Hepatitis E Virus Genotype 4, Denmark, 2012

To the Editor: Hepatitis E virus genotype 4 (HEV4) is most commonly reported in China and Japan; it has primarily been categorized as a zoonotic virus because it has been found in humans and several other animal species (1). In Europe, HEV4 has been identified in 6 countries, in humans and other animals. The first cases of HEV4 infection in a human and an animal (pig) were detected through strain surveillance activities in Germany (2) and Belgium (3), respectively. In May 2009, France reported an isolated case of HEV4 infection in a human; however, the source of infection could not be determined. Consumption of contaminated food was deemed unlikely , but receipt of contaminated blood during transfusion was possible (4). In 2011, an outbreak of HEV4 in France was associated with consumption of figatelli, a liver sausage that is traditionally consumed uncooked (5). Also in 2011, an outbreak in Italy was reported, in which contaminated water was suggested as a possible source of infection (6). HEV4 has also been detected in a patient in the United Kingdom. This patient, however, had just returned from India, so the infection was associated with travel (7). Transmission was suspected to be zoonotic because the sequence was most closely related to isolates from swine in India. From January 2010 through De-cember 2012, the Department of Microbiological Diagnostics and Vi-rology of the Statens Serum Institut received 1,112 samples from 823 patients with clinically suspected hepatitis for HEV diagnostic serologic and PCR testing. Blood samples were tested for HEV IgM and IgG by use of the DS-EIA-ANTI-HEV-M and DS-EIA-ANTI-HEV-G kits (DSI, Saronno, Italy) according to the manufacturer's instructions. Diagnostic real-time reverse transcription PCR (RT-PCR) amplifying a 79-bp fragment of open reading frame 3 (8) was conducted by using a QIAGEN OneStep RT-PCR Kit (Hilden, Germany). Samples from 59 (7%) patients were HEV positive according to serologic testing; of these, 20 (34%) were positive for HEV RNA according to RT-PCR. Genotyping was conducted by amplifying 804 bp of open reading frame 2. By sequencing of PCR products , 13 (65%) samples were success-were detected in 5 patients. In 2012, a total of 3 patients were infected with HEV genotype 4. The 3 sequences obtained in this study (GenBank accession nos. KC928081–KC928083) were subjected to phylogenetic analysis, along with reference sequences that included the sequences from the France and Italy outbreaks and the strain from the HEV4 virus …