2. Surveillance
Surveillance is the process of continuous scrutiny of the
factors that determine the occurrence and distribution of
disease and other condition of ill health.
Disease surveillance is the ongoing systematic collection,
consolidation and analysis of data, and the dissemination
of this information to those who need to know, so that
actions may be taken.
Surveillance is undertaken to inform disease prevention
and control measures.
3. Various definitions of Surveillance
“The continued watchfulness over the distribution and
trends in the incidence of disease through the systematic
collection, consolidation and evaluation of morbidity and
mortality reports and other relevant data”
“Continuous analysis, interpretation and feedback of
systematically collected data, generally using methods
distinguished by their practicality, uniformity and rapidity,
rather than by accuracy and completeness”
”The systematic ongoing collection and analysis of data for
public health purposes and the timely dissemination of
public health information for assessment and public health
response as necessary.”
4. • It is very important that more actions should be
taken at the level at which the data are obtained.
• This is especially true for district and peripheral
health centers, where most of the health services are
provided.
• If the managers at this level wait to take any action
until feedback comes from the center, it may be too
late.
5. Types of Surveillance
Routine surveillance:
• In routine surveillance, the data are collected
routinely and forwarded to higher levels on a routine
basis.
• For this purpose, health staff of health post and
health center collect information about the number
of cases of reportable communicable diseases
including the EPI target diseases that occur in their
health area.
• At the end of month they analyze the data and send
it to the district supervisor.
6. Sentinel surveillance:
• It occurs when data are collected from only selected
sites. This is rarely representative of population but
can be used to monitor trends and collect more
detailed information.
• Sentinel sites are chosen to report the number of
cases of disease that occur for a specific time period
and also in a certain age group.
• They may also provide a more consistent picture of
illness in a given area. Data collected from these sites
may also show whether the routine reporting data is
working.
• In Nepal, Early Warning and Reporting and Response
System has been developed for national priority
diseases and different sentinel sites has been
identified for the data collection.
7. Case/outbreak investigation
• In general, case investigation is investigation
of single case and an outbreak investigation is
that of many cases. However, when the
occurrence of a particular disease is very low,
even one case can be considered an outbreak
8. • The supervisors of concerned health facilities
should investigate every cases as soon as the case
is suspected.
• Case investigation of other EPI target diseases,
and other diseases of public health concern
should also be done when appropriate.
• The role of district supervisors in most outbreak
investigations is to analyze the surveillance data
and to notify higher officials of any disease trends
that might indicate occurrence of outbreak.
9. Special studies:
• These studies conducted by trained health
professionals, investigators or epidemiologists.
• They are used to measure the number of
cases of disease in an area and to evaluate the
reliability of the routine or sentinel reporting.
10. Surveillance can be classified as
passive or active
Passive surveillance:
• The health departments rely on health care
providers or laboratories to report cases of
disease
– Primary advantage is efficiency: simple and
requires relatively few resources
– Disadvantage is possibility of incomplete data due
to underreporting
– Majority of public health surveillance systems are
passive
11. Active surveillance:
• health department contacts health care
providers or laboratories requesting
information about conditions or diseases to
identify possible cases
– Requires more resources than passive surveillance
– Useful when important to identify all cases
12. Purpose of Surveillance
The surveillance is done for the following purposes:
• Observe disease trends and identify the disease as
per case definition and causes
• Establish disease priority
• Identify, investigate and control outbreaks
• Identify, investigate and manage adverse events
following immunization
• Document impact of services
• Estimate the requirement of vaccines/drugs and
other logistics
13. • Evaluate quality of health service delivery
• Identify specific population groups at high risk of
illness and deaths due to vaccine preventable
diseases (VPDs) and other health problems
• Ensure that national immunization program (NIP)
activities and resources are used efficiently
• Modify strategies for betterment
14. Example of Surveillance with Objective
Dysentry To detect outbreaks of dysentery by
monitoring the incidence of cases of acute
bloody diarrhoea
Acute
Respiratory
Infection
To monitor the incidence and case fatality
rate of acute respiratory infection (ARI) in
children under 5 years
Polio To monitor progress towards polio
eradication by monitoring the incidence of
poliomyelitis where wild poliovirus is
isolated in children under 14 years
15. Importance of Surveillance
• Highlighting the magnitude of the illness as a public
health problem
– Large number of children or women affected
– High mortality rates
– Causes of lifelong debilitating sequelae
– Assessing impact of services which includes achieving
goals of polio eradication, neonatal tetanus elimination
and control of measles as well as other VPDs like
diphtheria, pertussis and childhood tuberculosis
– Assessing if unequal weightage and importance is given to
either of the components of National Immunization
Program (NIP) and to take corrective measures in time
16. • Providing epidemiological data for planning
program interventions
– Which are the age groups most affected?
– Which locations/ geographical areas are more
affected?
– Are there seasonal variations?
– Are there cyclic trends?
– Are some groups of the community more vulnerable?
– Are there risk factors that affect complications and
mortality rates?
17. • Monitoring the quality of services
– Is the program having the expected impact on the
incidence and mortality rate?
– Do the trends commensurate with services
provided?
– Immunization status of cases
– Is the quality of the work has been assured by the
program?
18. • Identifying high risk pockets for additional actions
– Is the program having less than the desired impact
in some pockets?
– Are the reported incidence and mortality rates
higher in selected pockets?
– Is the reported incidence of severe adverse events
higher in selected pockets?
19. • Identifying outbreaks early
– Prevent deaths by early and appropriate case
management
– Prevent secondary cases
– Help in planning proper interventions
– Prevent spread of the outbreak to the other
vulnerable pockets
– Early and appropriate treatment to prevent deaths
20. • Estimating the requirement of vaccines for
the programs
– The surveillance data enables to judge the
magnitude of the problem, to identify the
population to be covered and to determine the
requirement of vaccine and other logistics in
certain geographical area.
21. • Documenting impact of services to show
– Declining trends of diseases
– Reduction in neonatal, infant and child mortality
rates
22. Conducting Surveillance
1) Collection of surveillance data
2) Analysis of surveillance data
3) Interpretation
4) Dissemination of surveillance findings
5) Appropriate action
24. Disease Surveillance System in Nepal
• In Nepal, a system is in place for regular
surveillance and reporting of suspected cases.
• Epidemiological services have been
undertaken to collect the disease
morbidity/mortality statistics from different
disease endemic districts.
• There are two surveillance systems exist to
report disease cases.
25. • Routine monthly reporting of aggregated data of
all cases (suspected, probable, confirmed) from
periphery to district, regional and central level
(Health Management Information System, HMIS).
• Sentinel surveillance through Early Warning
Reporting and Response System (EWARRS):
Sentinel sites must include all clinical cases
(suspected/probable/confirmed) in the
immediate and weekly EWARS reporting forms,
including "Zero" reports.
26. Disease Surveillance and Research
• EDCD’s Disease Surveillance and Research
Section was established in August 2013.
• It conducts the surveillance of reportable
diseases and is responsible for collecting,
analysing, interpreting, and reporting
information for infectious diseases.
• It monitors disease trends for early detection
and prompt response to outbreaks.
• It also assists in developing public health
policies and programme planning and
implementation related to communicable
diseases.
27. • The DSR section’s main strategies are to:
– monitor and describe trends of infectious diseases
through a sentinel surveillance network
– of hospitals, followed by public health action and
research;
– develop a comprehensive, computerized database
of infectious diseases of public health
– importance;
– expand and strengthen the Early Warning and
Reporting System (EWARS) to 75 districts; and
– implement the District Health Information System
platform for EWARS.
28. • EDCD is a secretariat of the Water Quality
Surveillance Committee, which is led by the EDCD
director.
• The committee is responsible for the regular
surveillance of water borne diseases, for
coordinating with stakeholders for quality
surveillance and for improving surveillance by
training human resources and through meetings
and other programmes.
• It is also responsible for facilitating water quality
testing when waterborne disease epidemics
occur and for recording the drinking water
distribution system through geographical
information system (GIS) data and providing
feedback to the responsible organization.
29. During Outbreak situations
• All outbreaks (suspected/probable cases) should be reported
immediately to the respective regional health services
directorate, the EDCD/DHS, and/or VBDRTC, Hetauda, for
immediate investigation and, if possible, laboratory
confirmation. The regional and central level should seek
follow-up data on patient outcome.
• During outbreak situations, surveillance should be intensified
with the introduction of active case finding whenever
possible.
• Laboratory confirmation should be performed as soon as
possible.
• Thereafter, weekly reports of cases, age groups, deaths,
regions, and hospital admissions should be set up.
30. • The surveillance has provided regular data for
assessing the disease distribution, morbidity and
mortality in different districts.
• Collected information has use for program
implementation and policy implications.
• In Nepal, health staff from HPs/SHPs, PHCs and
Hospitals collect information on the number of cases
of reportable communicable diseases that occur in
their catchment area in specific HMIS reporting
forms.
31. • At the end of each month, they have to send this
information to the DHO/DPHO, where this information
is compiled by district and sent to the
HMIS/Management Division, Department of Health
Services.
• HMIS strategy is oriented to assure timely reports from
all 75 districts of Nepal.
• In order to develop an active, timely and accurate
sentinel surveillance reporting system, districts
identified at high risk should be provided with facilities
for rapid dissemination of the information.
32. • This will be helpful not only to improve the
timeliness of the HMIS reports to the central level
but also facilitate the district analysis of their
information and will also provide the program
managers immediate access to the necessary
information produced by the districts to take
appropriate actions.
33. • The surveillance system has been established in the
country; however, due to weak supervision, monitoring
and training, it has been found that there is incomplete
and not timely reporting.
• The quality of information/data is questionable since the
case definition is not strictly followed.
• The lack of competent health personnel and poor
diagnostic facilities has further raised the question on the
quality.
• The efficiency of the surveillance system will be increased
by ensuring that the entire population is covered, up to
the smallest geographic and political unit, which is the
VDC level.
34. • Health personnel at all levels should be sufficiently
trained to ensure the quality of a decentralized
surveillance.
• All surveillance information should be standardized
and include the same type of data elements.
• The disease having complex signs and symptoms
confused with other viral and bacterial infection and
specific diagnostic tests need more technical skills
and specialized laboratories for an accurate
diagnosis.
35. Early Warning Reporting and Response System
(EWARRS)
• EWARS is a hospital-based sentinel surveillance system.
Initially it grew out of an interest in tracking cases of
poliomyelitis and it includes six diseases:
• Three vaccine-preventable diseases(VPDs):
– Polio (AFP)
– Measles
– neonatal tetanus
• Three vector-borne diseases
– Malaria
– kala-azar (KA)
– Japanese Encephalitis (JE).
36. • EWARS was started in 1996, and the Epidemiology and
Disease Control Division (EDCD) of the MoH has been the
implementing agency
• The EWARS has been established since 1997 in Nepal to
strengthen the flow of information on vector-borne and
other outbreak prone infectious diseases from the district
to the national health departments.
• Rapid Response Teams (RRTs) can be mobilized at short
notice to facilitate prompt outbreak response at Central,
Regional and District level, they can also support the local
levels (DHO/PHC/HP) for investigation and outbreak
control activities.
37. • This information system is hospital-based, hospitals
are selected as sentinel sites.
• In 1997 the program started with 8 sentinel sites and
was expanded to 24 sites in 1998, 26 sites in 2002, 28
sites in 2003, 40 sites in 2008. As of April 2015, there
were 81 sentinel sites throughout the country covering
all 75 districts
• The EWARS mainly focuses on the weekly reporting of
number of cases and deaths (including "zero" reports)
of six priority diseases: three vector-borne diseases
Malaria, Kala-azar and Dengue and three outbreak
potential diseases Acute Gastroenteritis (AGE), Cholera
and Severe Acute Respiratory Infection (SARI).
38. Objectives of EWARS
• to develop a comprehensive, computerized database
of infectious diseases of public health importance
• to monitor and describe trends of infectious
diseases through a sentinel surveillance network of
hospitals followed by public health action and
research
• to receive early warning signals of diseases under
surveillance and to detect outbreaks
• to initiate a concerted approach to outbreak
preparedness, investigation and response
• to disseminate data/information on infectious
diseases through an appropriate feedback system.
39. • The implementation of an Early Warning Reporting
and Response System (EWARRS) is not to replace
HMIS, but to complement it.
• By doing this, the EWARRS will allow the early
detection of focal outbreaks of communicable
disease which can lead to timely interventions for
the control of these diseases.
• The existing Health Management Information System
(HMIS) in Nepal, as elsewhere, is not designed to
provide timely information or facilitate early
response.
40. • In addition, hospital cases were inadequately
investigated, and there were inadequate definitions
and guidelines for diagnosis, investigation and
management of diseases. There was an inadequate
link between hospitals and the public health
infrastructure and actions
• EWARRS is designated to complement the country's
health management information system by providing
timely reporting for the early detection of selected
vector-borne and vaccine preventable diseases with
outbreak potential.
41. • The EWARRS mainly focuses on the weekly reporting
of number of cases and deaths (including zero
reports) of six priority diseases viz: acute flaccid
paralysis, measles, neonatal tetanus, severe and
complicated malaria, kala-azar and Japanese
encephalitis within 24 hours of diagnosis.
• Other communicable diseases besides these six
prioritized diseases also need to be reported in
EWARRS, whenever the numbers of cases exceed the
expected level.
42. • EWARRS provides systematic collection, collation,
analysis, interpretation and dissemination of data on six
identified diseases for immediate public health action in
order to monitor and timely respond to outbreaks of
these diseases.
• In the broader perspective, it also aids on program
planning, evaluation and the formulation of research
hypothesis.
43. Process of Reporting in EWARRS
• The sentinel hospitals send the weekly reports
immediately (reporting within 24 hours, in
case of an outbreak) and weekly to the Vector
Borne Disease Research and Training Center
(VBDRTC) in Hetauda by fax.
• VBDRTC serves as a focal point for EWARRS by
receiving and analyzing all immediate and
weekly reports sent from sentinel hospitals.
44. • The sentinel sites have been selected as pilot for
improved information collection and reporting, to
encourage health facilities to take quick action and to
upgrade laboratory-testing capacity through training
and equipment.
• VBDRTC then consolidates the reports and forwards
weekly summaries to the Epidemiology and Disease
Control Division (EDCD), Ministry of Health.
• EDCD compiles, analyze and publishes the weekly
report in the form of EWARS bulletin.
45. • Thus, national epidemiological data for the
week are disseminated to all sentinel sites
including all measure health institutions of 75
districts in Nepal.
46. Existing Vaccine Preventable Disease Surveillance
System in Nepal
• Vaccine preventable diseases are routinely reported through
HMIS system complemented by EWARRS and outbreak VBDRTC
serves as a focal point for EWARRS by receiving and analyzing
all immediate and weekly reports sent from sentinel hospitals.
1. Data collection :
Data are collected on following vaccine preventable diseases:
– Diphtheria
– Pertussis
– Neonatal tetanus
– Poliomyelitis
– Measles
– Tuberculosis
– Hepatitis B
47. • Data are collected for incidence of VPD and
deaths in following age groups:
– Within one week of birth
– Within one week to one month of birth
– Within one month to one year of birth
– Within one year to five years of birth
• Besides collection of data on disease,
information must also be collected on severe
adverse reactions following immunization.
48. • Data on outbreaks are collected and analyzed
separately. Investigation on outbreaks is useful
in identifying factors that led to the outbreaks
and evaluating efficacy of the control
measures.
• Such investigations provide useful experience
for undertaking appropriate action in future,
for disease(s), which are planned to be
controlled, eradicated or eliminated.
49. 2. Line listing/Recording:
The recording register includes following
information:
– Name
– Name of father or mother
– Age
– Sex
– Date of onset of symptoms
– Date of examination
– Date of reporting
– Immunization status
50. – Full address
– Diagnosis
– Outcome
– Laboratory investigation, if conducted
– Follow up action taken
– Hospital/ health center
– Hospital registration number
51. 3. Quality of data
• The quality of data collected depends on many
factors like regularity of reports, timeliness with
which these are received, completeness of data
submitted and diagnostic criteria used.
• If these factors are not checked and corrected,
they can often lead to fallacious conclusions
and ineffective use of surveillance data.
52. Regularity of reports
• Surveillance data are generally submitted once in a
month. All reporting sites must submit monthly
reports. If no cases are seen, a ‘nil’ report should be
submitted. At the PHC and district levels the receipt
of the reports should be monitored.
Prompt and timely reporting of cases
• Reports should be received within a reasonable
period of time. The effectiveness of follow up action
depends on the promptness with which these are
undertaken. A date should be fixed at each level for
receiving the monthly reports.
53. Completeness of the reports
• Reports must be complete in all respects and
all the columns in the format must be filled. If
no cases are seen, ‘0’ or ‘nil’ should be
entered.
4. Sources of data collection
– Hospitals
– Primary health care centers (PHCC)
– Health posts
– Sub-health posts
– Private practitioners
54. 5. Diagnostic criteria
• The diseases under VPDs, have a wide spectrum of
clinical presentation. Therefore there is a uniform
criterion of diagnosis for each VPDs under
surveillance. Standard case definitions have been
made and circulated.
6. Problems encountered in data collection
• Not all the hospitals submit data regularly or in time
• Not all cases are seen in the hospitals/ health centers
55. • Some cases are seen by more than one hospital/
health facility and the same case may be reported
from more than once (duplication resulting over
reporting)
• Criteria for diagnosis is not uniform
• Incomplete information
• Mandatory reporting (no clear instructions about
mandatory reporting)
56. 7. Data analysis
• After collecting the data, they are analyzed at
every level of the health system. Analysis at the
district level is important so that problems are
identified at the level where action can quickly be
taken to solve them. When analyzing surveillance
data, it is important to look for:
– Disease trend
– Disease clustering
– Changes in age groups
57. Monthly analysis of data
• Completeness of reporting
• Are there discrepancies in reported data?
• Increase in the reported number of cases
• Decrease in the reported number of cases
• Estimate degree of under-reporting of cases
Annual analysis of data
• Trends in disease incidence: annual compared with
previous years.
• The epidemic pattern of the disease
• Seasonal pattern of disease
• Preparation of a disease map
58. Locating High-risk areas
The high-risk areas can be categorized as follows:
• Inaccessible areas
• Disadvantaged ethnic groups
• Areas of poor immunization coverage
• Areas of known endemicity
• Peri urban-urban slums, peri-rural to rural slums
• Poor literacy areas leading to lack of awareness and
unsatisfactory health seeking behavior
• Crowded localities with poor sanitation conditions
• Areas of socio economic backwardness
59. Spot map for cases by residential address
• Spot mapping of cases by residential status is
important as often cases can come to a hospital from
large distances. Spot maps helps to identify:
– Pockets from where cases are consistently reported
– Pockets from where cases are expected but not
reported
– To know the trend of disease while comparing
similar maps for the corresponding period.
60. Determine the sex ratio of reported cases
• Identify the cases on the basis of sex. Line list can be
used to document the sex ratio of cases.
Analyze immunization status
• The immunization status of all cases should be
recorded, irrespective of diagnosis. A high proportion
of un-immunized cases seen in the hospitals is a
reflection of low immunization coverage levels in the
community.
61. • The immunization status of cases of VPDs should be
analyzed separately. As immunization coverage levels
increases, the proportion of cases with history of
immunization will also increase but the total number
of cases will fall.
• A rapid check of vaccine efficacy can be made. If the
vaccine efficacy is less than expected, the reasons
should be checked with the highest priority.
• These include over estimation of immunization
coverage levels, vaccination at the wrong age and
unsatisfactory quality of the cold chain.
62. Analyze age- groups affected
• Analysis of age group affected is important to
prioritize action for preventive measures and IEC
activities.
• Analysis of neonatal deaths by age in days is a
monitoring tool for assessment of neonatal tetanus
elimination.
Estimated degree of under reporting
• Rough estimates of expected number of cases and
deaths should be made. These should be compared
with the total numbers actually recorded.
63. 8. Differential diagnosis
• As immunization coverage levels increase and the
number of cases of vaccine preventable diseases
decline more stringent clinical criteria may be
required to confirm diagnosis to exclude cases which
are clinically similar to the vaccine preventable
diseases.
• The immunization program can lose credibility
because of the perceived poor impact of the services
if mis-diagnosed cases continue to be reported as
VPDs.
64. 9. Take action
• The data are collected and analyzed in order to solve
problems and reduce the number of cases of disease.
• For certain problems this might require immediate
action, for other problems the improvement of routine
immunization activities may be the relevant action.
• Identifying corrective actions is a responsibility of
health staff at every level.
• However, it is especially important for the health
center level to act promptly, since this is the level at
which immunization services are delivered.
65. 10. Identify and implement solutions
• While analyzing surveillance data, identify problems and
answer the question, why did the cases occur? What
can be done to prevent cases from occurring in future?
Solutions must address the cause of the problems.
• The health managers, after identifying the solution
should act as soon as possible because the sooner
solutions are implemented the fewer the cases of
disease will occur.
• If the approval of senior official is needed, request it as
quickly as possible.
66. 11. Submit the surveillance report
• After analyzing the surveillance data, and taking as
many actions as possible, send a report to higher
authorities.
12.Provide feedback
• Information must be promptly shared with all health
staff who are involved in the surveillance system,
regardless of what analysis shows.
• Feedback shows that reported data are used and
appreciated. Thus, feedback may improve the
accuracy and promptness of reports and raise the
morale of the staff.
67. Feedback includes:
• Comments on promptness of reports
• Information on the total number of cases of each
disease in the district
• Comparison of data from different geographical
areas
• Information about the effectiveness of services
• Suggestions for improving reporting
• Information that might be helpful in solving
problems
• Information on actions taken
• Encouragement to do a better job
68. Limitations of Disease Surveillance System
• Under-reporting- The passive reporting of notifiable disease by
physicians and other health care providers may lead to under
reporting of disease. The following are the reasons for the
underreporting of disease:
a) Lack of knowledge of the reporting requirement
- Unaware of responsibility and value to report
- Assume that someone else would report
- Unaware of which diseases must be reported
- Unaware of how or to whom to report
b) Negative attitude toward reporting
- Time consuming
- Too much hassle
- Lack of incentives
- Lack of feedback
- Distrust of government
69. Others:
• Lack of representativeness of reported cases
• Lack of timeliness
• Inconsistency of case definitions
