Thursday, March 1, 2012

Smallpox Eradication: Public Health One-Hit Wonder?

“It is my opinion that we never should have landed a man on the moon. It's a mistake. Now everything is compared to that one accomplishment. Now everybody goes ‘I can't believe they could land a man on the moon . . . and taste my coffee!’ I think we all would have been a lot happier if we hadn't landed a man on the moon. Then we'd go, ‘They can't make a prescription bottle top that's easy to open? I'm not surprised they couldn't land a man on the moon. Things make perfect sense to me now.’”

- Jerry Seinfeld (1994)

The eradication of smallpox was such an enormous scientific and humanitarian success that it has forever raised expectations for public health interventions--perhaps, as Jerry Seinfeld might point out, to the overall detriment of public health! If we can pool our resources, overcome political differences, make a commitment and eliminate a disease that once caused 10% of all deaths (Friedman and Issacs, 2009), then why can’t we eradicate malaria, malnutrition or HIV?

Smallpox presented a unique opportunity to the planners and leaders of eradication efforts. As Friedman and Issacs (2009) describe:

- Human beings were the only known reservoir for the virus.
- No asymptomatic carrier state existed.
- An effective vaccine was available.
- Vaccination of contacts resulted in prevention or modification of disease.

These features made smallpox eradication a feasible outcome objective and provided workable answers to key managerial questions:

Where are we? The problem was a virus that was (a) endemic in every country in the world and (b) had a 30-50% mortality rate. However, with no natural reservoir other than humans, eradication was possible. Variolation (AD 10th century India and China) and vaccination (Jenner in 1796) had been proven effective in mitigating or preventing infection.
Where do we want to be? The goal was complete, universal elimination of smallpox. Lesser goals were unacceptable both because of the severity of disease and the feasibility of eradication.
What should we do? Interestingly, the WHO Smallpox Eradication Programme is most accurately seen as a successful bottom-up effort, in that it appropriated techniques from successful local efforts, including those of the Soviet Union in the late 1950s (during the Cold War, no less!) (Tulchinsky and Varavikova, 2009). The WHO effort learned and adjusted rapidly, keeping in mind its overall outcome objective and avoiding the pitfall of “outcome displacement” (i.e., satisfying itself with activity measures and process objectives alone).
How do we know that we are getting there? The worldwide effort to eradicate smallpox was only as effective as its information was accurate. Without local-level surveillance efforts and case-reporting (exemplified by India’s 1975 Operation Smallpox Zero assessment index (UCL, 2006)), the WHO could not have known whether its vaccination, surveillance and isolation efforts were actually working.

Although the success of international efforts to eliminate smallpox cannot be directly translated to other infectious diseases (which have natural reservoirs, mutate more quickly or have asymptomatic carrier states), or to non-communicable public health problems (e.g., malnutrition, which has multiple contributing factors and determinants), some lessons are certainly applicable to all public health programs:

- Clearly identify the problem and the outcome objective to improve the chances of success. Furthermore, avoid the temptation of “outcome displacement” - do not substitute a surrogate outcome for the outcome of interest.
- Be willing to adopt effective local methods. There is almost always more than one process by which impact objectives can be reached. Let the local people work out their own solutions, so long as the overall objective is not compromised.
- Timely, accurate measurement and feedback is essential. To remain flexible and adaptive, any program has to have access to up-to-date and reliable information.

We may not land on the moon or eradicate smallpox’s equivalent health problem anytime soon, but lessons in successful management are nevertheless applicable to more modest projects.

References:

Cherones T. (Director). The Dinner Party, episode 77 (1994, February 3). Seinfeld [Television broadcast]. Beverly Hills, CA: Castle Rock Entertainment.

Friedman H. M. and Issacs S. N. (2009). Smallpox. In Basow D. S. (Ed.), UpToDate. Waltham, MA: Wolters-Kluwer Health.

Smallpox (2003). in Encylopaedia Britannica (15th ed). (Vol. 10, pp. 887-888). Chicago, IL: Encyclopaedia Britannica, Inc.

Smallpox control in India (2006). University College London (UCL). Retrieved from www.smallpoxhistory.ucl.ac.uk/India/IndProject.htm.

Tulchinsky T. H. and Varavikova E. A. (2009). The new public health (2nd ed.). Burlington, MA: Elsevier Academic Press.

Turnock B.J. (2009). Public health: What it is and how it works. (4th ed.). Sudbury, MA: Jones and Bartlett Publishers.