Non-travel related Hepatitis E virus genotype 3 infections in the Netherlands; a case series 2004 - 2006.
BACKGROUND
Human hepatitis E virus (HEV) infections are considered an emerging disease in industrialized countries. In the Netherlands, Hepatitis E virus (HEV) infections have been associated with travel to high-endemic countries. Non-travel related HEV of genotype 3 has been diagnosed occasionally since 2000. A high homology of HEV from humans and pigs suggests zoonotic transmission but direct molecular and epidemiological links have yet to be established. We conducted a descriptive case series to generate hypotheses about possible risk factors for non-travel related HEV infections and to map the genetic diversity of HEV.


METHODS
A case was defined as a person with HEV infection laboratory confirmed (positive HEV RT-PCR and/or HEV IgM) after 1 January 2004, without travel to a high-endemic country three months prior to onset of illness. For virus identification 148 bp of ORF2 was sequenced and compared with HEV from humans and pigs. We interviewed cases face to face using a structured questionnaire and collected information on clinical and medical history, food preferences, animal and water contact.


RESULTS
We interviewed 19 cases; 17 were male, median age 50 years (25-84 y), 12 lived in the North-East of the Netherlands and 11 had preexisting disease. Most common symptoms were dark urine (n = 16) and icterus (n = 15). Sixteen ate pork >/= once/week and six owned dogs. Two cases had received blood transfusions in the incubation period. Seventeen cases were viremic (genotype 3 HEV), two had identical HEV sequences but no identified relation. For one case, HEV with identical sequence was identified from serum and surface water nearby his home.


CONCLUSIONS
The results show that the modes of transmission of genotype-3 HEV infections in the Netherlands remains to be resolved and that host susceptibility may play an important role in development of disease.
Borgen
Katrine
K
Centre for Infectious Disease Control, National Institute for Public Health and Environment (RIVM), Antonie van Leeuwenhoeklaan 9, 3720 BA Bilthoven, The Netherlands. katrine.borgen@fhi.no
Herremans
Tineke
T
Duizer
Erwin
E
Vennema
Harry
H
Rutjes
Saskia
S
Bosman
Arnold
A
de Roda Husman
Ana Maria
AM
Koopmans
Marion
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D016000:Cluster Analysis; D021821:Communicable Diseases, Emerging / Q000453:epidemiology* / Q000635:transmission / Q000821:virology*; D004285:Dogs; D005260:Female; D005838:Genotype; D016751:Hepatitis E / Q000453:epidemiology* / Q000635:transmission; D016752:Hepatitis E virus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008460:Meat; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D010802:Phylogeny; D012307:Risk Factors; D013552:Swine; D015047:Zoonoses / Q000821:virology