Viral hepatitis leads to liver disease and kills almost 1.4 million people every year. It is caused by the hepatitis A, B, C, D and E viruses, with A, B and C being the most common. An estimated 240 million people are chronically infected with hepatitis B, and 150 million with hepatitis C. Yet viral hepatitis is still largely ignored or unknown.
For World Hepatitis Day on Monday, July 28, the World Health Organization (WHO) and its partners are urging policymakers, health workers and the public to "think again" about this silent killer. For more on World Hepatitis Day, you can visit the websites of WHO and the World Hepatitis Alliance.
Recently I interviewed Dr. Peter Sarnow, Professor in the Stanford University Department of Microbiology and Immunology and one of the Editors of Virology, about the disease, and what researchers are doing to combat it.
You can listen to the interview here: Interview with Peter Sarnow.mp3
Here is a summary of the interview.
Professor Sarnow, what is hepatitis?
Hepatitis can be caused by hepatitis C virus, hepatitis B virus, and also hepatitis A virus. They can infect the liver, but these viruses are very distinct from each other. Hepatitis A virus is a picornavirus that grows very poorly in the liver and does not persist in the liver. The Hepatitis B viral genome persists in the liver as a DNA intermediate. Hepatitis C virus is a flavivirus which has a positive-stranded RNA genome, but that virus can persist in the liver in a low copy number for over 30 years and, for reasons we don't quite understand, can evade the immune system..
So these three viruses are very, very different from each other; they have very different life "styles" and they cause very different degrees of pathogeneses. But in the end, all three can cause hepatitis and can cause liver damage and cirrhosis.
How are hepatitis viruses transmitted?
Well, hepatitis B and C viruses are transmitted only via blood. There is very little evidence that they are sexually transmitted. And hepatitis A virus, which is poorly infectious, is transmitted through oral-fecal routes.
How can hepatitis be prevented or treated?
While there are vaccines for hepatitis A and B virus, we don't have vaccines for hepatitis C virus. That is kind of the Holy Grail. But now, we do have compounds that eliminate or severely lower the yield of the virus. For example, sofosbuvirin has a sustained virology rate of about 95.95 percent or higher, which is amazing – it's unbelievable. This compound inactivates the virus-encoded RNA-dependent RNA polymerase that amplifies the viral RNA in the infected liver.
So we really feel very confident that in most cases we can eliminate the virus in infected people. But of course there will always be some people who may not be responding as well to the new class of compounds, so that's why I think it's good to continue to look for alternative ways, such as inhibitors of host cell molecules that are important for virus growth.
This year, World Hepatitis Day aims to make people think again and to raise awareness of viral hepatitis. What do you think the future holds for research in this area?
I think what is most important is that people who work with the hepatitis A, B, and C virus … really work together and share a lot of information that pertains to the strategy of how these viruses multiply in the liver as an organ. We need to learn from people who study the liver. For example, cholesterol is important for all three viruses, so we need to learn from scientists who know about cholesterol biosynthesis. We need to know about innate immune responses in the liver, we need to know about the function of liver infiltrating CD4+ T cells, for example. And we need to collaborate with people who study molecular aspects of viral replication in tissue culture cells, which are obviously dividing in contrast to the liver organ, to learn about mechanisms of viral proliferation.
So I really see that MDs and PhDs and pharma all need to work together and talk to each other — and also keep an eye on what we have learned from drugs that have been successful against HIV, for example, and what can we learn about similar drugs against and compounds to proteins that are encoded by hepatitis C virus.
World Hepatitis Day Virtual Special Issue
In this virtual special issue, you can read hepatitis research published in 2014 for free until 23 October 2014.
Production and characterization of high-titer serum-free cell culture grown hepatitis C virus particles of genotype 1–6
Christian K. Mathiesen, Tanja B. Jensen, Jannick Prentoe, Henrik Krarup, Alfredo Nicosia, Mansun Law, Jens Bukh, Judith M. Gottwein
Virology, Volumes 458–459, June 2014, Pages 190–208
Read more in the Virology Highlights blog post, written by the author.
Evidence-to-policy gap on hepatitis A vaccine adoption in 6 countries: Literature vs. policymakers' beliefs
Sachiko Ozawa, Lois A. Privor-Dumm, Angeline Nanni, Emily Durden, Brett A. Maiese, Chizoba U. Nwankwo, Kimberly G. Brodovicz, Camilo J. Acosta, Kathleen A. Foley
Vaccine, Volume 32, Issue 32, 7 July 2014, Pages 4089–4096
Are we there yet? Assessing achievement of vaccine-preventable disease goals in WHO's Western Pacific Region
Karen Hennessey, W. William Schluter, Xiaojun Wang, Liliane Boualam, Youngmee Jee, Jorge Mendoza-Aldana, Sigrun Roesel, Sergey Diorditsa, John Ehrenberg
Vaccine, Volume 32, Issue 34, 23 July 2014, Pages 4259–4266 [divider]
Antiviral strategies for hepatitis E virus
Yannick Debing, Johan Neyts
Antiviral Research, Volume 102, February 2014, Pages 106–118
Read the Antiviral Research Hepatitis C Symposium. [divider]
Mutagenesis of hepatitis E virus helicase motifs: Effects on enzyme activity
Vaibhav Mhaindarkar, Kavyanjali Sharma, Kavita S. Lole
Virus Research, Volume 179, 22 January 2014, Pages 26–33[divider]
Current Opinion in Virology
Nucleoside/nucleotide analog inhibitors of hepatitis B virus polymerase: mechanism of action and resistance
Luis Menéndez-Arias, Mar Álvarez, Beatriz Pacheco
Current Opinion in Virology, Volume 8, October 2014, Pages 1–9
Read the full issue: Antivirals and resistance, edited by Luis Menendez-Arias and Douglas Richman [divider]
Diagnostic Microbiology and Infectious Disease
Analysis of potential antiviral resistance mutation profiles within the HBV reverse transcriptase in untreated chronic hepatitis B patients using an ultra-deep pyrosequencing method
Sevgi Ciftci, Fahriye Keskin, Aris Cakiris, Filiz Akyuz, Binnur Pinarbasi, Neslihan Abaci, Erdinc Dincer, Selim Badur, Sabahattin Kaymakoglu, Duran UstekDiagnostic Microbiology and Infectious Disease, Volume 79, Issue 1, May 2014, Pages 25–30
Characteristics of the cellular immune response in HIV/HCV patients with hemophilia during peginterferon/ribavirin therapy in southern China
Lu Yingying, Wang Jiangrong, Liao Jing
Diagnostic Microbiology and Infectious Disease, Volume 78, Issue 1, January 2014, Pages 45–48
Journal of Clinical Virology
Hepatitis B virus DNA quantification with the three-in-one (3io) method allows accurate single-step differentiation of total HBV DNA and cccDNA in biopsy-size liver samples
Andrzej Taranta, Bui Tien Sy, Behrend Johan Zacher, Magdalena Rogalska-Taranta, Michael Peter Manns, Claus Thomas Bock, Karsten Wursthorn
Journal of Clinical Virology, Volume 60, Issue 4, August 2014, Pages 354–360
Severe acute hepatitis E in an HIV infected patient: Successful treatment with ribavirin
A. Robbins, D. Lambert, F. Ehrhard, V. Brodard, M. Hentzien, D. Lebrun, Y. Nguyen, T. Tabary, J.M. Peron, J. Izopet, F. Bani-Sadr
Journal of Clinical Virology, Volume 60, Issue 4, August 2014, Pages 422–423[divider]
International Journal of Infectious Diseases
High load hepatitis B virus replication inhibits hepatocellular carcinoma cell metastasis through regulation of epithelial–mesenchymal transition
Tianzhen Wang, Yinji Jin, Ran Zhao, Yiqi Wu, Yuhua Zhang, Di Wu, Dan Kong, Xiaoming Jin, Fengmin Zhang
International Journal of Infectious Diseases, Volume 20, March 2014, Pages 37–41[divider]
Journal of Infection
Therapy of chronic hepatitis C virus infection in the era of direct-acting and host-targeting antiviral agents
Vincenza Conteduca, Domenico Sansonno Sabino Russi, Fabio Pavone, Franco Dammacco
Journal of Infection, Volume 68, Issue 1, January 2014, Pages 1–20
High urine IP-10 levels associate with chronic HCV infection
Linda Petrone, Teresa Chiacchio, Valentina Vanini, Elisa Petruccioli, Gilda Cuzzi, Cristina Di Giacomo, Luigia Pucci, Marzia Montalbano, Raffaella Lionetti, Angela Testa, Daniele Lapa, Assunta Navarra, Ubaldo Visco-Comandini, Delia Goletti
Journal of Infection, Volume 68, Issue 6, June 2014, Pages 591–600
Elsevier Connect Contributor
Lucy Goodchild is Senior Marketing Communications Manager for Life Sciences, promoting Elsevier's virology and vaccinology journals and conferences from her home base in Amsterdam. She has a background in science writing and press relations through her previous work at the Society for General Microbiology and Imperial College London . Goodchild earned a BSc degree in genetics and microbiology from the University of Leeds and an MSc in the history of science, technology and medicine from Imperial College London.