An Auckland Regional Public Health Service (ARPHS) spokesperson said on Wednesday that in the past day it had received about 20 calls from people who ate the food provided by the meal kit company.
When fish isn't chilled properly, it can produce histamine that can be toxic to humans leading to scombroid poisoning, according to the New Zealand Food Safety website.
Meanwhile, the public health unit for the Greater Wellington region said it had also received a number of phone calls from "concerned members of the public on this matter."
Hello Fresh customers were warned yesterday to ditch the fish dish in their packs after its fish supplier advised of elevated histamine levels in trevally.
Three people were treated and discharged from hospital yesterday after eating the trevally meal.
ARPHS medical officer of health Dr Jay Harrower said symptoms of scombroid poisoning were often the combination of an allergic reaction and gastroenteritis.
Symptoms include tingling and burning around the mouth, facial flushing, diarrhoea, skin rash, vomiting, dizziness, and possibly respiratory distress and could last up to 48 hours, he said.
However, it did not usually result in any long-term effects.
"The illness typically begins within 30 minutes to an hour or two of consuming the fish," Harrower said.
"There are some fish varieties which are more likely to produce histamines at levels that are toxic, often when the fish is not kept chilled."
One of those varieties is trevally.
