A new study has found 58 people were admitted to Hawke’s Bay Hospital in relation to the 2016 campylobacter outbreak in Havelock North, compared to previously reported estimates of 42. (File photo).
More people than previously reported were hospitalised as a result of the 2016 campylobacter outbreak in Havelock North, a new study has found.
The study, published in the Medical Journal on Friday , found 58 individuals were admitted with complications of acute infection arising from the outbreak.That is up from previous publications which reported 42 people were hospitalised.
The majority of these hospitalisations occurred during the height of the outbreak. Some were admitted more than once with a total of 67 hospital admissions over the outbreak.
In August 2016, a large waterborne campylobacter outbreak occurred in the Hawke’s Bay town, after heavy rain led to the town’s reticulated, unchlorinated water supply being contaminated.
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It’s estimated more than 6260 of the town’s 14,000 residents, along with other visitors to the region, became unwell with symptoms of campylobacteriosis (a type of bacterial infection causing diarrhoeal illness).
Some suffered further health complications and serious illness. The outbreak was linked to at least four deaths including that of 89-year-old Jean Sparksman.
Hawke’s Bay District Heath Board medical officer of health Dr Nick Jones, who helped write the report, explained the higher figure came from adopting a more systematic search approach, analysing the medical records of 933 residents of the catchment believed to have become ill as a result of the outbreak.
“At the time we weren’t able to go through hospital notes in detail, so we were reliant on individual hospital doctors reporting the number of cases to Public Health.
“This reflects the reality that this passive reporting system does tend to undercount.”
He didn’t feel this had any health implications in the response to the outbreak, however, it may have impacted cost estimates.
He said the region likely would have seen more cases if not for the “great work” done by its general practitioners and nurses who were out in the community ensuring people were getting fluids.
The study found dehydration (74.1%), electrolyte imbalance (35.8%) and acute kidney injury (27.6%) were common among hospitalised cases, highlighting the importance of ensuring people who were older or had underlying conditions were given access to hydration early on.
“That’s a really practical and useful piece of information that’s come from this study,” Jones said.
The length of hospital stays varied significantly with a median of three days – the longest being 111 days, driven by multiple complications including pancolitis (a type of inflammatory bowel disease) and multi-organ failure.
Pre-existing underlying conditions and advanced age were also found to be significant risk factors for hospitalisation.
“The people most at risk from this kind of large outbreaks, and we’re seeing it at the moment with Covid, are people who are either older or have a condition that weakens them and makes them more vulnerable.”
The study also found campylobacter-caused illnesses had serious health impacts, including increased risk of death for these more vulnerable populations.
Those who were hospitalised had a risk of death at one year that was about five times that of non-hospitalised cases, when not accounting for other factors like age and underlying conditions.
Jones said while this was perhaps not surprising, it was a significant finding.
“Is there something about when you are in that situation that you are not as easily able to bounce back? Is there something like this that can come along and accelerate your frailty or decrease your resilience?”
He hoped these questions would be examined further in a separate study looking at this which he expected would be published in a few months time.
“That also has implications for the health system as a whole with the whole country ageing.”
Jones said the Havelock North outbreak was a “very significant event” which had sparked other notable changes including the recently paused Three Waters reforms.
“Obviously in this case that’s led to as a lot of changes about how drinking water is provided.”