Header graphic for print
Marler Blog Providing Commentary on Food Poisoning Outbreaks & Litigation

Hepatitis A in Shellfish – A Bit(e) of History

One of the great things about being a lawyer is that you can, if you want, continue to learn every day, even if you have been doing the same or similar thing for over 20 years.  I also get to reach out to the best experts in the world to ask for help in educating myself.  Thanks to to very good food safety people at NC State for updating the risk of Hepatitis A in shellfish.  Importers, be forewarned.

Hepatitis A outbreaks associated with shellfish, worldwide, from 1956 to 2016.  Adapted and expanded from Richards et al., 1985, Portnoy et al., 1975, and Fiore et al., 2004.  Outbreaks that were poorly investigated or had fewer than 30 cases were omitted.  Italics indicate the seafood was locally sourced with respect to the cases.  Asterisks denote outbreaks of “infectious hepatitis” before hepatitis A virus was specifically identified, and may have not been caused by hepatitis A virus.

Year # Cases Implicated food Location of cases Source of implicated food Suspected cause of contamination Reference
1956 629 Oysters Sweden Havstenssund Harbor, Sweden Oysters stored in polluted water Roos, 1956*; Pintó et al., 2009; Portnoy et al., 1975
1961 80


Oysters Mississippi, Alabama Pascagoula River, Mississippi Polluted harvesting areas Mason and McLean, 1962*
1961 459 Clams New Jersey Raritan Bay, New Jersey Polluted harvesting areas Dougherty and Altman, 1962*
1964 123 Clams Connecticut Multiple US sources, primarily Rhode Island Unknown Ruddy et al., 1969*
1973 281 Oysters Texas, Georgia, Louisiana Louisiana Stormwater runoff; investigated possible illegal harvesting Mackowiak et al., 1976; Portnoy et al., 1976
1980 312 Oysters Singapore Philippines Suspect contaminated harvesting waters Lee et al., 2011; Goh, 1981
1981 132 Cockles, whelks, mussels, prawns Southeast England United Kingdom Sewage discharge near harvesting beds, insufficient processing O’Mahoney et al., 1983
1982 225 Oysters Hondo City, Japan Ariake Bay, Japan Unknown Fujiyama et al., 1985
1984 75 Mussels and clams Livorno, Italy Livorno, Italy; Venice, Italy Sewage discharge near harvesting beds, improper handling at point of sale Mele et al., 1989
1988 61 Oysters Alabama, Georgia, Florida, Tennessee, Hawaii Florida Untreated sewage from residents and boats, possible illegal harvesting Descenclos et al., 1991
1988 292,301 Clams Shanghai, China Qi-Dong, China Untreated sewage Halliday et al., 1991
1992 800 Raw shellfish Western France Loire-Atlantique and Morbihan, France Unknown Apaire-Marchais et al., 1995
1996, 1997 5673,


Mussels and clams Puglia, Italy Italy Unknown Chironna et al., 2002
1997 444


Oysters New South Wales, Australia Wallis Lake, Australia Untreated sewage; stormwater runoff Conaty et al., 2000
1999 184 Coquina clams Valencia, Spain Peru Unknown Sanchez et al., 2002; Bosch et al., 2001
1999 32 Raw shellfish Bretagne, France Bay of Pampiol, France Unknown, harvesting sites near a busy tourist port Costa-Mattioli et al., 2000
2004 882 Mussels and clams Campania, Italy Primarily Campania, also other areas of Italy, Turkey Illegal storage of shellfish in contaminated seawater at point of purchase Pontrelli et al., 2008
2005 39 Oysters Alabama, Florida, South Carolina, Tennessee Louisiana Untreated sewage, possibly from recreational and other boats Bialek et al., 2007; Shieh et al., 2007
2007 111 Oysters Côtes d’Armor, France Côtes d’Armor, France Suspect contaminated water in tanks used on a shellfish farm, nearby untreated sewage Guillois-Bécel et al., 2009
2008 100 Coquina clams Spain Peru Unknown Pintó et al., 2009; Polo et al., 2010
2013 117 Suspect raw foods, especially seafood Taiwan Unknown Unknown Lung and Kay, 2013
2014 30 Raw bivalves: oysters, clams Taiwan Unknown Unknown Taiwan CDC, 2014
2016 292 Scallops Hawaii Philippines Unknown CDC, 2016; HI DOH, 2016



Apaire-Marchais, V., Robertson, B. H., Aubineau-Ferre, V., Le Roux, M. G., Leveque, F., Schwartzbrod, L., & Billaudel, S. (1995). Direct sequencing of hepatitis A virus strains isolated during an epidemic in France. Applied and environmental microbiology, 61(11): 3977-3980.

Bialek, S. R., George, P.A., Xia, G. L., Glatzer, M. B., Motes, M. L., et al. (2007) Use of molecular epidemiology to confirm a multistate outbreak of hepatitis A caused by consumption of oysters. Clin Infect Dis, 44: 838–840.

Bosch, A., Sánchez, G., Le Guyader, F., Vanaclocha, H., Haugarreau, L., Pintó, R. M. (2001). Human enteric viruses in Coquina clams associated with a large hepatitis A outbreak. Water Science and Technology, 43(12): 61–65.

Centers for Disease Control and Prevention (CDC). (2016). Outbreak of hepatitis A in Hawaii linked to raw scallops. Press Release. Published August 19, 2016. Available at http://www.cdc.gov/hepatitis/outbreaks/2016/hav-hawaii.htm

Chironna, M., Germinario, C., De Medici, D., et al. (2002). Detection of hepatitis A virus in mussels from different sources marketed in Puglia region (South Italy). Int J Food Microbiol, 75: 11–18.

Conaty, S., Bird, P., Bell, G., Kraa, E., Grohmann, G., McAnulty, J. M., et al. (2000). Hepatitis A in New South Wales, Australia from consumption of oysters: the first reported outbreak. Epidemiol Infect, 124: 121–130.

Costa-Mattioli, M., Monpoeho, S., Schvoerer, C., Besse, B., Aleman, M. H., Billaudel, S., et al. (2001). Genetic analysis of hepatitis A virus outbreak in France confirms the co-circulation of subgenotypes Ia, Ib and reveals a new genetic lineage. J Med Virol, 65(2): 233-40.

Desenclos, J. C., Klontz, K. C., Wilder, M. H., Nainan, O. V., Margolis, H. S., Gunn, R. A. (1991). A multistate outbreak of hepatitis A caused by the consumption of raw oysters. Am J Public Health, 81: 1268–1272.

Dougherty, W. J., and Altman, R. (1962). Viral hepatitis in New Jersey 1960–1961. Am J Med, 32: 704–716.

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

Fujiyama, S., Akahoshi, M., Sagara, K., Sato, T., Tsurusaki, R. (1985). An epidemic of hepatitis A related to ingestion of raw oysters. Gastroenterol Jpn, 20: 6-13.

Goh, K. T. (1981). Epidemiological studies of hepatitis A in Singapore. Ann Acad Med Singapore, 10: 25-33.

Guillois-Bécel, Y., Couturier, E., Le Saux, J. C., Roque-Afonso, A. M., Le Guyader, F. S., Le Goas, A., et al. (2009). An oyster-associated hepatitis A outbreak in France in 2007. Eurosurveillance, 14(10): 1-6.

Halliday, M. L., Kang, L.-Y., Zhou, T.-K., Hu, M.-D., Pan, Q.-C., Fu, T.-Y., et al. (1991). An epidemic of hepatitis A attributable to the ingestion of raw clams in Shanghai, China. J Infect Dis, 164: 852–859.

Hawaii Department of Health (HI DOH). (2016). Hepatitis A Outbreak 2016. Available at http://health.hawaii.gov/docd/hepatitis-a-outbreak-2016/

Lee, H. C., Ang, L. W., Chiew, P. K., James, L., & Goh, K. T. (2011). Changing epidemiological patterns of hepatitis A infection in Singapore. Ann Acad Med Singapore, 40(10): 439.

Lung, R.-Y. & Kay, L. (2013). CDC cautions against raw food as hepatitis A cases hit 4-year high. News Article. Published October 15, 2013. Focus Taiwan News Channel, The Central News Agency. Accessed online at http://focustaiwan.tw/news/asoc/201310150033.aspx

Mackowiak, P. A., Caraway, C. T., Portnoy, B.L. (1976). Oyster-associated hepatitis: lessons from the Louisiana experience. Am J Epidemiol, 103: 181–191.

Mason, J. O., & McLean, W. R. (1962). Infectious hepatitis traced to the consumption of raw oysters. Am J Hyg, 75: 90–111.

Mele, A., Rastelli, M. G., Gill, O. N., di Bisceglie, D., Rosmini, F., Pardelli, G., Valtriani, C. & Patriarchi, P. (1989). Recurrent epidemic hepatitis A associated with consumption of raw shellfish, probably controlled through public health measures. Am J Epidemiol, 130: 540–546.

O’Mahoney, M. C., Gooch, C. D., Smyth, D. A., Thrussell, A. J., Bartlett, C.L.R., Noah, N. D. (1983). Epidemic hepatitis A from cockles. Lancet, 1: 518–20.

Pintó, R. M., Costafreda, M. I., Bosch, A. (2009). Risk assessment in shellfish-borne outbreaks of hepatitis A. Appl Environ Micro, 75(23): 7350-7355.

Polo, D., Vilariño, M. L., Manso, C.F., Romalde, J. L. (2010). Imported Mollusks and Dissemination of Human Enteric Viruses. Letters to the Editor. Emerg Infect Dis, 16(6): 1036-1037. Accessed online at http://wwwnc.cdc.gov/eid/article/16/6/09-1748_article

Pontrelli, G., Boccia, D., Di Renzi, M., Massari, M., Giugliano, F., Celentano, L. P., … & Rapicetta, M. (2008). Epidemiological and virological characterization of a large community-wide outbreak of hepatitis A in southern Italy. Epidemiology and infection, 136(08): 1027-1034.

Portnoy, B. L., Mackowiak, P. A., Caraway, C. T., Walker, J. A., McKinley, T. W., Klein, C. A. (1975). Oyster-associated hepatitis: failure of shellfish certification programs to prevent outbreaks. JAMA, 233: 1065–1068.

Richards, G.P. 1985. Outbreaks of enteric virus illness in the United States: requisite for development of viral guidelines. J Food Prot, 48: 815-832.

Roos, B. (1956). Hepatitis epidemic transmitted by oysters. Sven Lakartidn, 53: 989–1003.

Ruddy, S. J., Johnson, R. F., Mosley, J. W., Atwater, J. B., Rossetti, M. A., Hart, J. C. (1969). An epidemic of clam-associated hepatitis. JAMA, 208: 649-655.

Sanchez, G., Pintó, R. M., Vanaclocha, H., Bosch, A. (2002). Molecular characterization of hepatitis A virus isolates from a transcontinental shellfish-borne outbreak. J Clin Microbiol, 40: 4148–4155.

Shieh, Y. C., Khudyakov, Y. E., Xia, G., Ganova-Raeva, L. M., Khambaty, F. M., et al. (2007) Molecular confirmation of oysters as the vector for hepatitis A in a 2005 multistate outbreak. J Food Prot, 70: 145–150.

Taiwan Centers for Disease Control. (2014). As Taiwan CDC confirms cluster of hepatitis A cases due to consumption of raw bivalves using genetic sequencing for the first time, public urged to pay attention to food safety. Press Release. Published December 8, 2014. Available at http://www.cdc.gov.tw/english/info.aspx?treeid=bc2d4e89b154059b&nowtreeid=ee0a2987cfba3222&tid=BA36E519A4A2F338 Also available on ProMED Mail at http://www.promedmail.org/post/3021721