+The New Epidemiology – Epidemiology of the 21st century

Pragna ChandrasekharJohn FriasPromila GonsalvesDhurv Misri

+Overview

Introduction to Epidemiology

Epidemiology in the 19th and 20th century

Diseases most prevalent 19th-21st century

Disease tracking and surveillance

21st century epidemiology – The “New” epidemiology

Training in applied epidemiology

Organizations involved in research and healthcare improvement

Epidemiology and Public Health

+Epidemiology

What is epidemiology?

What does it entail? Populations Measurements Comparison Multidisciplinary aspects

+Types of Epidemiology

“Shoe leather”

Microbial

Descriptive

“Risk factor”

Clinical

Molecular

Genetic

“Big”

Global

+19th and 20th Century Epidemiology

The dramatic decline of infectious diseases are attributable to these socioeconomic factors: Better sanitation and hygiene Discoveries of antibiotics and vaccines Quarantine and isolation Involvement of government in legislations Scientific and technological advances in detecting

and surveillance of infectious diseases

+19th and 20th century Epidemiology Sanitation and

Hygiene 19th century increased

population Industrialization and

migration Inadequate public water

supplies and poor waste management system

Around 1900s, repeated outbreaks declined with improved public health Chlorination of water

(1900s Animal and pest control

programs Proper waste disposal

Vaccines Various vaccine

campaigns virtually eliminated diseases

Eradication of small pox

+19th and 20th century Epidemiology

Antibiotics Discovery of penicillin

by Alexander Fleming (1928)

Antibiotic treatment used by civilians for about 57 years

Problem: Emergence of drug resistance in several disease-causing microorganisms

Quarantines and Isolations 1600s practices of

isolation and quarantine employed to prevent spread of certain diseases

Subsequently, 1800s, these practices had become common in the American colonies.

+19th and 20th century Epidemiology

Government Involvement in Legislations 1950s epidemiology

widely recognized with discovery of lung cancer linked to tobacco smoking

Scientific and Technological Advances Serological testing Viral isolation and

tissue culture Molecular technique

+TIMELINE OF PREVALENT DISEASES

+Prevalent diseases in the 19th Century

MALARIA

Caused by the female Anopheles Mosquito

400-900million infected 1-3 million death

yearly in the early centuries

225 million cases in 2009

CHOLERA

Infection of the small intestine - Vibrio Cholerae

8 million dead in India alone between 1900-1920

3-5million people affected worldwide yearly now 100,000-200,000

death yearly

BUBONIC PLAGUE

Third pandemic started in 1855 in China

Zoonotic disease by Yersinia pestis

12 million people died in India and China only

Last active case in 1959

+Prevalent diseases in the20th CenturySMALL POX

Caused by the Variola virus

Affects children and young adults

Causes lesions, fever, muscle pain and malaise

300-500million people dead

Eradicated in 1979

INFLUENZA

Spanish flu – 1918-1919

H1N1 influenza virus

More than 500 million infected with 50 -100 million death worldwide

Re-emerged in 2009 as Swine Flu

Killed more than 18000 people since 2009

TYPHUS

Caused by Rickettisiae – obligate parasite

Infected 20-30 million between 1918-22

Killed at least 3 million

Large decrease due to vaccines

+Prevalent Diseases in the 21st Century

AIDS First recognized in 1981

Caused by the Human Immunodeficiency virus

Killed 25 million people

About 40 million people living with HIV

CANCER Unregulated cell

growth

In 2008, 7.6 million death about 13% of the population

Projected increase of 45% in Cancer death by 2030

SARS Caused by SARS

coronavirus

Outbreak in 2002/2003

8,422 cases with 916 deaths

More potent in people >65 years; 50% mortality rate

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+Disease Tracking & SurveillanceAdvancements in 19th & 20th Century

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Diseases in red require immediate reporting by a physician, nurse, health care provider, healthcare facility, or school to the Department of Epidemiology.

Click icon to add picture

+Disease Tracking & SurveillanceWHO Reporting Requirements

Periodic Reporting Requirements

Items Mode of Communication

Immediate reporting

First identified individual fulfilling the confirmed case: - descriptive account of any evidence of human-to-human transmission including information about thenumber of cases and the likely chains of transmission· any unusual or unexplained events under investigation

E-mail or fax

Daily Reporting - number of confirmed cases- number of confirmed cases for which there is no reported at-risk exposure and no laboratory occupational exposure- number of confirmed cases for which exposure history is unknown or undetermined- number of persons for whom Diagnosis is being considered- number of new hospital admissions

E-mail, fax or via secure password-protected WHO Global Atlas web site upon request

Weekly Reporting

Case-based information in a line listing format including confirmed cases with updated results persons for whom diagnosis is being considered and discarded cases

E-mail

+Disease Tracking & SurveillanceReporting Methods: The Great Divide

Developed Countries

Utilization of Emerging Technology and Social Trends

Advanced Communication System

Abundant Awareness & Preventative Methods Resources

Developing Countries

Creative Projects Utilizing Basic Technology

Broken Communication Infrastructures

Lack of Medical & Awareness Resources

+Disease Tracking & SurveillanceImpact, Issues, & the Future Direction

Impact Issues

Lag in Detection

Evolution of Drug-Resistant Strains

Broken Link in Communication Structure

Rapid Globalization

Disproportionate Allocation of Funds

+Training in Applied Epidemiology Epidemic Intelligence Service (EIS)

Attracts pool of candidates with PhDs and doctoral degrees

2-year program involving various training programs: Applied epidemiology Biostatistics Public health surveillance Scientific writing Working with media Emerging public health issues

Degree and licensing Requirements and Eligibility Physicians Doctoral-level Scientists Veterinarians

+Organizations Involved in Research and Health Care Improvements

World Health Organization – Global Smallpox Eradication Programme (1980)

American Public Health Association Epidemiology

Global Health Quality Improvement Public Health Initiatives

Society of Epidemiologic Research

+The New Epidemiology of the 21st century

Applies epidemiology to modern healthcare

Safety risks of drugs – Reye syndrome and aspirin

Disproval of “safety signals” – birth defects due to exposure to bendectine

Medication benefits in disease prevention – folic acid supplementation

Treatment patterns

Primarily: cost of drugs and treatment

Number of trained pharmacoepidemiologists very small

PHARMACOEPIDEMIOLOGY CHALLENGES

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Advances in genomics, molecular studies, proteomics, likewise – dominates the field DNA transcriptional control

for population “stratification” and preventative measures

Human Genome Project Compilation of DNA

sequence variants Efficient, cost-effective

technology to determine polymorphic sites

Large-scale samples

Lack of statistical ability to interpret and analyze the plethora of data produced

Complex diseases difficult to identify in initial stages and replicate for research

Requirement of large tissue samples

Constantly changing methods of conducting studies

Lack of specifity in phenotype definitions leading to limitations in identifying chronic disease associations

MOLECULAR AND GENETIC CHALLENGES

The New Epidemiology of the 21st century

+Epidemiology and Public Health

“Methodologic backbone” of public health

Some discoveries made due to advances in the field: Identification of health and environmental risks due to use

of tobacco Linked neural tube defects in infants with folate deficiency –

prevention by fortification of wheat with folic acid Connected link between hepatitis B and liver cancer –

prevention by worldwide vaccination campaigns Played a major role in decline of cardiovascular deaths

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Increased number of people survived to old age More healthcare required Research studies and clinical trials optimally distributed to

include all generations and those prone to premature mortality and disease

Drastic decrease in infectious and communicable diseases Emerging resistant strains!

Future control of infectious agents Globalization Bioterrorism Climate change

Epidemiology and Public Health – Successes of Epidemiology

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