Communicable and
Non-Communicable Diseases…
A Public Health Perspective
Dr Gulzar Usman Manganhar
MBBS, MPH
Department of Community Medicine,
LUMHS, Jamshoro
Definition of Communicable diseases

A communicable disease is an illness due to
a specific infectious (biological) agent or its
toxic products capable of being directly or
indirectly transmitted from man to man, from
animal to man, from animal to animal, or from
the environment (through air, water, food,
etc..) to man.
Another Definition…

Communicable disease: a disease that can
be spread to a person from another person,
an animal or object. Ex: common cold,
influenza, tuberculosis, etc.

Non-communicable disease: a disease that
can NOT be spread from person to person.
Ex: cancer, heart disease, cirrhosis, etc.
Common Pathogens:
Viruses, Bacteria, Fungi & Protozoa

Virus: smallest simplest life form. Not alive, and cause upper
respiratory infections and many other type of diseases.

Bacteria: simple one-celled organisms. They are everywhere.
Not all bacteria is bad.

Fungi: more complex than bacteria, but cannot make their own
food. Thrive in warm, moist environments.

Protozoa: one celled, animal like organisms.
Communicable versus
non-communicable diseases

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Communicable diseases
Sudden onset
Single cause
Short natural history
Short treatment schedule
Cure is achieved
Single discipline
Short follow up
Back to normalcy
Non-communicable diseases
 Gradual onset
 Multiple causes
 Long natural history
 Prolonged treatment
 Care predominates
 Multidisciplinary
 Prolonged follow up
 Quality of life after
treatment
Usually…

The poor hygiene behaviors promote the transmission of
infectious diseases

The fecal-oral and respiratory routes are the most
common sources of transmission

Young children and adults may not wash their hands
after using toilets and before eating/preparing food.
CD- Modes of transmission

Direct
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Indirect
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Blood-borne or sexual – HIV, Hepatitis B,C
Inhalation – Tuberculosis, influenza, anthrax
Food-borne – E.coli, Salmonella,
Contaminated water- Cholera, rotavirus, Hepatitis A
Vector-borne- malaria, trypanosomiasis
Fomites
Zoonotic diseases – animal handling and feeding
practices (Mad cow disease, Avian Influenza)
How are pathogens spread?
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Direct Contact: hands and skin
ex: Scabies
Indirect Contact: coughs, sneezes, expelling pathogens
in the air ex: flu
Contact with animals or insects – animal and insect
bites ex: Lyme’s disease (ticks) – chills, fever,
headaches, discomfort, a skin eruption, and
inflammation with swelling of the joints.
Other contacts such as contaminated food or water. Ex:
Salmonellosis – infection of the digestive tract. Sharp
pain, fever, and bloody, watery diarrhea that occur 6 to
48 hours after eating. Nausea and vomiting are common.
Epidemiologic triad
•
•
•
Demographic characteristics
Biological characteristics
Socioeconomic characteristics
Host
Environment
Agent
•Biological agents
•Physical agents
•Chemical agents
•Nutrient agents
•Mechanical agents
•Social agents
•
•
•
Physical environment
Biological environment
Social environment
Few Important Terminologies related to
Communicable Diseases…
-Infection


Infection is the entry and development or
multiplication of an infectious agent in the body of
man or animals. An infection does not always cause
illness.
There are several levels of infection (Gradients of
infection):



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Colonization (S. aureus in skin and normal nasopharynx)
Subclinical or inapparent infection (polio)
Latent infection (virus of herpes simplex)
Manifest or clinical infection
contamination

The presence of an infectious agent on a
body surface, on or in clothes, beddings,
toys, surgical instruments or dressings, or
other articles or substances including water
and food
Infestation

It is the lodgment, development and
reproduction of arthropods on the surface of
the body or in the clothing, e.g. lice, itch mite.
This term could be also used to describe the
invasion of the gut by parasitic worms, e.g.
ascariasis.
Contagious disease

A contagious disease is the one that is
transmitted through contact. Examples
include scabies, trachoma, STD and leprosy.
Vector of infection

An insect or any living carrier that transports
an infectious agent from an infected
individual or its wastes to a susceptible
individual or its food or immediate
surroundings. Both biological and mechanical
transmissions are encountered.
Reservoir

Any person, animal, arthropod, plant, soil, or
substance, or a combination of these, in
which an infectious agent normally lives and
multiplies, on which it depends primarily for
survival, and where it reproduces itself in
such a manner that it can be transmitted to a
susceptible host. It is the natural habitat of
the infectious agent.
Incidence and Prevalence of infectious
diseases

Incidence of an infectious disease:
Number of new cases in a given time period

Prevalence of an infectious disease:
Number of cases (old and new) at a given time
Epidemic
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“The unusual occurrence in a community of
disease, specific health related behavior, or
other health related events clearly in excess
of expected occurrence”
(epi= upon; demos= people)
Epidemics can occur upon endemic states
too.
Endemic


It refers to the constant presence of a
disease or infectious agent within a given
geographic area or population group. It is the
usual or expected frequency of disease within
a population.
(En = in; demos = people)
Pandemic and Exotic

An epidemic usually affecting a large proportion of
the population, occuring over a wide geographic
area such as a section of a nation, the entire nation,
a continent or the world, e.g. Influenza pandemics.

Exotic diseases are those which are imported into a
country in which they do not otherwise occur, as for
example, rabies in the UK.
Sporadic

The word sporadic means “scattered about”. The
cases occur irregularly, haphazardly from time to
time, and generally infrequently. The cases are few
and separated widely in time and place that they
show no or little connection with each other, nor a
recognizable common source of infection.

However, a sporadic disease could be the starting
point of an epidemic when the conditions are
favorable for its spread.
Nosocomial infections

Nosocomial (hospital acquired) infection is an
infection originating in a patient while in a
hospital or another health care facility. It has
to be a new disorder unrelated to the
patient’s primary condition. Examples include
infection of surgical wounds, hepatitis B and
urinary tract infetions.
Opportunistic infection


This is infection by organisms that take the
opportunity provided by a defect in host
defense (e.g. immunity) to infect the host and
thus cause disease. For example,
opportunistic infections are very common in
AIDS. Organisms include Herpes simplex,
cytomegalovirus,
M. tuberculosis….
Incubation and Latent periods

Incubation period: time from exposure to
development of disease. In other words, the time
interval between invasion by an infectious agent and
the appearance of the first sign or symptom of the
disease in question.

Latent period: the period between exposure and the
onset of infectiousness (this may be shorter or
longer than the incubation period).
Dynamics of disease Transmission (Chain
of Infection)
I
Source or Reservoir
II
Modes of transmission
III
Susceptible host
Cases

A case is defined as “a person in the
population or study group identified as having
the particular disease, health disorder, or
condition under investigation”
Carriers

It occurs either due to inadequate treatment or immune
response, the disease agent is not completely
eliminated, leading to a carrier state.

It is “an infected person or animal that harbors a
specific infectious agent in the absence of (visible)
clinical disease and serves as a potential source of
infection to others.
(II): Modes of transmission
Mode of transmission
Direct
transmission
Direct contact
Droplet infection
Contact with soil
Inoculation into skin or mucosa
Trans-placental (vertical)
Indirect
transmission
Vehicle-borne
Vector-borne:•
•Mechanical
•biological
Air-borne
propagative
Cyclo-prop.
Cyclo-develop.
Fomite-born
Unclean hands
and fingers
(III): Susceptible host

An infectious agent seeks a susceptible host
aiming “successful parasitism”.

Four stages are required for successful parasitism:
1.
2.
3.
4.
Portal of entry
Site of election inside the body
Portal of exit
Survival in external environment
Common Communicable Diseases
The common cold is a respiratory infection
caused by over 200 different viruses.
Symptoms include congestion, sore throat
and cough. It can be spread through direct
and indirect contact. Treatment includes rest,
liquids and over the counter medications.
Prevention techniques include handwashing
and avoiding contact with infected persons.
Influenza, more commonly called “flu”, is a respiratory
infection caused by several groups of viruses.
Symptoms include high fever, fatigue, muscle and
joint aches. It is spread through direct contact with
infected people and water droplets in the air from
coughs and sneezes.
Treatment includes rest, liquids, and over the
counter medications. Prevention includes avoiding
contact with infected persons and vaccines.
Tuberculosis

2 billion people infected with microbes that cause TB.

A person is infected every second globally
22 countries account for 80% of TB cases.
 >50% cases in Asia, 28% in Africa (which also has the
highest per capita prevalence)
In 2005, there were 8.8 million new TB cases; 1.6 million
deaths from TB (about 4400 a day)
Highly stigmatizing disease
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Not everyone develops active disease
Tuberculosis and HIV

A third of those living with HIV are co-infected with TB
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About 200,000 people with HIV die annually from TB.
Most common opportunistic infection in Africa
70% of TB patients are co-infected with HIV in some countries in
Africa
Impact of HIV on TB
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TB is harder to diagnose in HIV-positive people.
TB progresses faster in HIV-infected people.
TB in HIV-positive people is almost certain to be fatal if
undiagnosed or left untreated.
TB occurs earlier in the course of HIV infection than many other
opportunistic infections.
Malaria
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Every year, 500 million people become severely ill with
malaria
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causes 30% of Low birth weight in newborns Globally.
>1 million people die of malaria every year. One child
dies from it every 30 seconds
40% of the world’s population is at risk of malaria. Most
cases and deaths occur in SSA.
Malaria is the 9th leading cause of death in LICs and
MICs
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11% of childhood deaths worldwide attributable to malaria
SSA children account for 82% of malaria deaths worldwide
Neglected diseases
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Cause over 500,000 deaths and 57 million
DALYs annually.
Include the following

Helminthic infections
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Protozoan infections
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Hookworm (Ascaris, trichuris), lymphatic filariasis,
onchocerciasis, schistosomiasis, dracunculiasis
Leishmaniasis, African trypanosomiasis, Chagas disease
Bacterial infections
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Leprosy, trachoma, buruli ulcer
Sexually Transmitted Diseases
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Chlamydia
Gonorrhea
Genital Herpes
Syphilis
HIV/AIDS
Importance of Communicable Diseases
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Significant burden of disease especially in
low and middle income countries
Social impact
Economic impact
Potential for rapid spread
Human security concerns

Intentional use
CDs have a significant economic impact in
affected countries

At the macro level
 Reduction in revenue for the country (e.g. tourism)
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Estimated cost of SARS epidemic to Asian countries: $20 billion
(2003) or $2 million per case.
Drop in international travel to affected countries by 50-70%
Malaria causes an average loss of 1.3% annual GDP in countries
with intense transmission
The plague outbreak in India cost the economy over $1 billion from
travel restrictions and embargoes
At the household level
 Poorer households are disproportionately affected
 Substantial loss in productivity and income for the infirmed and
caregiver
 Catastrophic costs of treating illness
International boundaries are
disappearing

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Borders are not very effective at stopping
communicable diseases.
With increasing globalization

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interdependence of countries – more trade and human/animal
interactions
The rise in international traffic and commerce
makes challenges even more daunting
Other global issues affect or are affected by
communicable diseases.
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climate change
migration
Change in biodiversity
Human Security concerns
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Potential magnitude and rapid spread of
outbreaks/pandemics. e.g. SARS outbreak
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Bioterrorism and intentional outbreaks
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No country or region can contain a full blown outbreak
of Avian influenza
Anthrax, Small pox
New and re-emerging diseases
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Ebola, TB (MDR-TB and XDR-TB), HPAI, Rift valley
fever.
Prevention

Ways to prevent Infectious Disease
–
–
–
Getting enough sleep, avoiding alcohol/cigarettes,
and eating a healthy diet.
Getting vaccines when available.
Staying away from disease carrying animals or
food/water that is dirty.
Personal Responsibility and action

Improved hygiene and sanitation
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Information, education and behavior change
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Hand washing, proper waste disposal, food
preparation and handling.
Changing harmful household practices
Livestock handling, knowledge about contagion
Cultural and social norms
Self reporting of illnesses and compliance with
interventions and treatment.
Partnerships and Collaboration

Importance of partnerships –

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MDG 8: “Develop global partnerships for
development”
Comparative advantage of partners
Inclusiveness
Examples of partnerships

Over 70 Global health partnerships available

Examples include the Stop-TB program, GFATM, RBM,
UNAIDS, GAVI, Global Outbreak Alert and Response
Network, GAIN, bilateral and multilateral organizations.
Isn’t Donor Collaboration Wonderful?
GTZ
WHO
CIDA
UNAIDS
RNE
INT NGO
3/5
UNICEF
Norad
WB
Sida
USAID
T-MAP
MOF
UNTG
CF
DAC
GFCCP
PRSP
PEPFAR
GFATM
HSSP
MOH
PMO
MOEC
SWAP
CCM
CTU
NCTP
CCAIDS
NACP
LOCALGVT
CIVIL SOCIETY
PRIVATE SECTOR
Source: WHO: Mbewe
NONCOMMUNICABLE DISEASES
Dr Gulzar Usman Manganhar
MBBS, MPH
Department of Community Medicine
LUMHS, Jamshoro
 Noncommunicable diseases are the leading killer
today and are on the increase.
 Nearly 80% of these deaths occurred in low- and
middle-income countries.
45
 More than nine
million of all deaths
attributed to
noncommunicable
diseases (NCDs) occur
before the age of 60.
• Around the world, NCDs
affect women and men
almost equally.
 NCDs are largely
preventable by means of
effective interventions that
tackle shared risk factors,
namely: tobacco use,
unhealthy diet, physical
inactivity and harmful use of
alcohol.
 NCDs are not only a health
problem but a
development challenge as
well.
Global status report on noncommunicable diseases
(April 2011 the World Health Organization (WHO) )
 The leading causes of NCD deaths in 2008 were:
cardiovascular diseases (17 million deaths, or 48% of
NCD deaths); cancers (7.6 million, or 21% of NCD
deaths); and respiratory diseases, including asthma
and chronic obstructive pulmonary disease (COPD),
(4.2 million). Diabetes caused an additional 1.3
million deaths.
 Behavioural risk factors, including tobacco use,
physical inactivity, and unhealthy diet, are
responsible for about 80% of coronary heart disease
and cerebrovascular disease.
48
Cardiovascular diseases
 Cardiovascular disease is caused by disorders of the
heart and blood vessels, and includes coronary heart
disease (heart attacks), cerebrovascular disease (stroke),
raised blood pressure (hypertension), peripheral artery
disease, rheumatic heart disease, congenital heart
disease and heart failure.
 Although heart attacks and strokes are major killers in
all parts of the world, 80% of premature deaths from
these causes could be avoided by controlling the main
risk factors: tobacco, unhealthy diet and physical
inactivity.
49
Cardiovascular diseases:
Contributing factors

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50
A person’s genetic make-up
The foundations of adult health are laid in early life
Socioeconomic group
Mental health
Diet
Overweight and obesity
Inactivity
Tobacco
Alcohol
Diabetes
Globalization and urbanization
Cardiovascular diseases:
Prevention
 Focusing on a combination of risk factors for
cardiovascular disease
 Implementing medical screening for individuals at
risk
 Providing effective and affordable treatment to
those who require it
51
Cancer
 Cancer is the uncontrolled growth and spread of
cells that arises from a change in one single cell. The
change may be started by external agents and
inherited genetic factors and can affect almost any
part of the body. The transformation from a normal
cell into a tumour cell is a multistage process where
growths often invade surrounding tissue and can
metastasize to distant sites.
52
Cancer: Interaction between a person’s genetic
factors and any of three categories of external
agents
 physical carcinogens, such as ultraviolet and ionizing
radiation or asbestos;
 chemical carcinogens, such as vinyl chloride, or
betnapthylamine (both rated by the International
Agency for Research into Cancer as carcinogenic),
components of tobacco smoke, aflatoxin (a food
contaminant) and arsenic (a drinking-water
contaminant); and
 biological carcinogens, such as infections from certain
viruses, bacteria or parasites.
Most chemicals to which people are exposed in everyday life have not been
tested for their long-term impact on human health.
53
Cancer:
the majority of cancer deaths
 Lung, breast, colorectal, stomach and liver cancers
 In high-income countries, the leading causes of
cancer deaths are lung cancer among men and
breast cancer among women.
 In low- and middle-income countries cancer levels
vary according to the prevailing underlying risks.
In sub-Saharan Africa, for example, cervical cancer
is the leading cause of cancer death among women.
54
Cancer:
risk factors for cancer
tobacco use
unhealthy diet
insufficient physical activity
the harmful use of alcohol
Infections (hepatitis B, hepatitis C (liver cancer), human
papillomavirus (HPV; cervical cancer), Helicobacter
pylori (stomach cancer)
 Radiation
 variety of environmental and occupational exposures of
varying importance





55
Cancer:
policy
WHO’s approach to cancer has four pillars:
 prevention,
 early detection,
 screening,
 treatment
 palliative care.
56
Chronic respiratory diseases:
Quick facts and figures
 According to the WHO Global Status Report on NCDs
2010, smoking is estimated to cause about 71% of all lung
cancer deaths and 42% of chronic respiratory disease
worldwide. Of the six WHO regions, the highest overall
prevalence for smoking in 2008 was estimated to be the
in the European Region, at nearly 29%.
57
Chronic respiratory diseases:
Quick facts and figures
 Survey data from 2002–2007 indicate that over half of all
children aged 13–15 years in many countries in the
European Region are exposed to second-hand tobacco
smoke at home. Second-hand smoke causes severe
respiratory health problems in children, such as asthma
and reduced lung function; and asthma is now the most
common chronic disease among children throughout
the Region.
58
Chronic respiratory diseases:
Quick facts and figures
 According to the latest available data for 1997–2006, over
12% of infant deaths in the world are due to respiratory
diseases.
 Indoor air pollution from biological agents related to
damp and mould increases the risk of respiratory
disease in children and adults. Children are particularly
susceptible to the health effects of damp, which include
respiratory disorders such as irritation of the
respiratory tract, allergies and exacerbation of asthma.
Damp is often associated with poor housing and social
conditions, poor indoor air quality and inadequate
housing hygiene.
59
Chronic respiratory diseases:
Quick facts and figures
 Most countries in the world and the European Region
have introduced a wide range of comprehensive policies
to reduce and eliminate tobacco smoke. For example,
the advertising of cigarettes and the sale of tobacco
products to minors have been banned in more than 80%
of the countries in the Region. Smoking in restaurants
and bars continues to be regulated less strictly, however.
Ireland, Turkey and the United Kingdom are the first
countries to make public places 100% smoke free.
60
Diabetes
 Diabetes is a chronic disease that occurs when the
pancreas does not produce enough insulin (a
hormone that regulates blood sugar) or
alternatively, when the body cannot effectively use
the insulin it produces. The overall risk of dying
among people with diabetes is at least double the
risk of their peers without diabetes.
61
Diabetes: Quick facts and figures
 About 347 million
people worldwide
have diabetes.
 There is an emerging
global epidemic of
diabetes that can be
traced back to rapid
increases in overweight,
obesity and physical
inactivity.
62
Diabetes: Quick facts and figures
 80% of diabetes deaths
occur in low- and
middle-income
countries.
 In developed countries
most people with
diabetes are above the
age of retirement,
whereas in developing
countries those most
frequently affected are
aged between 35 and 64.
63
Diabetes: Health implications
Elevated blood sugar is a common effect of uncontrolled
diabetes, and over time can damage the heart, blood
vessels, eyes, kidneys, and nerves.
Some health complications from diabetes include:
 Diabetic retinopathy
 Diabetic neuropathy
 Diabetes is among the leading causes of kidney failure;
10-20% of people with diabetes die of kidney failure.
 Diabetes increases the risk of heart disease and stroke;
50% of people with diabetes die of cardiovascular
disease (primarily heart disease and stroke).
64
Diabetes: Prevention
Without urgent action, diabetes-related deaths will increase
by more than 50% in the next 10 years. To help prevent type
2 diabetes and its complications, people should:
 Achieve and maintain healthy body weight.
 Be physically active - at least 30 minutes of regular,
moderate-intensity activity on most days.
 Early diagnosis can be accomplished through relatively
inexpensive blood testing.
 Treatment of diabetes involves lowering blood sugar and the
levels of other known risk factors that damage blood vessels.
 Tobacco cessation is also important to avoid complications.
65
Diabetes: Control
 People with type 1 diabetes require insulin; people with
type 2 diabetes can be treated with oral medication, but
may also require insulin.
 Blood pressure control
 Foot care
Other cost saving interventions include:
 Screening and treatment for retinopathy (which causes
blindness);
 Blood lipid control (to regulate cholesterol levels);
 Screening for early signs of diabetes-related kidney disease
and treatment.
These measures should be supported by a healthy diet,
regular physical activity, maintaining a normal body weight
and avoiding tobacco use.
66
Obesity
 Obesity is one of the greatest public health challenges of
the 21st century. Its prevalence has tripled in many
countries of the WHO European Region since the 1980s,
and the numbers of those affected continue to rise at an
alarming rate, particularly among children.
 In addition to causing various physical disabilities and
psychological problems, excess weight drastically
increases a person’s risk of developing a number of
noncommunicable diseases (NCDs), including
cardiovascular disease, cancer and diabetes.
 The risk of developing more than one of these diseases
(co-morbidity) also increases with increasing body
weight.
67
Obesity
 Overweight and obesity
are defined as "abnormal
or excessive fat
accumulation that may
impair health“
 Body mass index (BMI) – the
weight in kilograms divided by
the square of the height in
meters (kg/m2) – is a commonly
used index to classify
overweight and obesity in
adults. WHO defines overweight
as a BMI equal to or more than
25, and obesity as a BMI equal
to or more than 30.
68
Obesity: Quick facts and figures
 In 2008, more than 1.4 billion
adults were overweight and
more than half a billion were
obese. At least 2.8 million
people each year die as a
result of being overweight or
obese. The prevalence of
obesity has nearly doubled
between 1980 and 2008. Once
associated with high-income
countries, obesity is now also
prevalent in low- and
middle-income countries.
69
Obesity: Quick facts and figures
 Globally, over 40 million
preschool children were
overweight in 2008
 Childhood obesity is one of the
most serious public health
challenges of the 21st century.
Overweight children are likely
to become obese adults. They
are more likely than nonoverweight children to develop
diabetes and cardiovascular
diseases at a younger age, which
in turn are associated with a
higher chance of premature
death and disability.
70
Obesity: Quick facts and figures
 Supportive environments and
communities are fundamental
in shaping people’s choices and
preventing obesity
 Individual responsibility can
only have its full effect where
people have access to a healthy
lifestyle, and are supported to
make healthy choices.
 WHO mobilizes the range of
stakeholders who have vital
roles to play in shaping healthy
environments and making
healthier diet options
affordable and easily accessible.
71
Noncommunicable diseases:
country income
 About 30% of people dying from NCDs in low- and
middle-income countries are aged under 60 years
and are in their most productive period of life.
 The prevalence of NCDs is rising rapidly and is
projected to cause almost three-quarters as many
deaths as communicable, maternal, perinatal, and
nutritional diseases by 2020, and to exceed them as
the most common causes of death by 2030.
 In most middle- and high-income countries NCDs
were responsible for more deaths than all other
causes of death combined, with almost all highincome countries reporting the proportion of NCD
deaths to total deaths to be more than 70%.
72
Noncommunicable diseases:
Current status and trends in risk factors
 Common, preventable risk factors underlie most NCDs.
These risk factors are a leading cause of the death and
disability burden in nearly all countries, regardless of
economic development.
 The leading risk factor globally for mortality is:
1. raised blood pressure (responsible for 13% of deaths
globally),
2. followed by tobacco use (9%),
3. raised blood glucose (6%),
4. physical inactivity (6%),
5. overweight and obesity (5%).
73
Noncommunicable diseases:
Prevention and Control of NCDs
 Millions of deaths can be prevented by stronger
implementation of measures that exist today.
 These include policies that promote government-wide
action against NCDs:
1. stronger anti-tobacco controls
2. promoting healthier diets,
3. physical activity,
4. reducing harmful use of alcohol;
5. along with improving people's access to essential health
care.
74
Prevention
 Ways to prevent Non-Infectious or Non-Communicable diseases
– Avoiding triggers if you have allergies or asthma
– Having a healthy diet, getting plenty of exercise to prevent high blood
pressure, cancer, heart disease, stroke, and type 2 diabetes.
– Taking medication for diseases you are born with, like asthma, allergies,
and type 1 diabetes
– Going to the doctor regularly to get tested for things that may run in
your family, like high blood pressure, cancer, heart disease, etc.
THANK YOU
THANK YOU