Sunday, July 3, 2022

About-face on dung beetle assessment

One of the country’s most senior health officials has given the thumbs up to a review on the public health risk of dung beetle release.

Auckland medical officer of health Dr Denise Barnfather expressed her concerns earlier this year over the lack of risk assessment before beetle importation.

Approval for field trials on the beetle has been granted by the Environmental Protection Authority (EPA) and these are under way in Northland. The next step is field release.

But Barnfather said this week the Auckland Regional Public Health Service (ARPHS) applauded the Ministry of Health (MoH) decision to assess the potential public health risk the beetles posed before release occurred.

The assessment decision is an about-face for the MoH and a potential setback for the group introducing the beetle.

In February the MoH said it was aware of Barnfather’s concerns but believed the appropriate forum to address them was through the EPA.

The assessment is being undertaken by a team combining environmental, public, water, veterinary and epidemiology experts.

Preliminary research on Mexican dung beetles by University of Auckland has indicated they can carry E coli organisms at levels that can cause gastrointestinal diseases. 

A key part of Barnfather’s concerns around beetle release was the ability of the beetle to fly long distances and the possibility it would contaminate rural water supplies.

Crown research company Environmental Science and Research (ESR) has been contracted to oversee the study, with results expected by August.

The key areas to be examined were ways people could come into contact with pathogens dung beetles might carry and whether exotic dung beetles were likely to increase gastrointestinal disease rates in people.

Beetle technical advisory group chairman Andrew Barber remained adamant the beetles did not pose a health risk to the public.

“If you look all over the world, if dung beetles bring a public health issue, then the rest of the world must have a big problem,” Barber said.

He pointed to work in California in the United States, where the beetles did not even register as a public health risk.

Supporters of the beetle cite the Australian experience with the beetle, where there has not been any proven risk of rural water contamination or public health issues through beetle presence.

However, Barnfather and others have said the Australian landscape, climate and settlement differed significantly from New Zealand’s relatively densely populated rural regions.

Concern had even been expressed by Australian health officials on NZ’s intention to release the beetles without sufficient public health risk assessment.

University of South Australia dean of graduate studies Professor Philip Weinstein, with an equivalent footing to Barnfather in NZ, said in February the two countries were too different to use Australia as a comparison for NZ release.

Water run-off contaminated with bacteria from dung beetles was a key concern, he said.

An outspoken critic of the beetle release, Professor Grant Guilford, dean of faculty of science at Auckland University, also welcomed the study, despite it coming after beetles had been imported.

“It is good to hear that the Ministry of Health is undertaking this review,” Guilford said. “Independent, quantitative risk analyses like this should precede most new organism importations.

“They are the best tool we have to assess risks to our biosecurity, provided they carefully consider what is known alongside what is not known and don’t simply dismiss risk on the basis of an absence of knowledge. 

“But at the very least they help better define the areas of uncertainty that need to be clarified by research before a decision is made whether to release a new organism.”

Barber said he expected to see the final report from ESR by August.

If the report raised concerns, the group would take a cautionary approach to beetle release, he said.

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