Download Emerging and Re-emerging Infectious Diseases

Emerging and Re-emerging Infectious Diseases
Dr. Pramod
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Introduction
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Why focus on emerging infectious diseases
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List of emerging infectious diseases
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Examples of emerging & re-emerging infectious diseases in the SEAR
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Burden of emerging diseases
a. Global
b. India
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Economic impact
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Factors responsible for emerging infectious diseases
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Emerging infections in India: Trends and epidemiological features
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Combating emerging infectious diseases
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Preparedness at international level
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Preparedness in India
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Bioterrorism
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Recommendation
Introduction:
In 1948, the US Secretary of State remarked “the conquest of all infectious diseases was imminent”.
In 1962, F M Burnet, the Nobel Prize winner, made an optimistic statement “To write about infectious
disease is almost to write of something that has passed into history..., the most likely forecast about
the future of infectious disease, is that it will be very dull”.
In December 1967, the US Surgeon General William Stewart declared victory by announcing “The war
against infectious diseases has been won”. However, infectious diseases are a dominant public
health problem even in the 21st century.
The World Health Organization estimates 25% of the total 57 million annual deaths that occur worldwide
are caused by microbes and this proportion is significantly higher in the developing world.
In the landmark report to Institute of Medicine (1992) in the US, Joshua Lederberg and Robert Shope
identified the emerging microbial threats and attributed to the emergence of new pathogens due to
microbial evolution and adaptation, change in human behaviour, population movement, civil unrest and
industrial, agricultural and economic development.
Definition:
Emerging infectious diseases are those where the incidence in humans has either increased during the
last 20 years or threatens to increase in the near future. This group of diseases also includes those
identified for the first time and old ones spreading to new geographical areas. It also refers to those
diseases which were previously easily treated with antibiotics but have now developed resistance to
drugs.
Re-emerging infectious diseases are those that have increased after a significant decline in their
incidence. (OR Reappearance of a disease which was once endemic but had since been eradicated or
controlled, would classify it as a re-emerging infectious disease.)
Emergence may also be due to a new recognition of an infectious agent in the population or the
realization that an established condition has an infectious origin.
Impact of emerging and re-emerging infections:
 37 new pathogens with epidemic potential identified globally during last 3 decades
 Besides huge morbidity and mortality the emerging & re-emerging infectious disease outbreaks
have huge economic impact on national economy.
 The plague outbreak of 1994 in Surat caused an economic loss to the tune of $ 1.7 billion. Some
recent outbreaks are of Influenza A – H1N1, H5N1 and Crimean Congo Hemorrhagic Fever
(CCHF).
 Emerging and re-emerging infections increase awareness of our global vulnerability, highlight the
borderless impact of diseases and underscore the need for strong health care systems.
Why focus on emerging infectious diseases:
Despite remarkable advances in medical research and treatment during 20th century, infectious diseases
remain among the leading causes of death worldwide for three reasons1. Emergence of new infectious diseases
2. Re-emergence of old infectious diseases
3. Persistence of intractable infectious diseases
It is estimated that over 37 new infectious agents have been detected worldwide in the last three decades;
60 per cent of these are of zoonotic origin, and more than two-thirds of these have originated in the
wildlife. Epidemics or pandemics caused by these emerging and re-emerging infections often take a
heavy toll of life and by rapidly spreading across borders are responsible for much concern and panic.
Unfortunately, many of these diseases do not yet have any cure. These diseases are the leading cause of
death worldwide. These infectious diseases pose a great strain on the already stretched health services.
These also add to the socio-economic burden on families and individuals. Thereby, in 1997 the World
Health Day theme was "Emerging Infectious Diseases: Global Alert, Global Response". This theme
clearly stressed the need for all countries to strengthen efforts to successfully prevent and control
infectious diseases.
List of emerging microbes of public health importance identified in the last 39 years:
1973
1975
1976
1977
1977
1977
1977
1980
Rotavirus- Enteritis/Diarrhea
Parvovirus B -19 - Fifth disease
Cryptosporidium- Enteritis/Diarrhea
Ebola virus- VHF
Legionella- Legionnaire’s ds.
Hantan virus- VHF w/ renal flr
Campylobacter- Enteritis/Diarrhea
HTLV-1- Lymphoma
1993
Sin Nombre virus- Hanta Pulm. Synd(Aus)
1994
1994
1995
1995
1996
1997
1981
1982
Toxin prod. S.aureus- TSS
E.coli 0157:H7- HUS
1999
1999
1982
1982
1983
1983
1988
1989
1990
HTLV-II- Leukemia
Borrelia burgdorferi- Lyme disease
HIV- AIDS
Helicobacter pylori- Peptic ulcer ds
Hepatitis E- Hepatitis
Hepatitis C- Hepatitis
Guanarito virus- VHF
2001
2003
2003
2004
05-08
2009
2012
Sabia virus- VHF
Hendra virus- Respiratory ds
Hepatitis G- Hepatitis
H Herpesvirus-8- Kaposi sarcoma
vCJD prion- Variant CJD(UK)
Avianinfluenza(H5N1)Influenza(Hong
Kong)
Nipah virus- Encephalitis
West Nile virus- Encephalitis(USA,
Argentina)
BT Bacillus anthracis-Anthrax(USA)
Monkeypox- Pox
SARS-CoV- SARS(SEA, Canada)
H5N1- Avian Influenza(SEA)
2005/8-AI H5N1 (Asia, Europa and África)
Influenza A(N1H1)- Swine flu
Novel corona virus- Severe respiratory
infection
1991
1992
1992
Encephalitozoon- Disseminated ds
Vibrio cholerae O139- Cholera
Bartonella henselae- Cat scratch ds
Examples of emerging & re-emerging infectious diseases in the South-East Asia Region:
Emerging diseases include HIV/AIDS, cholera, tuberculosis, malaria, dengue hemorrhagic fever, viral
hepatitis, meningitis and Japanese encephalitis.
Re-emerging infectious diseases are plague and kala-azar.
There are also some infectious diseases that have occurred in other parts of the world but have the
potential to appear in the Region; for example, Hanta virus, and yellow fever and Ebola hemorrhagic
fever.
List of NIAID Emerging and Re-emerging diseases
Group I—Pathogens Newly Recognized in
the Past Two Decades
Group III—Agents with Bioterrorism Potential
NIAID—Category B
Acanthamebiasis
Australian bat lyssavirus
Babesia, atypical
Bartonella henselae
Ehrlichiosis
Encephalitozoon cuniculi
Encephalitozoon hellem
Enterocytozoon bieneusi
Helicobacter pylori
Hendra or equine morbilli virus
Hepatitis C
Hepatitis E
Human herpesvirus 8
Human herpesvirus 6
Lyme
borreliosis
Group II—Re-emerging
Pathogens
Parvovirus B19
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Enterovirus 71
Clostridium difficile
Mumps virus
Streptococcus, Group A
Staphylococcus aureus
Group III—Agents with Bioterrorism
Potential
NIAID—Category A
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Bacillus anthracis (anthrax)
Clostridium botulinum toxin
(botulism)
Yersinia pestis (plague)
Variola major (smallpox) and
other related pox viruses
Francisella tularensis (tularemia)
Viral hemorrhagic fevers
o Arenaviruses
 LCM, Junin
virus, Machupo
virus, Guanarito
virus
 Lassa Fever
o Bunyaviruses
 Hantaviruses
 Rift Valley Fever
o Flaviruses
 Dengue
o Filoviruses
 Ebola

Marburg
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Burkholderia pseudomallei
Coxiella burnetii (Q fever)
Brucella species (brucellosis)
Burkholderia mallei (glanders)
Chlamydia psittaci (Psittacosis)
Ricin toxin (from Ricinus communis)
Epsilon toxin of Clostridium perfringens
Staphylococcus enterotoxin B
Typhus fever (Rickettsia prowazekii)
Food- and waterborne pathogens
o Bacteria
 Diarrheagenic E.coli
 Pathogenic Vibrios
 Shigella species
 Salmonella
 Listeria monocytogenes
 Campylobacter jejuni
 Yersinia enterocolitica)
o Viruses (Caliciviruses, Hepatitis A)
o Protozoa
 Cryptosporidium parvum
 Cyclospora cayatanensis
 Giardia lamblia
 Entamoeba histolytica
 Toxoplasma
o Fungi
 Microsporidia
Additional viral encephalitides
o West Nile virus
o LaCrosse
o California encephalitis
o VEE
o EEE
o WEE
o Japanese Encephalitis virus
o Kyasanur Forest virus
NIAID—Category C
Emerging infectious disease threats such as Nipah
virus and additional Hantaviruses.
The Global burden of emerging diseases:
The emerging infectious diseases account for 26 per cent of annual deaths worldwide. Nearly 30 per cent
of 1.49 billion disability-adjusted life years (DALYs) are lost every year to diseases of infectious origin.
A literature survey identified 1,407 species of human pathogens, with 177 (13%) species regarded as
emerging or re-emerging. Distribution of emerging and re-emerging pathogens by groups shows that 37
per cent of emerging and re-emerging pathogens are viruses and prions followed by protozoa (25%). This
indicates that emerging and re-emerging pathogens are disproportionately viruses.
According to WHO, 440,000 new cases of multi-drug resistant tuberculosis (MDR-TB) emerge annually,
causing at least 150,000 deaths. A more virulent form called extensively drug-resistant tuberculosis
(XDR-TB) has been reported from 64 countries. Another example of global concern relates to the specter
of falciparum malaria resistant to artemisinin combination therapy (ACT) emerging at the Cambodia-Thai
border which has a potential to spread across countries.
Burden of emerging diseases in India:
India the second most populous country in the world is in the midst of a triple burden of diseases; the
unfinished agenda of communicable diseases, non-communicable diseases linked with lifestyle changes
and emergence of new pathogens and overstretched health infrastructure. Communicable diseases account
for nearly half of India’s disease burden. Many infections are associated with poor sanitation,
contaminated food, inadequate personal hygiene, or access to safe water and lack of basic health servicesconditions common to large parts of India.
Economic impact
Globally 350 million DALYs that is lost due to communicable diseases & South-East Asia Region
accounts for 89 million.
On an average, 2 to 2.5 million cases of malaria are reported annually with an estimated 27,000 deaths
and an annual economic loss of US$ 2 billion.
Tuberculosis continues to be the biggest killer of young adults. Multidrug resistant-TB is at least 100
times more expensive to cure.
The 1994 locally-contained outbreak of plague in India (Surat), estimated to cost US$2 billion.
Estimates on the cost of the SARS outbreak range from US$10 billion to US$30 billion.
Factors responsible for emerging infectious diseases:
The Convergence Model: At the center of the model is a box
representing the convergence of factors leading to the emergence of
an infectious disease. The interior of the box is a gradient flowing
from white to black; the white outer edges represent what is known
about the factors in emergence, and the black center represents the
unknown (similar to the theoretical construct of the “black box” with
its unknown constituents and means of operation). Interlocking with
the center box are the two focal players in a microbial threat to
health—the human and the microbe. The microbe– host interaction is
influenced by the interlocking do-mains of the determinants of the
emergence of infection: genetic and biological factors; physical
environmental factors; ecological factors; and social, political, and
economic factors.
Human pathogens emerge and re-emerge due to interaction of multiple complex factors between the host
and pathogen each driven by the need to secure the success of the species in changing environments.
Adaptation by one partner to exploit new environments will often stimulate the other to modify its
characteristics to take advantage of the change.
Thirteen individual factors—some reflecting the ways of nature, most of them reflecting our ways of
life—account for new or enhanced microbial threats. Any of these factors alone can trigger problems, but
their convergence creates especially high-risk environments where infectious diseases may readily
emerge, or re-emerge, affecting the world & posing particular challenges for the medical and public
health communities.
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Human demographics and behavior
Technology and industry
Economic development and land use
International travel and commerce
Microbial adaptation and change
Breakdown of public health measures
Human vulnerability
Climate and weather
Changing ecosystems
Poverty and social inequality
War and famine
Lack of political will
Intent to harm
1. Demographic factors and behavior: Infectious diseases can result from individual’s activities that
involve exposure to microbial pathogens or simply from the increased probability of infectious
disease as population grow and people come into closer contact. High population density carries
increased potential for spread of person-to-person disease, greater likelihood of global warming,
large number of travelers, increased hunger and malnutrition. Societal events: Population growth
and migration (movement from rural areas to cities); war or civil conflict; urbanization; sexual
behavior, intravenous drug use; use of high-density facilities
2. Technology and Industry: Advances in medical technologies (blood transfusions and organ &
tissue transplants), globalization of food supplies; changes in food processing and packaging; have
created new pathways for the spread of certain infections. Drugs causing immune-suppression make
people susceptible for infection; widespread use of antibiotics cause emergence of drug resistance
diseases.
3. Ecological changes (including those due to economic development and land use): New or
previously unknown infectious diseases have emerged from the increased human contact with
animal reservoirs that resulted from changing land-use patterns
e.g. Agriculture, dams,
deforestation/reforestation, flood/drought, famine, climate changes etc. Malaria, dengue fever and
schistosomiasis have increased in areas wherever artificial water bodies have been created.
Clearance of forests to build an international airport in Malaysia in the 1990s led to a devastating
outbreak of Nipah virus, carried by forest bats fleeing to agricultural lands.
4. International travel and commerce: The rapid and virtually unrestricted transport of humans,
animals, foods, and other goods lead to the broad dissemination of pathogens and their vectors
throughout the world e.g. SARS has been documented to be the one of the fastest moving
microorganisms in the history of mankind(SARS was carried through international air travel by
infected people to 31 countries that reported probable cases of SARS), the Spanish influenza
traveled around the world in less than 12 months, Hong Kong (1968-69) influenza took only six
months and a future pandemic is likely to spread more rapidly because of the speed and frequency
of human travel. Emerging infections can arise from animals and birds (e.g. chickens and H5N1)
and seed a pandemic through movements to distant countries through seasonal migrations or trade.
5. Microbial Adaptation and Change: The tremendous evolutionary potential of microbes makes
them adept at developing resistance to even the most potent drug therapies and vaccines.
6. Breakdown of Public Health Measures: In many places, the lack of basics such as potable water or
sanitation contributes to infectious diseases. But similar effects can also occur from inadequate
prevention programs (vaccine supplies, low immunization rates); inadequate sanitation and vector
control measures. A well functioning public health infrastructure can prevent many infections,
particularly those that are food-borne or water-borne. Defects in the health system can result in
massive epidemics. An efficient public health system not only quickly detects and responds to the
epidemic during its initial phase but is also sensitive enough to spot a new or unidentified infection.
Almost all the outbreaks of hepatitis E in India have been traced to the piped water that got
contaminated by sewage from the pipes carrying sewer.
7. Human Vulnerability: Susceptibility to infection can develop when normal defense mechanisms
are impaired by causes such as genetically inherited traits and malnutrition. Susceptibility can also
result from antimicrobial resistance induced by the promiscuous use of antibiotics.
8. Climate and Weather: Climate directly affects disease transmission through its impacts on the
replication, movement, and evolution of microbes and vectors; climate also operates indirectly
through its effects on ecology and human behavior. At warmer temperatures, parasites develop more
rapidly in mosquitoes. Consequently, there will be an increase in the incidence of malaria and
dengue fever.
9. Changing Ecosystems: Altered environments influence the transmission of microbial agents,
whether waterborne, airborne, food borne, or vector borne.
10. Poverty and Social Inequality: Poverty breeds ill health and ill health, in turn, breeds poverty.
Mortality from infectious diseases is closely correlated with global inequalities in income.
Economic trends affect not only the individuals at risk but also the structure and availability of
public health institutions necessary to reduce risks.
11. War and Famine: Displacement caused by war and sequelae of malnutrition from famine
contribute significantly to the emergence and spread of infectious diseases.
12. Lack of Political Will: Governments in the regions of highest disease prevalence must commit
themselves. The leaders of affluent regions that ultimately share the same global microbial
landscape should also commit.
13. Intent To Harm: The world today is vulnerable to the threat of deliberate biological attacks that can
cause large numbers of deaths and widespread social disruption. The likelihood of such events, in
fact, is high, and public health systems and health care providers must be prepared to address them.
Emerging infections in India: Trends and epidemiological features
In the recent past, India has witnessed many large outbreaks of emerging infections and most of them
were of zoonotic origin. A review of the list shows that of the eight aetiological agents, five are of viral
origin. Six of these infections are of zoonotic nature.
Cholera:
A large scale cholera outbreak occurred in India in 1992 starting in southern peninsular India and
spreading both inland and along coast line of Bay of Bengal. Vibrio cholerae O139, a new serogroup was
associated with this epidemic cholera. Reports of cholera outbreak due to this new serogroup have come
from various parts of the country. Patients infected with O139 strains were much older than those
infected with O1 strains. Over the previous one decade, O1 and O139 serogroups have coexisted in much
of the cholera endemic areas in India and elsewhere.
Plague:
The 1994 plague outbreak in Surat in Gujrat State created an unprecedented level of panic leading to
population exodus and internal migration, contributed in part by local and international media reports, and
to considerable negative social, political, and economic impact. Plague infection continues to exist in
sylvatic foci in many parts of India which is transmitted to humans occasionally. This has been
demonstrated with focal outbreaks of plague in India in 1994, 2002 and 2004. Epidemiological
investigations have attributed these recurrences to spillover from an epizootic cycle of plague in wild
rodents to commensal rodents driven by climate variation. Recent analysis of data from Kazakhstan
shows that warmer springs and wetter summers increase the prevalence of plague in its main host, the
great gerbil.
The National Centre for Disease Control (NCDC) has identified four sylvatic foci in India; the tri-junction
of Karnataka, Andhra Pradesh and Tamil Nadu, later Beed belt in Maharashtra, Rohru in Himachal
Pradesh and Uttarakhand. The plague outbreak in Surat, led not only to nationwide panic but to a near
international isolation of India. As a result, the country incurred direct economic losses to the tune of US
$ 1.7 billion.
Diphtheria:
The incidence of diphtheria, a vaccine preventable disease during 1980 was about 39,231, it reduced to
2817 cases in 1997. However, in the past two decades, there has been a sudden increase in diphtheria
cases with more than 8000 cases reported in 2004.
The primary immunization coverage for diphtheria has remained between 56 to 72 per cent in the past
two decades according to WHO UNICEF estimates. NFHS III also show that DPT 3 coverage during
1992-2006 was only 52-55 per cent. Persistence or resurgence of diphtheria in the country seems mainly
due to low coverage of primary immunization as well as boosters. There have been reports of diphtheria
outbreaks from various States including Delhi, Andhra Pradesh, Assam, Maharashtra, Chandigarh,
Gujarat. An epidemiological age shift has been noted in these outbreaks, with the disease now affecting
older children (5-19 yr) and adults. Majority of the cases were reported from children who were
unimmunized or partially immunized against diphtheria.
Chandipura virus:
A new virus belonging to family Rhabdoviridae was isolated in 1965 in the Chandipura (Nagpur) region
of India in two adult patients with febrile illness during an outbreak of febrile illness caused by
chikungunya and dengue viruses. It was named as Chandipura (CHP) virus.
This virus was not considered to have an epidemic potential until an outbreak of acute encephalitis in
children in Andhra Pradesh, India was attributed to CHP virus in 2003 with a case fatality rate of 55 per
cent. CHP virus is transmitted to humans by sandflies. Subsequently focal outbreaks have been reported
from Gujarat (2004), and Maharashtra (2007 and 2011). The outbreaks have predominantly focused in
rural areas and sandflies seem to be the main vector and maintainence host of the virus. Case distribution
was spotty without clustering and paediatric age group of 9 months to 14 years was involved.
Neurological sequelae was rare in recovered children.
Chikungunya fever:
Chikungunya fever, caused by the chikungunya virus, was first reported in Tanzania in 1953. Previous
outbreaks in India (1963 and 1973) were caused by the Asian genotypes. Non-human primates act as a
main reservoir of infection. After a quiescence of three decades, a resurgence of infection from southern
and central parts of the country was reported in 200647. This has been attributed to the East African
genotype earlier not prevalent in this part of the world. Currently, 22 States and Union Territories of India
have reported cases of chikungunya . Chikungunya is associated with joint pains lasting up to six months.
Although deaths are not known to occur but the morbidity and disability caused due to chikungunya are
enormous and 45.26 DALYs were lost per million population due to 2006 epidemic in India.
Influenza A (H5N1) viruses:
Avian influenza is an infection caused by Influenza A (H5N1) viruses, usually infecting poultry animals
and pigs. It was first reported in 1997 in Hong Kong. In 2003, changes in the strains of virus resulted in
emergence of ‘novel’ Z strain and, infection to human beings by this virus, contrary to earlier belief that
avian influenza virus cannot infect human beings due to differences in receptors. Vietnam reported first
human case due to H5N1 in 2003.
Till date 587 persons have been infected by Influenza A (H5N1) with 346 deaths from 15 countries. Cases
of bird flu were reported in Navapur tehsil of Nandurbar district of Maharashtra. So far India has not
reported any human cases of Influenza A (H5N1).
Pandemic HINI influenza virus(H1N1)
The pandemic HINI influenza virus emerged in humans in early April 2009 in Mexico and California.
The H1N1 strain then quickly spread worldwide through human-to-human transmission. Up till August
2010, worldwide more than 214 countries had reported laboratory confirmed cases of pandemic influenza
H1N1 2009, including over 18449 deaths.
On August 10, 2010, the WHO Director-General Dr Margaret Chan announced that the influenza H1N1
virus has moved into the post-pandemic period. In India, till August 8, 2010, a total of 15,4259 persons
were tested for H1N1 influenza and 23.4 per cent were found to be positive including 1833 deaths.
Transmission was intense in western States of Maharashtra and Gujarat.
Crimean-Congo haemorrhagic fever (CCHF):
Crimean-Congo haemorrhagic fever (CCHF) was first described as a clinical entity in 1944-1945 in
Crimea during World War II. CCHF virus circulates in an enzootic tick-vertebrate-tick cycle. The virus
causes disease among smaller wildlife species, e.g. hares and hedgehogs that act as hosts for the immature
stages of the tick vectors. A CCHF outbreak was reported in Gujarat in 2011. This outbreaks was
characterized by a zoonotic origin and a person-to-person spread in hospital setting. High index of clinical
suspicion, early laboratory diagnosis and institution of containment measures curtailed further spread of
the disease.
Epidemiologically, major at-risk group are farmers living in endemic areas and animal handlers. The
geographic range of CCHF virus is the most extensive among the tickborne viruses that affect human
health, and the second most widespread of all medically important arboviruses, after dengue viruses.
Changes in climatic conditions have been suggested to be one of the factors that have facilitated the
survival of a large number of Hyalomma spp. ticks and of the hosts of both their immature and adult
stages and consequently the increased incidence of CCHF.
Acute encephalitis syndrome (AES):
Acute encephalitis syndrome (AES) characterized by fever and seizures each year takes a heavy toll in a
few States of India, especially in children below the age of 10 years. During the past five years, the
incidence of AES in the country has been on the rise. Of the five States reporting the disease during 2011,
most cases and deaths were in Uttar Pradesh, followed by Bihar, Assam and West Bengal.
As a seasonal disease, AES often occurs in outbreaks during summer or following the rains. In a recent
outbreak in Muzzaffarpur district of Bihar, which began during late May 2012 had by Mid July accounted
for 389 cases and 160 deaths, with a case fatality rate of 41.13 per cent. Characteristically, in most
outbreaks, the aetiological agents responsible for this life threatening disease remain undetermined, with
Japanese encephalitis virus detected in about 15 per cent. Unfortunately, many gaps presently exist in our
understanding of the disease epidemiology including the mode of transmission, which hamper efforts at
effective control.
Nipah virus
The Nipah virus was first recognized in 1999 during an outbreak among pig farmers in Malaysia. Since
then, there have been 12 additional outbreaks, all in South Asia. Fruit bats of the Pteropodidae family are
the natural hosts for Nipah virus. Evidence shows that geographical distribution of Henipavirus (Nipah
and Hendra) overlaps with that of Pteropus . Over the years, the epidemiology of Nipah appears to have
changed. Evidence of person to person transmission and a high case fatality rate (60-70%) were some of
the alarming developments seen in Nipah outbreaks in India (2001) and Bangladesh (2001, 2006). Nipah
virus has also been categorized as a food borne disease from eating dates contaminated with urine or
saliva of infected bats.
The 1997 avian influenza in Hong Kong which is estimated to have cost hundreds of millions of dollars
lost in poultry production, commerce and tourism. It is difficult to measure the social and psychological
impact of these outbreaks.
Combating emerging infectious diseases:
EIDs will continue to challenge public health infrastructure, test credibility of health services, and
threaten to devastate health and economic development unless a strategic vision and an effective plan of
action are developed to combat these. This will increasingly require the application of sophisticated
epidemiologic and molecular biologic technologies, changes in human behaviour, and a national
perspective. In view of this, the WHO has made several recommendations for national strategies
including the need to strengthen epidemic preparedness and rapid response, public health infrastructure,
risk communication, research and its utilization, and advocacy for political commitment and partnership
building.
There are five strategic elements that are needed to combat emerging diseases. These include:
1. Epidemic preparedness and rapid response:
Surveillance in its simplest form is collection of information for action. A disease or an event under
surveillance is first picked up by the health care system which reports it to the public health authority for
interpretation and initiating action as shown below in conceptual framework for the surveillance and
response system for emerging infectious diseases. However, in many developing countries
implementation of this framework is hampered by several deficiencies like
 Inadequacies in data collection
 Incapability of analysis of data by health care workers
 Weak feedback mechanism
 Inadequate public health laboratory support system
Implementation of a national plan requires  Strengthening of capacity
 Development of infrastructure
 Availability of qualified and trained human resource
Objectives:
- Strengthening of routine in-country surveillance for emerging infectious diseases
- Enhance detection of outbreaks by the development of early warning systems
- Forging strong surveillance networks to facilitate flow of information and initiation of
appropriate action.
Fig: Conceptual framework for surveillance & response of emerging infectious diseases
Health care
system
Reporting
Event
Public health
laboratory
Data
Analysis &
Interpretation
Intervention
Information
Decision
(Feedback)
1. Public health infrastructure:
Public health infrastructure is the backbone of any efficient public health activity. It consists of
people who work in the field of public health, epidemiology, entomology, environmental hygiene,
infection control, laboratories and information and communication specialists at district, state and
national levels.
Fig: Public health infrastructure
The institutions, human resource, equipment and technologies as well as quality assurance of the activities
should be developed and strengthened in such a way that all contribute efficiently to achieve the
objectives of combating emerging infectious diseases. These include public health laboratories for
identification and molecular characterization of causative agents, development, appropriate use, and
availability of diagnostic tests and reagents; cooperation from informed communities, use of modern
communication and information technology.
Multisectoral involvement is needed for effective control of infectious diseases like national authorities
in different sectors namely private sector, academic institutes, the mass media, NGOs and various
international developmental partners. An enhanced public and private mix is needed to provide services to
manage emerging infectious diseases.
Human resource- There is a major shortage of qualified and trained public health staff. Each country
must ensure an adequate number of qualified, competent and trained professionals of different fields like
epidemiology, entomology, public health laboratories, information technology and communication.
Accurate and timely laboratory analysis is critical for identifying, tracking and limiting public health
threats.
Similarly, emerging disease surveillance should utilize modern computing and communication
technologies to transform data into useable information quickly and effectively. Accurate and efficient
data transfer with rapid notification of key partners and constituents is critical to effectively address the
threats of emerging diseases. A network of public health laboratories should be created with strong
linkages between various laboratories.
Information sharing and networking- International surveillance and response networks enable
countries to be better prepared and respond to epidemics as was seen during the SARS outbreak.
1. Risk communication:
Risk communication is an interactive process of exchanging information and opinion among individuals,
groups and institutions. Risk communication targets the general public as well as the mass media, the
latter to facilitate wide dissemination of appropriate messages so that it delivers messages that inform
without frightening and educate without alarming.
The objectives of risk communication are
 To ease public concern by informing them about the risk, the treatment, the transmission
dynamics and clinical features of disease outbreak
 To make the public aware of actions that need to be initiated by people themselves for their
benefit as well as for cutting short the transmission of infection.
2. Research and its utilization:
Research can play an important role during an outbreak, in identifying the etiological agent, developing
diagnostic tools, case management modules and preventive strategies.
(a) environmental factors which facilitate the emergence, maintenance and transmission of these
diseases, especially vector-borne and zoonotic infections. These factors mainly include deforestation,
developmental projects, global warming, urban ecology, dynamics of transmission between wild and
domestic animals.
(b) evolution of pathogenic infectious agents resulting in changes in infectivity, virulence,
transmissibility and adaptations based upon identification of changes at molecular level especially the
genetic composition of the organisms
(c) host factors that facilitate the emergence of infections and their spread including the use of
antimicrobial and immunosuppressant drugs and the protective factors in a host
(d) Development of new diagnostic tools that support rapid and accurate diagnosis even in field
conditions
(e) Social inequalities and behavioral factors that influence distribution of emerging diseases, their
course and the populations that are affected most
(f) Impact of environmental changes and climatic variability on the emergence of microbes: Scientific
research is also needed to guide public policy; develop evidence-based policies for rational use of
antimicrobial agents in humans, animals and the environment and the formulation of environmentfriendly and safe insecticides and pesticides.
3. Advocacy for political commitment and partnership building:
Prevention and control of emerging infectious diseases is the responsibility of national governments. This
cannot be delegated to any other agency or organization. At the same time, efficient program management
can be implemented only if there is a strong political will and commitment, adequate financial and human
resources as well as productive partnerships with different sectors. The goal can be achieved through a
strong infrastructure, competent and skilled human resources and an efficient intersectoral partnership.
The collaboration between government agencies is easier and feasible. It becomes challenging when the
private sector and the mass media are to be involved. The mass media and private sector has extensive
reach to community. Both are critical partners. A national plan for emerging infectious diseases should be
developed and a National Technical Advisory Group established to guide, advise and monitor the national
efforts against emerging infectious diseases. A national focal point should be identified to coordinate with
various sectors.
Preparedness at International level:
WHO continues to track the evolving infectious disease situation, alert the population, share expertise,
and mount the kind of response needed to protect populations from the consequences of epidemics,
whatever and wherever might be their origin.
International Health Regulation: "IHR (2005)" have been in force since 15 June 2007. The purpose of
the IHR (2005) is to prevent, protect against, control and provide a public health response to the
international spread of disease. IHR restricted to public health risks. Hence there is no interference with
international traffic and trade. The IHR (2005) provide a framework for WHO epidemic alert and rapid
response activities.
The IHR (2005) introduces new operational concepts including:
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Specific procedures for disease surveillance, notification and reporting of public health events
and risks to WHO by countries
Requests by WHO for verification of public health events occurring within countries
Rapid collaborative risk assessment with and assistance to countries
Determinations as to whether an event constitutes a public health emergency of international
concern
Coordination of international response
The Global Outbreak Alert and Response Network (GOARN): is a technical collaboration of existing
institutions and networks. It pools human and technical resources for the rapid identification,
confirmation and response to outbreaks of international importance. It is an operational framework that
links this expertise and skill. It keeps the international community constantly alert to the threat of
outbreaks and ready to respond. The Global Outbreak Alert and Response Network contribute towards
global health security by:
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Combating the international spread of outbreaks
Ensuring that appropriate technical assistance reaches affected states rapidly
Contributing to long-term epidemic preparedness and capacity building.
Strengthening surveillance and rapid response mechanisms
To mount an effective public health response, the surveillance forms an important cornerstone for control
of emerging and re-emerging infections. After the plague outbreak in 1994, the Government constituted a
technical committee to suggest measures to prevent recurrence of such outbreaks.
The Central Council of Health and Family Welfare (CCHFW) is the apex political and policy formulating
body with the Union Minister of Health and Family Welfare (as chairperson) and health ministers from all
the States / Union Territories of the country as members.
In 1995, the Council recommended the establishment of State and district level epidemiological units and
revitalization of procedures of identification and reporting of outbreaks through the primary health care
system. It also affirmed the need to strengthen public health system to effectively implement and evaluate
national health programmes and to prevent outbreaks that can have national and international
consequences.
In 1996, the National Apical Advisory Committee for National Disease Surveillance and Response
System (NAAC) was created.
In 1997, these initiatives and policy level decisions led to the establishment of the National Surveillance
Programme on Communicable Diseases (NSPCD).
In 1999, the Government of India constituted a technical advisory group on diseases of international
public health importance.
In 2004, the Integrated Disease Surveillance Project (IDSP) was established in 101 districts. Since then,
it has expanded to cover all States and districts in the country, meaning that each district now has a
surveillance unit and a rapid response team (RRT) to quickly manage the disease outbreak in any part of
the country.
To augment surveillance activities and response mechanisms a wide network of epidemiologists,
microbiologists and entomologists has been made available in all district and State headquarters under
IDSP. IT connectivity has been established with all the States, districts and medical colleges through 776
sites for rapid data transfer, video conferencing and distance learning activities. Over the years, there has
been an increase in the number of outbreaks reported by and investigated through IDSP with 1675
outbreaks in 2011 alone.
Preparedness in India
IDSP (Integrated disease surveillance project):
Project objectives:
1. To establish a decentralized state based system of surveillance for communicable & noncommunicable diseases, so that timely & effective public health actions can be initiated in response
to health challenges in the country at state & national level.
2. To improve the efficiency of the existing surveillance activities of disease control programs &
facilitate sharing of relevant information with the health administration, community and other
stakeholders so as to detect disease trends over time and evaluate control strategies.
Specific objectives:
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To integrate & decentralize surveillance activities
To establish systems for data collection, reporting, analysis and feedback using information
technology
To improve laboratory support for disease surveillance
To develop human resources for disease surveillance and action
To involve all stakeholders including private sector & communities in surveillance
Administrative structure:
National disease surveillance committee (State disease surveillance committee/ District surveillance
committee)
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Secretary health/Family Welfare- Chair person(Alternate)
DGHS(Co-chair)
JS Health
JS Family Welfare
Director NICD
Director NIB
Representative Ministry of Home, Ministry of Environment, IMA, NGO
National surveillance officer
National program managers- Polio, Malaria, TB, HIV/AIDS
Consultants (WHO, Medical college)
Preparedness for Swine flu:
Series of administrative actions instituted by GOI1. Surveillance at Ports & International airports
2. Integrated disease surveillance units in states alerted to report clusters of Influenza like illness &
pneumonia
3. Travel advisory issued for those travelling to the affected area to deter their plan
4. Establishment of state rapid response team- Any suspected cluster of Influenza like illness needs
to be investigated by State Rapid Response Team & managed in isolation facility with strict
infection control practices & if needed, Central Rapid Response team assist the state
5. Central government support the state in terms of guidelines, experts, lab supports, Oseltamivir &
personal protective equipments
6. Guidelines circulated to all medical colleges, infectious disease hospitals, hospitals identified
with isolation facilities & district level hospitals
7. Decentralization of stock of Oseltamivir & personal protective equipments to regional offices so
that state can use these in case of human cluster of Influenza like illness reported in state
8. Important contact sites
 Emergency Medical Relief (EMR) control room (Ministry of Health & Family Welfare)working 8am to 8 pm. Ph no. 011-23061469
 Outbreak monitoring cell control room (NICD) - work for 24x7 to attend calls from
public regarding reporting of influenza like illness. Ph no. 011-239221401
Steps of Government of India to prevent outbreak in country:
1. Early detection of cases among passengers coming from affected countries either by air , ship or
road
2. Massive mass media campaign to inform & educate people on dos and don’ts
3. Sharing information with public through media
4. Appeal made by government- People who have travelled from affected countries in past 10 days
& shows symptoms of Influenza should immediately contact the Ph no. as above or nearby Govt
hospital
Preventing infectious diseases- more to do:
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Enhance communication: locally, regionally, nationally, globally
Increase global collaboration
Share technical expertise and resources
Provide training and infrastructure support globally
Ensure political support
Ensure judicious use of antibiotics
Vaccines for all
Bioterrorism
What is Bioterrorism?
A bioterrorism attack is the deliberate release of viruses, bacteria, or other germs (agents) used to cause
illness or death in people, animals, or plants. These agents are typically found in nature, but it is possible
that they could be changed to increase their ability to cause disease, make them resistant to current
medicines, or to increase their ability to be spread into the environment. Biological agents can be spread
through the air, through water, or in food.
Terrorists may use biological agents because they can be extremely difficult to detect and do not cause
illness for several hours to several days. Some bioterrorism agents, like the smallpox virus, can be spread
from person to person and some, like anthrax, cannot.
Bioterrorism Agent Categories
Bioterrorism agents can be separated into three categories, depending on how easily they can be spread
and the severity of illness or death they cause. Category A agents are considered the highest risk and
Category C agents are those that are considered emerging threats for disease.
Category A
These high priority agents include organisms or toxins that pose the highest risk to the public and national
security because:
· They can be easily spread or transmitted from person to person
· They result in high death rates and have the potential for major public health impact
· They might cause public panic and social disruption
· They require special action for public health preparedness.
Category B
These agents are the second highest priority because:
· They are moderately easy to spread
· They result in moderate illness rates and low death rates
· They require specific enhancements of CDC's laboratory capacity and enhanced disease monitoring.
Category C
These third highest priority agents include emerging pathogens that could be engineered for mass spread
in the future because:
· They are easily available
· They are easily produced and spread
· They have potential for high morbidity and mortality rates and major health impact.
A Agents:
Variola major (smallpox)
Bacillus antrhacis (anthrax)
Yersinia pestis (plague);
B Agents:
Coxiella burnetti (Q fever)
Brucella species (brucellosis);
Burkholderia mallei (glanders)
C Agents:
Nipah virus,
antaviruses,
Tickborne hemorrhagic fever
viruses
Clostridium botulinum toxin Alphaviruses,
Tickborne
encephalitis
(botulism)
-Venezuelan encephalomyelitis, viruses,
-Eastern and western equine
encephalomyelitis;
Francisella
tularensis Ricin toxin from Ricinus Yellow fever, and
(tulararemia);
communis (castor beans);
Filoviruses,
Epsilon toxin of Clostridium Multidrug-resistant
-Ebola hemorrhagic fever;
perfringens; and
tuberculosis.
-Marburg hemorrhagic fever;
Arenaviruses,
� Staphylococcus enterotoxin
-Lassa (Lassa fever)
B
-Junin (Argentine hemorrhagic - A subset of List B agents
fever) and related viruses
includes pathogens that are
food or waterborne. These
pathogens includebut are not
limited to:
� Salmonella species,
� Shigella dysenteriae,
� Escherichia coli O157:H7
� Vibrio cholerae, and
� Cryptosporidium parvum
Recommendations
 Community Level
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Strict enforcement of laws regarding environmental pollution with stiff penalties for
default
Promotion of waste management systems like biogas plants
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School Health Programmes with, the active participation of parents, teachers and
community leaders, to focus on the importance of Environmental Protection and its
relationship to human diseases, and to help create civic sense among the children.
Regional and specific recommendations for farmers and different types of occupation
Promotion of early health seeking behavior and avoidance of self-treatment and quacks
Using existing organizations like residential association to sensitize the community
regarding the issue.
Institutional Level
o Creation of diagnostic facilities, particularly for virologic and genetic studies
o Ensuring hygienic practices in the hospitals and health settings
o Surveillance at the Clinical, Laboratory, Environment and Vector levels.
o Development of Protocols for diagnosis and treatment, and manuals for health workers
incorporating principles from modern medicine, ayurveda and homoeopathy
o Sensitisation of medical students, interns and residents.
o Regular CME programmes for practitioners in the non-academic service institutions
regarding surveillance, early diagnosis, proper & timely referral etc.
o Improvement in the infrastructure and staff pattern in all health institutions.
o Time bound and result oriented research in the efficacy and proper use of Ayurvedic
environmental purification and vector control measures, immune-boosters and other
indigenous methods and homoeopathy drugs.
o Adoption of nearby communities by health care educational institutions for taking care of
their health needs.
o Conducting household surveys: Students under the guidance of the teachers should
conduct surveys in the community to assess the incidence and prevalence of the various
emerging and re- emerging infectious diseases, environmental hygiene, presence of
vectors, life style etc.
Administrative Level
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Advocacy programmes for social workers
Dissemination of health tips for travelers
Proper registration of migrants.
Health monitoring of workers from other States
Research promotion at clinical, laboratory and community levels.
Empowerment of ASHA workers with more information related to the different streams,
along with monetary help.
Institution of field health staff and related structured framework in Ayurveda and
Homoeopathy systems, similar to the present public health system in modern medicine.
Involvement of the nursing and para-medical institutions, particularly in areas of IEC
(Information, Education & Communication) material development and dissemination,
school health programs and social research.
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Setting up of a regional epidemic management institute which could conduct courses and
research, and enable the faculty to conduct research into various aspects of epidemic
management, which could be useful even for the neighboring States
Regular updates on infectious diseases through internet and newsletters.
Monitoring and Supervision of activities.
Conclusions and the way forward :
For a country of size and population of India, the emerging infections remain a real challenge. A
meaningful response must approach the problem at the systems level. A comprehensive national
strategy on infectious diseases addressing the challenges of emerging and re-emerging infections
cutting across all relevant sectors, both governmental and non-governmental, should be in place.
Identification of national centres of excellence and their capacity building is of critical
importance. These centres of excellence should be encouraged to develop networking and
partnerships between public health organizations to improve their individual scientific capacity,
share best practices and expand collective knowledge base.
Concerted efforts are also needed to develop advanced countermeasures such as surveillance
tools, diagnostic tests, vaccines and therapeutics through basic, translational and applied research.
Sensitive rapid response mechanisms at various levels of health service are the cornerstone to
detect public health threats and respond quickly enough to protect valuable human lives. National
commitment and comprehensive efforts are necessary at all levels of health services in order to
meet the threat of emerging and re-emerging infections.
References:
1. National institute of Allergy & Infectious diseases
2. Emerging & re-emerging infections in India: An overview: Indian J Med Res 138, July 2013, pp
19-31
3. WHO, World Health Report 2007
4. THE LANCET Infectious Diseases Vol 1 December 2001
5. Emerging Infectious Diseases; 1995 January-March:Vol.1(1)
6. Combating Emerging Infectious Diseases in the SEA Region. WHO
7. Institute of Medicine
8. IDSP, GOI, mohfw, N. Delhi
9. http://www.ncbi.nlm.nih.gov/books/NBK20370/
10. David M. Morens*, Anthony S. Fauci, Emerging Infectious Diseases: Threats to Human
Health and Global Stability. National Institute of Allergy and Infectious Diseases,
National Institutes of Health, Bethesda, Maryland, United States of America .