Three months into a targeted oral-cholera-vaccine (OCV) campaign in Old Dhaka — one of the country's persistent cholera hotspots — the icddr,b epidemiology team behind it has begun seeing what they describe as early signal in the surveillance data. BHRF spoke to Dr. Anisur Rahman and Dr. Selina Ahmed at the icddr,b campus in Mohakhali.
BHRF: What does "early signal" mean here, in plain terms?
Dr. Rahman: We are seeing a measurable drop in laboratory-confirmed cholera among the catchment population that received the vaccine, compared to the prior three-year average for the same months. We need to be careful — three months is short, and we are still in a season where transmission can swing significantly. But the direction is consistent with what we expected.
BHRF: Was the rollout targeted at specific wards?
Dr. Ahmed: Yes, deliberately. We worked with the Dhaka South corporation to identify wards with the highest five-year incidence and the lowest piped-water coverage. The campaign covered approximately 320,000 individuals across those wards.
BHRF: What is the next milestone you are looking for?
Dr. Rahman: Six-month follow-up data. If the signal we are seeing now holds at six months, that is the point at which we can have a much more confident conversation with the Ministry of Health about scaling. Cholera is one of those diseases where the science of what to do is settled — the question is the willingness to do it at scale.
The full transcript is on the BHRF interviews shelf.
