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Memórias do Instituto Oswaldo Cruz
Fundação Oswaldo Cruz, Fiocruz
ISSN: 1678-8060 EISSN: 1678-8060
Vol. 90, Num. 2, 1995, pp. 303-306
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Memorias Instituto Oswaldo Cruz, Vol. 90(2):303-306
mar./apr. 1995
Schistosomiasis Control in a Primary Health Care System
Taha Abdel Gawad El-Khoby
Endemic Diseases Control Department, Meglis El Shaab Street, Ministry of
Health, Cairo, Egypt
Code Number: OC95060
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Text: 24K
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The successful implementation of a Primary Health Care System (PHC) in any
country depends primarily on the ability to adapt its concepts and principles
to the country's culture and development stage. Thus, the PHC system should
reflect a balanced interaction between available resources, such as health
manpower capabilities, and the nature and magnitude of the health problems.
In addition, PHC should be viewed as the inlet to a multi-level pyramidal
health system which caters to both community and individual needs in a
balanced way. The adage that Ministries of Health should "work with and for
the people" in health development, is especially true in the area of PHC, and
hence, the health policy should aim to integrate health services in community
development and involve people in its planning, implementation and
evaluation.
Key words: schistosomiasis - control - primary health care - chemotherapy -
snail control - community participation
In relation to schistosomiasis control, a PHC approach means the utilization
of persons from the community who are trained to explain, interpret and
undertake a control programme. This approach is flexible and adaptable to the
conditions of each endemic country according to epidemiological, social and
cultural characteristics. Experience is now demonstrating that the control of
schistosomiasis is optimal when specific control tasks are carried out within
the PHC system. Thus, wherever possible, schistosomiasis control should be
integrated with health services, and decentralization of decision-making will
add an important new dimension in disease control allowing greater community
involvement.
THE PRIMARY HEALTH CARE SYSTEM IN EGYPT
The Regional Distribution of PHC - The PHC pyramid of units consists
of Rural Health Units, Rural Health Centers, Rural Hospitals, Endemic Disease
Hospitals and District General Hospitals. The distribution of the Rural
Health Units is such that there is one unit for every 5,000 population.
Services provided by PHC - The terms of reference for the PHC system include
the prevention and control of communicable diseases, family planning,
Maternal and Child Health (MCH), curative medical care, control of endemic
diseases (including schistosomiasis), forensic medicine, and improved
environmental sanitation.
Feasibility of PHC Approach to Schistosomiasis Control - In Egypt,
schistosomiasis control measures have been carried out long before the
current ongoing National Programme began. Chemotherapy - by Tartar Emetic -
started as early as 1920; Snail Control - by Copper Sulphate - commenced in
1927. In 1928, the Health Department which was then attached to the Ministry
of Interior, established a special Department for Endemic Diseases Control,
and started a project for mobile hospitals to treat endemic diseases. When
the Ministry of Health (MOH), was established as a specialized Ministry in
1936, the Endemic Diseases Control Department (EDCD) was one of the four
departments. Initially all administration was carried out centrally, however,
as local Governments developed and increasing numbers of field units were
established, decentralization proceeded to Intermediate (Governorate) level
and then Local (District) level. The staffing of the various administrative
levels should be according to the load of work needed.
The control measures carried out through the PHC system to date have been
successful due to the available organization, existing facilities, laboratory
equipment and trained personnel. Thus any individual from the catchment
population who contacts the PHC for other services, should be directed for
schistosomiasis screening, and treatment if positive. The community
participation ideals in the PHC system can be utilised to initiate and
support community participation in the schistosomiasis control programme.
The capability of the PHC system to carry out control activities has been
facilitated by (i) the easy Health Education process, (ii) relatively simple
diagnostic techniques, (iii) the availability of a safe, easily administered
and effective drug, and (iv) the location of snail-control field units in
PHC's.
ADMINISTRATION IN PHC
Organization of Schistosomiasis Control - Administrative Aspects - The
General Administration components are staff management, the supply system,
and fiscal management. The Control components are chemotherapy,
snail-control, health education, and morbidity management. The Supervision
depends on quality control, monitoring system, and assessment of PHC
performance. The Control Activities are developed through training personnel
(offering guidelines and obstacle identification), defining strategies,
carrying out field trials, and improving facilities, equipment and
techniques. The Progress is evaluated through data management, evaluation,
and control of problems. Technical Support is essential, and there should be
mobile teams for specific areas with identified high prevalence, with new
Schistosoma mansoni or changing pattern in mixed infections, with frequent
serious morbidity, with a dense population, or distant settlements.
SUPPORT SYSTEM IN PRIMARY HEALTH CARE APPROACH
Community Participation - Schistosomiasis is a man-made disease
through water pollution and water contact, and so community participation is
regarded as an essential element of any schistosomiasis control programme. A
detailed knowledge and understanding of community structure is a
pre-requisite if community participation is to be achieved. Health education
activities must result in culturally acceptable responses and mobilization of
the community to support the programme. Community participation has the
potential to achieve a reduction of water pollution and water contact, high
community coverage in laboratory examination and treatment, and co-operative
participation in habitat modification and installation of water supply and
sanitary appliances. Community participation may decline with time, and so
continuous monitoring is recommended so that weakness can be investigated and
corrected.
Integration with Endemic Diseases Hospitals - It is important that the
work in the Rural Health Units be integrated with the higher units in the PHC
system. Co-ordination is achieved by periodic visits by District Endemic
Diseases Hospital physicians to the morbidity clinics in PHC Units. PHC
staff are called for periodic meetings in Endemic Diseases Hospitals at which
there are case discussions. There is a Case Referral System from PHC Units to
Rural and Higher Hospitals to confirm diagnosis, case assessment and
treatment. PHC physicians visit hospitals to follow-up cases referred to
hospital or cases identified in hospital surveys. The reverse referral from
Hospital to PHC Unit may occur for follow-up after treatment, and for further
treatment (if within the scope of PHC). The District Hospitals are equipped
with mobile facilities, e.g. Sonography - for a morbidity case finding
programme.
Intersectoral Co-ordination - Co-ordination is achieved at all stages of the
PHC system. The Rural Council coordinates with Local Government at village
level by having the PHC physician as a member of the council.
A special Health Care Physician is responsible for School Health, while
Habitat Modification is the responsibility of the Agricultural society at the
village level.
Water Supply & Sanitation improvements are achieved through local
co-operation through the Village Community Development Society.
In each governorate, a local Schistosomiasis Committee is headed by the
Governor and includes the Rural Council and the Governorate Authority.
OBSTACLES AND DEFICIENCIES
Identification of Obstacles Encountered in Primary Health Care - There
are several factors which may limit the success of the PHC in schistosomiasis
control: (i) Accessibility: there may be a number of satellite villages and
hamlets served by any one PHC unit; (ii) Environmental: there may be a higher
probability of water contact related to area irrigated by different stretches
of water courses; (iii) Geographical Accessibility: the distance between
satellite villages and hamlets and unit's services may be large. Generally
coverage is higher in nearby villages and lower in distant villages; (iv)
Competition with other Programmes: PHC Units provide a variety of services
that may compete for resources during different seasonal work loads. eg
emergency activities, new programmes may be introduced; e.g.: mass
vaccination, communicable disease control, and examination of school
children; (v) Size of Population served per unit: the population size has a
high effect on coverage rate, effectiveness, and level of performance
especially with the standard facilities, personnel, and working hours; (vi)
Multiplicity of Duties: multiple services performed according to population
size are not usually carried out on a full time basis. Hence, most of PHC
personnel may carry out more than one job; (vii) Lack of continuity of
personnel: most PHC personnel regularly shift to other jobs or are
transferred to carry out the same job in a main city; (viii) There may be a
decline in personnel vigilance, enthusiasm, morale, attitudes and continued
interest.
All these points need to be monitored, early diagnosed, motivated and
corrected.
STRATEGY OF SCHISTOSOMIASIS CONTROL IN PRIMARY HEALTH CARE APPROACH
Selective Population Chemotherapy - Praziquantel, the drug of choice
is administered orally at 40 mg/kg as a single dose. Its ease of
administration, effectiveness against both S. haematobium and S. mansoni, and
safety, mean that it is capable, even if used alone, of achieving excellent
short-term results. Unfortunately, unless combined with other measures these
results would not be sustainable long-term. Praziquantel achieves a high cure
rate, a high reduction of intensity, as measured by the reduction of number
of eggs passed by individuals and at the community level, and if early and
properly used should prevent development of morbidity. Health Education is an
important ingredient in control, and in chemotherapy, because only when the
community are well educated in the disease, its effects, its mode of
transmission and means of control will a control campaign be successful.
Snail Control - The role of PHC in Snail Control is crucial. Snail Control
units are located in PHC field units from where they are responsible for
routine snail surveys, identification of transmission sites, and
mollusciciding at village level. Where possible they will also recommend and
coordinate habitat modification through agricultural cooperative societies,
for field canals and drains. Trained staff are necessary for identifying the
criteria for identification of transmission sites. These include learning the
ability to recognize water contact sites, sites of pollution, intermediate
hosts, sites with infected snails both within villages and outside where many
people are infected or at risk.
The current snail control strategy is to select sites meriting control by
application of molluscicides. When the human prevalence rate is low,
molluscicide treatments are limited to sites in which infected snails have
been found. However when human prevalence is high (say over 25%), then snail
control should cover all water contact and potential transmission sites. The
timing of the applications is every 4-6 weeks (equivalent to the parasite
incubation period in Biomphalaria and Bulinus respectively), during the
transmission season of March - October.
The strategy of only carrying out focal mollusciciding is due to the high
cost of blanket treatment, the proven focal nature of transmission sites, the
undesirable effects specially on fish population, and the lack of proof of
the control of transmission by blanket control.
Health Education in PHC Approach - A major role of the PHC worker is
liaison between community and specialists, to inform, motivate, and encourage
the community and leaders to join to improve their health. Meanwhile using
the Mass Media, a national TV campaign has been used to increase the
community awareness towards the problem. Short (two minute) films using
characters from local communities, typical water contact sites, shots in PHC
Units, each discourage water pollution and water contact and encourage
periodic visits to PHC's for stool and free urine laboratory examination, and
treatment if positive.
Face to face health education is capable of more in depth and wider
information dissemination, for example through health classes in PHC Units,
health visits calling for examination and treatment, and during school health
activities.
Community Organizations participate through Rural Council (local government)
and co-operative societies to develop community participation in habitat
modification and installation of water supply and sanitation facilities.
Morbidity Management in PHC Approach - The PHC system plays an
important role in morbidity management through chemotherapy of symptomatic
morbidity. Symptomatic treatment at the PHC Unit is the first line of attack
and therefore ultimately responsible for the disease maintenance phase thus
justifying the reinforcement of PHC Units. In the absence of a
parasitological diagnosis, schistosomiasis may be diagnosed from clinical
signs and symptoms thus (i) S. haematobium could be assumed from hematuria,
dysuria, and/or frequency of urination, and (ii) S. mansoni is associated
with dysenteric symptoms, enlarged liver and spleen and haematemesis.
Each PHC should have a specially arranged Morbidity Clinic, to be regularly
visited by Endemic Hospital staff. This should ensure that clinical or
symptomatic cases are dealt with properly in earlier stages of disease, thus
preventing serious morbidity.
Thus within the PHC system the strategy would be: (i) Passive case finding
supported where possible by active measures (house calling); (ii) Intensive
treatment, if indicated, in areas with high prevalence and intensity and
(iii) In areas with frequent serious morbidity, supplementary measures may be
necessary.
FOLLOW-UP
Assessment of Performance - The assessment of the performance of the PHC
system can be through the following measurements: (1) Contact Rate - Number
of people who contacted PHC/Target Population (2) Screening Rate - Number
received laboratory examination/Number made contact (3) Treatment Rate -
Number received treatment/Number of positive cases (4) Follow-up Rate -
Number who received follow-up examination/Number received treatment (5)
Continuity Product - Contact Rate x Screening Rate x Treatment Rate x
Follow-up Rate.
Each indicator (Rate) is based on the assumption that if each person
successfully passes the proceeding element of care he proceeds to the
succeeding step.
USING CONTINUITY PRODUCT
The Continuity Product expresses the probability of an individual to contact
PHC, be screened, treated and followed-up. The continuity product could be
examined to identify the points of weakness and intervention could be
introduced.
Monitoring System - A household census is to be carried out, and all
houses numbered. The houses are then grouped into 10 sectors for future
sampling (a through j), thus (a) 1 - 11 - 21 etc.; (b) 2 - 12 - 22; (c) 3 -
13 - 23; (d) 4 - 14 - 24; (e) 5 - 15 - 25; (f) 6 - 16 - 26; (g) 7 - 17 - 27;
(h) 8 - 18 - 28; (i) 9 - 19 - 29; (j) 10 - 20 - 30.
Subsequently each sector is to be called and examined in a specific period of
time. Prevalence is estimated after correction for: age, sex, and sample
size, and Compliance Rate is to be estimated from number attended.
PROGRESS ESTIMATION
Evaluation - The indices of the status of the disease are the
prevalence of infection, the intensity of infection as measured by egg
output, the incidence of new infections (transmission) and the morbidity in
the population; (i) Prevalence: the prevalence is quoted as percentage
infection in age specific groups; (ii) Intensity: S. haematobium: % No. of
individuals with: - less than 50 eggs per 10 ml urine or - more than 50 eggs
per 10 ml urine; S. mansoni: % No. of individuals with: - less than 100 eggs
per gm stool or - more than 100 eggs per gm stool; (iii) Incidence: the
incidence is defined as the number of negative cases who revert to being
positive in a subsequent examination during a period of (say) one year. This
gives a measure of transmission, and highlights the need for further snail
control; (iv) Morbidity: S. haematobium: (a) Hematuria: (1) % No. of
individuals who have bloody urine at the time of examination and within the
last month; (2) % No. of individuals who have bloody urine in the past (more
than one month and less than six months ago); (3) % No. of individuals who
have hematuria by reagent strips at time of examination. (b) Dysuria -
Percentage of individuals with Dysuria in the last six months; (c) Frequency
of urination - Percentage of young individuals urinating more than four times
a day. S. mansoni: (a) Percentage of individuals with history of
haematemisis; (b) Percentage of school age children with hepatic &
splenic enlargement.
PROBLEMS ENCOUNTERED
(a) Increasing Prevalence - In some areas, there is a rising prevalence
& intensity in identified foci. The factors which may have caused this
increase are - (i) The Operational Approach: with chemotherapy as the main
method used, leading to good short term results, but a relapse after initial
treatment; (ii) No substantial change achieved in either water supply,
sanitation, snail population and/or habitat modification; (iii) PHC
Characteristics: the PHC system may have been ineffective due to the focus
being distant from the PHC services, a oversize population being served
limiting population coverage; (iv) Personnel and Community Attitudes may not
be cooperative due to a declining Community Participation spirit or reduced
personnel vigilance.
In order to improve these situations, better management is needed and PHC
activities should be supported through mobile central teams (at district
level), more frequent chemotherapeutic treatment offered and increased
targeted treatment for school children.
(b) Changing Schistosomiasis Pattern - In countries with both S.
haematobium and S. mansoni, the balance of the two species may change due to
ecological changes: (i) In some areas, with previously high prevalence of S.
haematobium and low S. mansoni infection, the pattern have been reversed as
Biomphalaria alexandria infestation increases and Bulinus truncatus
decreases; (ii) Another possibility is that S. mansoni starts to appear in
areas where S. haematobium had been the only prevalent species. Again this
is usually linked with the spread of the host snail B. alexandria.
Action in these cases must be decisive and PHC activities are to be supported
with teams at district level. Initially, population mass survey & treatment
of positive cases is recommended and this should be supplemented by surveys
of water-courses, mollusciciding of feeding canals and all branches of
drainage; tributaries and main drains. Finally a follow-up of both human and
snail surveys should be carried out.
Other areas requiring special attention are those with frequent serious
morbidity. The indicators of these areas are - (i) High prevalence and
intensity; (ii) Inadequate water supply and sanitation; (iii) Water contact
sites with high snail populations and infected snails; (iv) Ineffective
community participation; (v) Obstacles with PHC utilization.
The recommended measures in areas of high morbidity are an intensive active
case finding programme, in which maximum coverage is needed, and concurrent
snail control using mollusciciding and habitat modification. Health Education
should be initiated to correct and sustain community participation, and if
possible initiate improvement of water supply and sanitation through local
authorities and community co-operation.
Where there are cases of high morbidity, then it is important to initiate
immediately active case finding, diagnosed on symptomatic and simple
laboratory examination. This should be followed by early and proper
treatment. To assess the degree of morbidity, the use of sonography is
essential. This will allow assessment and follow-up of cases, and morbidity
clinics are to be visited by specialized physicians from district hospitals
for consultation.
Copyright 1995 Fundacao Oswaldo Cruz (FIOCRUZ)
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