Introduction: Hepatitis A virus (HAV) epidemics occurred repeatedly in Iceland in the early 20th century, but since then few cases have been reported and no epidemics since 1952. The latest Icelandic studies on HAV from around 1990 showed low incidence of infection and de­-
creasing prevalence of antibodies. The objective of this study was to determine the incidence, clinical presentation and origin of HAV, abroad or in Iceland.

Material and methods: A retrospective search was undertaken on all patients with positive anti-HAV IgM during the 11 years period of 2006-2016 in the virological database of the National University Hospital of Iceland. Clinical data was collected from medical records on symptoms at diagnosis, blood test results and possible route of transmission.

Results: A total of 12 individuals were diagnosed with acute hepatitis A during the period and 6691 HAV total andibody tests and 1984 HAV IgM antibody tests were performed. Nine (75%) had been abroad within 7 weeks from initial symptoms. The most common symptoms were jaundice (83%), fever (67%) and nausea and/or vomiting (58%). 50% were admitted to a hospital. 42% had elevated INR/PT. Everyone sur­vived without complications.

Conclusion: Annually, approximately one case of acute hepatitis A was diagnosed in Iceland during the study period but a very high number of antibody tests were performed. The majority of cases occurred among individuals who had recently been abroad. If patients have jaundice, fever and nausea, testing for HAV infection should be undertaken. HAV is not endemic in Iceland.

Table I Results for each case that was diagnosed with hepatitis A, F for female, M for male and age at diagnosis in numbers. For categorical variables, "1" means that variable was present and "0" that it was not present. "Abroad" is present if patient stayed abroad within 7 weeks from initial symptoms, "jaundice" if mentioned in medical records that the patient had jaundice or if bilirubin measured higher than double the upper limits of normal range, and "admission" if the patient was admitted to a health care facility because of hepatitis A. For blood test results, the highest measured value of the disease course is shown. Reference range: ALP: <6 months, 75-290 U/L; <16 years, 120-540 U/L; >16 years, 35-105 U/L. ASAT: <6 months, <72 U/L; 6 months-10 years, <52 U/L; males, <45 U/L; females, <35 U/L. ALAT: males, <70 U/L; females: <45 U/L. Bilirubin: 5-25 µmol/L. INR: 0.8-1.2. PT: 12.5-15.0 seconds.

Table II Number of antibody tests for hepatitis A at the virology department of the National University Hospital of Iceland during the study period, and their results. Positive IgM antibodies confirm the diagnosis of acute hepatitis.

Figure I Annual incidence of hepatitis A per 100,000 inhabitants in the study period. Number of cases per year ranged from zero to four.

Figure II Number of annually sold doses of monovalent HAV vaccines (Havrix og Vaqta) and combined HAV and hepatitis B vaccines (Twinrix) in Iceland since they were licensed in Iceland. Numbers obtained from the Icelandic Medicines Agency.