To introduce major concepts related
to emerging and re-emerging
Emerging and Re-emerging infectious
Factors contributing to emerge
Basic concept of the infectious diseases
Challenges to prevent the emergence
“Emerging” & “Re-Emerging”
in small numbers
Diseases that once were
major health problems
globally or in a particular
country, and then declined
dramatically, but are again
becoming health problems
for a significant proportion of
Diseases thought to be
making a “comeback” are
NEW DISEASE EMERGE
OLD DISEASE RE-EMERGE
Ecological disruption and human
intrusion into new ecological
system increases the exposure of
human to new infectious agents.
Usually tropical & Developing
countries are HOT SPOT of
Climate change is another potential
driver that shifts the ecological niche
or range of the diseases.
Long-term impact of global warming, some
major climatic events caused disease
outbreaks in the areas that have not
experienced the disease before.
Urbanization and Industrialization
impact the prevalence and scope of
both infectious and chronic diseases.
High risked sexual practices, multiple
sexual partners and use of substances
directly transmit the diseases
Overcrowding causes person to person rapid
spreading of diseases.
Poor housing quality, poor sanitation and
water supply infrastructure.
International trade of goods and services through
international border facilitate the spread of diseases
by bringing pathogen to new geographical areas.
Travelers are exposed to variety of pathogen, many
of them have never encountered and no immunity to
EVOLUTION OF THE INFECTIOUS
Mutations in bacterial genes that confer
resistance to antibiotics – 20%
Multidrug-resistant & extremely drug-
Multi drug resistant P.falciparum
REDUCED HUMAN IMMUNITY
(breakdowns in public
War & Political conflict
cuase breakdown of
infrastructure has role
in emergence of
Poor primary health
care services may not
be equipped to deal
Year recognized Disease Infectious agent
New viral strain
Pandemic Influenza Influenza virus
1967 Murburg hemorrhagic
Before 1976 Salmonellosis Salmonella entertidis
1976 Ebola hemorrhagic
1983 AIDS Human Immuno-deficiency
1983 Gastric ulcers Helicobacter pylori
1989 Hepatitis C Hepatitis C virus (HCV)
1998 Nipah encephalitis Nipah encephalitis
2002 VRSA infection Vancomycin resistant
2003 SARS (severe acute
2015 Zika Zika virus
DENGUE FEVER Dengue virus
MALARIA Plasmodium species
MENINGITIS Group A Streptococcus
SCHISTOSOMIASIS Schistosoma species (helminth)
RABIES Rabies virus
CHOLERA Vibrio cholerae 0139
YELLOW FEVER Yellow fever virus
TUBERCULOSIS Mycobacterium tuberculosis
SARS: The First Emerging
Infectious Disease Of The 21st
Century (China, 2003)
(Severe Acute Respiratory Syndrome)
Total 8429 cases; 824 deaths
30 countries in 7-8 months
The 2014 Ebola outbreak is the largest in
Primarily affecting Guinea, Northern Liberia,
and Sierra Leone.
Ebola virus disease (EVD), previous known as
Ebola hemorrhagic fever (Ebola HF)
Fatality rate of up to 90%
Transmitted by direct contact with the blood,
body fluids and tissues of infected animals or
Tuberculosis or TB is an infectious
bacterial disease caused by
Mycobacterium tuberculosis, which
most commonly affects the lungs.
In the 18th and 19th centuries, a
tuberculosis epidemic rampaged
throughout Europe and North America.
In 1993 the World Health Organization
(WHO) declared that TB was a Global
Emergency; the first time that a
disease had been labeled as such.
Approximately 390 million people worldwide infected
with the dengue virus each year.
2014, swine flu
has claimed the
lives of over
1,300 people in
India, making it
outbreak of the
virus in the
SWINE FLU (H1N1 Virus)
The cause of this condition is an inactivating PH mutation in the
EVER1 or EVER2 genes which are located adjacent to one
another on Chromosome 17
Infectious agent is Plasmodium species
Malaria is transmitted among humans by female
mosquitoes of the genus Anopheles.
Causative agent is
Water borne diseas
Varying pathogenicity (mortality ranging from
Responsible for 1967 outbreak in Europe.
Outbreaks in 2000 in Democratic Republic of
the Congo and 2005 in Angola.
Currently no vaccine or treatment.
(Murburg Hemorrhagic Fever)
EID IN SEA REGION
EID – a leading cause of death globally
17 m die annually from ID – SEA accounts for 41%
or 7 m deaths
EID cause suffering & impose financial burden on
Plague outbreak in 1994 cost India over 1.5 B USD
due to loss in trade, employment & tourism
In Thailand cost of one AIDS patient more than 5000
Overall costs for India on account of AIDS
estimataed at 11 b USD
Increasing or persistent poverty & poor living
conditions continue to expose millions of people to
the hazards of infectious diseases.
The low priority & support given to public health
MANAGEMENT OF EID
A proactive and planned approach to ensure the
appropriate prevention and control of the spread
of disease. Strategic planning should include:
Phase I (non-alert) is a routine, preparatory state;
Phase II (alert) is the detection, confirmation and
declaration of changes identified during non-alert
Phase III (response) includes the ongoing assessment
of information and the planning and implementation of an
appropriate response, which includes the coordination
and mobilization of resources to support intervention
Phase IV (follow-up) activities include re-evaluation,
Strengthening epidemiological surveillance &
laboratory capabilities and services .
Establishment of a rapid response team.
Monitoring antimicrobial resistance.
Establishment of international disease
surveillance. networking and advocacy.
Screening on International travels and trades.
Networks of laboratories that link countries and
regions need to be established.
Strong national and regional public health