Summary

Between 28 June 2022 and 3 July 2023, an outbreak of Hepatitis A occurred in New Zealand caused by imported frozen berries. This page details the case update during the course of the outbreak.

Latest updates

As at 12 July 2023 the total number of locally-acquired cases of hepatitis A, reported since 28 June 2022 and linked to the current outbreak is 39. All 39 cases in the outbreak associated with imported frozen berries have identical (or near identical) sequence profiles in the region analysed.

In line with international convention, the hepatitis A outbreak associated with imported frozen berries was declared formally over on 3 July 2023 which is two maximum incubation periods (100 days for hepatitis A) following the onset of symptoms for the latest case.

Information on making frozen berries safe to eat is available on the New Zealand Food Safety website at: https://www.mpi.govt.nz/food-safety-home/safe-eat/making-frozen-berries-safe-to-eat/

Previous updates

2 May 2023

As at 2 May 2023 the total number of locally-acquired cases of hepatitis A, reported since 28 June 2022 and linked to the current outbreak is 39. All 39 cases in the outbreak associated with imported frozen berries have identical (or near identical) sequence profiles in the region analysed.

If there are no further cases identified the outbreak will be declared over on 3 July 2023.

All 39 cases in the outbreak associated with imported frozen berries have identical (or near identical) sequence profiles in the region analysed.

 

14 April 2023

One new confirmed case of locally-acquired Hepatitis A has been identified. This new case has an identical sequence profile to the other cases in the outbreak associated with imported frozen berries.


This brings the total number of locally-acquired cases of hepatitis A, reported since 28 June 2022 and linked to the current outbreak to 37.


In the last update on 9 February it was stated that the outbreak would be considered over on 11 April 2023, however due to the identification of this recent case this date of closure of the outbreak will be reviewed.

9 February 2023

Since 28 June 2022, 36 locally-acquired cases of hepatitis A with identical or near-identical sequence profiles have been linked to the current outbreak. The majority of cases (72.2%) occurred between 16 September to 18 November 2022. The onset of symptoms for the most recent case is 1 January 2023. Unless there are further cases, there will be no further updates on the outbreak. In line with international convention, the outbreak will formally be considered over once two incubation periods (100 days for hepatitis A) have passed since the onset of symptoms for the last case. If there are no further cases, this will be 11 April 2023.


The source of the 2022 Hepatitis A outbreak was highly likely to be imported frozen berries from Serbia. The risk management interventions put in place by New Zealand Food Safety including consumer education and preventing the sale of some potentially affected product have likely contained the source of illness as evidenced by the decline in reported cases. However, we cannot rule out the possibility of small numbers of further cases because of the long incubation period of Hepatitis A virus, the long shelf-life of frozen berries and the possibility of secondary transmission.


For standard advice on making frozen berries safe to eat: www.mpi.govt.nz/food-safety-home/safe-eat/making-frozen-berries-safe-to-eat/

 

2 February 2023

Since 28 June 2022, 36 locally-acquired cases of hepatitis A with identical or near-identical sequence profiles have been linked to the current outbreak.

 

No new cases associated with the outbreak have been identified since the last update.

 

26 January 2023

Since 28 June 2022, 36 locally-acquired cases of hepatitis A with identical or near-identical sequence profiles have been linked to the current outbreak. No new cases associated with the outbreak have been identified since the last update.

 

19 January 2023

Since 28 June 2022, 36 locally-acquired cases of hepatitis A with identical or near-identical sequence profiles have been linked to the current outbreak. One new case associated with the outbreak has been identified since the last update.

 

Of all cases, 18 (50%) were hospitalised. Seven cases with the outbreak sequence profile did not report consuming berries.

 

All 36 cases are genotype IA and have an identical or very similar sequence profile, which indicates they likely came from the same source.

 

12 January 2023

Since 28 June 2022, 35 locally-acquired cases of hepatitis A with identical or near-identical sequence profiles have been linked to the current outbreak.

 

Three new cases associated with the outbreak have been identified since the last update. Seven cases with the outbreak sequence profile did not report consuming berries.

 

Of all cases, 34 are genotype IA and have an identical or very similar sequence profile, which indicates they likely came from the same source. Sequencing for one case linked to the outbreak is pending.  

 

22 December 2022

Since 28 June 2022, 32 locally-acquired cases of hepatitis A with identical or near-identical sequence profiles have been linked to the current outbreak. Of all cases, 14 (44%) were hospitalised.

 

Four cases with the outbreak sequence profile did not report consuming berries.

 

No new outbreak cases have been reported since 9 December. However two confirmed locally-acquired cases of hepatitis A with no other risk factors are awaiting sequencing.

 

Of all cases, 29 are genotype IA and have an identical or very similar sequence profile, which indicates they likely came from the same source.

 

The next update will be published on Thursday, 12 January 2023.

 

15 December 2022

Since 28 June 2022, 32 locally-acquired cases of hepatitis A have been linked to the current outbreak. No new cases associated with the outbreak have been identified in the past week. Of all cases, 14 (44%) were hospitalised.

 

Of all cases, 29 are genotype IA and have an identical or very similar sequence profile, which indicates they likely came from the same source. Sequencing for two confirmed cases and one probable locally acquired case is pending.

 

Of these New Zealand cases, 28 have reported consumption of uncooked imported frozen berries. Four cases with the outbreak sequence profile did not report consuming berries and are likely due to secondary transmission.

 

8 December 2022

Since 28 June 2022, 32 locally-acquired cases of hepatitis A have been linked to the current outbreak. This includes three new cases in the past week. Of all cases, 14 (44%) were hospitalised.

 

Of all cases, 29 are genotype IA and have an identical or very similar sequence profile, which indicates they likely came from the same source. Sequencing for two confirmed cases is pending.

 

Of these New Zealand cases, 28 have reported consumption of uncooked imported frozen berries. Four cases with the outbreak sequence profile did not report consuming berries and are likely due to secondary transmission.

 

1 December 2022

Since 28 June 2022, 29 locally-acquired cases of hepatitis A have been linked to the current outbreak. This includes one new case in the past week. Of all cases, 12 (41%) were hospitalised.

 

Of all cases, 28 are genotype IA and have an identical or very similar sequence profile, which indicates they likely came from the same source. Sequencing for one case is pending.

 

Of these New Zealand cases, 25 have reported consumption of uncooked imported frozen berries. Four cases with the outbreak sequence profile did not report consuming berries and are likely due to secondary transmission.

 

24 November 2022 

Since 28 June 2022, 28 locally-acquired cases of hepatitis A have been linked to the current outbreak. This includes two new cases in the past week. Of all cases, 12 (43%) were hospitalised.

 

Of all cases, 26 have an identical or very similar sequence profile, which indicates they likely came from the same source. Sequencing for the remaining two cases is pending.

 

Of these New Zealand cases, 25 have reported consumption of uncooked imported frozen berries. Three cases with the outbreak sequence profile did not report consuming berries and are likely due to secondary transmission.

 

New Zealand Food Safety (NZFS) advises that testing of leftover berries from the home of one of the cases linked to the outbreak has revealed the presence of Hepatitis A. NZFS will be considering this new data point alongside all the other evidence gathered to date.

 

It’s important to note that, although this result supports the recall and assumption that Serbian berries are implicated in the current outbreak, on its own it is not enough to be absolute about the source of outbreak.

 

In the meantime, NZFS advice to consumers is to consider heat treating frozen berries to kill any potential pathogen.

 

More information, including details of the products under recall

 

16 November 2022

Since 28 June 2022, 26 locally-acquired cases of hepatitis A have been linked to the current outbreak, including one new case in the past week.

 

Of these New Zealand cases, 24 have reported consumption of uncooked imported frozen berries.Two cases from Hawke’s Bay with an identical outbreak sequence profile did not report consuming berries and are being further investigated.

 

Twenty-five cases are genotype IA and all have identical (or near identical) sequence profiles in the region analysed. Sequencing for 1 berry-associated case is pending.

 

10 November 2022

Since 28 June 2022, 25 locally-acquired cases of hepatitis A have been identified as linked to the current outbreak. This includes two new cases in the past week.

 

Of these New Zealand cases, 24 have reported consumption of uncooked imported frozen berries. One case with an identical outbreak sequence profile did not report consuming berries and is being further investigated.11 (44%) cases were hospitalised.

 

Of all New Zealand cases, 22 have an identical or very similar sequence profile, which indicates they likely came from the same source. Sequencing for the remaining three cases is pending.

 

3 November 2022

Since 28 June 2022, 23 locally-acquired cases of hepatitis A associated with frozen berry consumption have been identified, including two in the past week. 

 

All New Zealand cases have reported significant consumption of uncooked imported frozen berries. 11 (48%) cases were hospitalised.

 

Of all New Zealand cases, 17 have an identical sequence profile, which indicates they likely came from the same source. Sequencing for the remaining 6 cases is pending.

 

27 October 2022

Since 28 June 2022, 21 locally-acquired cases of hepatitis A associated with frozen berry consumption have been identified, including three in the past week. All New Zealand cases have reported significant consumption of uncooked imported frozen berries. Nine (43%) cases were hospitalised.

 

Of all New Zealand cases, 17 have an identical sequence profile, which indicates they likely came from the same source.

 

20 October 2022

Since 28 June 2022, 18 locally-acquired cases of hepatitis A associated with frozen berry consumption have been identified, including three in the past week. 

 

All 18 New Zealand cases have reported significant consumption of uncooked imported frozen berries. Nine (50%) cases were hospitalised.

 

Of the 18 cases, 14 have been sequenced to date, and all 14 have have an identical sequence profile, which indicates they likely came from the same source.

 

13 October 2022

Since 28 June 2022, 15 locally-acquired cases of hepatitis A associated with frozen berry consumption have been identified, including three in the past week.

 

All 15 New Zealand cases have reported significant consumption of uncooked imported frozen berries. Seven (47%) cases were hospitalised.

 

Of the 15 cases, 11 have an identical sequence profile, which indicates they likely came from the same source.