Hiroaki Okamoto

42.8k total citations · 11 hit papers
710 papers, 32.6k citations indexed

About

Hiroaki Okamoto is a scholar working on Hepatology, Epidemiology and Infectious Diseases. According to data from OpenAlex, Hiroaki Okamoto has authored 710 papers receiving a total of 32.6k indexed citations (citations by other indexed papers that have themselves been cited), including 435 papers in Hepatology, 263 papers in Epidemiology and 227 papers in Infectious Diseases. Recurrent topics in Hiroaki Okamoto's work include Hepatitis C virus research (241 papers), Hepatitis Viruses Studies and Epidemiology (229 papers) and Hepatitis B Virus Studies (219 papers). Hiroaki Okamoto is often cited by papers focused on Hepatitis C virus research (241 papers), Hepatitis Viruses Studies and Epidemiology (229 papers) and Hepatitis B Virus Studies (219 papers). Hiroaki Okamoto collaborates with scholars based in Japan, United States and Indonesia. Hiroaki Okamoto's co-authors include Masaharu Takahashi, Tsutomu Nishizawa, Makoto Mayumi, Fumio Tsuda, Shunji Mishiro, Fumio Tsuda, Yuzo Miyakawa, Y. Miyakawa, Y. Akahane and Yoshiki Sugai and has published in prestigious journals such as New England Journal of Medicine, Proceedings of the National Academy of Sciences and The Lancet.

In The Last Decade

Hiroaki Okamoto

679 papers receiving 31.4k citations

Hit Papers

Typing hepatitis C virus by polymerase chain reaction wit... 1988 2026 2000 2013 1992 1997 1988 2014 1998 250 500 750 1000
What are hit papers?

Hit papers significantly outperform the citation benchmark for their cohort. A paper qualifies if it has ≥500 total citations, achieves ≥1.5× the top-1% citation threshold for papers in the same subfield and year (this is the minimum needed to enter the top 1%, not the average within it), or reaches the top citation threshold in at least one of its specific research topics.

  1. Typing hepatitis C virus by polymerase chain reaction with type-specific primers: application to clinical surveys and tracing infectious sources
    1992 1.1k citations Hiroaki Okamoto, Toru Tanaka et al. Journal of General Virology profile →
  2. A Novel DNA Virus (TTV) Associated with Elevated Transaminase Levels in Posttransfusion Hepatitis of Unknown Etiology
    1997 991 citations Tsutomu Nishizawa, Hiroaki Okamoto et al. Biochemical and Biophysical Research Communications profile →
  3. Typing Hepatitis B Virus by Homology in Nucleotide Sequence: Comparison of Surface Antigen Subtypes
    1988 887 citations Hiroaki Okamoto, Fumio Tsuda et al. Journal of General Virology profile →
  4. Consensus proposals for classification of the family Hepeviridae
    2014 565 citations Hiroaki Okamoto et al. Journal of General Virology profile →
  5. Molecular cloning and characterization of a novel DNA virus (TTV) associated with posttransfusion hepatitis of unknown etiology
    1998 516 citations Hiroaki Okamoto Hepatology Research profile →
  6. Full-length sequence of a hepatitis C virus genome having poor homology to reported isolates: Comparative study of four distinct genotypes
    1992 509 citations Hiroaki Okamoto, Takeshi Tanaka et al. profile →
  7. Sporadic acute or fulminant hepatitis E in Hokkaido, Japan, may be food-borne, as suggested by the presence of hepatitis E virus in pig liver as food
    2003 490 citations Masaharu Takahashi, Tsutomu Nishizawa et al. Journal of General Virology profile →
  8. Transmission of Hepatitis C Virus from Mothers to Infants
    1994 473 citations Hiroaki Okamoto, Shunji Mishiro et al. profile →
  9. Hepatitis B viruses with precore region defects prevail in persistently infected hosts along with seroconversion to the antibody against e antigen
    1990 455 citations Hiroaki Okamoto, S Yotsumoto et al. Journal of Virology profile →
  10. Proposed reference sequences for hepatitis E virus subtypes
    2016 321 citations Hiroaki Okamoto et al. Journal of General Virology profile →
  11. ICTV Virus Taxonomy Profile: Hepeviridae 2022
    2022 213 citations Hiroaki Okamoto et al. Journal of General Virology profile →

Peers — A (Enhanced Table)

Peers by citation overlap · career bar shows stage (early→late) cites · hero ref

Name h Career Trend Papers Cites
Hiroaki Okamoto Japan 87 23.3k 15.9k 11.8k 5.3k 2.8k 710 32.6k
Robert H. Purcell United States 114 31.6k 1.4× 24.7k 1.6× 15.0k 1.3× 2.5k 0.5× 2.5k 0.9× 488 44.2k
Harry B. Greenberg United States 103 5.9k 0.3× 8.1k 0.5× 18.9k 1.6× 8.2k 1.5× 7.3k 2.6× 549 37.1k
Marc Van Ranst Belgium 68 2.8k 0.1× 5.9k 0.4× 11.8k 1.0× 4.9k 0.9× 4.8k 1.7× 438 20.2k
Yong Poovorawan Thailand 54 4.3k 0.2× 8.2k 0.5× 6.0k 0.5× 1.2k 0.2× 1.6k 0.6× 763 15.4k
Michael Gale United States 94 7.3k 0.3× 9.7k 0.6× 8.5k 0.7× 1.8k 0.3× 1.8k 0.6× 331 33.2k
Jacques Izopet France 77 14.9k 0.6× 6.2k 0.4× 12.4k 1.0× 341 0.1× 582 0.2× 530 22.3k
Mary K. Estes United States 103 4.3k 0.2× 4.0k 0.3× 31.5k 2.7× 14.0k 2.6× 12.3k 4.3× 523 38.9k
Hubert G.M. Niesters Netherlands 65 4.1k 0.2× 8.5k 0.5× 4.9k 0.4× 962 0.2× 1.5k 0.5× 304 14.3k
Rolf M. Zinkernagel Switzerland 115 1.4k 0.1× 8.7k 0.5× 5.9k 0.5× 1.6k 0.3× 911 0.3× 400 50.7k
Rafi Ahmed United States 137 2.1k 0.1× 15.0k 0.9× 10.0k 0.8× 1.2k 0.2× 614 0.2× 469 76.0k

Countries citing papers authored by Hiroaki Okamoto

Since Specialization
Citations

This map shows the geographic impact of Hiroaki Okamoto's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by Hiroaki Okamoto with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites Hiroaki Okamoto more than expected).

Fields of papers citing papers by Hiroaki Okamoto

Since Specialization
Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by Hiroaki Okamoto. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by Hiroaki Okamoto. The network helps show where Hiroaki Okamoto may publish in the future.

Co-authorship network of co-authors of Hiroaki Okamoto

This figure shows the co-authorship network connecting the top 25 collaborators of Hiroaki Okamoto. A scholar is included among the top collaborators of Hiroaki Okamoto based on the total number of citations received by their joint publications. Widths of edges represent the number of papers authors have co-authored together. Node borders signify the number of papers an author published with Hiroaki Okamoto. Hiroaki Okamoto is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

20 of 20 papers shown
1.
Nosaka, Takuto, Kazuto Takahashi, Hidetaka Matsuda, et al.. (2025). Identification of novel antiviral host factors by functional gene expression analysis using in vitro HBV infection assay systems. PLoS ONE. 20(3). e0314581–e0314581.
2.
3.
Nakaya, Yuki, et al.. (2024). Establishment of a Hepatitis B Virus Reporter System Harboring an HiBiT-Tag in the PreS2 Region. The Journal of Infectious Diseases. 231(1). 204–213. 1 indexed citations
4.
5.
Kanda, Tatsuo, Masayuki Honda, Ryota Masuzaki, et al.. (2023). Hepatitis E Virus Infection Caused Elevation of Alanine Aminotransferase Levels in a Patient with Chronic Hepatitis B and Choledocholithiasis. SHILAP Revista de lepidopterología. 6(4). 55–55. 3 indexed citations
6.
Takahashi, Masaharu, Satoshi Kunita, Tsutomu Nishizawa, et al.. (2023). Infection Dynamics and Genomic Mutations of Hepatitis E Virus in Naturally Infected Pigs on a Farrow-to-Finish Farm in Japan: A Survey from 2012 to 2021. Viruses. 15(7). 1516–1516. 4 indexed citations
7.
Yoshida, Yuichi, Akiko Suzuki, Tamami Abe, et al.. (2023). Seroprevalence and incidence of hepatitis E virus infection in the general population of Iwate prefecture, Japan: A retrospective cohort study. Hepatology Research. 54(1). 24–31. 4 indexed citations
8.
Primadharsini, Putu Prathiwi, Shigeo Nagashima, Takashi Nishiyama, et al.. (2022). Development of Recombinant Infectious Hepatitis E Virus Harboring the nanoKAZ Gene and Its Application in Drug Screening. Journal of Virology. 96(6). e0190621–e0190621. 19 indexed citations
9.
10.
Primadharsini, Putu Prathiwi, Shigeo Nagashima, & Hiroaki Okamoto. (2019). Genetic Variability and Evolution of Hepatitis E Virus. Viruses. 11(5). 456–456. 87 indexed citations
11.
Tanggis, Tominari Kobayashi, Masaharu Takahashi, et al.. (2018). An analysis of two open reading frames (ORF3 and ORF4) of rat hepatitis E virus genome using its infectious cDNA clones with mutations in ORF3 or ORF4. Virus Research. 249. 16–30. 20 indexed citations
12.
Hoshino, Takashi, Hitoshi Takagi, Atsushi Naganuma, et al.. (2016). Fatal fulminant hepatitis caused by infection with subgenotype A1 hepatitis B virus with C1766T/T1768A core promoter mutations. Clinical Journal of Gastroenterology. 9(3). 160–167. 4 indexed citations
13.
Tsatsralt‐Od, Bira, et al.. (2015). Prevalence of hepatitis viruses in patients with acute hepatitis and characterization of the detected genotype 4 hepatitis E virus sequences in Mongolia. Journal of Medical Virology. 88(2). 282–291. 4 indexed citations
14.
Shiraishi, Tetsuya, Hiroaki Okamoto, Toshihiro Mineta, et al.. (2004). Increased cytotoxicity of soluble Fas ligand by fusing isoleucine zipper motif. Biochemical and Biophysical Research Communications. 322(1). 197–202. 46 indexed citations
15.
Takano, Masaoki, Y. Mori, Minoru Horie, et al.. (1999). Detection of bikunin mRNA in limited portions of rat brain. Life Sciences. 65(8). 757–762. 12 indexed citations
16.
Sakamoto, Yasuhiro, Nobutaka Tanaka, Hiroaki Okamoto, et al.. (1997). Surgical Management of Late Esophageal Perforation. The Thoracic and Cardiovascular Surgeon. 45(6). 269–272. 32 indexed citations
17.
Tsuda, Fumio, Naoto Sawada, Masako Fukuda, et al.. (1996). Infection with GB virus C (GBV-C) in patients with chronic liver disease or on maintenance hemodialysis in Indonesia. Journal of Medical Virology. 49(3). 248–252. 90 indexed citations
18.
Saitoh, H., et al.. (1994). Prompt Decrease of Circulating Hepatitis C Virus in Patients with Chronic Hepatitis C after Treatment with Interferon. Journal of Interferon Research. 14(5). 239–244. 7 indexed citations
19.
Miyamoto, Hiroshi, Hiroaki Okamoto, Koei Sato, Toru Tanaka, & Shunji Mishiro. (1992). Extraordinarily low density of hepatitis C virus estimated by sucrose density gradient centrifugation and the polymerase chain reaction. Journal of General Virology. 73(3). 715–718. 90 indexed citations
20.
Okamoto, Hiroaki, S Okada, S Yotsumoto, et al.. (1990). The 5'-terminal sequence of the hepatitis C virus genome.. PubMed. 60(3). 167–77. 424 indexed citations

Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive bibliographic database. While OpenAlex provides broad and valuable coverage of the global research landscape, it—like all bibliographic datasets—has inherent limitations. These include incomplete records, variations in author disambiguation, differences in journal indexing, and delays in data updates. As a result, some metrics and network relationships displayed in Rankless may not fully capture the entirety of a scholar's output or impact.

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