Handwashing can cut infections by 50%, but most people still don’t do it properly

It's the health habit everyone thinks they already have. Handwashing. You do it after the bathroom, before a meal, maybe after a sneeze. But according to Dr Deepesh Agrawal, Consultant Physician and Head of Critical Care Medicine at Saifee Hospital, Mumbai, most people are doing it wrong and that gap between the habit we think we have and the one that actually works is costing us more than we realise.
"Handwashing is one of the simplest and most effective measures to prevent the spread of infections, but it is not a habit that everyone does," says Dr Agrawal. And even among those who do wash their hands regularly, the technique, duration, and timing often fall short of what's actually needed to break the chain of infection.

Most people associate infection spread with the air: a cough, a sneeze, a crowded metro. But a significant proportion of common illnesses travel via contaminated hands touching the mouth, nose, food, or frequently touched surfaces. The common cold. The flu. Diarrhoea. Typhoid. All of these, says Dr Agrawal, are spread through exactly this route. And yet, the moment hands look clean, most people consider them clean.
According to the CDC, handwashing education and promotion can reduce the number of people who get sick with diarrhoea by 23 to 40%, cut diarrhoeal illness in people with weakened immune systems by 58%, and reduce respiratory illnesses like the common cold in the general population by 16 to 21%. And the impact on children is particularly striking. Research has found that rates of absenteeism among primary school students due to gastrointestinal illnesses can be reduced by 29 to 57% with proper handwashing practices. For parents managing school-going children, that number alone makes the case.

There's a common assumption that any handwashing is better than none, and that water will do in a pinch. Dr Agrawal is clear on this point. "Soap will liquefy the outer fatty layer of viruses and bacteria, including influenza viruses and coronaviruses, which helps to wash them away, although water will remove visible dirt," he explains.

As for alcohol-based sanitisers, something many people now reach for as a default, Dr Agrawal says they have a role, but a limited one. "Alcohol-based sanitisers may be helpful if soap and water are not available, but they are not always a substitute for soap and water, particularly if hands are visibly soiled."

This is the part most people don't want to hear. The average handwash lasts a few seconds, a quick rinse and dry. But Dr Agrawal says it takes at least 20 seconds of proper washing with friction to be effective. And certain areas of the hand are almost always missed. "Some parts of the body that are not washed regularly are the backs of the hands, between the fingers, knuckles, thumbs, fingertips, and wrists," he notes. "Wet hands can spread germs more easily than dry hands," says Dr Agrawal, and damp kitchen or bathroom towels can themselves become a source of reinfection.

Timing, it turns out, is as important as technique. Dr Agrawal identifies the highest-risk moments as before eating or preparing food, after using the toilet, after coughing or sneezing, after touching a sick person, after handling garbage or animals, and after touching frequently-touched public surfaces.

Children are among the most important groups to establish this in, and for reasons that extend beyond their own health. "Good hygiene practices in handwashing can help to substantially decrease school absenteeism due to diarrhoeal and respiratory diseases and help to keep elderly family members at home from getting sick," says Dr Agrawal. In multigenerational households, which remain the norm across much of India, a child who washes their hands properly is protecting grandparents and infants in the same home.