Despite Advances, Measles Eradication Still Far Off

Jan. 19, 2007 — -- In what has been hailed as an historic victory for global health, directors of many of the world's largest health organizations announced Thursday that through an effort called the Measles Initiative, the death rate from measles declined by 60 percent between 1999 and 2005.

Now they have set a new goal -- to reduce measles deaths by 90 percent by 2010. And some have suggested that eliminating measles may be a possibility.

"We have an opportunity here to leave a lasting mark on the world through the eradication or elimination of diseases," said Kathy Bushkin, executive director of the United Nations Foundation in a press conference held Thursday. "We've already seen the eradication of smallpox, and we're close to eradicating polio."

But the total eradication of measles could be a different issue altogether. And some disease experts say such a goal may be difficult, or even impossible, to achieve.

One such expert is Dr. Samuel Katz, chairman emeritus of pediatrics at Duke University Medical Center. He said that through current means, the complete eradication of measles is "just not feasible."

"It is a little bit overly optimistic to talk about getting rid of measles entirely, and I think that we are whistling "Dixie" if we think we are going to get rid of measles in a few years," Katz said.

Dr. Pascal Imperato, chairman of the department of preventive medicine at the SUNY Downstate Medical Center, is no stranger to the measles battle; he immunized African children himself in the 1960s and 1970s.

And he said that though eliminating the disease is technically possible, it is a very difficult goal to achieve.

"Our hope at that time was to control it, not to eradicate it, because we knew that we could not hope to eradicate it," Imperato said.

"I think eradication is possible. But whether it is probable or not is another question."

High Immunization Rates

The good news is that it would technically be possible to completely eliminate measles using a tool that we already have.

This tool is the same measles vaccine that has existed for more than 40 years.

Now for the bad news -- measles is so contagious that to eradicate it, nearly every child would have to be immunized over an extended period of time.

"It is probably the most contagious of any of the viruses we deal with, and the transmission is very rapid," Katz said.

Worse, the disease is so infectious that sick children can infect others before they even exhibit any symptoms.

"It is a virus that is very, very likely to spread to other children who are unimmunized," Katz said. "All you need are a few children who are not immunized, and you have a problem."

"To get herd immunity we need to achieve at least 95 percent coverage," said Dr. Margaret Chan, director-general of the World Health Organization, at Thursday's press conference.

This means that 95 percent of children in affected countries would have to get measles shots for it to be possible to eliminate the disease.

The prospects of such an achievement face many challenges, most of which have to do with distributing the vaccine.

Many affected children may live in remote communities with little infrastructure and few amenities. Getting trained personnel to administer the shots is another consideration.

And regional conflicts in certain developing countries could threaten the effort, which would need to be sustained over many years to ensure complete effectiveness.

"I think with any immunization campaign, conflict in an area really increases the challenge of reaching children," said Dr. Julie L. Gerberding, director of Centers for Disease Control and Prevention.

Still, the directors of the Measles Initiative say eradication of measles may become more feasible as more and more milestone goals are met.

"We do ask ourselves the same question, whether it is realistic now to talk about eradication given the complexity of factors affecting the epidemiology of the disease and the extremely high level of immunization coverage that has to be reached," Chan said.

"At this stage I think it is too early to talk about eradications, but it is something that we can talk about and see the next stage after we have achieved the new goal."

Will the Reduction Be Sustainable?

Regardless of whether eradication is possible, there is little doubt that the Measles Initiative has made a dramatic impact on the world measles picture.

More than half a million fewer deaths from measles were seen in 2005 than in 1999. And cumulatively, Chan said, immunization efforts through the Initiative have saved 2.3 million lives so far.

But now that measles is on the ropes, the question is whether this effort can be sustained into the future to deliver a knockout blow.

"At the moment I think we can celebrate the fact that we've been wonderfully effective in decreasing death from the disease," Katz said.

"But to maintain progress of this sort it requires an incredible commitment -- one that has to be sustained every year. You can't just do it and walk away, because if there is one person around who still has the virus, it can be spread."

Imperato said that sustaining the progress would also required a continued effort to not only immunize against measles, but also to address the other factors that contribute to measles mortality in developing nations.

"When we have an outbreak over here, we have a mortality rate of less than 1 percent," he said. "Why do they have a 10 percent or higher mortality rate in Sub-Saharan Africa? The difference is not that the virus in any different; the difference is the children. In these children it's not just measles; measles is what tips the balance."

Other factors, including malnutrition, parasitic infections and other diseases such as cholera, make measles much more deadly. And lack of adequate infrastructure and amenities worsens the problem.

"Measles was the only childhood disease I remember having because I was so sick," Imperato said. "So you can imagine a poor child in a developing country, living in a place with no running water or electricity, running a temperature of 110 degrees and malnourished."

The Initiative will also need continued funding. The effort so far has cost an estimated $308 million, said Bonnie McElveen-Hunter, chairwoman of the American Red Cross, at Thursday's press conference.

And the 90 percent reduction targeted for 2010 will take about $500 million more. Of this total, Chan said the initiative has currently secured $140 million to $150 million.

Still, directors of the effort said they are confident that the Measles Initiative will continue to drive down measles deaths.

"I'm very hopeful that we will be successful, and I think we have every reason to be hopeful," said Gerberding.