Transcript Surveillance of Measles

Surveillance of Measles
and Tetanus
Dr Pushpa Raj Sharma
Professor of Child Health
Overview
 Measles, global view and control strategies
 Epidemiology,clinical presentation and vaccine
 Measles surveillance
 Outbreak investigation
In 1998 it is estimated that there were
approximately one million deaths from measles
7
120
In other words,
6
100
the measles virus killed …..
5
63%
4
80
Millions
40
2,410 children each day
100 children each hour
20
…. 150 children died
0
during
the time elapsed
by the MORBIDITY
end of this
PRE-VACCINE ERA
presentation
1998
WHO unpublished data
Millions
60
83%
3
2
1
0
MORTALITY
PRE-VACCINE ERA
1998
MEASLES: A leading cause of childhood deaths
Causes of 1.6 million vaccine-preventable deaths
among children, 2000
Hib
22%
Neonatal
Tetanus
12%
Measles
48%
(777,000
Deaths)
Diphtheria
0.2%
Pertussis
16%
Source: WHO/IP
Yellow Fever
2%
There are three WHO Regions with established measles
elimination goals: the Pan American region, 2000, the European region, 2007 and the
Eastern Mediterranean region 2010.
The other regions: Africa, South East Asia and the Western Pacific have goals to control
measles transmission.
2007
2010
2000
Block-area outbreak prevention/
elimination goal
The number of reported global measles cases
has reduced and measles vaccine coverage has
increased from 1983-1998
100
Cases
90
Coverage
3
80
70
2
60
50
1
40
0
30
1983
1985
1987
1989
1991
Year
1993
*Reported to WHO Headquarters, as of August 8, 1999
1995
1997
Percent Coverage
Number of cases (millions)
4
Measles Mortality Reduction Strategies
Strengthen
measles surveillance
Supplemental
measles immunization
Improved Routine
Immunization
Improved case
management
Vitamin A
supplementation
Countries providing second opportunity for
measles immunization, 2002
Yes 2nd opportunity (174 countries or 81%)
No 2nd opportunity (40 countries or 19%)
Since 1999, additional 12 countries
National Immunization Program of Nepal
National Policy:
Immunization is
- the national priority program of His
Majesty’s Government of Nepal.
- immunization ranks third among 20
prioritized interventions
Goal of the Immunization Program:
•Reduce morbidity and mortality associated
with Vaccine Preventable Diseases and thus
contribute reduction of :
-infant Mortality from 64.4/1000 live births,
to 50/1000 and
- under five mortality from 91.2/1000 live
birth to 70/1000 by the year 2003.
WHO/UNICEF Global Strategic Plan
2001-2005
Objective:
• Reduce global measles-related mortality
by half by 2005.
Surveillance Goals
• Identify cases / outbreaks;
by date and geographical area
• Age distribution and vaccination status of
cases and deaths
• Identify high risk populations/areas
• Investigation and verification of outbreaks
• Maintain timeliness and completeness
• Provide feedback
Suspected Measles
Clinical Case Definition
Cough OR
Fever + Maculopapular + Coryza (runny nose) OR
Rash
Conjunctivitis (red eyes)
OR
Clinician
Suspects
Measles
Measles Case Definition To Assist
Communities in
Notifying Health Facilities
ANY PERSON
with
FEVER and RASH
Key Information to Collect on
Suspected Measles Cases
Person
 Age
 Vaccination status
 Lab data
Time
 Date of rash onset
Place
 Residence at onset
 Potential exposures (places, persons)
What should health care provider do
when she/he suspects measles?
• Notify case
• Complete case investigation form
• Collect blood sample
• Manage case (Vitamin A, supportive tx,
etc.)
High risk areas: How to identify them?
Most susceptibles
Status of measles
vaccination coverage
Most affected groups
Analysis of measles
surveillance data
Transmission is facilitated
Socio-demographic
characteristics of population
High risk area is where:
there is a significant number of
susceptibles
disease remains endemic
conditions facilitate contact between
susceptible and infectious individuals
conditions facilitate chances of
“effective” transmission
greater risk of severe measles and
higher CFR
Measles
Dengue
Other Viral Exanthems
Rubella
Kawasaki
Rash Illness
Scarlet Fever
Meningococcemia
Toxoplasmosis
Roseola Infantum
Mononucleosis
Measles Vaccine
• Live virus vaccine
• Freeze dried (lyophilized) and used with diluent
• Store vaccine at 2°-8° C (but can be frozen)
• Protect from light at all times
• Efficacy:
• 85% at 9m (EPI schedule)
• 95% at 12-15m
• Duration of immunity: life long
Outbreak Response
1.
2.
3.
4.
5.
Case notification
Case verification
Field investigation
Management
Post outbreak activities
What is an outbreak?
•
•
•
•
“Number of cases observed in a given
geographical area is greater than that
normally expected in the area during a
given period of time”
Increase over “usual number” of cases
Problem – we don’t know usual number!
Look for clustering of cases by
time/place
Arbitrary guideline – 5 or more cases in
one week at one site
Steps in Outbreak Response
• Step 1: Pre-outbreak planning &
preparation
• Step 2: Detection, notification, &
verification
• Step 3: Pre-investigation planning
• Step 4: Field investigation
• Step 5: Post-outbreak activities
Detection, notification, and
verification
Upon suspecting or being notified of a
possible outbreak, following information
should be collected:
– Number of suspected cases & number
hospitalized
– Population at risk (school, rural village,
urban area, non-Nepali-speaking, etc.)
– Location of outbreak and accessibility of
the location
Notification
• SMO: Notify PEN Main office and
DHO/DPHO
• PEN Main Office: notify EDCD
• SMO: Verify outbreak, if possible
Case Management
Vitamin A supplementation
Respiratory isolation of hospitalized
cases
Supportive treatment (antipyretics,
antibiotics, fluids)
Treatment of complications as needed
Measles Treatment with Vitamin A
AG E
Im m e d ia te ly
o n D ia g n o s is
5 0 ,0 0 0 IU
N ext
D ay
5 0 ,0 0 0 IU
6 -1 1 m o n th s
1 0 0 ,0 0 0 IU
1 0 0 ,0 0 0 IU
> 1 2 m o n th s
2 0 0 ,0 0 0 IU
2 0 0 ,0 0 0 IU
0 -6 m o n th s
* For ocular manifestations, give a 3rd dose 2-4 weeks after the 2nd dose
Measles: Key Messages
• Leading cause of mortality in developing
world
• Safe effective vaccine is available
• High routine coverage and second
opportunity needed to stop measles
transmission
• Effective surveillance needed to direct control
strategies
• Investigation should include blood collection
and contact tracing (in future?)
• All suspected measles cases should be
reported
Neonatal tetanus
A silent killer disease
Presentation Overview
Global overview and strategies of
MNTE
Surveillance
Epidemiology and clinical
presentation
Prevention and vaccination
Challenges ahead
1990 - 561,000 cases*
Countries with MNT eliminated: 76
2000 - 238,000 cases*
Countries with MNT eliminated: 104
SOUTH EAST ASIA
64,000 deaths
What is neonatal tetanus
elimination?
“The reduction of neonatal tetanus cases to fewer than
1 case per 1,000 live births in every district of every
country”
WHO and UNICEF target:
Elimination by 2005!
NT incidence < 1 / 1000 live births in every district
 High Routine & supplementary
Immunization
• All pregnant mothers
• WCBA
 Clean deliveries and cord
practice
 Effective NT surveillance
• health facility based
• community involvement
To sustain elimination
• Increase routine TT coverage for pregnant
women
• Increase routine DPT coverage for
children
• Increase women’s access to and use of
clean delivery services
Countries with SIAs in High Risk Areas, as
of December 2001
MNT eliminated or potentially eliminated (106)
MNT not eliminated, no SIAs initiated (34)
MNT not eliminated, SIAs initiated (21)
Standard Case Definition
Confirmed Neonatal Tetanus
Any neonate with a normal ability to suck
and cry during the first 2 days of life, and
between 3 and 28 days of age cannot
suck normally, and becomes stiff and/or
has convulsions
Suspect Neonatal Tetanus
Any neonatal death between 3 and 28
days of age in which the cause of death is
unknown; or any neonate reported as
having suffered from NT between 3 and
28 days and not investigated
Reasons for Under-Reporting
• Awareness
(Many deaths occur at home without ever
presenting to the medical system)
• Difficulties in disease diagnosis (in
peripheral health facilities)
• Newly introduced program
(where to report)
NT Cannot Be Eradicated
• Widely prevalent in environment
• Does not require human-to-human contact
for transmission or survival
• Only VPD that is infectious, but not
contagious
• Can only be eliminated (1 case/1000 live
births in given district)
Tetanus Clinical Features
• Incubation period 8 days (range, 3-21 days)
• Three clinical forms: Local (uncommon), cephalic
(rare), generalized (most common)
• Generalized tetanus: descending symptoms of
Masseters-trismus (lockjaw), difficulty swallowing,
muscle rigidity, spasms, Facail muscle-risus
sardonicus, Muscle of back and neck-opisthotonus
• Spasms continue for 3-4 weeks; complete recovery
may take months
Differential Diagnosis
• Bacterial meningitis
• Encephalitis
• Severe mouth or dental may simulate
trismus
• Rabies
• Strychnine poisoning
Management
•Isolation
•Wound debridement
•Toxin neutralization: TIG 500 U IM (30006000)
Or TAT 50,000-100,000 U IM
•Antibiotic
•Sedative
•Supportive
Recommended Schedule – DPT
(for infants)
•DPT1 – 6 weeks
•DPT2 – 10 weeks
•DPT3 – 14 weeks
•Injected IM in the outer part of the thigh
•Dose – 0.5ml
•Given together with OPV
Challenges Ahead
• Balancing priorities in immunization
– polio NIDs, measles, MNT, introduction of new
vaccines & improving routine
• Achieving elimination:
– Ensuring 80% coverage of TT SIAs in each high risk
district targeted
• Maintaining elimination:
– Identifying innovative strategies and funding to
routinely achieve 80% TT2+ and DPT3/measles in
every district
– Appropriate strategies for school immunization
programmes
% of pregnant women immunized with
TT2
100
90
80
60
2000
2001
50
40
30
20
10
R
R
W
D
FW
D
Regions
M
R
C
D
R
R
ED
W
D
at
io
n
al
0
N
Percent
70
Source:MIS
Thank you!