The presentation details different methods and terminologies used in disease management. It briefs about different types of disease control programs run at global, regional, and national levels. It also tells about the success and failure of different disease control programs. The presentation also briefed about methods of disease control.

1. Control and Eradication of
Animal diseases
Dr. Bhoj R Singh, Principal Scientist (VM)
Head Division of Epidemiology
Indian Veterinary Research Institute, Izatnagar-243122, Bareilly, UP,
India.

2. • Control of Disease: Reduction in prevalence
Reduction in morbidity and mortality due to disease, it can be
achieved by:
1. Control: Treatment, Hygienic measure
2. Prevention: Reduce both incidence and prevalence, vaccines, hygienic measures
3. Eradication: Extinction of disease and disease agent from the globe (only few
diseases belong to this group, small pox, RP)
• Or
• Reduction in prevalence to the level at which no more transmission is possible
(usually regional eradication).
• Or
• Reduction in prevalence to the level at which it ceases to be a major health problem
though transmission of disease still exist.
• Or
• Regional extinction of disease and disease agent (FMD from Many countries of
Europe, rabies from Newzealand).
• Or
• Elimination, in which Agent persists but disease does not.
• Eradication is the reduction of an infectious disease's prevalence in the global host
population to zero.
• Elimination, describes either the reduction of an infectious disease's prevalence in a
regional population to zero, or the reduction of the global prevalence to a negligible
amount.
• Clearance of an infection means total removal of a given pathogen from an individual.

3. Global attempts of disease eradication
• Eight attempts have been made to date to eradicate
infectious diseases
a. Four aborted programs targeting Hookworms, Malaria, Yaws
and Yellow fever.
b. Two successful programs targeting Smallpox (Last case in
Somalia, 1977) and Rinderpest (On 8 August 2011, the United
Nations held a ceremony declaring the disease eradicated, making
rinderpest only the second disease in history to be fully wiped out,
following smallpox, the last confirmed case of rinderpest was
diagnosed in 2001 in Kenya).
c. Two ongoing programs targeting Poliomyelitis (Eliminated from
US in 1979) and Drancunculiasis (Guinea worm disease, Guinea-
worm disease is now restricted to 14 countries in Africa).
d. Five more infectious diseases have been identified as of April
2008 as potentially eradicable with current technology by the Carter
Centre International Task Force for Disease Eradication – Measles,
Mumps, Rubella, Lymphatic filariasis and Cysticercosis.

4. Regional elimination
• Some diseases have already been eliminated from large regions of the world, and/or
are currently being targeted for regional elimination. This is sometimes described as
"eradication", although technically the term only applies when this is achieved on a
global scale.
• Bovine spongiform encephalopathy (BSE) and new variant Creutzfeldt–Jakob
disease (vCJD)
Following an epidemic of vCJD in the UK in the 1990s, there have been campaigns
to eliminate BSE in cattle across the EU and beyond which appear to have achieved
large reductions in the number of cattle with this disease. Cases of vCJD have also
fallen since then, for instance from an annual peak in the UK of 28 cases in 2000 to 3
cases in 2010. Following the ongoing eradication effort, only 22 cases of BSE were
reported worldwide in 2011, the fewest since at least 1988
• FMD: Ongoing program to control (eliminate) FMD from cattle and buffalo, in India
and several other countries in Africa is going on. The disease has already been
eradicated from Oceania, Japan, many of the European and North American
countries.
• Neonatal tetanus has been eliminated in over 100 countries but the disease
continues to kill almost 300 000 newborn babies every year, and tetanus kills about
40 000 mothers as well.
• Leprosy: The number of countries where the disease is a public health problem has
been reduced from 122 in 1985 to only 28. But leprosy remains a serious problem in
16 countries which together account for over 90% of all cases.

5. Extinction
• Finally, the literature sometimes refers to extinction as a possible
policy goal for control of a disease.
• In the context of infectious disease control, the concept is
problematic for two reasons.
– First, proving that an organism has become extinct is impossible. To do so would
require demonstrating not only that the organism no longer exists in nature but
also that it no longer exists in any controlled environment—a practical
impossibility.
– Second, de novo synthesis of viral agents from published genomes (Cello, Paul,
and Wimmer 2002) now put the concept in peril, although much research
remains to be done in this area.
Extinction, in the context of infectious diseases, may no longer be
irreversible.

6. Re-emergence
• Diseases once considered all but eradicated in the United States
have re-emerged in the past several years. The resurgence of
diseases like pertussis, tuberculosis, measles and mumps is an
expression of the dangers posed by failing infrastructure and
declining living standards for the working class.
• According to the CDC, approximately 90 percent of food-related
illnesses, hospitalizations, and deaths were due to seven
pathogens: Salmonella, norovirus, Campylobacter, Toxoplasma,
E.coli O157, Listeria and Clostridium perfringens.
• In 1993, the United States suffered the worst episode of water-borne
disease with the outbreak of Cryptosporidiosis in Milwaukee

7. Types of Prevention of Diseases
• Primary: Prevent occurrence of new cases, i.e.,
cutting in incidence (vaccination)
• Secondary: Diagnose and treat the disease to
cut short the course of disease to prolong the life
span (in humans DOTS for TB)
• Tertiary: Treat chronic disease to reduce their
severity, prolong life span (care to HIV cases).

8. Frameworks for eradication of a disease
• Scientific considerations: nature of potential reservoirs for disease-causing microbes or their
vectors, technologies available for interrupting disease transmission, changes in host capabilities
to deter infections and disease, and satisfactory containment of organisms in laboratories.
• Geographic and Environmental Controls: The limit of endemicity for microbes and their
associated diseases is determined in part by their ability to exist in nature outside the main host.
Both geographic and temporal variations determine the ecological niche of microbes, resulting in
variable annual incidence rates throughout the world. This niche limitation is further extended to
intermediary vectors and hosts in complex biological systems.
• Potential Reservoirs: A microbe and associated disease can not be eradicated if the microbe is
capable of persisting and multiplying in a reservoir. Microbes that thrive in reservoir species may
reemerge if control efforts cease, thus leaving the populations susceptible
• Transmissibility: The inherent rate of a microbe's ability to cause secondary infections is defined
by an organism's reproductive rate in a fully susceptible (R0) and partially susceptible (R)
population. The reproductive rate of organisms that infect individuals only once because of
durable immunity is inversely proportional to the average age of infection in an endemic area.
• Natural Resistance to Reinfection: Many natural infections induce long-lived immunity to
reinfection. Although the most commonly used vaccines have been available for fewer than 50
years—less than the lifetime of an individual—they, too, are assumed to offer long-lasting
immunity.
• Laboratory Containment: Laboratory specimens containing the organism targeted for
eradication could serve as reservoirs. Considerable effort may be necessary to ensure their
maximum security. That these microbes may be inconspicuous in specimens collected for other
purposes poses special challenges.

9. Components of a eradication program
• Optimization of control requires a fundamental appreciation of the biological systems that
govern the ecology of microbes and their intermediary and human hosts. The reproductive
rate, R, is influenced by many local factors, including population density (of vectors,
intermediary hosts, and final host) and other environmentally determined conditions, all
highly variable throughout the world. For a disease to be controlled to stop transmission,
the intervention-altered reproductive rate must be maintained below 1.0. At the same time,
all reservoirs of the responsible microbe must be controlled.
• Three main components of possible eradication programs are
– surveillance, including environmental sampling where appropriate and
clinical testing
– interventions, including vaccination and chemotherapy or
chemoprophylaxis or both
– environmental controls and certification of eradication.
• Economic Considerations: Control and eradication programs have many economic dimensions:
private versus social net benefits, short-term versus long-term net benefits, and local versus
international net benefits. Such interventions also have implications for existing public health
programs.

10. Strategies to control and prevent
the diseases
1. Leave to the nature, seasonal diseases
like Malaria, Dengue, Blue tongue,
trypanosomiasis, where vector itself
vanish with change in season (in hot
summers and winters)
2. Minimize the risk of introduction of
exotic livestock diseases (Quarantine,
trade control).

11. 3. Minimize the risk of national spread of disease by restricting
hazardous animal trade practices and by improving peacetime biosecurity
measures and institution of appropriate and effective actions for the control
of disease outbreaks. Vaccination and prophylactic measures [Test and
slaughter, vaccination, regional restriction on movement, alternate/ mixed/
sequential grazing/ stall feeding (parasitic diseases), control of biological/
mechanical vectors, improving general sanitation (disinfection of fomites),
niche filling (Nurmi effect, fowl typhoid and S. Enteritidis), genetic
improvement through selective breeding , transgenics (genetic diseases/
hereditary disorders e.g. canine hip dysplasia, canine cyclic neutropenia),
improvement in environment, animal husbandry practices (mastitis control).
Required services to effectively implement the control programs at
National, regional level:
– Health tests and certification to assure that livestock and poultry are free
of diseases when they are sold or shipped.
– Analyzing the state’s livestock population through continuous monitoring
and testing at livestock markets and shows.
– Coordination of animal and poultry disease eradication programs.
– Investigations of drug residue cases and tracebacks associated with
suspect animals.

12. • Effective legislation [Animal disease
Act, Farcy and Glanders Act, Notifiable
disease Act, Animal Disease Control Act
(In India different states enacted these in
1960s)]
• Effective disease surveillance and
early detection of disease (Animal
Disease intelligence).

13. Improving animal disease
intelligence
• Animal disease intelligence is the analysis of animal disease events
and information on related environmental or economic variables to
identify the causes or drivers of disease introduction and spread that
may represent risks to animal and human health or people's
livelihoods.
• Animal disease intelligence is essential for prevention of diseases in
humans, livestock or wildlife.
• What is needed? Integration of national and regional data from
animal and human demographic statistics, field and laboratory
disease surveillance results, and environmental or agro-system
variables with the existing global surveillance systems. This
integration is essential to improve early and rapid disease detection,
robust analyses, expedient warning and timely risk management.

14. What affect the disease control and
eradication program?
What are the incentives for states to participate in an eradication effort? To begin,
assume that countries are symmetric, meaning that all countries have the same
benefits and costs of control. Assume as well that eradication is feasible. Four
possible situations then exist (Barrett 2003):
• First, the global net benefit of eradication may be negative—the cumulative
programmatic costs outweigh the net present value of the cumulative benefits. In this
case, elimination would also yield a negative net benefit to every country, and so no
country would eliminate the disease.
• Second, the global net benefit of eradication may be so large that each country
would choose to eliminate the disease even if others did not. In this case, all
countries would eliminate the disease, and the disease would therefore be
eradicated. In these two cases, no need exists for an international policy.
• Third, each country may have an incentive to eliminate a disease only if all
other countries have eliminated it. In this case, achieving global eradication
requires coordination. Here a role exists for international policy, but all that is required
is for each country to be assured that all others will eliminate the disease.
• Finally, and noting that the "last" country to eliminate a disease would get just
a fraction of the global dividend from eradication, under some circumstances no
incentive may exists for this country to eliminate the disease—even if all other
countries have done so and even if the entire world would be better off if it did. This
case is the most worrisome, because implementation of the efficient outcome would
likely require enforcement.

15. Strengthening Laboratory and
Epidemiology Networks
• Regional veterinary laboratory and epidemiology
networks are an efficient and effective platform for
sustainable infectious disease management.
• These networks represent an ideal mechanism to foster
leadership, develop regional expertise centres, enhance
performance and harmonization, build trust, and create
tangible results which can inspire healthy emulation
within and outside a given region.
• Combining laboratories and networks with public health,
socioeconomic, wildlife conservation or communication
professionals greatly increases the usefulness of these
systems for policy makers involved in animal and human
health.

16. Aspects of Animal Disease
control/ prevention
• Socioeconomics
• Animal diseases have multidimensional
impacts in people’s livelihoods
• People play a vital role in the prevention and
the emergence of animal diseases.
• Understanding and managing societal and
institutional drivers of disease emergence,
spread and maintenance is critical in developing
appropriate approaches to disease prevention
and control by the identification of critical control
points for surveillance or intervention.

17. One-Health
• Human health is inextricably linked to environment, animal health and
production.
• These links are particularly important in developing countries where
many people rely on animals for food, income, transportation,
draught power, fuel and clothing.
• About 70 percent of the new human diseases that have appeared
during the past two decade originate from animals or from products
of animal origin.
• Animal diseases that affect humans undermine the efficient
production of food, particularly of high-quality protein and can create
barriers to trade.
• The FAO VPH unit & WHO supports “One-Health” initiative for
capacity building in countries for the effective prevention and control
of diseases of animal origin that affect human health and well-being,
at all stages from production to consumption.

18. Wildlife and Ecosystems
• The health of people, livestock, wildlife and the environment are
intricately interconnected. The One-Health approach addresses
public health and pandemic disease concerns through
multidisciplinary, cross-sectoral, multi-institutional cooperation.
• It is well known that wildlife can serve as the reservoir of certain
diseases that impact livestock and human health, but the challenge
remains in identifying and implementing actions that prevent disease
transmission, enables wildlife conservation, and concurrently
promotes food security and rural development.
• Wild birds have been implicated in the transmission of influenza
viruses along their migratory routes and within diverse agro-
ecological settings and their roles in the epidemiology of avian
influenza viruses are currently being evaluated through surveillance,
outbreak response activities, and migration and ecology studies
using satellite telemetry.
• SARS-CoV, MERS-CoV and SARS-CoV-2 are the recent examples.

19. Global Early Warning System for
Animal Diseases including
Zoonoses (GLEWS)
• The overall objective of GLEWS
To improve the early warning and response capacity to animal
disease threats of the three sister organizations (FAO, OIE and
WHO) for the benefit of the international community.
Action out puts:
1. Tracking of zoonotic disease outbreaks that merit further validation.
Sources of information can be official or unofficial from the global
human and veterinary public health communities.
2. Information sharing and validation is performed through the
appropriate organizations. GLEWS links with the International Food
Safety Authorities Network (INFOSAN) to ensure that food safety
events are managed along the farm to table continuum.
3. Multidisciplinary disease analysis provides added value to global
early warning of zoonotic disease.

20. What triggers GLEWS
• A potential event is assessed according to criteria
derived from the International Health Regulations (2005)
and the Terrestrial Animal Health Code from OIE:
• Is the public health impact of the event serious?
– High morbidity and/or high mortality in humans and/or animals.
– Emerging disease with significant mortality and/or morbidity or
zoonotic potential.
• Is the event unusual or unexpected?
– First occurrence or reoccurrence of a disease/strain.
– Unusual event for the area or season.
– Event associated with an unknown agent.
• Is there significant risk of international spread or
interference with international travel or trade?

21. Collaborating centres in GLEWS
International Organizations
• The Mediterranean Zoonoses Control program (MZCP)
• Codex Alimentarius
• Food and Agriculture Organization of the United Nations (FAO)
• World Organisation for Animal Health (OIE)
Non-Governmental Organizations
• Consortium for Conservation Medicine (CCM)
• Organisation for Economic Co-operation and Development
(OECD)
• Wildlife Conservation Society (WCS)
• World Conservation Union (IUCN)
• WWF

22. Emergency Prevention System (EMPRES)
for transboundary animal and plant pests
and diseases.
• The EMPRES-livestock: an FAO
initiative.
• Source of information
http://www.fao.org/DOCREP/004/W3737E/
W3737E05.htm
• EARLY WARNING,
• EARLY/RAPID REACTION,
• ENABLING RESEARCH and
• COORDINATION

23. Vision of EMPRES
• Early Warning is identified as all disease initatives, which would be based
predominantly on epidemiological surveillance, that would lead to improved
awareness and knowledge of the distribution of disease or infection and that
might permit the forecasting further evolution of an outbreak.
• Early Reaction is identified as all actions that would be targeted at rapid
and effective containment of, and leading, to the elimination of a disease
outbreak, thus preventing it from turning into a serious epidemic. This
includes contingency planning and emergency preparedness.
• Enabling Research is identified as a prime element of EMPRES which
emphasizes the collaboration between FAO and scientific centres of
excellence in directing research efforts towards problem solving.
• Coordination involves either coordination of global eradication for an
identified animal disease, such as rinderpest, eg., through the Global
Rinderpest Eradication program, or encouraging regional initiatives for
eradication of a given transboundary animal disease.

24. Vaccines that are instrumental in prevention
and control of infectious diseases
Diseases
Annual deaths
(all ages) if no
immunization Prevented Occurring / year % prevented
Smallpox 5.0 million 5.0 million -- 100
Diphtheria 260,000 223,000 37,000 86
Whooping cough 990,000 630,000 360,000 64
Measles 2.7 million 1.6 million 1.1 million 60
Neonatal tetanus 1.2 million 0.7 million 0.5 million 58
Hepatitis B 1.2 million 0.4 million 0.8 million 33
Tuberculosis 3.2 million 0.2 million 3.0 million 6
Polio (cases of lifelong
paralysis)
640,000 550,000 90,000 86
Malaria/other parasitic
infections
2.2 million -- 2.2 million 0
HIV/sexually transmitted
diseases
1.3 million -- 1.3 million 0
Diarrhoea/enteric fevers* 3.0 million -- 3.0 million 0
Acute respiratory infections 3.7 million -- 3.7 million
0
COVID-19 2.5 million ----- 200 million
Vaccines failed to
prevent

25. Epidemiologic features of smallpox that
favor eradication
• Reservoir and host Man
• Transmissibility Relatively low
• Subclinical cases Never or rare
• Incubation Long—12 days
• Public concern Very great
• Vaccine
– Efficacy >98%
– Logistics Practical, bifurcated needle
– Cost Minimal
• Seasonality Striking

26. Essential principles in WHO smallpox
eradication program
1. Development and use of uniformly potent smallpox vaccines tested at several
international laboratories
2. Provision of widespread vaccination of populations in target countries where
smallpox was endemic
3. Principle outcome measure was the absence of cases of smallpox
– Program relied on active surveillance
– When cases were identified, their contacts were immediately vaccinated to abort
further transmission
• Surveillance
1. Mobile surveillance teams visit bazaars, schools, train and bus stations, beggar colonies, bustees
2. Rewards for notification of smallpox cases—at train and bus stations, rickshaw announcers, school
children, soccer games
3. Intensive search around areas of outbreaks
4. Epidemiologic investigation of every smallpox outbreak to detect source, travel of case, and travel of
contacts
5. Monthly municipal area house-to-house search
6. In later stages, national house-to-house search
All smallpox supplies were supposed to be kept in two maximum containment locations
• 1. CDC, Atlanta
• 2. Novosibirsk, Russia

27. Animal Disease eradication programs
• EU
• Bovine tuberculosis
• Bovine brucellosis
• Ovine and caprine brucellosis (B. melitensis)
• Bluetongue in endemic or high risk areas
• African swine fever
• Swine vesicular disease
• Classical swine fever
• Avian influenza
• Rabies
• Transmissible spongiform encephalopathies (TSE)
• Salmonellosis (zoonotic salmonella)
• US eradication programs include scrapie in sheep and goats, tuberculosis in
cattle and cervids, pseudorabies and brucellosis in swine, and brucellosis in
cattle and bison.
• USDA announced on July 10, 2009, that for the first time in the history of the
Brucellosis program, all 50 States were Class Free for the disease in domestic cattle
herds. The Cooperative State Federal Brucellosis Eradication Program was
established in 1934.

28. The main aspects of the TB and Brucellosis Diseases
Eradication Schemes in US
• Annual testing for TB (the "Round" test) of the national herd and/or designated categories of
animals, with primary responsibility is assigned to farmers;
• Follow-up and focused strategic additional testing, including use of blood testing for TB in certain
circumstances;
• Restriction of holdings when reactors are disclosed.
• Movement of any animal into or out of a restricted holding is prohibited, except with the
written permission of the DVO and on foot of a movement permit.
• Restriction of inconclusive TB reactor animals to herd for life or direct to slaughter or via a feedlot
direct to slaughter.
• Restriction, pending test, of relevant herds contiguous to a high risk TB breakdown where those
herds were not tested in the previous four months.
• Rapid removal of reactors to meat factories or, in the case of calves which are deemed to be of no
commercial value, to knackeries (subject to age/weight limitations). Removal is paid for by the
Department).
• A range of compensation (on market rates) measures for farmers whose herds are affected by
disease;
• Delays in testing or removing reactors due to lack of co-operation by the farmer, for whatever reason
(including valuation/compensation issues), may lead to a reduction in compensation.
• A badger culling program where they are implicated in a disease breakdown.
• Improved epidemiology and feedback to farmers;
• A comprehensive research program aimed at preventing TB spread by wildlife and the development
of blood tests, vaccines and other technological tools required to improve effectiveness of programs.
• Payment of disease levies by farmers on cattle slaughtering/live exports and milk deliveries.

29. New Zealand
• New Zealand is free from all the major epidemic diseases, such as rabies and
the transmissible spongiform encephalopathies. The once endemic conditions
of sheep scab (Psoroptes ovis), bovine brucellosis (Brucella abortus), hydatids
(Echinococcus granulosus) and Aujeszky’s disease have been eradicated.
Anthrax (Bacillus anthracis) is no longer considered endemic and Pullorum
disease (Salmonella Pullorum) has effectively been eradicated from
commercial poultry flocks.
• There are current control programs for bovine tuberculosis (Mycobacterium
bovis), enzootic bovine leucosis in dairy cattle, infectious bursal disease, ovine
epididymitis (Brucella ovis), and caprine arthritis encephalitis.

30. Some Control Programs for Animal
Disease in India
• RP Control and eradication program
• CBPP Control and eradication program
• FMD Control and eradication program
• PPR Control Program
• Glanders Control Program
• Brucellosis Control Program
• CSF-Control Program