While working in the maternity wards around 1846, Dr. Ignaz Semmelweiss noticed that the mortality rates in the clinics cared for by medical students were considerably higher than in the clinics cared for by midwives and observed that these medical students were coming from performing autopsies in the morgue into the delivery rooms after washing their hands with only soap and water.
After he began requiring them to wash their hands with a chlorine solution before providing care, the mortality rates decreased from 10% to 1%. Around the same time in Boston, Dr. Oliver Wendell Holmes came to a similar conclusion and believed that disease-causing bacteria were being spread among patients on the hands of doctors.
Both Semmelweiss and Holmes were met with resistance from their colleagues but were eventually recognized for their work in hand hygiene.
We all have bacteria on our hands and are considered to be colonized with microorganisms such as coagulase-negative Staphylococcus, Corynebacterium species, and even fungi like Malassezia species, meaning that they are present but are not likely to cause disease. However, since healthcare personnel is more likely to have direct contact with patients that are infected with pathogens associated with healthcare-acquired infections such as Staphylococcus aureus, Proteus mirabilis, Klebsiella species