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 diseasesCommunicable diseases Sudden onset Single cause Short natural history Short treatment schedule Cure is achieved Single discipline Short follow up Back to normalcy

Communicable versus non-communicable diseases

Non-communicable diseasesNon-communicable diseasesGradual onsetMultiple causesLong natural historyProlonged treatmentCare predominatesMultidisciplinaryProlonged follow upQuality 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 Blood-borne or sexual – HIV, Hepatitis B,C Inhalation – Tuberculosis, influenza, anthrax Food-borne – E.coli, Salmonella, Contaminated water- Cholera, rotavirus, Hepatitis A

Indirect Vector-borne- malaria, trypanosomiasis Fomites

Zoonotic diseases – animal handling and feeding practices (Mad cow disease, Avian Influenza)

How are pathogens spread?

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

Host

Agent Environment•Biological agents•Physical agents•Chemical agents•Nutrient agents•Mechanical agents•Social agents

• Physical environment• Biological environment• Social environment

• Demographic characteristics• Biological characteristics• Socioeconomic characteristics

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): 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

“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)

Source or Reservoir Modes of transmission Susceptible host

I II III

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

Indirecttransmission

Direct contactDroplet infection

Contact with soil

Inoculation into skin or mucosa

Trans-placental (vertical)

Vehicle-borne

•Vector-borne:•Mechanical•biological

Air-borne

Fomite-born

Unclean hands and fingers

propagative

Cyclo-prop.Cyclo-develop.

(III): Susceptible host

An infectious agent seeks a susceptible host aiming “successful parasitism”.

Four stages are required for successful parasitism:1. Portal of entry

2. Site of election inside the body

3. Portal of exit

4. Survival in external environment

Common Communicable Common Communicable DiseasesDiseasesThe 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. Not everyone develops active disease 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

Tuberculosis and HIV

A third of those living with HIV are co-infected with TB 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

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

Every year, 500 million people become severely ill with malaria

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 11% of childhood deaths worldwide attributable to malaria SSA children account for 82% of malaria deaths worldwide

Neglected diseases

Cause over 500,000 deaths and 57 million DALYs annually.

Include the following Helminthic infections

Hookworm (Ascaris, trichuris), lymphatic filariasis, onchocerciasis, schistosomiasis, dracunculiasis

Protozoan infections Leishmaniasis, African trypanosomiasis, Chagas disease

Bacterial infections Leprosy, trachoma, buruli ulcer

Sexually Transmitted Diseases Chlamydia Gonorrhea Genital Herpes Syphilis HIV/AIDS

Importance of Communicable Diseases 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)

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 Borders are not very effective at stopping

communicable diseases. With increasing globalization

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.

climate change migration Change in biodiversity

Human Security concerns

Potential magnitude and rapid spread of outbreaks/pandemics. e.g. SARS outbreak No country or region can contain a full blown outbreak

of Avian influenza Bioterrorism and intentional outbreaks

Anthrax, Small pox New and re-emerging diseases

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

Hand washing, proper waste disposal, food preparation and handling.

Information, education and behavior change 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 –

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.

MOH MOEC

MOF

PMO

PRIVATE SECTORCIVIL SOCIETYLOCALGVT

NACP

CTU

CCAIDS

INT NGO

PEPFAR

Norad

CIDA

RNE

GTZ

SidaWB

UNICEF

UNAIDSWHO

CF

GFATM

USAID

NCTP

NCTP

HSSP

HSSP

GFCCPGFCCPDAC

CCM

T-MAP

3/5

SWAPSWAP

UNTG

PRSP PRSP

Isn’t Donor Collaboration Wonderful?Isn’t Donor Collaboration Wonderful?

Source: WHO: Mbewe

NONCOMMUNICABLE DISEASES

Dr Gulzar Usman ManganharMBBS, 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.

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.

Global status report on noncommunicable diseases (April 2011 the World Health Organization (WHO) )

48

Cardiovascular diseasesCardiovascular 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

50

A person’s genetic make-up The foundations of adult health are laid in

early lifeSocioeconomic groupMental healthDietOverweight and obesityInactivityTobaccoAlcoholDiabetesGlobalization and urbanization

Cardiovascular diseases:Prevention

51

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

Cancer

52

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.

Cancer: Interaction between a person’s genetic factors and any of three categories of external agents

53

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.

Cancer: the majority of cancer deaths

54

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.

Cancer: risk factors for cancer

55

tobacco useunhealthy dietinsufficient physical activitythe harmful use of alcoholInfections (hepatitis B, hepatitis C (liver

cancer), human papillomavirus (HPV; cervical cancer), Helicobacter pylori (stomach cancer)

Radiationvariety of environmental and occupational

exposures of varying importance

Cancer: policy

56

WHO’s approach to cancer has four pillars:

prevention, early detection, screening, treatment palliative care.

Chronic respiratory diseases:Quick facts and figures

57

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%.

Chronic respiratory diseases:Quick facts and figures

58

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. 

Chronic respiratory diseases:Quick facts and figures

59

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.

Chronic respiratory diseases:Quick facts and figures

60

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.

Diabetes

61

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.

Diabetes: Quick facts and figures

62

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.

Diabetes: Quick facts and figures

63

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.

Diabetes: Health implications

64

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 retinopathyDiabetic 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).

Diabetes: Prevention

65

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.

Diabetes: Control

66

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 controlFoot careOther 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.

Obesity

67

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.

Obesity

68

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.

Obesity: Quick facts and figures

69

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.

Obesity: Quick facts and figures

70

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 non-overweight 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.

Obesity: Quick facts and figures

71

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.

Noncommunicable diseases: country income

72

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 high-income countries reporting the proportion of NCD deaths to total deaths to be more than 70%.

Noncommunicable diseases: Current status and trends in risk factors

73

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%).

Noncommunicable diseases: Prevention and Control of NCDs

74

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.

PreventionWays 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