WORLD HEALTH ORGANIZATION
ORGANISATION MONDIALE DE LA SANT~
REGIONAL OFFICE FOR
THE WESTERN
PACIFIC
BUREAU REGIONAL DU PACIFIQUE OCCIDENTAL
REGIONAL COMMrITEE
TECHNICAL DISCUSSIONS
Twentieth Session Manila
WPR/RC20/I'D5 13 August 1969 ORIGINAL: ENGLISH·
23-30 September 1969
BASIC CONSIDERATIONS ON THE ORGANIZATION AND PIANNING OF EPIDEMIOLOGICAL SERVICE'S AT COUNTRY LEVELl
by
K. RaSka, M.D., D.Sc. Director, Division of Communicable Diseases, Geneva
~Ckground document for reference use at the Technical Discussions .. on "The Planning and Organization of a National Epidemiological Service".
WPR;Rc20/rI1.i
pagel
1.
INTRODUCTION
1.1 Any discussion on the epidemiologieal services existing, or rather required, in different countries poses very difficult problems. guidelines or definite standards have been established. No clear In addition" to
the differences in the existing level of development of health services, available material and human resources, and relevant social, economic and politiQal factors in both developed and developing countries, considerable differences also exist in the concept and understanding of the role of modern epidemiology and epidemiological methodology within the national health services. The problem will, therefore, be discussed more with regard to the general concept of work than to the organizational structure and administrative lines of command at various levels. 1.2 The public health problems of many countries in the tropical regions, as in other developing countries of the world, are mainly of an infectious nature. This fact means that a high priority should be given to the control and prevention of oommunicable diseases. Due to the tremendous advances in the control of communicable diseases, based mainly on progress in microbiology, (including virology, parasitology, immunology, etc.), and the use of antibiotics, chemotherapeutics and insecticides, the risk and relative importance of some infections in developed countries are changing and continuously decreasing. However, in developing countries the spread of infections and hav~
their importance have been maintained or
even continued to increase.
Therefore, the gap between developed and developing countries in the field of communicable disease control is continuing to widen. This unfavourable situation cannot be explained or excused in the long run only because of lack of human or material resources; it is at the same time due to a lack of experience and to insufficient understanding of the concept of epidemiology and of the possibilities of controlling communicable diseases that are possible at the present time.
/1.3 The solution
•••
WPR,fflc2olm5 page 2
1.,
The solution of the problems of communicable diseases in tropical b~
areas as elsewhere requires Dot only a speoific knowledge of the natural history and eoology of individual diseases/infections, disoiplinary approaoh. This aspect of the effort of organizing national very often neglected in the past and epidemiological table" service only. he~th se~ices
also a multi-
servioes was were
frequently planned and organized as a bureaucratic-administrative "green This is very well illustrated in those countries where the step-by-step building up of community oriented microbiological laboratory and statistical services was neglected, or where the need for their integration and close co-operation with epidemiologioal services was not understood or was impossible because of the weakness of epidemiological services. 2. EPIDm.1IOLOGICAL SERVICES
2.1 Aim of epidemiological services.
Epidemiological surveillance
Epidemiological services are a specialized health service dealing with the control and prevention of communioable diseases and their sequelae. and
This aim can be aocomplished by the determination and
follow-up of the principal and oontributing factors causing a disease faoilitating the spread of infection in the human and animal !
.
'
populations and by finding, implementing and evaluating methods to control these factors. This necessitates an effective s~tem
of
epidemiological surveillance which would provide a soientific basis for early recognition of the problem, for planning, imple~ntation I
and evaluation of control measures, for epidemiological fbrecasts (When possible), and for decision making.l,2 Surveillance also includes the periodic publication and dissemination of pertinent epidemiological information to all concerned. In addition, epidemiological servioes represent an organization
for the investigation and control of outbreaks of disease and for systematio and oo-ordinated studies of specifio diseases.
.' Role of •••
/2.2
WPR/.RC20il'D5 page' 2.2 Role of ttl.. t!lCMl'GDIIIent Since many human diseases arise from natural foci ot infection or from man IS· environment that has been either polluted, altered or entirely oreated by himselt, epidemiological servioes should closely co-operate with environmental health services (sate water supply, waste and sewage disposal). and other branches of hygienic services (food hygiene, etc.). Many animal infections are transmissible to man. Epidemiological
services are consequently linked to, or closely co-operating with, the respeotive veterinary services of the ministry of agriculture.
2.,
Role ot
~10
and preventive agents and its evaluation
Chemotherapeutics, antibiotics, immune sera and vaccines play a highly important role in the control and prevention of communicable diseases and their sequelae. Epidemiological services should therefore be involved in the evaluation ot their efficacy and possible side effects. In addition,
these agents may influence and change the spread of infections, biological properties of etiological agents and the natural history ot diseases. Epidemiological services should accordingly be able to tollow, quickly recognize and promptly react in control and preventive measures (epidemiological surveillance) to the changing situation. 2.4 Disinfection, disinsection. deratisation
•
Disinfection, deratisation and disinsection also play a very important role in the control and prevention of communicable diseases and all epidemiological services should be able to use these methods
(trained personnel). 2.5 f'lamSJlg and training
Epidemiological services should also participate in long-term planning and give technical guidance in the training (basic and postgraduate), ot medical and other health personnel in a wide variety ot /disoiplines, (public •••
WPR;RC2011'D5 page .Ij. disciplines, (public health officers, epidemiologists, m~ical
miorobio-
logists, sanitarians, sanitary engineers, laboratory technicians, statisticians, entomologists, ecologists, etc.) including health education. 2.6 Operational and management techniques The control and prevention of communicable diseases often involve large-scale and expensive health campaigns. niques, servioes. 3. PROBLEMS
Their succe.sful implemen-
tation necessitates the use of proper operational and managerial techThis type of non-medical staff has recently been recognized as bran~hes
extremely valuable in the epidemiological and other
of health
3.1 Multi-disciplinary approach.
Epidemiological surveillance
From the short description given of the general functions of national epidemiological services, the need is evident for the !
participation of several disciplines (multi-discipltnary approach). Practically all epidemiological services at national level need the servioes of well-trained personnel (graduate and at least the following disciplines: epidemiology, medical microbiology (bacteriology, virology, parasitology, mycology, immunology), entomology, health statistics, sanitary engineering, veterinary health, laboratory and field personnel inspectors, etc.), They should have the necessary equipment for laboratory and field activities (transport, collection and storage of biological material, mobile laboratory, equipment for eoological studies, etq.). /la.ally epidemiologioal. ,t, (sanitarians, non-gr~uate)
from
•
Ideally epidemiological services at national level should be supported by a central institute I.e.g., the National Communicable Disease Center (NCDC),
Atlanta, the Institute of Epidemiology and Microbiology, National Institutes of Healt~. or a central public health laboratory where highly qualified staff in all these disciplines work together. _;-These central institutions apart from their research activities (which could take from 20% to 50% of their time) support epidemiological services in the following ways: Ca) (b) (c) (d) the investigation and control of outbreaks of diseases of national importance; they guide and co-ordinate studies of specific diseases; direct epidemiological surveillance of the most important infections in the country; they undertake national reference laboratory work in microbiology and technical guidance (standardization) of work in public health laboratory services at regional and district level; (e) (f) they train personnel in epidemiology, statistics, medical microbiology, etc.; they disseminate epidemiological information periodically.
If such a level in the development of epidemiological services in
a country has not yet been attained, the administrative (decision making) part of epidemiological services should co-operate with and utilize the services of existing laboratories (in microbiology, statistics, environmental health, entomology, etc.). •.. It is sometimes very surprising to note that in some developing countries with one very poorly equipped and staffed public health laboratory service, there also exists a university department of microbiology that has no interest in the current and often very serious problems of communicable diseases and public health. In the past, in several European countries, university departments (ministry of education) have played a very important role in the study and control of communicable diseases in co-operation with the public health services. This has also /work of ••• a very favourable effect on the teaching activities and orientation of
WPR/RC20jrD5 page 6
work of these medioal schools. These minimum requirements form the most diffioult ~oblems in organizing effioient and productive epidemiological services in many oountries of the world because of: 3.2 Weakness of health services The concept of epidemiological services and epidemiological surveillance and their role in the successful control and prevention of communioable diseases is not yet widely understood. Health services in many developing countries are stial weak and suffer from a lack of personnel and material resources. !loung'medical doctors and other key personnel at the national level are: not sufficiently interested in working in the fields of public health, epidemiology or microbiology. These activities are usually less advanta~ous
and provide
fewer career prospects than clinical medicine or private practice. It is more a political than a technical question to recognize in time that. without the availability of such well trained national personnel a country cannot be really independent of outside help and successful in the control of communicable diseases. It is again primarily a political question that thes~ I
public health
disciplines (epidemiology, microbiology, etc.) that are extremely important, should provide attractive career opportunities for very talented medical and other graduate personnel. In the last twenty years WHO and other international organizations
have made every effort to help developing countries in education and training, and have provided training facilities in different fields of medical sciences, especially microbiology. epidemiology. etc. However. the results until now have not been too successful. because of very complex reasons. One very important reason is t~t
training in
developing countries was not always well gUided and supetvised with regard to the health problems, priorities and needs of the country (e.g., communicable disease problems, community-oriented work in /microbiology and •••
WPRftiC20!rD5 page 7 microbiology and not PhD diplomas in microbiology with subsequent interest in the narrow field of research only).
3.3 Weakness or practical non-existence of a suitable statistical basis for epidemiological services Health statistics are a basic component of epidemiological services, not only in the collection, recording and processing of data (morbidity and mortality reports), but also in the manifold planning and implementa-
tion of different field surveys and epidemiological studies. In many countries the collection, recording and processing of statistical data are still centralized in a statistical bureau and morbidity and mortality data are then given to the ministry of health with some delay. It should be recognized (and there are many examples illustrating this) that the collection and processing of morbidity and mortality data in the field of communicable diseases cannot be successful and useful unless it is processed and interpreted (with due relation to the data from other sources Lfield,laborato~, under the direct supervision of a trained epidemiologist. This could be effected either by establishing a statistical laboratory for communicable diseases within the epidemiological services, or by ensuring that this part of the general statistical section should co-operate and be technically guided by the epidemiological section; alternatively, and this is a very good solution, it could be allocated to the department of epidemiology of the Central Institute (e.g., NCDC, Atlanta, etc.).
3.4 Weakness of eXisting public health laboratory services
and a frequent lack of concept with regard to the community needs and the importance of support of epidemiological services
Medical microbiology is an independent branch of medical sciences and its application in public health is a vitally important instrument
for epidemiological services.
Traditionally, the sciences of epidemiology /Furthermore, the •••
(of communicable diseases) and microbiology have been closely associated.
. Purthermore. the demand tor the establishment of pUbl.I0 ries arose not from baoterialogists, but from However, in the majority of countries the
h~th
laborato-
epidemiolog~sts.3 mioroblol~ical
laboratoThey were
rIes or institutions were built up betore a olear ooncept, evolved and development of modern epidemiological services were started. mainly organized in olose relation to indIvIdual patIent dIagnosIs (hospItal laboratorIes) to the detriment of the interest~ of epidemiological services (community or population-oriented 1abo~tory
,
work).
There are various reasons for this; otten because health services in general were or still are oriented mainly to curative medicine. In some countries the idea of integrated laboratory services4 was
not properly understood or implemented, especially with regard to clinical pathology. It is erroneous to believe that thr~e
or at the
most four years of superficial training in eight or more different laboratory disciplines is a sufficient teohnieal curriculum for the personnel of national laboratory servioes in view of the need for community-oriented microbiology at central level. When considering integrated public health laboratort services it must be a priori clear that a minimum of two branches should exist: (a) (b) medical microbiology (including laboratory investigation of drinking water, food) serving both the cooimunity and hospitals; biochemistry, haematolOgy, histopathology. etci. utilized for hospitals and individual patient care mainly. These two branches use different laboratory methods and equipment and service, co-operate with or are technically influenCed by different departments of the health services. . . For example, the first branch (a) - microbiology - is influenced by epidemiological set1Vices. the second branch (b) - biochemistry, etc. - by different medical care and hospital departments. It is again rot only a technical but also a political responsibility to ensure that existing progress in the field of medical microbiology facilitates the successful control and preventi~n
of many
/communicable diseases •••
WPR/RC2011'D5 page
9
conmun1oable diseasas.
'lb1s is true to such an extent that any delay
in the application of existing knowledge causes serious harm to the
health and eoonomy of a oountry. Even with a full understanding of the question, the reoruitment and adequate training of talented and keenly interested nationals for
different fields of laboratory services require several years. It would be unwise not to forecast in time these actual and urgent needs of national health servioes in view of the importance of communicable diseases and their preventability. Some of the more developed countries present other diffioulties. Health services are usually reasonably well organized and epidemiologioal services particularly at oentral and regional levels exist. Such countries also have microbiologioal laboratories and research or university microbiological institutes with a good number of well and sometimes highly qualified staff in different fields of medical microbiology. However, even in these countries the role of the microbiological laboratory in the planned control and prevention of communicable diseases, (e.g., in the planning, implementation and evaluation of vaccination and other control programmes, in epidemiological surveillance, etc.), is not yet fully appreciated. The work of these relatively well-stafted and equipped microbiologioal institutions is sometimes mainly oriented to individual patient diagnosis and often to the narrow field of individual research interest. This situation can partly be explained by the fact that microbiologists do not realize how tascinating and important (practically and scientifically) community-oriented microbiological work is.
On
the other hand, epidemiologists in these countries have also not taken steps to define the role of modern microbiology in the control and prevention of communicable diseases.
Another important reason is that very often microbiologists with high
seniority and scientific status do not wish to be subordinated to /recently developed •••
, WPR/RC20/rD5 page 10
recently developed epidemiological services. Such a situation could be resolved in a spirit of good teamwork and co-operation. It should be recognized that modern epidemiology and epidemiological services can only be successful when they are based on highly qualified laboratory work in microbiology. It is not crucial (and depends on the conditions in individual countries) whether the microbiological institution or branch of the public health laboratory services is subordinate to the public health laboratory or epidemiological or other departments of the health administration. Both should elosely co-operate and their activities be integrated and mutually influenced.
,
3.5 Public health administrators (decision makers) in
~y
countries
do not yet realize the high priority that should be given to the strengthening of epidemiological services in order to ensure that they are sufficiently staffed and equipped. They are also not sufficiently aware that the use of existing epidemiological methodology and laboratory means has a far-reaching effect on the improvement of planning, implementation and evaluation of control and measures, and that this provides the best scientific decisions. In several countries where during the last twenty years campaigns p~eventive !
bas~s
for taking
have been organized (more or less successfully) against different diseases, (tuberculosis, yaws, leprosy, smallpox, etc.), isolated units dealing with particular diseases are still found in the ministry of health. Sometimes in these cases the vitally importapt communicable wo~d
diseases control (e.g., epidemiological) section that disease programmes in the country does not exist.
be responsible
for planning and executing well-balanced and synthetized! communicable
Learning from past experience it is hoped that the smallpox eradication programme, which is progressing well, could be used in some parts of the world in the near future as a spearhe~
for the stepThus •••
by-step strengthening of national epidemiological and basic health /sertices.
WPR,IRC20;'rD5 page 11 servioes. Thus 1 in the final stages of the smallpox eradication
programme its personnel and resources could be simultaneously utilized for the control and prevention of one or even more important communicable diseases (meningococcal meningitis, tuberculosis l etc.).
4.
ORGANIZATIONAL STRUCTURE AND AIMINISTRATIVE LINES OF COMMAND
Epidemiological services at central level are based on two parts: (a) (b) administrative (decision making) in the ministry of health; technical laboratories, (research institutions or the central
public health laboratory), with transport and other means for laboratory studies and field investigations, (mobile laboratories, equipment for collection, transport and storage of biological material, etc.), which provide the health authorities with the necessary surveillance data for making decisions. As has been previously mentioned, there is no single prescription that could be recommended for all countries because of their very different levels of development of health services and political and socio-economic situations. Using experience gained from different countries of varying Size, population and political structure, but where the epidemiological services are well organized, productive and successful in control and prevention, the following possible
organizational scheme has been worked out showing the administrative lines of command for services at national, regional and district (provincial) levels (Table 1). The most important factors involved are understanding and aoceptance of a basic concept of epidemiology and epidemiologioal surveillance, the need for teamwork (co-operation) and above all the oomplete interest of everybody concerned in solving the most important health problems of the country. The establishment of epidemiological services is a long-term and complex process involving many factors, (epidemiological situation, size of the COuntryl available human and material resources and existing organizational structure of health services, etc.).
15.
Role of •••
L ___ _ r----I
Table 1 ORGANIZATIONAL SCHEME OF EPIDEMIOLOGICAL SERVICES IN A COUNTRY MINISTRY OF HEALTH
-r-M-IN-I-STR-Y-O-~---""--···------~MINISTRY OF EDUCATION AGRICtn.TURE
i~ I-' 1\)1\)
f
-r Preventive-:;-~cine
~ Section Medical Research Council
~
-z ~
~
Institute of Epidemiology and Microbiology • Institute of Hygiene • Other Research
Medical Schools Departments of Epidemiology , Microbiology and Hygiene Veterinaty Microbiological Laborat·
I l -...... Regioual Veterinary i§'
~
•........................•..........•.................••.....•......................... Regional Epidemiological Unit Regional Public Health Laboratory Servi,
I
··········1············· .......•.••.......••........•............••.•. District
......................... .. ,
Regional Veterlnaty Microbiological Laboratory .. .. .. .. .. .. .. .. . . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .............................................. ..
~
i)
t------011- ___ .., , : - - - - - - - - - - - - - - - --I
.~ ______________ , : I
District Public Health Laboratory (Hospital) Health Centre
Epidemiological Unit (Health Centre)
:- - - - - _ _ _ \ - - - - _ _ _ _ _ I
,
._-----
~---------~
-,
L ____________
District Veterinary Microbiological Laboratory
I I ~
l5'
.. '" <
,
-
• Institute of Epidemiology and Microbiology and Institute of Hygiene could be integrated in the Central Public Health Laboratory at could be a part of a National Institute of Health, etc.
Unes of command (full supervision) Unes of co-operation Depending on the stage of development and size of the country
•
,
,
..
5. ROLE OF WHO WHO has made every effort to strengthen epidemiologioal services as an integral part of general health services and to stress that microbiological laboratories constitute the most important tool of epidemiologioal services. WHO has also repeatedly stressed the need for a multi-disciplinary approach and for an improved use of methodology (operational, management, etc.). All these aspects were clearly illustrated during the Technical Discussions at the Twenty-first World Health Assembly in 1969 on the National and Global Surveillance of Communicable Diseases. 5 The participation of public health laboratory services in surveillance at national and international levels was further elaborated by Ra!ka. 6 WHO has been playing a very important role in this field during the last twenty years in many aspects, such as: (a) providing technical advioe in building-up and strengthening epidemiological, public health laboratory and statistioal services; (b) (c) providing training grants; providing methodological advice and reference material (sera, strains, antigens. etc.) from the network of WHO Reference Centres; (d)
participating in the surveillance activities of health services of individual Member States by providing methodological advice and/or means for collection, transport and storage of biological material (blood, etc.) for investigation (WHO Serum Reference Banks);
(e)
providing in the WHO Serum Reference Banks
~
WHO Reference
Centres or in other co-operating research institutes, laboratory investigation services which could not be carried out in many countries where such services were needed.
6.
SUMMARY
The tremendous developments in science and technology have provided means for the efficient control and prevention of most of the /communicable diseases •••
WPR/RC20/l'D5
page 14 communicable diseases in the world. However, in developing countries the spread of infection still continues to be a most important cause of illness, invalidity and death, as well as an economic burden. The solution to this problem lies not only in a specific knowledge of the natural history and ecology of individual diseases and infections, but also in having sufficiently strong, well-organized and equipped epidemiological services as an integral part of the health services of a country. Depending on the available human and material resoUI1ces, the political and socia-economic situation and different conclepts, the development and organizational structure of epidemiological services in individual countries also vary to a very great extent. The step-by-step building-up and strengthening of epidemiological services is a long-term and complex process which could be influenced by many factors. The aims, the organizational structure of epidemiological services and the concept of work based mainly on epidemiological surveillance activities, have been stressed. A multi-di~ciplinary ,
approach and the full participation of several scientific disciplines and health laboratory services, (microbiology, statistic~, environ-
mental health, etc.), are indispensable. An analysis was made of several causes of the present unfavourable situation in the field of communicable disease control and prevention in developing countries, and possible solutions were considered.
.. WPR!RC20;TD5 page 15 References 1. 2. Ra§ka. K. (1966) National and international surveillance of comml.Ulicable diseases, ebron. Wld IDth Org. 20. 315-321. Ra§ka, K. (1969) Concept or epidemiological surveillance or comml.Ulicable diseases (Working Paper No 1 for the InterRegional Seminar on the Methodology and Co-ordination of Epidemiological Surveillance of Commtmicable Diseases, Liblice) The Public Health Laboratory Service (1957) Wld IDth Org. techno Rep. Ser. ~. Planning, Organization and Administration of a National Health Laboratory Service (1962) Wld IDth Org. techno Rep. Ser. ~. National and Global Surveillance of Communicable Diseases (1968) (Backgrol.Uld document for the TWenty-first World Health Assembly, A2l)Technical Discussionsl5) Ra§ka, K. (1969) Role of the microbiological laboratory in surveillance programme activities (Working Paper No 35 for the Inter-Regional Seminar on the Methodology and Coordination of Epidemiological Surveillance of Comml.Ulicable Diseases, Liblice)
3.
4. 5.
6.
)