The Hawke’s Bay District Health Board put the number affected by the gastrointestinal outbreak at more than 4,000 people since the outbreak began one month ago.

Giardia lamblia/CDC
Giardia lamblia/CDC

The number of confirmed cases of campylobacter are 171 and the probable cases are at 379, for a total of 550.

Chief executive, Dr Kevin Snee, Hawke’s Bay District Health Board said extra surveillance was in place for two other bugs that have a longer incubation time than campylobacter – cryptosporidium and giardia. Giardia has an incubation time of up to 21 days and will have been killed by the chlorine and the boil water notice was put in place to kill cryptosporidium, which has an incubation period of up to 20 days.

Dr Snee said the good news was we have only seen the bug in a small proportion of fecal specimens but we are being extra vigilant and have a lot of additional surveillance in place. This means we will get reports as soon as there is any increase in sickness in the community with general practice, pharmacies, district nurses, schools and early childhood centres reporting back to us. “We will let the public know straight away if we begin to see any signs of increased sickness.”

“So far we have only seen the bug in a small number of people, but it can take longer to develop so we remain alert,” Dr Snee said.

The boil water notice remains in place for Havelock North only. The advice is to boil water for one minute.