Pathogens

Odd one out Select an odd one out from each line. Bacteria Virus Flea Germ Pathogen

How do we catch different illnesses? Catching a cold Catching flu Chicken Pox Food poisoning Diarrhoea Measles Cold sore ‘Sickness’

Catching a disease

What are micro-organisms and microbes? They are the same thing There are 5 different groups; Viruses Bacteria Fungi Algae Protozoa A pathogen is a micro-organism that causes a disease A disease is the effect of a pathogen e.g. Varicella zoster virus is the pathogen and the disease is Chicken Pox . An infectious disease is something that you catch

How are bacteria and viruses different from each other? Smaller than a bacteria Reproduce rapidly Do not produce toxins Need to live inside living cells, as they take over the cell to reproduce They damage our cells which make us ill. They all cause disease Larger than a virus Reproduce rapidly Produce toxins that make you feel ill Many are harmless Some harm the cells directly

Why would these people be more likely to catch a disease?

Droplet infection Droplets full of pathogens get breathed in by others.

Direct contact Some diseases are spread by direct contact of the skin.

Contaminated food and drink Eating raw or undercooked food, or drinking water containing sewage means millions of pathogens get straight into your gut.

Pathogen enter the body directly via cuts, scratches and punctures. Break in the skin Pathogen enter the body directly via cuts, scratches and punctures.

... otherwise known as childbirth fever What links... Elizabeth of York (Henry VIII’s mother) Jane Seymour (Henry VIII’s third wife) Katherine Parr (Henry VIII’s sixth wife) ... and 17% of women who gave birth in Vienna General Hospital in 1842? They all died of puerperal fever... ... otherwise known as childbirth fever Mary Wollstonecraft (Early Feminist Writer) Isabella Beeton (Cookbook Writer)

Early pioneer of antiseptic procedures. Described as the "saviour of mothers" Semmelweis was a doctor at Vienna General Hospital The hospital ran two maternity clinics - over 10% of mothers in the First Clinic regularly died of puerperal fever Ignaz Semmelweis (1818 – 1865) Hungarian physician - half as many mothers in the Second Clinic died of puerperal fever The First Clinic was used to train medical students The Second Clinic was used to train midwives

They did not wash their hands after finishing Medical students spent their mornings before their clinic doing dissections on cadavers They did not wash their hands after finishing 1847: Semmelweis’s friend, Jacob Kolletschka dies after he is accidentally stabbed with a student’s scalpel during a dissection Jakob Kolletschka (1803 - 1847) Professor of Forensic Medicine at Vienna General Hospital Kolletschka’s symptoms were similar to those of puerperal fever CONCLUSIONS The students were transferring something from the cadavers to the mothers on their hands He could prevent deaths from puerperal fever by getting the medical students to disinfect their hands

Semmelweis made doctors who had been carrying out dissections Semmelweis made doctors who had been carrying out dissections or autopsies wash their hands with a chlorine handwash before seeing patients This dramatically cut deaths from puerperal fever

Semmelweis had difficulty persuading other Semmelweis had difficulty persuading other doctors to wash their hands because he couldn’t explain why washing hands was important We now know that puerperal fever is caused by a type of bacteria known as Streptococci These bacteria are found in the throat and nasal passages of most healthy people

Ignaz Semmelweiss What did Semmelweiss observe happening in hospitals? What did he tell his medical students to do? What effect did this have? How has this impacted on what we do today in hospitals? Why was Semmelweiss ideas not accepted initially? Discuss if these reasons are justified