Hive Swabbing: Catching AFB Before It Costs You
- Team Mānuka Orchard
- Jul 30, 2025
- 3 min read
American Foulbrood (AFB) is every beekeeper’s nightmare with it being hard to spot early, devastating if missed, and costly to clean up. At the 2025 Manuka Orchard Open Day, John Mackay from dnature diagnostics & research presented research showing that hive swabbing, particularly at the entrance, can detect AFB spores before clinical signs appear, giving beekeepers time to act and protect both hives and honey.
Since 2018, the dnature team has compared bee samples, baseboard swabs, and entrance swabs across apiaries in Gisborne, Wairarapa, Wellington, and Ashburton. Swabs were analysed using qPCR to estimate spore levels, with a major breakthrough coming from pooling samples: testing multiple swabs together to cover more hives for less cost.
This swabbing technology offers three big advantages:
Earlier detection - finding problems before they’re visible
Reduced spread - by removing or sanitising contaminated equipment quickly.
Cost savings - avoiding massive losses from contaminated honey and removing infected hives early.
The impact is clear in one case study. A mānuka honey company saw contamination spread from 1 tonne of honey to 23 tonnes after undetected infection. Through targeted swabbing and the destruction of contaminated hiveware, losses dropped to under 1 tonne-avoiding a potential $445,000 hit at $20/kg wholesale.
A key figure in the adoption of hive swabbing is Barry Foster, an early adopter alongside John Maynard. Known as the Foster Method, this process combines swabbing with strategic hive inspections to quickly identify and remove infection sources. It’s a practical, scalable approach that could dramatically reduce AFB losses across New Zealand and indeed, may already be having an effect as AFB prevalence decreases. But dnature takes pains to say that it doesn’t replace visual inspections for the disease.
In practice, swabbing has proven its worth even at stages where infection isn’t visible to the naked eye.
As John explained:
“We’ve had beekeepers inspect hives we called clinical and they couldn’t find it. But because we’d called it clinical, they went over every cell and found the infection buried in one corner of a frame. They had thought the hive had died of something else and were preparing to use it for the upcoming season—which means several hives were probably saved from future infection.”
Looking ahead, John sees swabbing not as a silver bullet but as a valuable addition to the beekeeper’s toolkit.
“The Foster Method is only an additional tool,” he said. “Together with visual inspections and other tools coming, then NZ really does have an opportunity to continue the downward trend in AFB prevalence. But we’re also keen to see the Foster Method used as a biosecurity safeguard, as the sampling method has been used for varroa in Australia, the small hive beetle, and the USA are looking at it for tropilaelaps.”
Not only does it protect hive health, but it also safeguards the integrity of our honey - ensuring every jar upholds the high standards customers expect from Kiwi producers.
At Manuka Orchard, we’re committed to sharing our partners' insights like this so beekeepers across the country can strengthen their operations, protect their bees, and keep New Zealand’s honey industry thriving.
The work of the dnature research team shows that entrance swabbing and pooled testing have the potential to become standard practice for responsible beekeeping. With AFB control relying on speed, accuracy, and decisive action, this proven technique stands out as one of the most practical and effective tools available to today’s New Zealand beekeepers.
Find out more about dnature's testing capabilities at their website here
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