A household survey of intrafamily norovirus transmission.

Norovirus (NoV) is a leading cause of epidemic and sporadic gastroenteritis in people of all ages. Humans are the primary source of NoV and household contact is one of the risk factors for NoV transmission. However, the mechanisms underlying person-to-person NoV transmission are poorly understood. Here we conducted a survey to profile the frequency and characteristics of intrafamily NoV transmission. Stool samples were collected every week from three households between 2016 and 2020; the total number of samples was 1105. The detection of NoV and the genotyping were performed by reverse transcription-polymerase chain reaction targeting the capsid region and direct sequencing methods. NoV was detected in 3.4% of all samples. Eight NoV genotypes were identified. The most common genotype was GII.17, followed in order by GII.6, GI.6, GII.4, GI.3, and GI.2/GI.8/GI.9. Most NoV-positive samples were obtained from asymptomatic individuals. The highest number of NoV transmissions was found in household 3 (6 infections), followed by household 2 (2 infections), while household 1 had no NoV transmission, suggesting that asymptomatic NoV carriers play a major role in infection as NoV reservoirs in the households. Further clarification of the mode of infection will contribute to improved understanding and an appropriate prevention.

Complete genome analyses of G12P[8] rotavirus strains from hospitalized children in Surabaya, Indonesia, 2017-2018.

Rotavirus A (RVA) is a major viral cause of acute gastroenteritis (AGE) worldwide. G12 RVA strains have emerged globally since 2007. There has been no report of the whole genome sequences of G12 RVAs in Indonesia. We performed the complete genome analysis by the next-generation sequencing of five G12 strains from hospitalized children with AGE in Surabaya from 2017 to 2018. All five G12 strains were Wa-like strains (G12-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1) and were clustered into lineage-III of VP7 gene phylogenetic tree. STM430 sample was observed as a mixed-infection between G12 and G1 strains: G12/G1-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1. A phylogenetic tree analysis revealed that all five Indonesian G12 strains (SOEP379, STM371, STM413, STM430, and STM433) were genetically close to each other in all 11 genome segments with 98.0%-100% nucleotide identities, except VP3 and NSP4 of STM430, suggesting that these strains have originated from a similar ancestral G12 RVA. The VP3 and NSP4 genome segments of STM430-G12P[8] were separated phylogenetically from those of the other four G12 strains, probably due to intra-genotype reassortment between the G12 and G1 Wa-like strains. The change from G12P[6] lineage-II in 2007 to G12P[8] lineage-III 2017-2018 suggests the evolution and diversity of G12 RVAs in Indonesia over the past approximately 10 years.

Viral shedding and the durability of immunoglobulin G antibodies to severe acute respiratory syndrome coronavirus 2.

We followed 45 participants in Surabaya, Indonesia, for 10 months and compared their PCR and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin G (IgG) results. As much as 13 out of 45 participants were IgG seropositive at least once while the remaining 32 stayed IgG seronegative throughout the study. Among 13 seropositive participants, 9 were consecutively seropositive at least twice and were eligible for IgG longevity evaluation. The duration of IgG detection varied from 47 to ≥233 days. We observed intermittent re-positive PCR results suggestive of viral shedding in participants with a longer duration of IgG detection.

Predominance of norovirus GI.4 from children with acute gastroenteritis in Jambi, Indonesia, 2019.

Norovirus (NoV) is one of the most important viral causes of acute gastroenteritis (AGE) in children worldwide. Only a few studies have reported AGE with NoV-positive in some cities in Indonesia. This study aimed to investigate the incidence and clinical characteristic of NoV infection, and also genotype distribution of NoV in children with AGE in Jambi, as the capital and the largest city of Jambi province, Indonesia. Stool samples were collected from children (≤15 years of age) with AGE at three participating hospitals in Jambi from February to April 2019. The detection of NoV and its genotyping were carried out by reverse-transcriptase polymerase chain reaction and direct sequencing. Of the 91 stool samples collected, 14 (15.4%) were positive for NoV. Fever, vomiting, and severe diarrhea were commonly observed in AGE with NoV, while level of dehydration was statistically significant difference between children with NoV-positive and those with NoV-negative. The most prevalent genotype was GI.4 (42.9%), followed by GII.6 (28.6%) and some other genotypes. Interestingly, this study found the predominance of GI.4, differed from previous reports in Indonesia. Continuously investigation of the circulating genotype is needed to control the NoV-infected AGE.

Analysis of genetic and serology of hepatitis A virus infection during and after outbreak in two junior high schools in Surabaya, Indonesia.

Outbreaks of hepatitis A have occurred in some cities in Indonesia. In Surabaya, the capital city of East Java province, Indonesia, hepatitis A outbreaks have been reported since2013, with a marked increase in the number of cases in 2015. The aim of the present study was to analyze the genetic and serology of acute symptomatic cases (early infection) during a hepatitis A outbreak and asymptomatic cases after the outbreak in two junior high schools in Surabaya in 2015 to 2016. Students with acute symptomatic hepatitis A during the outbreak and other students who were asymptomatic 3 to 4 months after the outbreak were enrolled. Asymptomatic students had no symptoms from the outbreak until they were enrolled. Sera were collected to identify anti-hepatitis A virus (HAV) IgM (by enzyme-linked immunosorbent assay) and HAV genetic variations/genotypes (using polymerase chain reaction [PCR]-sequencing and phylogenetic analysis). A total of 33 (97.1%) out of 34 sera of students with acute symptoms were positive for anti-HAV IgM and 18% of them were positive by PCR, identified as HAV subgenotype IA. No prominent amino acid variations were observed from reported HAV sequences from Indonesia. Among 38 sera of asymptomatic students, most (55.3%) were positive for anti-HAV IgM, while none were positive by PCR. In conclusion, HAV-IA was the only subgenotype identified in acute symptomatic cases during the outbreak. The percentage of HAV-specific IgM-positive cases was very high among acute symptomatic students, but that was also high among asymptomatic students, which might contribute as the important source of infection during the outbreak.

PREVALENCE AND RISK FACTORS OF HEPATITIS B AND C VIRUS INFECTIONS AMONG HEMODIALYSIS PATIENTS FROM PRIVATE HEMODIALYSIS UNITS IN SURABAYA, INDONESIA.

The aims of the present study were to profile seroprevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections, and possible risk factors among hemodialysis (HD) patients in private hemodialysis units (HDU) in Surabaya, Indonesia. Sera were obtained from 180 HD patients in 4 different private HDUs and tested for hepatitis B surface antigen (HBsAg) and antibody to HCV (anti-HCV). Patients without HBsAg and anti-HCV at first sampling were followed serologically every 3 months for 9 months, while those with HBsAg or anti-HCV positive sera were subjected continually to PCR to detect HBV DNA and HCV RNA. The prevalence of hepatitis infections varied widely between the HDUs, from 0% to 8.1% of patients positive for HBsAg and 0% to 60.6% of those positive for anti-HCV, respectively. These values were markedly higher than those among the general population, but not as high as in governmental HDUs in Indonesia. New incidence of HBV was not detected in any HDU, whereas that of HCV was found in two HDUs, HCV-1b in one HDU and HCV-1a in the other. Inappropriate practices were observed, such as shortage of medical staff and malfunctions in infection-control committees. Prevalence of HBV and HCV infection among HD patients in private HDUs were high and varied among the HDUs. Isolation of both HBV- and HCV-infected patients and staff education should help to reduce the prevalence of hepatitis infections in HDUs.

Ultradeep Sequencing for Detection of Quasispecies Variants in the Major Hydrophilic Region of Hepatitis B Virus in Indonesian Patients.

Quasispecies of hepatitis B virus (HBV) with variations in the major hydrophilic region (MHR) of the HBV surface antigen (HBsAg) can evolve during infection, allowing HBV to evade neutralizing antibodies. These escape variants may contribute to chronic infections. In this study, we looked for MHR variants in HBV quasispecies using ultradeep sequencing and evaluated the relationship between these variants and clinical manifestations in infected patients. We enrolled 30 Indonesian patients with hepatitis B infection (11 with chronic hepatitis and 19 with advanced liver disease). The most common subgenotype/subtype of HBV was B3/adw (97%). The HBsAg titer was lower in patients with advanced liver disease than that in patients with chronic hepatitis. The MHR variants were grouped based on the percentage of the viral population affected: major, ≥20% of the total population; intermediate, 5% to <20%; and minor, 1% to <5%. The rates of MHR variation that were present in the major and intermediate viral population were significantly greater in patients with advanced liver disease than those in chronic patients. The most frequent MHR variants related to immune evasion in the major and intermediate populations were P120Q/T, T123A, P127T, Q129H/R, M133L/T, and G145R. The major population of MHR variants causing impaired of HBsAg secretion (e.g., G119R, Q129R, T140I, and G145R) was detected only in advanced liver disease patients. This is the first study to use ultradeep sequencing for the detection of MHR variants of HBV quasispecies in Indonesian patients. We found that a greater number of MHR variations was related to disease severity and reduced likelihood of HBsAg titer.

Full genome characterization and phylogenetic analysis of hepatitis B virus in gibbons and a caretaker in Central Kalimantan, Indonesia.

Hepatitis B virus (HBV) from gibbons was characterized, and the possibility of horizontal transmission between gibbons and humans was examined in a gibbon rehabilitation center in Central Kalimantan, Indonesia. Ten gibbons that were positive for the hepatitis B surface antigen (HBsAg) on arrival and 13 caretakers for those gibbons were included in this study. The duration of stay at the rehabilitation center ranged from 1 to 10 years. Serological and molecular analyses were performed. Six gibbons were positive for HBsAg, whereas HBV DNA was detected in all ten of the gibbons sampled. On the other hand, HBsAg was detected in only 1 of the 13 caretakers. HBV samples from seven gibbons and from the one infected human were chosen for complete genome sequencing. A phylogenetic analysis revealed that the cluster of gibbon strains in this study was distinct from strains previously reported from other countries. In the pre-S1 region, we found a unique amino acid residue substitution (P89K), three insertions between T87 and L88 in the genomes of three gibbons, and a 33-nucleotide deletion at the start of pre-S1 that is common in non-human primates. The caretaker sample was identified as HBV subgenotype B3, the most common type in Indonesia. For the complete HBV sequences, the similarity between gibbons in this study and other non-human primate and human HBV isolates was 90-91.9 % and 85.5-89.6 %, respectively. In conclusion, the gibbon HBV genotype was influenced by geographic location and species. To the best of our knowledge, this is the first report characterizing the HBV genes and genomes of indigenous gibbons in Indonesia.

Interleukin-28B polymorphisms and response of chronic hepatitis C patients from Indonesia to pegylated interferon/ribavirin treatment.

This study demonstrated that Indonesian patients with chronic hepatitis C (mostly ethnic Java people) mostly were infected with hepatitis C virus (HCV) genotype 1; however, they carried mainly the major genotypes of interleukin 28B (IL-28B) single nucleotide polymorphisms (SNPs) (rs12979860 CC, rs11881222 TT, rs8103142 AA, and rs8099917 TT), and they mostly achieved sustained virological responses to pegylated interferon/ribavirin treatment.

A deep-sequencing method detects drug-resistant mutations in the hepatitis B virus in Indonesians.

OBJECTIVE: The long-term administration of a nucleos(t)ide analogue (NA) for the treatment of chronic hepatitis B may encourage the emergence of viral mutations associated with drug resistance. Minor populations of viruses may exist before treatment, but are difficult to detect because of technological limitations. Identifying minor viral quasispecies should be useful in the clinical management of hepatitis B virus (HBV) infection. METHODS: Six treatment-naïve Indonesian patients with chronic HBV infection participated in this study. The polymerase region of the HBV genome, including regions with known drug-resistant mutations, was subjected to capillary sequencing and MiSeq sequencing (Illumina). Mutations were analyzed with Genomics Workbench software version 6.0.1 (CLC bio). RESULTS: The mean mapping reads for the six samples was 745,654, and the mean number of amplified fragments ranged from 17,926 to 25,336 DNA reads. Several known drug-resistant mutations in the reverse transcriptase region were identified in all patients, although the frequencies were low (0.12-1.06%). The proportions of the total number of reads containing mutations I169L/M, S202R, M204I/L or N236S were >1.0%. CONCLUSION: Several known NA-resistant mutations were detected in treatment-naïve patients in Indonesia using deep sequencing. Careful management of such patients is essential to prevent drug-resistant mutations from spreading to other patients.

Hepatitis B and C virus infection among hemodialysis patients in Yogyakarta, Indonesia: Prevalence and molecular evidence for nosocomial transmission.

Hemodialysis patients are at an increased risk of acquiring hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. However, the prevalence of hepatitis viral infection and its genotype distribution among hemodialysis patients in Indonesia are unclear. In order to investigate these issues and the possibility of nosocomial transmission, 161 hemodialysis patients and 35 staff members at one of the hemodialysis unit in Yogyakarta, Indonesia, were tested for serological and virological markers of both viruses. HBV surface antigen (HBsAg) was detected in 18 patients (11.2%) and in two staff members (5.7%). Anti-HCV was detected in 130 patients (80.7%) but not in any staff members. Occult HBV and HCV infection were detected in 21 (14.7%) and 4 (12.9%) patients, respectively. The overall prevalence rates of HBV and HCV infection among patients were 24.2% and 83.2%, respectively. HCV infection was independently associated with hemodialysis duration and the number of blood transfusions. Phylogenetic analysis revealed that 23 of 39 tested HBV strains (59%) were genotype B, 11 (28.2%) were genotype C, and 5 (12.8%) were genotype A. HCV genotype 1a was dominant (95%) among 100 tested HCV strains. Nosocomial transmission was suspected because the genotype distribution differed from that of the general population in Indonesia, and because the viral genomes of several strains were identical. These findings suggest that HBV and HCV infection is common among hemodialysis patients in Yogyakarta, and probably occurs through nosocomial infection. Implementation of strict infection-control programs is necessary in hemodialysis units in Indonesia.

Hepatitis E virus infection in two different regions of Indonesia with identification of swine HEV genotype 3.

Hepatitis E is an emerging disease with a high incidence globally. Few data are available on hepatitis E virus (HEV) infection in Indonesia. To obtain molecular information on HEV infection in two regions of Indonesia with different customs and swine breeding conditions, serum samples from 137 swine farm workers, 100 blood donors and 100 swine (27 fecal samples also obtained) in Yogyakarta (Central Java) and from 12 and 64 swine farm workers, 42 and 135 local residents and 89 and 119 swine in Tulungagung (East Java) and Mengwi (Bali), respectively, from our previous study, were compared.Serological tests for anti­HEV antibodies by ELISA, HEV­RNA detection by RT­PCR and phylogenetic analysis were performed. The total prevalence of anti­HEV antibodies in humans was higher in Bali(11.6%) than in Java (5.1%; P=0.015). No significant differences in anti­HEV prevalence among swine farm workers and local residents in Java were found. The finding of swine HEV genotype 3 in specimens from Yogyakarta and genotype 4 from Tulungagung and Bali is somewhat different from other reports.We suggest other factors in addition to close contact with swine might play an important role in HEV transmission of non­endemic/related custom groups. To the best of our knowledge, this is the first report on swine HEV genotype 3 in Indonesia.

GB virus C infection in Indonesian HIV-positive patients.

GB virus C (GBV-C), a human virus of the Flaviviridae family that is structurally and epidemiologically closest to hepatitis C virus (HCV), has been reported to confer beneficial outcomes in HIV-positive patients. However, the prevalence of GBV-C in HIV-positive individuals in Indonesia is unknown. Since GBV-C is more prevalent in anti-HCV positive patients than in anti-HCV negative subjects, transmission of GBV-C and HCV could be by the same method. This study examined the prevalence and molecular characteristics of GBV-C infection in HIV patients in Yogyakarta, Indonesia. The prevalence of GBV-C among HIV patients (n = 125, median age 31 years) based on the 5'UTR region was 111/125 (88.8%), including 39/48 (81.3%) and 72/77 (93.5%) HIV-infected patients with and without HCV infection, respectively. GBV-C isolates were of genotype 2a, 3 and 6 in 58.3%, 12.6% and 28.4% of patients, respectively. Patients with genotype 3 were significantly younger than those with genotypes 2a or 6 (P = 0.001 and P = 0.012, respectively). Genotypes 3 and 6 were significantly associated with injection drug use (P = 0.004 and P = 0.002, respectively) and HCV co-infection (P < 0.001 for both genotypes), indicating a shared transmission route with HCV. In conclusion, the prevalence of GBV-C among HIV-positive patients in Indonesia is high, and three genotypes were detected, namely genotype 2a, 3 and 6.

Detection of highly prevalent hepatitis B virus co-infection with HIV in Indonesia.

AIM: The prevalence of hepatitis B virus (HBV) co-infection with HIV is increasing worldwide because of shared transmission routes. This study aimed to assess the prevalence of HBV and HIV co-infection in Indonesia, and its molecular and clinical characteristics. METHODS: A total of 118 serum samples from HIV-infected patients (age 33.3 ± 8.9 years, 99 male, 19 female) collected in 2009 were serologically examined. HBV DNA was assessed by polymerase chain reaction (PCR) analysis targeting the S region. RESULTS: Overall, 15.3% (18/118) of the patients were hepatitis B surface antigen (HBsAg) positive, whereas 27.1% (32/118) were HBsAg negative but HBV DNA positive, and were considered to have occult HBV infection. HBsAg antibodies and/or HBV core antibodies were detected in 45.6% (31/68) of HBV DNA negative patients. CONCLUSION: HBV co-infection, including occult HBV infection, was common in Indonesian HIV patients. Hepatic damage by the interaction of host immunity and HBV is still a remaining issue in these immunosuppressive patients, and further study will be needed.

[Research activities in Kobe-Indonesia Collaborative Research Centers].

Kobe-Indonesia Collaborative Research Center was established in Institute of Tropical Disease (ITD), Airlangga University, Surabaya, Indonesia in 2007 under the program of ''Founding Research Centers for Emerging and Reemerging Infectious Diseases'' supported by the Ministry of Education, Culture, Sports, Science and Technology, Japan, and then it has been under the Japan Initiative for Global Research Network on Infectious Diseases (J-GRID) since 2010. Japanese researchers have been stationed at ITD, conducting joint researches on influenza, viral hepatitis, dengue and infectious diarrhea. Also, another Japanese researcher has been stationed at Faculty of Medicine, University of Indonesia, Jakarta, carrying out joint researches on'' Identification of anti-hepatitis C virus (HCV) substances and development of HCV and dengue vaccines'' in collaboration with University of Indonesia and Airlangga University through the Science and Technology Research Partnership for Sustainable Development (SATREPS) supported by the Japan Science and Technology Agency (JST) and Japan International Cooperation Agency (JICA) since 2009. In this article, we briefly introduce the background history of Kobe University Research Center in Indonesia, and discuss the research themes and outcomes of J-GRID and SATREPS activities.

SARS-CoV-2 IgG antibody status in unvaccinated and 2-dose vaccinated Indonesians by AstraZeneca.

Indonesia began deploying a COVID-19 vaccine in January 2021, prioritising vaccination for high-risk groups such as healthcare workers, the elderly and those with comorbidities, and ending with the general public due to limited vaccine availability. Our study aimed to evaluate antibody response in Indonesians who had received two doses of the vaccine vs. those who had not. The study design was a cohort study involving 46 unvaccinated people and 23 people who had received the second dose of the AstraZeneca vaccine in three months. Methods used for the qualitative and quantitative detection of IgG antibodies included rapid RI-GHA and ELISA tests. Findings showed that positive IgG antibodies qualitatively detected by the rapid RI-GHA test were significantly higher in those vaccinated (60.9%) than in unvaccinated people (26.1%). Using the ELISA assay, all vaccinated individuals qualitatively showed positive antibodies (cut-off ≥4.33 BAU/ml), and the average quantitative titer of anti-SARS-CoV-2 s-RBD IgG was significantly higher in vaccinated (157.06±238.68 BAU/ml) than in unvaccinated (51.90±87.60 BAU/ml) individuals. Some unvaccinated individuals with no history of infection were found to have anti-SARS-CoV-2 antibodies that may have been previously asymptomatic, although their mean antibody titers were certainly lower than those in the 2-dose group. Approximately 56% of vaccinated individuals had antibody titers above 60 BAU/ml as a cut-off for protective threshold, a significantly higher proportion than unvaccinated individuals. In conclusion, vaccination with two doses AstraZeneca increased anti-SARS-CoV-2 antibodies which resulted in enhanced immunity against symptomatic COVID-19.

Clinical and virological characteristics of hepatitis B or C virus co-infection with HIV in Indonesian patients.

Hepatitis virus-related liver disease increases substantially the mortality rate of patients with HIV on highly active antiretroviral therapy (HAART). Therefore, early diagnosis of hepatitis B virus (HBV) and hepatitis C virus (HCV) is important. However, the prevalence of HBV and HCV infection in Indonesian patients infected with HIV is unknown. Therefore, this study examined the molecular and clinical characteristics of HBV and HCV in 126 patients infected with HIV, mostly on HAART, at Dr. Sardjito Hospital, Yogyakarta, Indonesia. The rates of triple infection, HIV/HCV co-infection, HIV/HBV co-infection, and mono-infection were 4.8%, 34.1%, 3.2%, and 57.9%, respectively. Seven HCV genotypes were detected, with genotypes 1a, 1b, 1c, 3a, 3k, 4a, and 6n found in 23 (52%), 1 (2%), 4 (9%), 5 (11%), 7 (16%), 3 (6%), and 1 (2%) patients, respectively, indicating multiple modes of transmission. HBV-DNA was detected in 2/10 patients with hepatitis B surface antigen; both patients were HAART naive. Univariate analysis revealed that male sex, higher education level, injection drug use, sexual contact, alanine aminotransferase ≥40 IU/L, and aspartate aminotransferase-to-platelet ratio index > 0.5 were associated with HCV co-infection. In multivariate analysis, injection drug use (OR: 26.52; 95% CI: 3.52-199.54) and alanine aminotransferase ≥40 IU/L (OR: 6.36; 95% CI: 1.23-32.89) were independently associated with HCV co-infection. HCV co-infection was common among Indonesian patients infected with HIV, particularly among injecting drug users, and was a risk factor for disease progression of HIV.

Mutations within enhancer II and BCP regions of hepatitis B virus in relation to advanced liver diseases in patients infected with subgenotype B3 in Indonesia.

Studies on the characteristics of mutations within the hepatitis B virus (HBV) genome, their roles in the pathogenesis of advanced liver diseases, and the involvement of host properties of HBV-infected individuals have not been conducted in subgenotype B3-infected populations. For addressing this issue, 40 cases with HBV surface antigen (HBsAg)-positive advanced liver diseases, including advanced liver cancer and cirrhosis (male 31, female 9, age 54.4 ± 11.6-year-old), were collected and compared with 109 cases with chronic hepatitis B (male 71, female 38, age 38.0 ± 13.4-year-old). Mutations in enhancer II (Enh II) and basal core promoter (BCP)/precore regions were analyzed by PCR-direct sequencing method. HBV viral load was examined by real-time PCR. For all examined regions, the prevalence of mutation was significantly higher in cases with advanced liver diseases. Multivariate analysis showed that, in patients older than 45 years, C1638T and T1753V mutations constituted independent risk factors for the advancement of liver diseases. The presence of C1638T and T1753V mutations may serve as predictive markers for the progression of liver diseases in Indonesia and other countries, where subgenotype B3 infection is prevalent.

Another novel subgenotype of hepatitis B virus genotype C from papuans of Highland origin.

Hepatitis B virus (HBV) genotypes and subtypes have been identified worldwide. As HBV genotypes/subtypes, the HBV subgenotypes seem to be associated with their geographical distribution and ethnic origin. A previous study showed the novel HBV subgenotype C6 based on the complete genome sequences of isolates in Papua, Indonesia. In the present study, further characterization of HBV in Jayapura (capital of Papua Province), particularly from native people of Papua originating from the highland (highland Papuans) and those from the lowland (lowland Papuans) were examined. Of 32 HBV isolates from both highland and lowland Papuan blood donors with HBsAg positive, part of the S gene and the core gene sequences were analyzed. Analyses of some isolates from highland Papuans were confirmed by the complete genome sequences. Most HBV isolates were classified into genotype C (78.1%), followed by genotype B (18.8%), and genotype D (3.1%). The subtype adr was predominant (71.9%), followed by adw2 (25.1%), and ayw2 (3.1%). As with previous findings, phylogenetic analyses revealed that most HBV isolates from Papuans, C/adr, belonged to subgenotype C6. Interestingly, some C/adr isolates from highland Papuans formed a distinct cluster from all reported subgenotypes of HBV/C, and they differed from HBV/C1-C10 by 4.2-7.2% over the complete genome. SimPlot analysis showed no evidence of recombination with HBV/C1-C10. The isolated life and closed social systems of highland Papuans, even though some have been moving to Jayapura, likely contribute to the formation of this unique cluster of infection with a novel subgenotype of HBV, named C11.

Prevalence of hepatitis E virus among swine and humans in two different ethnic communities in Indonesia.

The purpose of this study was to investigate the prevalence of hepatitis E virus (HEV) infection in swine and humans in different environments in Java and Bali, Indonesia. The prevalence of anti-HEV antibodies in people over 20 years old living in communities in Bali was significantly higher than that in Java. While 68.8% and 90.0% of swine in Bali were anti-HEV positive at 1 and 2 months of age, respectively, swine in Java were at significantly lower risk of HEV infection by the age of 2 months. Our present data suggest that substantial differences in swine-breeding conditions and human living environments affect the rate of HEV infection in humans and swine.