• Question: Which disease is the deadliest disease to have infected humans and how did it affect us?

    Asked by benjamin2809 to Ettie on 8 Jun 2019.
    • Photo: Ettie Unwin

      Ettie Unwin answered on 8 Jun 2019:

      Really great question – but the answer isn’t very clear cut. A disease being deadly can be thought of in at least two ways:
      1) It kills nearly everyone who gets it
      2) It may not kill everyone who gets it but it spreads very easily between humans so lots of people get it.

      One example of a disease of type 2 is flu (or its full name influenza). Last year was the 100 year anniversary for the flu outbreak typically known as Spanish flu after world war one. This was a pandemic (cases of the disease were found all around the world) and about 50 million people died. The type of flu that was around that year is related to the flu we still get, but was particularly bad. It spread fast and caused similar but more serious symptoms than the temperatures, sore throats and muscle aches you get now. There is a danger that a flu closely related to the Spanish flu will come back again and could cause massive deaths across the world. Thats why people in my department are trying to use maths to predict the chance of this happening and work with vaccine developers to try and stop it happening. Flu enters the human population from birds and sometimes pigs – hence you may have heard of swine and bird flu.

      In my opinion type 1 diseases are more deadly. A type of disease like this is Ebola. Unfortunately most people who get this disease die because there is no treatment and only trial vaccines. There is currently an outbreak of Ebola in the Democratic Republic of Congo in Africa. People in my department and I are working with the world health organisation to analyse live data about this. It is thought that Ebola comes from bats – either a human is bitten by one or eats some meat from an animal that either ate an infected bat or was bitten too. It spreads through bodily fluids so health care workers and families can be at great risk. Also people in these cultures show respect to the dead by touching and kissing the bodies – this is another huge source of cross infection .