530 likes | 765 Views
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.
E N D
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 In other words, the measles virus killed ….. 2,410 children each day 100 children each hour …. 150 children died during the time elapsed by the end of this presentation 7 120 6 100 5 80 63% 83% 4 60 3 Millions 40 2 Millions 1 20 0 0 MORTALITY MORBIDITY PRE-VACCINE ERA PRE-VACCINE ERA 1998 1998 WHO unpublished data
MEASLES: A leading cause of childhood deaths Causes of 1.6 million vaccine-preventable deaths among children, 2000 Source: WHO/IP
There are three WHO Regions with established measleselimination 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
1983 1985 1987 1989 1991 1993 1995 1997 Year The number of reported global measles cases has reduced and measles vaccine coverage has increased from 1983-1998 4 100 Cases 90 Coverage 3 80 70 2 Percent Coverage Number of cases (millions) 60 50 1 40 0 30 *Reported to WHO Headquarters, as of August 8, 1999
Strengthen measles surveillance Supplemental measles immunization Improved Routine Immunization Improved case management Vitamin A supplementation Measles Mortality Reduction Strategies
Countries providing second opportunityfor 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.
Objective: WHO/UNICEF Global Strategic Plan 2001-2005 • 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 Coryza(runny nose)OR Conjunctivitis(red eyes) Maculopapular Rash Fever + + 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 facilitatecontact between susceptible and infectious individuals • conditions facilitate chances of “effective” transmission • greater risk ofsevere measles and higher CFR
Measles Dengue Other Viral Exanthems Rubella Kawasaki Rash Illness Scarlet Fever Meningococcemia Toxoplasmosis Mononucleosis Roseola Infantum
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 • 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 * 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 TetanusAny 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 TetanusAny 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 (3000-6000) 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