Lecture 2: Infectious Disease Flashcards
Infectious diseases in the developing worlds vs Now
Before:
- 25 million deaths circa 1998 (per year)
- 1/3 of the world had tuberculosis
- 4 million died per year from curable diseases from bad water
- 6 million died per year from HIV and Malaria
Now:
- 17 million die per year (down 1/3)
- 1/4 of the world had tuberculosis
- 500k children die per year from curable diseases from bad water
- 405k million died per year from Malaria (228 million cases); 690k from HIV (1.7 million new infections and 38 million total)
What causes malaria?
protozoan parasite Plasmodium falciparum (severe) or vivax (limited and nonlethal)
How is malaria transmitted?
anopheles mosquito
How has malaria cases been reduced?
widespread use DDT (mosquito repellant) until resistance to treatment evolved
What is the leading global infectious disease killer worldwide?
Human Immunodeficiency Virus (HIV/AIDS)
What does 1/2 of people infected with HIV also develop?
Tuberculosis (1/3 of deaths)
What does HIV do?
infects immune system cells, destroys T-cells
how does HIV lead to death?
Death is the direct result of other microbes co-infecting the patient
What is the main cause of enteric diseases?
drinking contaminated water or undercooked food (Escherichia coli and rotavirus)
How are enteric diseases treated?
with fluids and prevented with sewage treatment
What is a problem in developed countries with enteric diseases?
resistance to antibiotics
Who mapped cholera and to where?
John Snow mapped cholera to a contaminated well (Considered the
founding event in ID
epidemiology)
Cholera Bed
Beds with holes cut in them so people did not have to get up to go to the bathroom cause they would lose about 10L of bodily fluids in a day and could not get up to walk
Antibiotic resistant bacteria restore the potential threat of bacterial infections, for example:
VRE, MRSA, multi-drug resistant TB
New viruses that have emerged as threats
HIV, West Nile Virus, Ebola
How was HIV first described in clinical settings?
described in gay men in LA in 1980
The spread of HIV
extremally fast and by 1990 there were few AIDS free places on earth
Where were the largest populations of HIV?
Sub-Saharan Africa and SE Asia
West Nile Encephalitis
Long known to cause disease in animals
and people in Africa
Where was west nile thought to be restricted?
tropical environments
When was west nile first seen in the US?
1999
How many cases of west nile per year in US?
5000 cases, 500 deaths
Containment of west nile?
no real chance to contain the virus because its spread by mosquito between birds and humans
Bovine Spongiform Encephalopathy
“Mad Cow Disease”
What causes Bovine Spongiform Encephalopathy?
infectious protein particle, a prion
How is Bovine Spongiform Encephalopathy spread?
spread through cattle population by rendering dead cattle and sheep in feed
Where was Bovine Spongiform Encephalopathy first seen and when?
Contaminated British beef in 1990s
How many cases of Bovine Spongiform Encephalopathy in Britain by 2002?
138 cases of vCJD
What is MDR TB resistant to?
most antibiotics (needs a “cocktail”
What is MRSA resistant to?
all antibiotics except vancomycin
What is VRE resistant to?
virtually all antibiotics
What is VRSA (VISA) resistant to?
potentially resistant to all antibiotics
