Transcript of We’re the Survivors Hosts and pathogens have a profound evolutionary influence on each other.
We’re the Survivors
Hosts and pathogens have a profound evolutionary influence on each other.
Host------------> increased resistance
Pathogen--------->decreased virulence
Balanced Polymorphismselection that maintains a
genetic disease in a population because heterozygotes resist an infectious disease
Heterozygote advantage
Malaria is one of leading causes of morbidity and mortality in the developing world (along with TB, acute respiratory syndrome, diarrhea and HIV) but still not recognized in developed countries as a disaster like AIDS or EBOLA.
Each year, 300-500 million people become ill with malaria.
More than 2 million people, mostly children, die from malaria each year.
Around 2.5 billion people (at least 40% of the world’s population) are at risk in over 90 countries.
Malaria kills more people today than three decades ago. Reasons include:
Increasing drug resistance
Increased migration and immigration
People moving from countryside to cities.
Tourist and business travel Decreased mosquito control
Deforestation
Pathogen:Plasmodium falciparum(and 3 other plasmodium species)
Vector:female ‘Anopheles’ mosquitoes
Symptoms:fever, chills, headache, muscle ache.
Every six months nets are dipped in insecticide and dried before use.
Sickle cell anemia-------malaria
Cystic fibrosis-------cholera
Tay Sach’s disease----tuberculosis
HH Hh hh
CC Cc cc
TT Tt tt
How Mutation SpreadsInfectious Disease
Altered host (eg: parvovirus) New toxin (eg: Eco 157:H7 invasive Strep A) New route of transmission (eg: Ebola) Drug resistance