OUR MODERN SOCIETY IS FUNDAMENTALLY DEPENDENT ON SCIENTIFIC RESEARCH AND DEVELOPMENT. YOUR FUTURE WILL DEPEND ON SOCIETAL DECISIONS IN THE GENERAL AREA OF BIOLOGY. THIS CLASS WILL USE BIOLOGICAL DATA TO ADDRESS MODERN MEDICAL AND SOCIAL ISSUES. BIO 101 BIOLOGY OF THE HUMAN CONDITION

200 COUNTRIES, 200 YEARS, 4 MINUTES… Data are from Gapminder.org

SURVIVORSHIP THROUGHOUT HISTORY McMichael, 2001

PUBLIC HEALTH IN 20 TH CENTURY 1918 Flu pandemic

Flu over the last few years From CDC website

INFLUENZA Eight genomic segments Three groups A,B,C with many subgroups of A Hemagglutinin (H) Neuraminidase(N) E.g., H1N1 Antigenic drift and shift. Mutation Reassortment Seasonal vs. Pandemic flu.

HA AND TROPISM Avian flu (H5N1) is deadly in humans but it doesn’t transmit effectively Sialic acid Avian flu tropism can be modified to binding 2,6 or both 2,6 and 2,3 by one or two mutations Microbe 2: 489 (2007)

REASSORTMENT FLU VIRUSES Jon Cohen, Science 325: (2009). TRIG, ~1998. Evolved. European. TRIG: Triple Reassortment, Internal Genes

Flu PB1-F2 expression The 1918 strain produces this protein. It goes to the mitochondrion and causes cell death. Swine origin H1N1 does not make it. Lamb and Takeda (2001) Nature Medicine 7:1286.

FLU STRATEGY UNDER REVIEW Science 306:1123 (Nov. 12, 2004) Visit

TRANSMISSIBILITY WITHIN A POPULATION R o > 1 R o = 1 R o < 1 Time New Cases R o = “Reproductive rate” = Number of new cases per current patient. R o depends on many factors including the organisms, social practices that affect transmission (sharing food, handwashing, etc.), and the level of acquired immunity in the population.

OPTIMAL STRATEGY FOR MINIMIZING DEATHS IN A PANDEMIC Computer simulations based on parameters from the 1957 pandemic to determine optimal strategy for achieving Ro < 1. Average pre-vaccination Ro = 1.4. Solid line is current US population profile. Gray bars are numbers vaccinated in specific age groups. Can be done with only 61 million doses. We currently administer ~135M doses/yr. Medlock et al. (2009), Science 325:1705. Age groups Millions of people

MINIMIZING VARIOUS COSTS YLL = Years of Life Lost. CV = Contingent Valuation (based on surveys). “Cost” includes costs of vaccination and of disease.

OPTIMAL STRATEGY-3 Former CDC = kids 19 months to 5 yrs and adults > 49 yrs. Seasonal (2009 CDC), includes kids through age 18, adults >49. Uniform treats all ages > 6 months equally (CDC recommendation since ) Pandemic = kids 6 month to adults 25 yrs (close to 5-19, above) Optimal is kids 5 yrs to 19, some adults to 24 yrs, and some adults 30 to 39 yrs. Optimal strategy would do better than all other strategies, although 5 to 19 yrs is close. Medlock et al. (2009), Science 325:1705. If vaccine supply limited to only 40 million doses:

THE EBOLA EPIDEMIC

EBOLA

EBOLA EPIDEMIOLOGY

EBOLA GEOGRAPHY Outbreaks have been observed since the 1970’s Previous epidemics in Central Africa died out quickly due to low population densities Higher densities and travel have contributed to the current epidemic

EBOLA CONTROL Put out the fire in Africa  Stopping sparks that land in US and Europe is relatively easy In Africa  Isolate those infected and use great precautions  Educate the public  Funerals are major avenues for transmission Be vigilant for future outbreaks  Monitor for Ebola and for more virulent mutants  Vigilance for other emergent pathogens The Viral Storm, Nathan Wolfe