EPIDEMIOLOGY AND PUBLIC HEALTH

 DEFINITION OF SOME TERMS

1. Contamination – it is the presence of a living agent on the exterior of the body or on an article of clothing

2. Infection – The entry and multiplication of a microorganism or parasite in the body of a host.

3. Infection disease – This is infection plus signs and symptoms.

4. Reservoir – The normal habitant where the agent lives and multiplies. It is where the agent propagates itself in nature. A dead and host or temporary resting place of the agent is not a reservoir.

5. Carrier – A person or animal that harbor an infectious agent yet manifest no discernible signs of infection.

6. Zoonosis – It is an infection naturally transmitted between non human animals and humans.

7. Communicable diseases – A disease that can be transfer from one person to another.

8. Transmission – The mechanism by which an agent is spread from one host to another.

9. Immunity – host factors that alter the likelihood of infection and disease after the agent is encountered.

10. Portal – An entry and exit safe into or out of the host for an age 

11. Immunization – The act of acquiring immunity

12. Quarantine – It is isolation of healthy and normal person till the incubation is over.

EPIDEMIOLOGY AND PUBLIC HEALTH

Meaning and concept of epidemiology:- 

     Epidemiology is derived from Greek word "epi" - Upon among "demos" people, district, "Logos" - study, word. Epidemiology is a medical science involves the study of and analysis of the distribution (who, when, and where) and determinants of health and disease condition s in define populations. it is a cornorstone of public health, and shapes policy decisions and evidence – based practice by identifying risk factors for decisions and target for preventive health Care. Epidemiologists' help with study design, collection, and statistical analysis of data, amend interpretation of results. Epidemiology has helped develop methodology used in clinical research, public health studies, and to a lesser extent, basis research in the biological science.

       W.H.O. - Define epidemiology as the study of the distribution and determinants of health related state or events including disease and the application of the study to the control of diseases and other problems. Various methods can be used to carry out epidemiological investigations.

         Epidemiology involves the study of the distribution and determinants if health related states or events including disease and the application of this study to the control of diseases and other health problems. Various methods can be used to carry out epidemiological investigations.

1. Epidemiological methods for disease surveillance, outbreak investigation, and observational studies to identify brisk factors of Zoonotic diseases in both human and animal populations knowledge of these risk factors is used to direct further research investigation and to implement disease control measures, the use of hazard analysis critical control point (HACCP) system depends greatly on information produced by epidemiological studies.

2. Epidemiological methods are used for disease surveillance to identify which hazards are the most important.

3. The methods are also used to identify risk factors which may represent critical control points in the food production system.

AREAS OF EPIDEMIOLOGY STUDY

• Disease causation
• Transmission
• Outbreak investigation
• Diseases surveillance
• Forensic Epidemiology
• Screening
• Bio monitoring
• Comparisons of treatment
• Occupational Epidemiology

Epidemiologist rely on other scientific disciplines such as:- 

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• SOCIAL SCIENCE - In order to understand better proximate and distal causes.
• Biology – To better understand the processes of diseases 
• Statistics – This is the use of data to draw appropriate conclusions.
• Engineering – for exposure assessment

Epidemiology is concerned with the incidence of diseases in populations and does not address the questions of the cause of an individual's disease. This question, sometimes referred to as specific causation, is beyond the Dorian of the science of epidemiology. Epidemiology has it's limits at the point where an inference is made that the relationship between an agent and a disease is casual and where the magnitude of excess risk attribute to the agent has been determined, that is, epidemiology address whether an agent can cause a disease, not whether an agent did cause a specific plain tiff's disease. The term epidemiology is widely applied to cover the description and causations of not only epidemic diseases , but the general disease and even many non – disease, health related conditions such as high blood pressure and obesity. Epidemiology is based upon how the pattern of the disease causes change in the function of every one.

THE ROLE OF EPIDEMIOLOGY

   Epidemiology is often considered the key scientific under pinning of public health practice. The role of epidemiology was emphasized by the institute of medicine in its definition of the substance of public health as organized community efforts.

It aimed at the prevention of diseases and promotion of health, with linkages to many discipline of epidemiology. Epidemiology is the study of the health of human populations. Have Man – Nies et-al in their book stated the following as functions of epidemiology. 

1. To discover the agent host and environment factors that affect health, to provides the scientific basis for the prevention of disease and injury and promotion of health.
2. To identify those section of the population that have the greatest risk from specific cause of I'll health so that the indicated action may directed appropriately.
3. To determine the relative importance of causes of illness, disability, and death, to establish priorities for research and action.
4. To evaluate the effectiveness of health programmes and services in improving the health of the population.

HISTORY OF THE GREAT PIONEERS EPIDEMIOLOGIESTS

   The greek physician Hippocrates known as the father of medicine ought to a logic to sickness, he is the first person known to have examined the relationship between the occurrence of diseases and environment influence. Hippocrates believed sickness of the Human body to be caused by an imbalance of the four humors viz:- 

HISTORY OF THE GREAT PIONEERS OF EPIDEMIOLOGY

The greek physician Hippocrates known as the father of medicine ought to logic to sickness, he is the first person known to have examined the relationship between the occurrence of diseases and environment influence. Hippocrates believed sickness of the Human body to be caused by an imbalance of the four humors, remove or add to the  humor in question to balance of the body. This belief led to the application of bloodletting and dieting in medicine. He coined the terms endemic (for diseases usually found in some places but others) and epidemic (for diseases that are seen at some times but not others). 

In the 16th century, a Doctor from Verona Named GIROLAMA FRACASTORO was the first to propose a theory that these very small, useable, particles that cause disease were alive. They were considered to the able to spread by air, multiple by themselves and to be destroyable by fire. in this way he refuted. He was the first to promote personal and environmental hygiene to prevent disease from his book in 1543.

          The development of sufficiently Powerful microscope by ANTONIE VAN LEEUWENHOEK in 1675 provided visual evidence of living particles consistent with a germ theory of disease.

         In 1582–1652 WU YOUKE develop the concept that some disease were caused by transmissible agents which he called liquid (pastilential factors) can be regarded as the main etiological work that brought forward the concept, ultimately attributed to epidemic diseases. His concept is still considered in current scientific research in relation to traditional Chinese medicine studies.

       In the late 1600s THOMAS SYDENHAM between 1624–1689, he was the first to distinguish the leavers of Londoners in his theory on cures fevers and met with 

much resistance from traditional physicians at the time.

     In 1847s, PETER ANTON SCHLEISNER is remembered for his work on the prevention of the epidemic of neonatal tetanus on the vestmana island in iceland.

      Another important pioneer was HUNGARIAN IGNAZ SEMMELWEIS, who in 1847 brought down infant mortality at a Vienna hospital instituting a disinfection procedure. His findings were published in 1850.

 

      John snow was famous for his investigation into the causes of the cholera epidemics, and was also known as the Father of the modern epidemiology. His work was preserved as a major event in the history of public health and regarded as the founding event of the science of epidemiology.

EPIDEMIOLOGY AND COMMUNICABLE DISEASES

     Epidemiology is a medical science that involves the study of the incidents and distribution of disease in large populations, and the condition influencing the spread and severity of disease.

      In short, tho means that medical provides are legally required to report certain conditions to public health. These guidelines form the reportable diseases list.

PREVENTION OF INFECTIONS

      Methods to prevention infections can be directed either to host or environment and include the following:- 

 

• Standard percussions
• Enteric precessions

STANDARD PERCUSSIONS

• Hand hygiene – This single most important of infection control. Hand washing before any contact with patient, after any activity that contaminate the hands, after removing protective clothing, after using the toilet and before handing food.
• Uses of personal protective equipment (PPE) such. as glove, eye protection, face marks etc
• Handle and disposal of sharp safely
• Management of blood and body fluid
• Manage linen safely
• Place patient with infection in appropriate accommodation 
• Maintain a clean clinical environment
• Prevent occupational exposure to infection
• Disposal of contaminated waste safety
• Decontaminated equipments. Cleaning the disinfection and sterilization 
• Manage sharp injuries and blood splash incident

ENTERIC PERCUSSIONS

• Disinfection especially important in Nurses
• Hand washing
• Correct disposal of excretion and soiled nutrients
• Soiled cloth and bed linen places in a hot wash (>60 degree sensuous)
• Disinfections especially important in nurses schools and residential and institutions

ORGANISATION OF INFECTION CONTROL

Setting and person responsible

• Hospital infection control team
• Community hospital control team (all environment outside hospital including nursing
• Residential Homes, Nurseries/school and workplaces)

HOSPITAL INFECTION CONTROL

      Health care association infection (HCAI) is infection that occurs patient or health care worker as a result of health Care interventions control of health care association is an important part risk

Management and clinical governance programs overall responsibility rests with the chief executive and the trust board and the director of infection prevention and control (DIPC). A hospital infection control team comprises an infection control Doctor (usually a medical microbiologist). One or more infection control disciplinary infection control committee who liases with senior management.

AIMS OF INFECTION TEAM

The following are the aims of infection control team

• To maintain an effective programme for the prevention of hospital acquired infection
• Containment of infection brought into the hospital by patients staff and visitors

ROLES AND FUNCTION OF CONTROL TEAM

1. Hospital must ensure the management of infection control programmed are under taken by competent, qualified infection control Nurse Available
2. Provision of ongoing education for all health care staff
3. Develop infection control policies and ensure accessible to all staff
4. Facilities and equipment are available to enables compliance with policies

COMMUNITY INFECTION CONTROL

      The local health protection team takes a main role community infection control. It works with all. community organization that provide health care or treatment outside hospital including Nursing, residential Homes, Nurseries and Schools. The HPT advises and help s maintain good infection control practice in the community settings. It is achieved through the direct input of health protection practitioners.

REGULAR AND LEGAL POWERS FOR THE CONTROL OF INFECTION

In England, the health protection teams in conjunction with the local authority have responsibility for enforcing key regulations relating to protecting health of the public. This include:-

Public health Law. The public health control of diseases ACT 1984 amended by health and social care Act 2008 and subsequent health protection regulation 2010 and health protection part 2A order. The registration of 2010 concern two keys or health production

1. Firstly the outline statutory notification duties of registered medical practitioners.
2. They give UK local authorities' power to be imposed an people and in respect of things and/or premises to protect Human health, provided strict criteria are met. The power is exercised either directly or indirectly through the proper officer who is the consultant in community disease. Broadly there are two types of power.
3. Local authority power
4. The 2A orders

The local authority power provide a range of measure that can be used to prevent, protect against, contact or provide a health protection response to an incident or spread of infection or contamination that presents or could prevent, significant harm to Human health.

         2A order. This is imposing restrictions or requirements on a person, thing, a body or Human remains or premises for example for a person to be detained in Hospital, to restrict and person' movement or contact with other people, or to require that a premises is closed or decontaminated.

PRINCIPLES OF DISEASE CONTROL AND PREVENTION

Communicable disease can be controlled and prevented by adequate measure, this include the following:-

1. Diagnosis
2. Notification
3. Isolation
4. Treatment
5. Quarantine
6. Investigation
7. Disinfection
8. Blocking
9. Immunization
10. Health education

INFECTIOUS DISEASES PROCESS

1. Agent 
2. Reservoir
3. Portal
4. Mode of transmission
5. Immunity

TYPES OF RESERVOIR

There are four types of reservoir namely:-

1.  Symptomatic cases
2. Carries:-

• In apparent throughout history
• Incubatory
• Convalescent

      3. Animals