Wednesday, September 30, 2015


Dr Mfonfu Daniel 
Independent researcher
Tel: +237 677601207,


1.      Introduction:
Generally in epidemiological surveillance all health institutions should declare weekly the number of cases and deaths of diseases with epidemic potential; and others placed under epidemiological surveillance by the Ministry of Public Health. 

Some diseases with epidemic potentials are:
Cholera ; Meningitis; Measles ; Neonatal Tetanus; Maternal tetanus; Acute Flaccid Paralysis; Typhoid Fever; Pertussis; Dysentery; Malaria, Common Cold, Haemorrhagic fever; Ebola, HIV/ADS; etc.
Each week several health facilities send the declaration of cases and deaths of diseases to the higher level where synthesis is made.

2.      Definition of epidemiology
Epidemiology is the study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems.
a)      Study—Epidemiology is the basic science of public health. It's a highly quantitative discipline based on principles of statistics and research methodologies.
b)     Distribution—Epidemiologists study the distribution of frequencies and patterns of health events within groups in a population. To do this, they use descriptive epidemiology, which characterizes health events in terms of time, place, and person.
c)      Determinants—Epidemiologists also attempt to search for causes or factors that are associated with increased risk or probability of disease. This type of epidemiology, where we move from questions of "who," "what," "where," and "when" and start trying to answer "how" and "why," and “what next” is referred to as analytical epidemiology.
d)     Health-related states—Although infectious diseases were clearly the focus of much of the early epidemiological work, this is no longer true. Epidemiology as it is practiced today is applied to the whole spectrum of health-related events, which includes chronic disease, environmental problems, behavioral problems, and injuries in addition to infectious disease.
e)      Populations—One of the most important distinguishing characteristics of epidemiology is that it deals with groups of people rather than with individual patients.
f)       Control—Finally, although epidemiology can be used simply as an analytical tool for studying diseases and their determinants, it serves a more active role. Epidemiological data steers public health decision making and aids in developing and evaluating interventions to control and prevent health problems. This is the primary function of applied, or field, epidemiology.
g)      The goal of epidemiology is to identify subgroups of the population who are at a higherrisk of disease than usual and who will benefit the most from disease specificinterventions. Epidemiological information can be used to develop prevention strategiesaccording to:
·         Time (peaks at a particular season);
·         Place (limited to specific geographic areas); or
·         Person (groups at risk).

3.      Definition of surveillance
Surveillance is “collection and analysis of data for action” Epidemiological Surveillance (Public health surveillance)is defined as the on-going and systematic collection, analysis, interpretation, and dissemination of data about cases of a disease and it is used as a basis for planning, implementing, prevention, control and evaluating disease.

Types of Surveillance:
a)      Passive Surveillance: Surveillance is passive when data/ reports are sent by designated health facilities or individuals on their own, periodically as a routine
b)       Active Surveillance: Surveillance is active when a designated official, usually external to the health facility visits periodically and seeks to collect data from individuals or registers, log books, medical records at a facility to ensure that no reports/data are incomplete or missing.
c)      Institutional surveillance refers to the collection of data (actively or passively) from pre-identified and designated fixed facilities regardless of size.
d)     Community-based surveillance refers to the collection of data from individuals and households at the village/locality level rather than from institutions or facilities. Analysis of surveillance data helps us to know the following:

-          Where the disease is occurring (place)
-          When the disease is occurring (time)
-          In whom the disease is occurring (person)

4.      Use of epidemiological surveillance
i)                    Detection of epidemics
ii)                   Quantitative estimates of the magnitude of a health problem
iii)                 Shows the natural history of a disease by indicating the incidence rate over a period of time

Documentation of the distribution and spread of a health event
v)                  Making decisions
vi)                 Setting priorities,
vii)               Planning
viii)              Implementation of interventions
ix)                 Monitoring of health intervention programs
x)                  Evaluation of control and prevention measures

5.      Definition of the health system:
The health system of in most countries is the District Health System. This Health System is pyramidal with three levels: the central level or strategic –Ministry of Public Health, the intermediate level or regional – The Regional level with the Regional Delegation of Public Health, and the peripheral or operational level – The Health District.
The Health District is divided into Health Areas with principal or leading health centres or Medical Centres. The Health Area and its Health Centre is the entry point of the population into the health system. The leading health centre declares cases of diseases to the District Health Service.
In other very large countries after the Health District there are Health Zones before the Health Areas

6.      Epidemiological surveillance cycle
The epidemiological surveillance cycle shows its cyclic functions in Fig 1. The epidemiological surveillance cycle shows the treatment of data and use of the results at all levels of the health system instead of forwarding raw data to hierarchy. The epidemiological surveillance cycle represent the routine Health Management Information System (HMIS) that should be carried out at all levels of the Health system as shown in Fig II.

7.      Difficulties of epidemiological surveillance
It has always been believed that surveillance data collected at local level are sent to the higher level or international level for analysis and feedback before action is taken at the lower level, which is contrary to the notion of ‘data collection for action.’ At the level of the Health District and Region or Province the staff face a lot of difficulties in making synthesis of all the data from Health Areas because manual synthesis is tedious, thus surveillance data are never available. Moreover unqualified or recalcitrant staff is usually assigned to compile statistical data. In this computer era health statistics should no longer be processed manually at all levels of the health system.  Simple software should be elaborated to enable health personnel to make synthesis and analysis health data at lower levels in order to use the results to control diseases before external assistance is available.  

8.      Solution to epidemiological surveillance data analysis
It is for this reason that I decided to produce a software for epidemiological surveillance to make the synthesis and analysis of weekly declaration or notification data because in this computer era health statistics should no longer be processed manually at all levels of the health system for the sake humanity so that decisions and interventions should be made based on sound and appropriate judgement.

9.      Description of the software
The epidemiological surveillance software is an excel folder made of the follow sheets:
        i.            Guide – gives the detail directives on how to use the software; it should be read carefully.
      ii.            Cases and Deaths: It is the only sheet to be filled.
    iii.            Cases – The sheet fills automatically. It could be considered as incidence sheet.
    iv.            Deaths - It fills automatically. It could be considered as morbidity sheet.
      v.            Case fatality rate per week - It fills automatically.
    vi.            Case fatality per Unit of Health Care – It fills automatically.

10.  Use of the software
This software is essentially for the local recording and analysing of data from weekly declaration, studying the trends or patterns of evolution of incidence of a disease under surveillance through epidemic curves, taking decisions, and intervening precisely and early.  

One of the advantages of the software is that late data can be inserted in the correct corresponding week.
The software can be used at the level of big health institutions which are divided into wards, and health areas that are divided into quarters or zones according to the health system.
The software facilitates the treatment and transmission of data from the lower level to the higher level.
The epidemic curves in the software could be printed and pasted on the walls or put in reports of health services.
More often only questionnaires are developed and inserted in the internet; simple excel programmes are not developed to analyse the data, because the process of developing them have been mystified. Let us try to make simple tools for the analysis of health statistics.

11.  Conclusion
Taking into consideration the tediousness and the absence of health statistics at various levels of the health system I decided to produce this software on epidemiological surveillance to make the synthesis and analysis of weekly declaration or notification data in order to help humanity take decisions and carry out interventions based on sound, pertinent and relevant reflection.
I can establish simple software for synthesis and analysis of any questionnaire for the appreciation of health events in any given community. I am available for any consultancy.
I am providing this software to health personnel for the sake of humanity. I hope you will appreciate my effort and appreciate my effort by inviting.

I have included the English and French versions of this software for download and use. Thanks

1)      The Johns Hopkins and the International Federation of Red Cross and Red Crescent Societies, Epidemiology and surveillance, Public health guide for emergencies Epidemiology and surveillance - Johns Hopkins Bloomberg Hopkins Bloomberg School of Public Health
2)      EXCITE | Epidemiology in the Classroom | An Introduction to Epidemiology
3)      Public health surveillance,
4)      An Introduction to Applied Epidemiology and Biostatistics, U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES, Centers for Disease Control and Prevention (CDC),

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