#1257 1974 · Smallpox Eradication Programme, Bangladesh (WHO / Government of Bangladesh) · Public health
Bangladesh's smallpox hunt stopped searching for cases, paid villagers to find them
the problem
House-to-house searches for smallpox cases were slow, and villagers hid infected relatives from the search teams
background
By the early 1970s the global smallpox eradication campaign had shifted from mass vaccination to a 'search and containment' strategy: find every active case fast, ring-vaccinate everyone around it, and stop transmission before it spread further. In war-ravaged, flood-prone Bangladesh, that meant tens of thousands of government health workers combing hundreds of thousands of villages on repeated house-to-house searches — a search apparatus that was expensive, exhausting to sustain month after month, and still missed cases that families hid out of fear, stigma or distrust of the vaccination teams themselves.
More searchers and more search rounds were the obvious lever, and the program kept adding both, but government searchers were also outsiders asking villagers to hand over information families sometimes had reason to conceal. The people best positioned to know when a case appeared — neighbors, market vendors, boatmen, relatives — had no stake in telling a stranger with a vaccination kit, and the program's own accountability rules made things worse: vaccinators were being penalized for outbreaks discovered in their assigned area, which quietly rewarded them for not looking too hard.
what everyone would do
The standing playbook was to scale up the official search: recruit more health workers, run more house-to-house rounds, tighten supervision of vaccinators — all of which kept the detection burden on a small paid workforce that villagers had reason to evade and that couldn't physically cover every household fast enough.
what they saw
The fastest detector wasn't a searcher who might reach a village weeks later — it was the case's own neighbors, who already knew. The bottleneck was nobody had given bystanders a reason to say anything.
the move
Starting in August 1974 the program began paying cash rewards, initially around 50 taka and rising to 250 taka by 1975, to any member of the public — not health workers — who reported a confirmed smallpox case, turning the entire population into a paid surveillance network and running publicity to make sure everyone knew the reward existed.
why it works
A cash reward converts thousands of people who already possess the information into an unpaid, real-time reporting network operating at a scale and speed no official search team could replicate, while removing the penalty on vaccinators for discovered outbreaks eliminated the perverse incentive to look away. Because the reward attaches to the case, not to who's searching, it also works around the concealment problem — a family hiding a sick relative still has neighbors with an incentive to report what they've seen.
the payoff
Bangladesh recorded the world's last endemic variola major case in 1975, and smallpox was certified eradicated there the next year.
where it breaks
The reward must be large enough to overcome any incentive to conceal, publicized widely enough that the target population actually knows it exists, and paid reliably or trust collapses; corrupt intermediaries who intercept or falsely claim rewards can also poison the system. It also depends on the condition being unambiguous enough for an untrained bystander to correctly identify and report, which limits how far the mechanism generalizes beyond visibly distinctive conditions like smallpox's rash.
what came after
The reward-driven surveillance model, alongside the removal of vaccinator penalties for reported outbreaks, became a template cited in WHO's global eradication history and in later disease-surveillance design, where crowdsourced case reporting from the public is now standard practice for polio, Ebola and other outbreak responses.
references
- [1]Smallpox Eradication in Bangladesh, 1972–1976Vaccine / U.S. Centers for Disease Control and Prevention, 2011stacks.cdc.gov
- [2]India eliminated smallpox in the 20th century – and women played a massive partWorld Economic Forum, 2019weforum.org