norovirus they are largely ineffective; better to use soap and water.