At present eight hepatitis B virus (HBV) genotypes have been characterized: A to H. The most common genotype in Northern Europe is genotype A. So far there is no record of the specific HBV genotype distribution in Iceland. Iceland has a small population whose homogeneity has changed due to increasing migration during the past decades. The distribution of HBV genotypes in Iceland was analyzed using sera from 170 Icelandic patients. The samples were obtained before 1989, during an HBV epidemic among intravenous drug users in 1989 to 1992 and after 1994. A fragment of the HBV S-gene was amplified, sequenced and subjected to phylogenetic analysis. Among samples derived before 1989 genotypes A, C, and D were found. Most of the samples diagnosed during the epidemic belonged to genotype D and a smaller portion to genotype A. This suggests that the epidemic was most likely caused either by an endogenous HBV strain or by a strain imported from Europe or the USA. Among samples obtained after 1994, genotypes A to E and G were found, but the majority were of genotypes A, C, and D. This is consistent with an increase in migration and immigration from regions in Asia and Africa during the past 10 years. Thus, the changing prevalence of HBV genotypes in a small isolated community such as Iceland reflects the influence of migration and increasing contacts with regions outside the Western World.

BACKGROUND: The TT virus (TTV) is a newly identified blood-borne virus. Its association with disease is still unknown, and screening of blood donors has not been implemented. Several genotypes of the TTV have been identified.STUDY DESIGN AND METHODS: Three hundred seventy healthy blood donors were randomly selected and tested for TTV by the PCR method. Sequencing of a part of the genome was performed to identify various genotypes of the virus. ALT levels were determined in both infected and uninfected individuals.RESULTS: The TT virus (TTV), was detected in the sera of 23 (6.2%) of 370 healthy Icelandic blood donors; this prevalence is lower than that reported in Japan but higher than that in Scotland. The virus was found in all groups over the age of 19. Sequencing and phylogenetic analysis of 202 bp from open reading frame 1 demonstrated genotypes 1b and 2b 2c and genotype 4 isolates, with the latter bearing 89-percent nucleotide homology with other genotype 4 sequences deposited at GenBank. One sample showed a mixed genotype 1b/ 2c infection. Serum ALT levels were within normal limits in all infected individuals.CONCLUSION: The TTV carrier state does not cause significant liver injury.

This study describes the prevalence of hepatitisG virus (HGV) in Iceland, in blood donors and in persons with parenteral risk factors. Among 370 randomly selected Icelandic blood donors, the prevalence of HGV viraemia was 3.8%, whereas the prevalence of HGV antibodies in the same donor group was found to be 13.2%, thus indicating that at least 17% of blood donors in Iceland had previously been exposed to HGV. Previous exposure was seen in all age groups and also in older blood donors. Among intravenous drug users (IVDUs), the prevalence of HGV was much higher. Among 109 hepatitisC virus (HCV) antibody-positive serum samples collected in the years 1992-1997, 33. 9% were polymerase chain reaction (PCR)-positive for HGV and 48.6% had HGV antibodies. Thus, the pattern of HGV in IVDUs was similar to findings among IVDUs in other western countries. HGV viraemia was detected neither in 10 patients with haemophilia nor in five dialysis patients. However, six of the 10 haemophilic patients and one of the five dialysis patients had HGV antibody. In conclusion, unlike hepatitis C, which seems to have been introduced into Iceland relatively recently and has remained virtually confined to IVDUs, exposure to HGV is common among all age groups in the general population, suggesting that the virus has been prevalent in Iceland for much longer, making additional routes of transmission probable.

OBJECTIVE:First to measure plasma HIV-1 RNA in Icelandic HIV infected individuals and second to evaluate the initial effects of new combination regimens on viral load and CD4+ cell counts in HIV infected patients in Iceland.MATERIAL AND METHODS:The cohort studied consis notted of all HIV infected individuals we received samples from during the period September 1995 to November 1996. HIV-1 RNA and CD4+ cells were measured initially and subsequently every three to six months except when a change was made in the antiretroviral regimen, when samples were measured before the change, three to four weeks later and then every three to six months. The quantitative measurement of viral RNA was performed using the Amplicor HIV Monitor Test (Roche Diagnostic Sys nottems). CD4+ cell counts were measured by flow cytometry.RESULTS:A total of 44 patients were evaluated. The initial RNA ranged from %lt; 2.6 logio to 6.13 logio with a mean of 5.02 log. CD4+ cell counts ranged from 2 to 641 per mm3 (mean 230 cells/mm3). Eleven patients had never been treated with antiretroviral drugs and had greater than 10 000 viral copies per mL of plasma. Twenty five of the patients were evaluated following a change in or initiation of a new treatment. The initial change in treatment led to a +0.7 to -2.88 log change in plasma RNA (mean -0.9 log) and a mean of 6.9 cells per mm3 increase in CD4+ cells. Saquinavir was added to two reverse transcriptase (RT) inhibitors in 11 patients with a resulting mean of 0.23 log fall in RNA levels (range +0.70 log to -0.78 log). Saquinavir plus one RT inhibitor were added to one RT inhibitor in six patients with a subsequent mean of 0.65 log reduction in viral load (range +0.24 to -2.26 log). Saquinavir plus two RT inhibitors were given to four antiretroviral naive patients with a resulting mean of 2.37 log reduction in viral load (range -1.8 log to -2.67 log).CONCLUSIONS:1. In a mixed cohort of RT inhibitor naive and treated patients, the viral RNA ranged throughout the range of the RNA assay. 2. Changes in viral load following changes in treatment were quite variable. 3. Saquinavir alone added to two RT inhibitors did not lead to a significant reduction in viral load. 4. In antiretroviral naive patients the viral load was reduced 100 fold following treatment with saquinavir and two RT inhibitors.

According to antibody analysis, approximately two of every three intravenous drug users in Iceland have become infected with hepatitis C virus (HCV). In this study, serum samples from 55 HCV antibody-positive intravenous drug users (39 males and 16 females) were analyzed by polymerase chain reaction, and the viral strains were grouped into genotypes. Only three genotypes--1a, 3a, and 1b--were found among the drug users. Of 40 persons who were positive by polymerase chain reaction, 23 (57.5%) had type 1a, 15 (37.5%) had type 3a, and one (2.5%) had type 1b. One serum sample was untypeable. HCV viral RNA was detectable in 84.6% of the males and 43.7% of the females, which is a significant difference between the sexes (p < 0.01). In addition, 41 randomly selected HCV antibody-positive intravenous drug users (17 males and 24 females) were tested for HCV viral RNA with a commercially available polymerase chain reaction technique. In this subset of drug users, 76.4% of the males and 33.3% of the females had detectable HCV RNA in their serum, which is also a significant sex difference (p < 0.01). This study shows that two HCV genotypes predominate among intravenous drug users in Iceland, and the results indicate that women eliminate virus more effectively than men.

Eight antibody-positive individuals were detected among 12,000 blood donations during the first year of screening blood donors for hepatitis C virus (HCV) antibodies in Iceland. All 8 were found to have a history of intravenous drug abuse. Six of these 8 individuals had previously donated blood to 27 patients who could be traced and examined for HCV infection. The great majority (23/27, 85%) of the recipients had demonstrable HCV antibodies. Furthermore, RNA analysis with the polymerase chain reaction showed that all patients with HCV antibodies had HCV RNA in their serum and in one hemodialysis patient without HCV antibodies viral RNA could be demonstrated. Genotyping of the HCV strains showed that the genotype of the donor was also identified in all but one of the infected recipients of his/her blood or blood products. This study, therefore, substantiates high infectivity of the HCV by blood or blood factor donation and shows that viremic HCV antibody-negative individuals exist.

During the three year period of October 1990 to October 1993, 124 individuals were identified with antibodies against the hepatitis C virus at the Department of Medical Virology, University of Iceland. The large majority of these were intravenous drug users but also some had become infected by receiving infected blood or blood products. A hepatitis C antibody prevalence study on 1537 randomly picked serum samples demonstrated the prevalence of 0.20%. This prevalence is lower than in most other countries.

This study demonstrates a very high prevalence of antibodies to hepatitis C virus among Icelandic intravenous (i.v.) drug users. Of 152 identified i.v. drug users 95 (63%) were shown to have antibodies to the hepatitis C virus. In contrast the seroprevalence in the general Icelandic population is low, (0.2%). Almost all cases of hepatitis C virus infection in Iceland are due to i.v. drug use or to use of infected blood or blood products. Sporadic cases with unexplained modes of transmission, a significant portion of hepatitis C infections elsewhere, are virtually non-existent in Iceland. The results of this study are consistent with the hypothesis that the sporadic community-acquired cases could be caused by blood transfer due to bites from insect vectors such as mosquitoes which are not found in Iceland.