Measles immunization campaign reduces measles cases and deaths in Malawi

 

Malawi on course to eliminate measles

In Malawi, government commitment to eliminate measles has led to a dramatic reduction in measles cases and deaths. This achievement has involved support from community volunteers and concerted efforts to train health workers, improve immunization safety, strengthen disease reporting systems, and mobilize parents to immunize their children against measles.

Measles kills more children than any other vaccine-preventable disease -- most of them in developing countries. The highly contagious disease accounts for almost one in ten of all deaths among children under five -- half of them in children less than a year old. In 1998, there were an estimated 30 million cases of measles worldwide and about 900 000 deaths. Measles can also lead to lifelong disabilities, including brain damage, blindness, and deafness, especially in developing countries. The disease thrives in cities -- especially in deprived urban areas where overcrowding ensures the continued circulation of the measles virus.

Yet measles deaths and disability can be prevented. A vaccine against measles has been available for over three decades. It is safe, effective, and costs only US$ 0.26 for the single dose needed to immunize a child. But in 1998, one in five of the world's children were not immunized against measles during their first year of life. And in Africa, which accounts for more than half of the world's measles cases, less than 50% of children were immunized. Meanwhile, in six African countries, only one in three -- or less-- were protected against measles.

Against this backdrop of low immunization coverage in Africa, Malawi has succeeded in boosting immunization coverage against measles from only 50% in 1980 to almost 90% today. As a result, the number of reported cases and deaths has fallen dramatically. During 1999, only two laboratory-confirmed cases were reported. And, for the first time ever, no measles deaths. Yet only two years earlier, almost 7000 measles cases were reported and 267 deaths (although most cases go unreported and WHO estimates that nine times as many cases and almost five times as many deaths actually occurred).

This turnaround has been achieved in one of the world's poorest countries. One in five of the population do not have access to health services, less than 50% have access to safe water, and only 3% have access to adequate sanitation. In 1998, life expectancy hovered at just below 40.

The first key step in reducing measles deaths in Malawi was a sustained increase in routine immunization coverage. This led to an encouraging sharp drop in measles cases and deaths. However, while epidemics have become less frequent, they still occur every 3-5 years -- triggered by a build-up in the number of children who have not been immunized and by the vaccine's inherent 15% failure rate. In an epidemic in 1992, for example, 11 000 cases were reported.

Then in 1998, Malawi launched a campaign to eliminate measles. The strategy, developed in the Americas, where measles has almost been eliminated, involves a 3-pronged attack to halt transmission of the virus: a nationwide immunization campaign usually targeting every child from nine months to 14 years ("catch-up"); sustained routine immunization coverage of at least 95% of children during the first year of life ("keep-up"); and nationwide campaigns every 2-5 years usually targeting children born after the initial catch-up campaign ("follow-up"). The aim is to ensure that few if any children slip through the immunization net.

In June 1998, a nationwide immunization campaign in Malawi targeting 4.7 million children from 9 months to 14 years succeeded in reaching over 90% of the target population. In addition, vitamin A supplements -- which can prevent one in four child deaths from infectious diseases -- were given to all children aged six months to five years. The cost of the campaign -- including delivery costs -- was US$ 0.78 for every child vaccinated.

Malawi's success in reducing the death toll from measles has involved concerted efforts to train health workers, improve immunization safety (including vaccine quality assurance and injection safety), and strengthen disease surveillance and monitoring skills. A key factor has been the success of social mobilization campaigns in encouraging parents to immunize their children against measles. In some cases, community volunteers have helped organize door-to-door immunization or set up vaccination posts nearby to ensure that previously unreached children could be immunized.

Today, in an effort to prevent epidemics of measles, Malawi is continuing efforts to ensure that at least 95% of children are immunized during the first year of life and to identify populations where children are unimmunized and at high risk of continued transmission of the measles virus. These children will be targeted in the follow-up phase of the campaign.