Lecture 25: Infectious Diseases
April 25, 2017
No effect of MMR withdrawal on the incidence of autism.
In Japan, they stopped administering the MMR vaccine because of a manufacturing problem for
a while: no effect on autism!
Even leaders of the movement know that they are supporting fraud.
But emotions sometimes lead to irrationality
Does a sustained non-vaccinated population have lower autism rates?
Human parasites carry disease
Causative agent of epidemic typhus – researchers died studying the bug.
Spread by lice!
→ Charles Nicolle of the Institut Pasteur discovered this
- Learned this by accident
- Tunis was full of typhus patients, increasing every day
- Observed that patients infected others, but clothes did too
- After a hot bath and clean clothes, patients stopped being infectious
- Must be a transmitting vector: lice.
- Injected chimps with blood from a patient suffering from typhus
- After several days, he collected a few lice from the injected chumo, and transferred it to
- After about 10 days, this other chimp developed typhus
Genome of the virus is RNA, so must be made back into DNA
Over time, person loses amount of T cells that they had, then develop bad immune system
→ There are drugs that inhibit almost every stage of the cycle.
HIV came from a chimp sometime around 1910.
Humans are not the natural hosts of HIV-1 or HIV-2 Instead, these viruses have entered the human population as a result of cross-species
Likeliest way: HIV-positive primate being killed for food, someone had a cut and there was
blood to blood transmission. (DNA shows the spillover was in Z