Evolving Ideas on Emerging Infectious Diseases Flashcards
Why did the life expectancy in Britain rise from 17 to 52 between 1700-1900?
Death rate from TB had fallen by 80%
In the US which three diseases caused 30% of deaths?
TB, pneumonia, and diarrheal disease
What factors influenced the decrease in infectious diseases in the 20th century? Which is the biggest?
- better nutrition
- antibiotics
- improved hygiene and sanitation
- immunizations
- safe food and water - biggest, and yet today safe water and food is not accessible for a lot of the population
- better housing
What two significant technological advances occured between 1940-60 that helped the battle against infectious diseases?
- antibiotics
- vaccine development
Are infectious diseases still the most important cause of death?
no - chronic diseases
What are three major misconceptions about infectious diseases?
- medicine and technology will address issues of infectious disease emergence
- the majority of emerging infectious disease (EID) events occur in geographic areas near the equator
- viral pathogens (particulary RNA viruses) represent a major threat and most likely to result in EIDs
Why, despite in technological and medical advances, successful prevention and control efforts, are there 13 million deaths each years from infectious diseases?
Disproportionate allocation of resources?
What infectious diseases have hit the developing world hard?
penumonia > diarrhoeal disease > AIDS > TB > malaria > measles
What factors have lead to the emergence of infectious diseases?
- changes in society, technology, and the microorganisms themselves are contribuitng to: emergence of new diseases, re-emergence of diseases once controlled, the development of antimicrobial resistance
- these factors have lead to increases of host susceptibility and/or disease transmission and the evolution of new or drug-resistant microorganisms
Describe the global trends of EIDs
- EIDs have risen over time
- EIDs are dominated by zoonoses, majority of these (72%) originate in wildlife
- the number of pathogen sp.s (as with other species) increases towards the equator –> humans and other animals will ↑ come into contact with new or emerging infections agents
What was the old way in which we thought of EID distribution (what were the implications, why’d we argue this?) and what is the new way?
previously: latitudinal spatial gradient of human pathogens ↑ towards the equator
- why we didn’t worry too much
- argument: due to richness in taxonomic groups + ↑ temperatures and amount of precipitation
new: EIDs are actually concentrated in ↑ latitudes
Why are there more vector borne zoontoic disease around the equator
more biodiversity
Why do RNA viruses have greater potential to adapt to new hosts?
↑ rates of NT substiutions and poor mutation error correction ability
What pathogens actually represent a major threat and most likely to result in EIDs?
- newly evolved pathogen strains (e.g. multi-drug resistant TB, vancomycin-resistant S. aureus, and cholorquine resistant malaria
- pathogens that have recently entered human population for the first time (e.g. HIV-1, SARS)
- pathogens that have been present in humans historically, but have seen an increase in incidence (e.g. LD)
Besides increasing our capacity to report disease events, what other factor has contributed to the increase in EID incidence?
increased susceptibility to infection
