MEASLES

ERADICATION

BY DR.VENU BOLISETTI

ERADICATION : Termination of all transmission of infection by extermination of the infectious agent through surveillance and containment .

It implies that disease will no longer occur in a population.

The term elimination is sometimes used to describe "eradication" of disease (e.g., measles) from a large geographic region or political jurisdiction .

WHO defines elimination of measles as the absence of endemic measles for a period of > 12 months in the presence of adequate surveillance.

One indicator of measles elimination is a sustained measles incidence < 1/100,0000 population.

63rd world health assembly

These targets are set for 2015 and are to: Achieve at least 90% measles vaccination

coverage nationally and 80% coverage in all districts.

Reduce measles cases to <5 per million.

Reduce measles mortality by 95% compared to 2000 levels.

Why do eradicate the measles ?

Measles is an extremely contagious viral disease that affected almost every child in the world before the widespread use of measles vaccine.

Measles is associated with high morbidity and mortality in developing countries.

Measles is endemic virtually in all parts of the world.

It tends to occur in epidemics when the proportion of susceptible children reaches about 40 per cent .

When the disease is introduced into a virgin community more than 90 per cent of that community will be infected.

Measles tends to be very severe in the malnourished child, carrying a mortality up to 400 times higher than in well-nourished children having measles.

Pneumonia is the most common life-threatening complication.

Pneumonia occurs in less than 10 per cent of cases in developed countries and 20-80 per cent cases in developing countries.

Measles is 100 to 400 times more likely to cause death in a preschool child of a developing country, than it is in the US and Europe.

In developing countries, case fatality rates range from 2 to 15 per cent as compared to less than 0.2 per 10,000 notified cases in developed countries.

Pulmonary complications account for more than 90 per cent of measles related deaths.

Measles during pregnancy is not known to cause congenital abnormalities of the foetus.

Associated with spontaneous abortion and

premature delivery.

The World Health Organization estimates that over 40 million cases still occur worldwide each year, contributing to approximately 530,000 deaths including 182,000 in the South East Asian region as reported in 2003.

Epidemics often occur every 2 to 3 years and usually last between 2 to 3 months, although their duration varies according to population size, crowding and immune status of affected population.

In India more than 50% of measles cases are currently reported in children less than five years of age, indicating insufficient routine measles immunization.

More than one third of all measles deaths worldwide (around 56 000 in 2011) are among children in India.

With support from WHO, in November 2010, India launched a massive polio-style measles vaccination project in 14 high-burden states, in a three-phase campaign.

FACTORS AMENABLE TO ERADICATE MEASLES

The measles virus is a paramyxovirus, There is

only one antigenic type of measles virus.

Infection confers life Long immunity.

Measles virus is rapidly inactivated by heat,

light, acidic pH, ether and trypsin.

It has a short survival time (<2 hours) in air or on

objects and surfaces.

Man is the only natural host of measles virus.

The only source of infection is a case of measles.

Carriers are not known to occur.

Second attacks are rare.

Transmission occurs directly from person to person mainly by droplet infection and droplet nuclei- No animal reservoirs.

A day or two before the appearance of the rash Koplik's spots like table salt crystals appear on the buccal mucosa opposite the first and second lower molars.

They are small, bluish-white spots on a

red base, smaller than the head of a pin.

Their presence is pathgnomonic of

measles.

ERUPTIVE PHASE- characterized by a typical, dusky-red, macular or maculo-papular rash which begins behind the ears and spreads rapidly in a few hours over the face and neck.

Extends down the body taking 2 to 3 days to progress to the lower extremities.

The rash may remain discrete, but often it becomes confluent and blotchy.

In the absence of complications, the lesions and fever disappear in an other 3 or 4 days signaling the end of the disease.

The rash fades in the same order of

appearance leaving a brownish discoloration which may persist for 2 months or more.

Specific IgM antibodies are being used for diagnosis.

Isolation of the patient for a week from the onset of rash more than covers the period of communicability.

Measles is best prevented by active immunization.

Only live attenuated vaccines are recommended for use; they are both safe and effective.

Heat stable measles vaccines able to maintain their potency for more than 2 years at 2-8 deg C, have been developed.

The vaccine has demonstrated to provide immunity to even severely malnourished children.

Single dose vaccine .

Immunity conferred by vaccination against measles has been shown to persist for at least 20 years and is generally thought to be life long for most individuals.

Measles vaccine can be combined with other live attenuated vaccines such as mumps, and rubella vaccines (MMR vaccine), measles, mumps, rubella and varicella (MMRV), and measles and rubella (MR), and such combinations are also highly effective .

Measles vaccination definitely constitutes a protection against the neurological and other complications by preventing natural measles from occurring.

To protect individual high-risk patients during an outbreak, vaccination within 2 days of exposure may modify the clinical course of measles or even prevent clinical symptoms.

Recipients of measles vaccine are not contagious to others.

Measles may be prevented by administration of immunoglobulin (human) early in the incubation period.

Strategies to eradicate measles

WHO's measles elimination strategy comprises a three parts:

vaccination strategy are

CATCH-UP (SIA)

KEEP-UP

FOLLOW-UP (SIA)

Catch-up is defined as a one-time, nationwide vaccination campaign targeting usually all children aged 9 months to 14 years regardless of history of measles disease or vaccination status.

Keep-up is defined as routine services aimed at vaccinating more than 95 per cent of each successive birth cohort .

Follow-up is defined as subsequent nationwide vaccination campaign conducted every 2-4 years targeting usually a children born after the catch-up campaign.

Achieving high routine measles vaccination coverage of infants at 9-12 months of age; provide measles vaccine to children over 1 year if not vaccinated earlier at the earliest contact.

Establish effective measles surveillance that provides information about number of cases and deaths by month.

Age and vaccination status of cases and deaths and conduct outbreak investigation supported by laboratory confirmation.

Improving management of measles cases, including vitamin A supplementation and adequate treatment of cases.

Based on evaluated measles immunization coverage and surveillance data, providing a second opportunity for measles immunization to appropriate age groups of children through either a second routine dose of measles vaccine or through supplemental immunization activities.

Planning and implementation of regular immunization sessions at fixed and out reach immunization sites.

Special strategies for reaching the un-reached. Reduction of missed opportunities and dropout

rates. Training to improve management of immunization

services at all levels. Enhancement of supervision. Design and implementation of information

education and communication activities and materials.

MEASLES SURVEILLANCECase definitionsClinical measlesLaboratory confirmed measles. Epidemiologically confirmed measles.MEASLES SURVEILLANCE STRUCTURESurveillance activities at the local levelSurveillance activities at the district levelSurveillance activities at the state level .

MEASLES OUTBREAK INVESTIGATION

Objectives of outbreak investigationsEpidemic Response Team (ERT)Identifying a measles outbreak

Identifying measles outbreaks that need to be investigated and assigning an outbreak number.

Preliminary search

Measles outbreak should be verified if five or more than five clinically diagnosed cases of measles are identified in a block in a week, (Or)

Five or more than five clinically diagnosed cases of measles occur in an area bordering several blocks in a week, (Or)

One or more than one death due to clinically diagnosed measles occurs in a block in a week.

Mobilization of Epidemic Response TeamOrientation & planning meeting at the local

level Conducting measles case searchCollection and shipment of specimens to the

laboratoryLaboratory confirmation of the outbreakData analysisUsing data for actionReport writingGiving feedbackInitiating actions.

MEASLES CASE MANAGEMENT

Measles case diagnosis

Clinical assessment

Severity status and case management

Uncomplicated measles

Complicated measles

Administration of vitamin A

MEASLES LABORATORY NETWORK

Categories of laboratories:

Serological tests

Tests to isolate measles virus &

genetic sequencing

MONITORING AND EVALUATION

Monitoring & evaluation of Routine

immunization coverage

Surveillance indicators

Outbreak monitoring & evaluation

Specimen collection and transport

Proficiency testing of laboratories

Project progress indicators .

RESULTS OF ERADICATION During 2000–2011, the number of countries

providing a second dose of measles-containing vaccine (MCV2) through routine services increased from 97 (50%) to 141 (73%).

Overall, 225 million children received measles vaccination during 39 supplemental immunization activities (SIAs) conducted during 2011.

During 2000–2011, the number of countries reporting annual measles surveillance data to WHO increased from 169 (88%) to 188 (97%).

During 2004–2011, the number of countries using case-based surveillance increased from 120 (62%) to 182 (94%).

During 2000–2011, the number of measles cases reported worldwide each year decreased 58%, from 853,480 to 354,922, and

Measles incidence decreased 65%, from 146 to 52 cases per million population per year, with declining cases and incidence reported in all WHO regions.

HURDLES Weak immunization and disease surveillance

systems. Difficulties in vaccinating hard-to-reach

populations (including in areas affected by conflict or natural disaster).

Lack of political and financial commitment. Approximately 15% of children vaccinated at 9

months and 5%-10% of those vaccinated at 12 months of age are not protected after vaccination.

STRATEGIES FOR MEASLES MORTALITY REDUCTION IN INDIA

Achieving high routine immunization

Establish effective measles surveillance system

Improved measles case management

Providing a second opportunity for measles immunization

National level coordination for measles control

Thank you