The Ministry of Health said on Thursday afternoon that the number of confirmed cases linked to the outbreak had grown to 18 in total. Of these, nine (50%) have been hospitalized.

As of Thursday, 14 of the 18 cases have been sequenced to date – all 14 have an identical sequence profile, indicating they likely came from the same source.

Hepatitis A is spread by contact with feces of an infected person. It can be passed on through poor personal hygiene (such as when people don’t wash their hands properly), contaminated food and close personal contact.

All 18 cases reported “significant” consumption of uncooked, imported frozen berries.

Food safety officials have advised that Pams – a New Zealand division of supermarket giant Foodstuffs – was recalling various imported frozen berry products as a precaution, over a possible link to recent cases of the contagious virus in fruit from Serbia.

Hepatitis A outbreaks associated with fresh, frozen, and minimally processed produce, worldwide, from 1983 to 2016—adapted and expanded from Sivapalasingam et al., 2004 and Fiore, 2004. Italics indicate instances where the food was locally sourced with respect to the cases. The implicated foods were raw unless listed otherwise.

Year# CasesImplicated foodLocation of casesSource of implicated foodSuspected cause of contaminationReference
198324Raspberries (frozen)ScotlandScotlandInfected pickers or packersReid et al., 1987[1]
19875Raspberries (frozen)ScotlandTayside, ScotlandInfected pickers Ramsay and Upton, 1989[2]
1988202Iceberg lettuceKentuckyUnknown, suspected to be from MexicoBelieved to have occurred prior to distribution, since multiple restaurants involved Rosenblum et al., 1990[3]
199035 Strawberries (frozen)Montana, GeorgiaCaliforniaSuspect an infected picker at farmSivapalasingam et al., 2004;[4]Niu et al., 1992[5]
199630Salad ingredientsFinlandImported salad ingredientsUnknownPebody et al., 1998[6]
1997256Strawberries (frozen)Michigan, Maine, Wisconsin, Arizona, Louisiana, TennesseeGrown in Mexico,processed and frozen at a single California facility a year before consumption Inconclusive due to time between harvest and consumption, suspect barehanded contact with berries at harvesting, coupled with few latrines and handwashing facilities on siteHutin et al., 1999[7]
199843Green onionsOhioOne of two Mexican farms or a farm in CaliforniaBelieved to be contaminated before arrival at restaurantDentinger et al., 2001[8]
200031Green onions or tomatoesKentucky, FloridaGreen onions: California or MexicoTomatoes: UnknownUnknownWheeler et al., 2005[9]; Datta et al., 2001[10]; Fiore, 2004[11]
200281BlueberriesNew ZealandNew Zealand, one orchard Inadequate bathroom facilities in fields, workers had barehanded contact with product, polluted groundwater from nearby latrines a possibilityCalder et al., 2003[12]
2003601Green onions Pennsylvania, Tennessee, Georgia, North CarolinaMexico, two farmsContaminated during or before packing at farmCDC, 2003[13]; Wheeler et al., 2005[14]
2009562Tomatoes (semidried)AustraliaUnknown; imported and domestic product involvedProduct suspected to be imported due to concurrent outbreaks elsewhere at the time, source of contamination unknownDonnan et al., 2012[15]
200913Tomatoes (semidried)NetherlandsUnknown; imported product suspectedIdentical strain to the 2009 Australian outbreakPetrignani et al., 2010[16]
201059Tomatoes (semidried)FranceLikely Turkey, single batch of productUnable to determine when and where contamination occurred. Virus was slightly different from one in the 2009 Australian and Dutch outbreaks. Gallot et al., 2011[17]
2012 9Pomegranate seeds (frozen)CanadaEgyptSuspect product contamination before export. Some history of travel to endemic areas among workers at Canadian processing facility, but less likely as only one product was associated with illness.CDC 2013[18]; Swinkels et al., 2014[19]
2013 103 Strawberries (frozen)Other frozen berries may have been involvedDenmark, Finland, Norway, SwedenSuspected Egypt and Morocco based on virus strain and import historyUnknown, some cases matched the strain of the larger 2013 European outbreak (see below)Nordic Outbreak Investigation Team, 2013[20]
20131589Berries (frozen)Italy (90% of cases), Austria, Bulgaria, Denmark, England, Finland, France, Germany, Ireland, the Netherlands, Norway, Poland, SwedenMultiple food items containing frozen mixed berries (cakes, smoothies); Bulgarian blackberries and Polish redcurrants were the most common ingredients in the implicated lotsUnknown, no single source found. Some cases also related to travel to Italy.Severi et al., 2015[21]; EFSA 2014[22]; Chiapponi et al., 2014[23]; Rizzo et al., 2013[24]; Guzman-Herrador et al., 2014[25]; Fitzgerald et al., 2014[26]
2013165Pomegranate arils (frozen)Arizona, California, Colorado, Hawaii, New Hampshire, New Jersey, New Mexico, Nevada, Utah, WisconsinTurkeyUnknownCollier et al., 2014[27]; CDC 2013[28]
2016143Strawberries (frozen)Arkansas, California, Maryland, New York, North Carolina, Oregon, Virginia, West Virginia, WisconsinEgyptUnknownCDC 2016[29]

[1]           Reid, T., Robinson, H. (1987). Frozen raspberries and hepatitis A. Epidemiol Infect, 98: 109–112.

[2]           Ramsay, C. N. and Upton, P. A. (1989). Hepatitis A and frozen raspberries. Lancet, 1: 43–44.

[3]           Rosenblum, L. S., Mirkin, I. R., Allen, D. T., Safford, S., Hadler, S. C. (1990). A multifocal outbreak of hepatitis A traced to commercially distributed lettuce. American Journal of Public Health, 80(9): 1075-1079.

[4]           Sivapalasingam, S., Friedman, C. R., Cohen, L., Taube, R. V. (2004). Fresh produce: a growing cause of outbreaks of foodborne illness in the United States, 1973 through 1997. J Food Prot, 67: 2342-2353. 

[5]           Niu, M. T., Polish, L. B., Robertson, B. H. (1992). Multistate outbreak of hepatitis A associated with frozen strawberries. J Infect Dis 166: 518-524.

[6]           Pebody, R. G., Leino, T., Ruutu, P., Kinnunen, L., Davidkin, I., Nohynek, H., & Leinikki, P. (1998). Foodborne outbreaks of hepatitis A in a low endemic country: an emerging problem? Epidemiology and infection120(1): 55-59.

[7]           Hutin, Y. J., Pool, V., Cramer, E. H., Nainan, O. V., Weth, J., Williams, I. T. et al. (1999). A multistate, foodborne outbreak of hepatitis A. New England Journal of Medicine, 340(8): 595-602.

[8]           Dentinger, C. M., Bower, W. A., Nainan, O. V., Cotter, S. M., Myers, G., Dubusky, L. M., Fowler, S., Salehi, E. D. P., and Bell, B. P. (2001). An outbreak of hepatitis A associated with green onions. J Infect Dis, 183: 1273-1276.

[9]           Wheeler, C., Vogt, T. M., Armstrong, G. L., Vaughan, G., Weltman, A., Nainan, O. V. et al. (2005). An outbreak of hepatitis A associated with green onions. New England Journal of Medicine353(9): 890-897.

[10]         Datta, S. D., Traeger, M. S., & Nainan, O. V. (2001). Identification of a multi-state outbreak of hepatitis A associated with green onions using a novel molecular epidemiologic technique [abstract 896]. In Program and abstracts of the 39th Annual Meeting of the Infectious Diseases Society of America. Alexandra, VA: Infectious Diseases Society of America (Vol. 192).

[11]         Fiore, A. E. (2004). Hepatitis A transmitted by food. Clinical Infectious Diseases, 38(5): 705-715.

[12]         Calder, L. , Simmons, G., Thornley, G. (2003). An outbreak of hepatitis A associated with consumption of raw blueberries. Epidemiol Infect,131: 745-751

[13]         Centers for Disease Control and Prevention (CDC). (2003). Hepatitis A outbreak associated with green onions at a restaurant–Monaca, Pennsylvania, 2003. MMWR, 52(47): 1155-1157. Available at

[14]         Wheeler, C., Vogt, T. M., Armstrong, G. L., Vaughan, G., Weltman, A., Nainan, O. V. et al. (2005). An outbreak of hepatitis A associated with green onions. New England Journal of Medicine353(9): 890-897.

[15]         Donnan, E. J., Fielding, J. E., Gregory, J. E., et al. (2012). A multistate outbreak of hepatitis A associated with semidried tomatoes in Australia, 2009. Clin Infect Dis, 54: 775–781.

[16]         Petrignani, M., Harms, M., Verhoef, L. (2010). Update: a food-borne outbreak of hepatitis A in The Netherlands related to semi-dried tomatoes in oil, January-February 2010. Euro Surveillance, 15(20): 19572. 

[17]         Gallot, C., Grout, L., Roque-Afonso, A., Couturier, E., Carrillo-Santisteve, P., Pouey, J. et al. (2011). Hepatitis A Associated with Semidried Tomatoes, France, 2010. Emerging Infectious Diseases, 17(3): 566-567. 

[18]         Centers for Disease Control and Prevention (CDC). (2013). Multistate outbreak of hepatitis A virus infections linked to pomegranate seeds from Turkey (Final Update). Available at:

[19]         Swinkels, H. M., Kuo, M., Embree, G., Andonov, A., Henry, B., Buxton, J. A. (2014). Hepatitis A outbreak in British Columbia, Canada: the roles of established surveillance, consumer loyalty cards and collaboration, February to May 2012. Euro Surveillance, 19: 20792.

[20]         Nordic Outbreak Investigation Team C (2013). Joint analysis by the Nordic countries of a hepatitis A outbreak, October 2012 to June 2013: frozen strawberries suspected. Euro Surveillance, 18(27): 20520.

[21]         Severi, E., Verhoef, L., Thornton, L., Guzman-Herrador, B. R., Faber, M., Sundqvist, L. et al. (2015). Large and prolonged food-borne multistate hepatitis A outbreak in Europe associated with consumption of frozen berries, 2013 to 2014. Euro Surveillance, 20(29): 1-9.

[22]         European Food Safety Authority (EFSA). (2014). Tracing of food items in connection to a multinational hepatitis A virus outbreak in Europe. EFSA Journal, 12(9): 3821-4007. Available at http://  

[23]         Chiapponi, C., Pavoni, E., Bertasi, B., Baioni, L., Scaltriti, E., Chiesa, E., et al. (2014). Isolation and genomic sequence of hepatitis A virus from mixed frozen berries in Italy. Food Environ Virol, 6(3): 202-206.

[24]         Rizzo, C., Alfonsi, V., Bruni, R., Busani, L., Ciccaglione, A., De Medici, D., et al. (2013). Ongoing outbreak of hepatitis A in Italy: preliminary report as of 31 May 2013. Euro Surveillance, 18(27): 20518. 

[25]         Guzman-Herrador, B., Jensvoll, L., Einoder-Moreno, M.,
Lange, H., Myking, S., Nygard, K., et al. (2014). Ongoing hepatitis A outbreak in Europe 2013 to 2014: imported berry mix cake suspected to be the source of infection in Norway. Euro Surveillance, 19(15): 20775. 

[26]         Fitzgerald, M., Thornton, L., O’Gorman, J., O Connor, L., Garvey, P., Boland, M., et al. (2014). Outbreak of hepatitis A infection associated with the consumption of frozen berries, Ireland, 2013 – linked to an international outbreak. Euro Surveillance: European communicable disease bulletin, 19(43).

[27]         Collier, M. G., Khudyakov, Y. E., Selvage, D., Adams-Cameron, M., Chiepson, E., Cronquist, A., et al. (2014). Outbreak of hepatitis A in the USA associated with frozen pomegranate arils imported from Turkey: an epidemiological case study. Lancet Infectious Diseases, 14(10): 976-981.

[28]         Centers for Disease Control and Prevention (CDC). (2013) – Multistate outbreak of hepatitis A virus infections linked to pomegranate seeds from Turkey (Final Update), supra note 85.

[29]         Centers for Disease Control and Prevention (CDC). (2016). 2016 – Multistate outbreak of hepatitis A linked to frozen strawberries (Final Update). Available at