Disease Control Emerging Id

Front 1

What are "emerging infectious diseases"?

Back 1

National Institutes of Medicine: “New, re-emerging, or drug-resistant infections whose incidence in humans has increased within the past 2 decades or whose incidence threatens to increase in the near future."

Front 2

what are the four Characteristics of Emerging Infectious Diseases ?

Back 2

1. Often linked to introduction of an infectious agent into a new host population, followed by dissemination within that population ("adoption").
 
2. Many EID originate as zoonoses, and establishment depends on mortality, transmissibility, and characteristics of reservoir host or vector.

3. Most EID are caused by pathogens already present in the environment that are given a selective advantage by changing conditions. These changing conditions can include:
Human actions (deforestation, antibiotic use)
Natural causes (climactic change, natural disasters)
 
4. EID frequently move from rural to urban areas with migrating populations (e.g. HIV, cholera, dengue)

Front 3

What are the Factors in Emergence of Infectious Diseases?

Back 3

1) Ecological Change and Agricultural Development.

2) Changes in Human Demographics and Behavior

3)International Trade and Commerce

4) Technology and Industry

5) Microbial Adaptation and Change

Front 4

Factors in Emergence of Infectious Diseases Describe Ecological Change and Agricultural Development.

Back 4

Frequently associated with zoonoses with high mortality rates (e.g. hantavirus pulmonary syndrome).
 
Examples: Lyme Disease (US; movement of people into areas of reforestation, increased numbers of deer and deer ticks)
Junin Virus (Argentine Hem. Fever, conversion of grassland to maize--> more rodent reservoir pop.)
 
Influenza (pig-duck farming in China--> reassortment of genes from influenza strains in ducks, mixing of mammalian strains in pigs)
 
Expansion of standing water can result in increased numbers of arthropod vectors of EID and outbreaks (Japanese Encephalitis)

Front 5

Factors in Emergence of Infectious Diseases:
Describe Changes in Human Demographics and Behavior

Back 5

Urbanization brings more obscure rural diseases to larger populations (e.g. HIV, Dengue hemorrhagic fever [with second infections due to newly imported strains])
 
Human behavior can change disease patterns (STDs, HIV)

Front 6

Factors in Emergence of Infectious Diseases
Describe International Trade and Commerce

Back 6

Historically, trade between Asia and Europe brought the rat and bubonic plague to Europe; ships carrying West African slaves brought Aedes aegypti and yellow fever to the New World.
 
Recent examples:
 Aedes albopictus introduced to US, Brazil from Asia introduces new vector for Eastern Equine Encephalitis and West Nile Virus
 Vibrio cholerae reintroduced into South America in the ballast of ships from Asia
 

Front 7

Factors in Emergence of Infectious Diseases
Describe Technology and Industry

Back 7

Mass food production and globalization of food sources increases efficiency but also increases potential impact of contamination.
 
Small inocula may propagate in larger batches of food (e.g. E. coli O157-H7 in hamburger), and incomplete decontamination of animal feed or use of inappropriate animal feeds can contaminate animal food sources (e.g. bovine spongiform encephalitis [BSE] from transfer of scrapie from sheep to cattle, from sheep byproducts in cattle feed).

Front 8

Factors in Emergence of Infectious Diseases Describe
Microbial Adaptation and Change

Back 8

Antibiotic resistance can result in emergence or re-emergence of infections (e.g. tuberculosis, vancomycin resistant enterococcus).
 
Mutations and acquisition of virulence factors can result in new outbreaks (antigenic shift in influenza, H. influenzae biogroup aegypticus in Brazilian purpuric fever, necrotizing fasciitis due to group A Streptococci)

Front 9

Factors in Emergence of Infectious Diseases Describe Breakdown of Public Health Infrastructure.

Back 9

Breakdown of Public Health Infrastructure.

Breakdown in public health efforts to control waterborne or vector-borne pathogens and vaccine preventable diseases have led to emergence of older pathogens (e.g. tuberculosis, cholera) and new EID (e.g. cryptosporidiosis in drinking water from Milwaukee associated with inadequate filtration).
 
New pathogens may require sophisticated testing strategies that are not available or improperly controlled at the local level (e.g. E. coli 0157:H7, Cryptosporidium, Cyclospora).
TB primary example

Front 10

Addressing the Threats of EIDs: The CDC Prevention Strategy for the United States:

What are the 4 main goals?

Back 10

Goal 1. Detect, promptly investigate, and monitor emerging pathogens, the diseases they cause, and factors influencing their emergence.
 
Goal 2. Integrate laboratory science and epidemiology to optimize public health practice.

Goal 3. Enhance communication of public health information about emerging diseases and ensure prompt implementation of prevention strategies.
 
Goal 4. Strengthen local, state, and federal public health infrastructures to support surveillance and implement prevention and control programs.
 

Front 11

Addressing the Threats of EIDs: The CDC Prevention Strategy for the United States:

Besides the 4 main goals, what else does the program try to do?

Back 11

Program attempts to address the skewed distribution of federal funds for surveillance of infectious diseases (95% of funds allocated to the states in 1992 were designated for 4 disease categories: TB, HIV, STDs, and vaccine preventable diseases); no funds designated for support of notifiable disease system.
 
Detection of new problems or EIDs depends on the ability to identify and track the routine and the unusual.