**2. Pollutant removal**

## **2.1 Sources of water pollution**

Water, especially surface water, is exposed to the dangers of pollution, as the water source is considered polluted when it directly or indirectly changes its composition or condition as a result of human action, that is, if it becomes less suitable for some or all uses. These include sewage, household waste, hospital wastewater, and rainwater, where these pollutants are loaded with large quantities of various organic and inorganic materials and many types of microorganisms that cause many diseases, as well as urination, defecation, and throwing dead animals into the water, especially in rural areas, as well as picnic places represented by excreta. and food waste, where the type of sewage network systems plays a major role in the aggravation of these

*Algae Toxins and Their Treatment DOI: http://dx.doi.org/10.5772/intechopen.102909*

pollutants, as there are two types of sewage network systems in Baghdad, which are the separate system and the combined system. Also, the term (red tide) is considered to refer to types of Plankton (phytoplankton) that are spread in high density in any water body (may reach more than ten million cells per liter) and are known as harmful algae. Of the (4400 species) of Plankton plant there are only from (50–60 poisonous species). One of the most important spread of the phenomenon of red tide is a defect in environmental factors, including the difference in the ratio of phosphorous to nitrogen through sewage pollution. The higher the phosphorous rate in the water mass, the higher the rate of red tide or harmful algae appearing with the availability of other environmental conditions. The effects of the red tide are the destruction of fish from economic fish farms if this phenomenon spreads in the farm and costs thousands or even millions of dollars annually. The eyes, nose and mouth are irritated during the presence of algae toxins in the tourist beaches. The toxins increase the toxicity rate of marine food, which is transmitted to humans through marine meals (**Figure 1**).


**Author details**

José Luis Navarro-Olvera1 \*, Armando Armas-Salazar1 , José Damián Carrillo-Ruiz1,2,3, Jesús Q. Beltrán1 , Gustavo Parra-Romero1 and Gustavo Aguado-Carrillo1

1 Unit of Functional and Stereotactic Neurosurgery and Radiosurgery, General Hospital of Mexico. "Dr. Eduardo Liceaga", Mexico City, Mexico

2 Faculty of Health Sciences, Anahuac University, Mexico City, Mexico

3 Research Direction, General Hospital of Mexico. "Dr. Eduardo Liceaga", Mexico City, Mexico

\*Address all correspondence to<EMAIL_ADDRESS>
© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


**6. Conclusion**

The increasing prevalence of previously transplanted patients makes it likely that every anesthesiologist will care for patients with end-organ failure or a transplanted organ, either for accidental or transplant-related surgery in the future. Local, regional, or general anesthesia can be safely delivered to transplant recipients and a successful anesthetic and perioperative management can be provided. However, for the safe management of solid organ recipients, it is essential to have an appropriate knowledge of the physiology of the transplanted organ, the pharmacology of the immunosuppressive drugs, and the presence of associated organ dysfunction.

[4] Keegan MT, Plevak DJ. The transplant recipient for nontransplant surgery. Anesthesiology Clinics of North America. 2004;**22**(4):827-861. PMID: 15541938. DOI: 10.1016/j.atc.2004.05.

Anesthetic Considerations in Transplant Recipients for Nontransplant Surgery

http://dx.doi.org/10.5772/intechopen.74329

249

[5] Shapiro R, Young JB, Milford EL, Trotter JF, Bustami RT, Leichtman AB. Immunosuppression: Evolution in practice and trends, 1993-2003. American Journal of Transplantation. 2005;**5**(4 Pt 2):874-886. PMID: 15760415. DOI: 10.1111/j.1600-6135.2005.00833.x [6] Dickinson DM, Dykstra DM, Levine GN, Li S, Welch JC, Webb RL.Transplant data: Sources, collection and research considerations, 2004. American Journal of Transplantation.

2005;**5**(4 Pt 2):850-861. PMID: 15760413. DOI: 10.1111/j.1600-6135.2005.00840.x

**9**(6):587-595. PMID: 12783400. DOI: 10.1053/jlts.2003.50102

actions of tacrolimus. Hospital Pharmacology. 2015;**2**:291-296

transplant patients. Drugs & Aging. 2007;**24**:913-932. PMID: 17953459

[7] Reding R, Gras J, Sokal E, Otte JB, Davies HF. Steroid-free liver transplantation in children. Lancet. Dec 20, 2003;**362**(9401):2068-2070. PMID: 14697809. DOI: 10.1016/S0140-6736

[8] Greig P, Lilly L, Scudamore C, Erb S, Yoshida E, Kneteman N, Bain V, Ghent C, Marotta P, Grant D, Wall W, Tchervenkov J, Barkun J, Roy A, Marleau D, McAlister V, Peltekian K. Early steroid withdrawal after liver transplantation: The Canadian tacrolimus versus microemulsion cyclosporin A trial: 1-year follow-up. Liver Transplantation. 2003;

[9] Ozbilgin M, Egeli T, Unek T, Ozkardesler S, Avkan-Oguz V, Sagol O, Ozbilgin S, Bacakoglu A, Astarcıoglu I. Incidence of late acute rejection in living donor liver transplant patients, risk factors, and the role of immunosuppressive drugs. Transplantation

[10] Papalois VE, Hakim NS. New immunosuppressive drugs in organ transplantation. In: Hakim NS, editor. Introduction to Organ Transplantation. London: Imperial College

[11] Eide TR, Belenker S. Effect of cardiopulmonary bypass on plasma cyclosporin A levels in a renal transplant patient. Anesthesia and Analgesia. 1992;**74**:288-290. PMID: 1731551

[12] Campana C, Regazzi MB, Buggia I, Molinaro M. Clinically significant drug interactions with cyclosporin. An update. Clinical Pharmacokinetics 1996;**30**:141-179. PMID: 8906896

[13] Rancic N, Vavic NN, Kovacevic AM, Mikov MM, Drgojevic-Simic VM. Drug-drug inter-

[14] Aliabadi AZ, Zuckermann AO, Grimm M. Immunosuppressive therapy in older cardiac

[15] Lill J, Bauer LA, Horn JR, Hansten PD. Cyclosporine-drug interactions and the influence of patient age. American Journal of Health-System Pharmacy. 2000;**57**(17):1579-1584.

[16] Gelb AW, Freeman D, Robertson KM, Zhang C. Isoflurane alters the kinetics of oral

[17] Freeman DJ, Sharpe MD, Gelb AW. Effects of nitrous oxide/oxygen/isoflurane anesthesia on blood cyclosporine concentrations in the rabbit. Transplantation. 1994;**58**:640-642.

cyclosporine. Anesthesia and Analgesia. 1991;**72**(6):801-804. PMID: 2035864

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006

(03)15104-5

Press; 1997. pp. 225-236

PMID: 10984808

PMID: 8091495

Many of the perioperative problems in the transplant population have not been specifically studied, and there are no formal recommendations for their management. Additional research should be performed in order to identify perioperative issues and facilitate the formulation of guidelines for anesthesia in this particular transplanted population.


**4. Concluding remarks and perspectives**

*Drug Repurposing - Hypothesis, Molecular Aspects and Therapeutic Applications*

repurposing process.

stromal tumors [79].

in human diseases [84].

targets or biomarkers.

**3.2 Computational approaches**

**3.1 Experimental approaches**

of appropriate drugs for potential indications is crucial for production of candidate compounds. At present, two approaches are widely used for drug repurposing including experimental screening approaches and molecular docking by computer. In the following items, we make a detailed description of these two methods in drug

Experimental screening approaches are usually regarded as the first stage in the process of drug discovery and drug repurposing. Proteomic techniques such as affinity chromatography and mass spectrometry have been widely employed to identify drug candidates [75]. Nowadays, drug target analysis and drug repurposing are inseparable. Drug repurposing is distinct from drug discovery in terms of alteration of drug target. Cellular thermo stability assay technique can predict the affinity of drug ligands by mapping the contact patterns of intracellular targets [76]. The molecular on and off targets have been disclosed for many clinically approved drugs via this method. Especially in the field of kinases, new targets of well-known drugs are obtained through affinity matrices [77, 78]. For example, imatinib, a tyrosine kinase inhibitor, has been successfully reused in the treatment of gastrointestinal

In addition, chemical compounds with disease-related effects can be defined in the model through phenotype screening [80]. Phenotype screening has always been more successful than target screening in the facet of drug development [81, 82]. In the case of drug repurposing, if the compounds selected through phenotypical assays are approved clinical drugs or ongoing clinical trials, they are probable to reuse. Several drugs approved for tobacco dependence have been evaluated, and it has been found that topiramate changes nicotine- or ethanolinduced behavior in zebrafish models [83]. However, there are some challenges that the efficacy of drug candidates in in vitro experiments require to be validated

Molecular docking by a computer is also an important method for evaluating drug target binding kinetics and drug residence times of existing drugs or drug candidates [85]. Large amounts of computational drug repositioning methods choose transcriptomic data to identify potential new indications for drugs. Furthermore, these methods have applied techniques such as comparison of gene expression profiles between a disease model and drug-treated condition [86], network integration [87], prediction of drug-protein interactions [88], and utilization of genotype–phenotype associations. Recently, a proteotranscriptomic-based computational drug repositioning method named Drug Repositioning Perturbation

Score/Class (DRPS/C) for Alzheimer's disease occurs on the basis of inverse associations between disease-induced or drug-induced gene and protein perturbation patterns [89]. Briefly, these approaches can be applicable to discovery of drug

It should be considered that for many neurological disorders, drugs require good penetration into BBB. Then, the therapeutic approaches of targeting brain have been classified as invasive and noninvasive categories [90, 91]. The invasive approaches contain the temporary increase of BBB permeability, and noninvasive approaches involve modification of drug molecule via physiological, chemical, or colloidal carrier system approach. Meanwhile, these methods are also related

**86**

Drug repurposing is a vital strategy for developing new therapeutic values of existing drugs or drug candidates due to its ability to save time and reduce cost [96]. This type of innovative concept will undoubtedly expedite the drug development process. Meanwhile, some limitations need to be considered during drug repurposing process in neurological diseases. Owing to complex molecular and cellular signaling mechanisms in neuropathological states, drug repurposing may be difficult. Additionally, drugs not only respond to a single target but also affect multiple targets [97], causing a variety of adverse reactions. A comprehensive assessment of the advantages and disadvantages of these side effects can help us understand drug repositioning from a more all-round perspective [98, 99].

In order to overcome limitations faced during drug repurposing, we make proposals in the following descriptions. Firstly, it is foremost to establish a comprehensive data analysis platform to maximize data sharing. Information science services and artificial intelligence can help unlock and reanalyze the large amount of data accumulated by approved drugs or drug candidates to clinical trials. These data may be stored in a diversified way. Storage locations, formats, and types may vary, including different storage locations, formats, and types. The data obtained from clinical trials and biological databases are too large and complex that the traditional data processing methods cannot deal with it, which leads to the bottleneck in the research process [99]. Big data can significantly improve our understanding of the disease and make more accurate disease-related strategies. However, there is a big gap between generating biomedical data and data analysis [99, 100]. To ensure the efficiency of research, it takes time, energy, and expertise to find technical solutions to integrate them. Secondly, it is encouraged to provide more financial support for clinical trials of drug repurposing, including technical support. The preclinical research of drug repurposing requires financial support to obtain the data in clinical trials. In this case, drugs that can be developed to treat rare diseases are more likely to apply in clinical neurological diseases therapeutics [101]. Finally, in order to facilitate drug repurposing process, we advocate it is indispensable to solve patent restrictions and take reasonable supervision. All applications of drug repurposing should be accompanied by a risk management plan. Drug's safety can be supported by clinical trial data or post marketing data.

In conclusion, drug repurposing is a novel approach for expediting drug development process in neurological diseases. Repurposed drugs may provide an efficient avenue for improving a plethora of pathological conditions including neurological disorders. In the future, it is essential to exploit molecular mechanisms during drug repurposing processes due to the possibility that targets of repurposed drugs in neurological diseases are distinct from original targets in treating other diseases, in order to make these drugs more effective and safe.


**4. Chronological precedence of protein formation over codon formation**

To understand the establishment of primitive organisms, the chronological precedence of protein and codon formation is a very important subject in biological evolution. Unfortunately, this theory has not yet been proven, because primitive organisms were formed under so many unknown factors an extremely long time ago. However, a simulation analysis based on a random choice of amino acids or nucleotides was carried out, which assumed that their polymerization depended on their free monomer concentrations, according to the chemical reaction rule that governs natural phenomena. Amino acid polymerizations produced a protein which reflected original free amino acid concentrations without codons, while nucleotide polymerizations did not produce functional proteins, even after considering the codon table, as shown in **Figure 2** [25]. Therefore, it seems difficult to predict "the RNA world" which presumes that RNA polymers formed primitive life forms [26]. Additionally, the possibility of the accumulation of RNA, which has a UV absorbance at around 250 nm, might be very low under the strong UV irradiation present on the primitive Earth. These results suggest that protein formation might chronologically precede codon formation at the end of prebiotic evolution, although we have no explanation of how the nucleotide sequence information necessary for proteins might have been transmitted to the nucleotide polymerization that established the codons. The

#### **Figure 2.**

*Computational amino acid compositions of an* Ureaplasma urealyticum *gene. Upper panel: random choice of amino acids was carried out in the original gene (5005 amino acid pool). Lower panel: random choice of nucleotides was carried out in the original gene (15,018 nucleotides). In the simulation using nucleotides, the stop codon and Trp were discarded from the calculation of amino acid compositions, and a triplet formed was immediately counted as an amino acid. This figure was adapted from Sorimachi and Okayasu [25].*

"amino acid world" [21] seems a better fit for primitive life forms rather than the "RNA world." There are several hypotheses for codon formation [27–29], but the process of codon formation has not yet been determined.

According to our simulation analyses [25], proteins that were components of primitive life forms might reflect the free amino acid concentrations on the primitive Earth. As shown in **Figure 1**, the cellular basic amino acid composition, the "star-shape," is characterized by comparatively high concentrations of hydrophobic amino acids, such as valine, leucine, and isoleucine. The glycine and alanine contents were also comparatively high. The former might contribute to self-aggregation of proteins via hydrophobicity to form primitive life forms under low protein concentrations, and the latter might reflect their easy formation on the primitive Earth. In fact, simple amino acids such as glycine and alanine have been identified in meteorites [30, 31] and can be formed by electrical discharge in an atmosphere presumed to reflect primitive Earth [32]. Conversely, the phenylalanine, tryptophan, and tyrosine content, which can absorb ultraviolet light, were quite low. Strong ultraviolet irradiation might induce photodegradation of these amino acids. The differences in amino acid contents in cellular amino acid compositions seem to reflect the presumed free amino acid concentrations on the primitive Earth and eventually resulted in the formation of the "star-shaped" cellular amino acid compositions (**Figure 1**).

### **5.  This resulted in the amino acid composition deduced from the complete genome resembling the cellular amino acid composition obtained from the amino acid analyses of cell lysates [21], as shown in **Figure 3**. This coincidence is difficult to understand because of the different origins of both values, until the genome structure has been clarified, as shown in the next section.

**13**

**Figure 4.**

*Visible Evolution from Primitive Organisms to* Homo sapiens

*DOI: http://dx.doi.org/10.5772/intechopen.91170*

**6. Homogeneity of genome structure**

*respectively, to compare with data based on amino acid analysis.*

**Figure 3.**

Each gene has its characteristic amino acid or nucleotide sequence, and its amino acid or nucleotide composition differs not only in inter-species but also in intraspecies. Conversely, gene assemblies encoding 3000–7000 amino acid

*Radar charts of amino acid compositions calculated from various units of the complete genome of*

Methanobacterium thermoautotrophicum*. (A) The complete genome structure of* M. thermoautotrophicum *(B) radar charts of amino acid compositions calculated from the complete genome, and (C) from various units. The complete genome, comprising 1869 protein genes, was divided into 10 or 20 units. Ten units (1–10); based on 186 and 195 genes, half size units (1-H–9-H); based on 93 genes, single genes (1-F–9-F); based on the first single gene of each unit. Glutamine and asparagine were calculated as glutamic acid and aspartic acid, respectively, and tryptophan (<1%) was omitted in the radar charts [18]. This figure was adapted from Sorimachi [36].*

*Radar charts of cellular and genomic amino acid compositions. Values are expressed as the percentages of total amino acids.* Pyrococcus horikoshii *was examined. The cellular amino acid composition was obtained from three independent analyses. In genomic calculations, Gln and Asn were also incorporated into Glu and Asp,*

*Visible Evolution from Primitive Organisms to* Homo sapiens *DOI: http://dx.doi.org/10.5772/intechopen.91170*

**Figure 3.**

*Cheminformatics and Its Applications*

**Figure 2.**

"amino acid world" [21] seems a better fit for primitive life forms rather than the "RNA world." There are several hypotheses for codon formation [27–29], but

*Computational amino acid compositions of an* Ureaplasma urealyticum *gene. Upper panel: random choice of amino acids was carried out in the original gene (5005 amino acid pool). Lower panel: random choice of nucleotides was carried out in the original gene (15,018 nucleotides). In the simulation using nucleotides, the stop codon and Trp were discarded from the calculation of amino acid compositions, and a triplet formed was immediately counted as an amino acid. This figure was adapted from Sorimachi and Okayasu [25].*

According to our simulation analyses [25], proteins that were components of primitive life forms might reflect the free amino acid concentrations on the primitive Earth. As shown in **Figure 1**, the cellular basic amino acid composition, the "star-shape," is characterized by comparatively high concentrations of hydrophobic amino acids, such as valine, leucine, and isoleucine. The glycine and alanine contents were also comparatively high. The former might contribute to self-aggregation of proteins via hydrophobicity to form primitive life forms under low protein concentrations, and the latter might reflect their easy formation on the primitive Earth. In fact, simple amino acids such as glycine and alanine have been identified in meteorites [30, 31] and can be formed by electrical discharge in an atmosphere presumed to reflect primitive Earth [32]. Conversely, the phenylalanine, tryptophan, and tyrosine content, which can absorb ultraviolet light, were quite low. Strong ultraviolet irradiation might induce photodegradation of these amino acids. The differences in amino acid contents in cellular amino acid compositions seem to reflect the presumed free amino acid concentrations on the primitive Earth and eventually resulted in the formation of the "star-shaped" cellular amino

the process of codon formation has not yet been determined.

**5.  This resulted in the amino acid composition deduced from the complete genome resembling the cellular amino acid composition obtained from the amino acid analyses of cell lysates [21], as shown in **Figure 3**. This coincidence is difficult to understand because of the different origins of both values, until the genome structure has been clarified, as

**12**

acid compositions (**Figure 1**).

shown in the next section.

*Radar charts of cellular and genomic amino acid compositions. Values are expressed as the percentages of total amino acids.* Pyrococcus horikoshii *was examined. The cellular amino acid composition was obtained from three independent analyses. In genomic calculations, Gln and Asn were also incorporated into Glu and Asp, respectively, to compare with data based on amino acid analysis.*

## **6. Homogeneity of genome structure**

Each gene has its characteristic amino acid or nucleotide sequence, and its amino acid or nucleotide composition differs not only in inter-species but also in intraspecies. Conversely, gene assemblies encoding 3000–7000 amino acid

#### **Figure 4.**

*Radar charts of amino acid compositions calculated from various units of the complete genome of*  Methanobacterium thermoautotrophicum*. (A) The complete genome structure of* M. thermoautotrophicum *(B) radar charts of amino acid compositions calculated from the complete genome, and (C) from various units. The complete genome, comprising 1869 protein genes, was divided into 10 or 20 units. Ten units (1–10); based on 186 and 195 genes, half size units (1-H–9-H); based on 93 genes, single genes (1-F–9-F); based on the first single gene of each unit. Glutamine and asparagine were calculated as glutamic acid and aspartic acid, respectively, and tryptophan (<1%) was omitted in the radar charts [18]. This figure was adapted from Sorimachi [36].*

residues show very similar amino acid compositions [33] and nucleotide compositions [34] in intraspecies examinations. Consistent results were obtained from whole chromosomes consisting of putative small units of 3000–7000 amino acid residues [33]. Additionally, it has been shown mathematically that 3000–7000 amino acid residues represent the amino acid composition of a certain amino acid pool [35]. Thus, genome structure, which is constructed homogeneously from putative similar small units, can be represented by a "pearl-necklace," as shown in **Figure 4**. The fact that the structure of a genome is homogeneously constructed with putative similar small units indicates that micro-alterations of nucleotide sequences are canceled out within the small unit and that the small unit represents the whole genome characteristics. Macro-alterations represented by the small unit, and based on species differences, occur synchronously over the genome [33]. This conclusion has never been obtained from the analysis of nucleotide or amino acid sequences of actual genes. Based on these results, the ratios of amino acids to the total amino acids or those of nucleotides to the total nucleotides form useful indices for characterizing a genome whose nucleotide numbers differ among species.


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## Meet the editors

Dr. Luis Rodrigo, MD, is an Emeritus Professor of Medicine at the University of Oviedo, Spain. He has been the chief of Gastroenterology Service at the HUCA Hospital in Oviedo for more than forty years. He obtained a Ph.D. in 1975 and since then has developed a long career in teaching and research. He has published 707 scientific papers, 425 written in English and 282 in Spanish. He has participated as the main investigator in

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Prof. Xiaozhong Guo is the director of the Department of Gastroenterology, General Hospital of Northern Theater Command (formerly General Hospital of Shenyang Military Area). He has practiced in the field of digestive diseases and digestive endoscopy for more than thirty years. His major achievements include experimental and clinical research on the management of pancreatic diseases, especially pancreatic cancer, and stem cells for di-

gestive diseases, such as liver cirrhosis and ulcerative colitis. He has published more than 500 papers and edited more than ten books. He has received six funds from the National Natural Science Foundation of China. He received first prizes from the Natural Science and Science and Technology Progress Awards of Liaoning Province.

Dr. Xingshun Qi obtained his medical doctoral degree at the Fourth Military Medical University, China, and completed his post-doctoral fellowship at the General Hospital of Shenyang Military Region. Currently, he is a deputy director at the Department of Gastroenterology, General Hospital of Northern Theater Command (formerly General Hospital of Shenyang Military Region). His research interests include the etiology, diagnosis, and management of liver cirrhosis, portal hyContents

**Section 1**

**Section 2**

**Section 3**

*by Alberto Frosi*

**Section 4**

**Section 5**

*by Talari Praveen*

Hepatitis C: An Overview

*by Syed Manzoor Kadri and Marija Petkovic*

Extrahepatic Manifestations of Hepatitis C Infection

Host-Targeting Antivirals for Treatment of Hepatitis C

in Patients with HIV and HCV Co-Infection *by Elena Dumea and Simona Claudia Cambrea*

Liver Transplantation and HCV Genotype 4 *by Saad Alghamdi and Waleed Al-hamoudi*

*by Bouchra Kitab, Michinori Kohara and Kyoko Tsukiyama-Kohara*

The Influence of Protease Inhibitors on the Evolution of Hepatitis C

**Preface XI**

Discovery of Hepatitis C Virus **1**

**Chapter 1 3** Discovery of Hepatitis C Virus: Nobel Prize in Physiology and Medicine 2020

Hepatitis C Virus Characteristics and Evolution **13**

**Chapter 2 15**

Extrahepatic Manifestations **27**

**Chapter 3 29**

Antiviral Treatments **45**

**Chapter 4 47**

**Chapter 5 67**

Liver Transplantation **81**

**Chapter 6 83**

pertension (especially portal vein thrombosis and Budd-Chiari syndrome), and hepatocellular carcinoma. He serves as an associate editor of *BMC Gastroenterology*, an academic editor of the *Canadian Journal of Gastroenterology and Hepatology*, and an academic editor of *Frontiers in Medicine*. His H-index is 37 with 4546 citations.

### Contents

Preface

*Advances in Hepatology* presents new achievements in the clinical management of chronic liver disease patients, including effective treatments for chronic infection mainly related to the hepatitis C virus (HCV). It examines the relationship between obesity and liver diseases such as nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). To prevent and treat deleterious liver effects, bariatric surgery may be indicated in selected patients, which the book

The development of direct-acting antiviral (DAA) agents for the treatment of HCV infection has completely transformed the management of this disease in the last decade. The advantages of using DAA therapies include high efficacy (sustained virological response (SVR) rate > 95%) with minimal side effects, good tolerability, easy drug administration (once-daily oral dosing), and short duration of treatment

Hepatitis C is a high-prevalence disease, representing a global impact health problem. Lately, many changes have been made in treatment guidelines because of the commercialization of second-generation DAAs due to their high effectiveness,

In one recently published study (Liver Int. 2021;41: 456-73) using a mathematical program, the authors evaluated the possibilities of the complete elimination of HCV from the world by the end of 2030, as defined by the World Health Organization (WHO), considering that is attainable with the availability of highly efficacious therapies. This study reports progress made in the timing of HCV elimination in

Disease progression models of HCV infection for each country were updated with the latest data on chronic HCV prevalence and annual diagnosis and treatment levels, assumed to remain constant in the future. Modeled outcomes were analyzed to determine the year in which each country would meet the WHO 2030 elimination

Of the forty-five countries studied, eleven (Australia, Canada, France, Germany, Iceland, Italy, Japan, Spain, Sweden, Switzerland, and United Kingdom) are on track to meet the WHO's elimination targets by 2030; five countries (Austria, Malta, Netherlands, New Zealand, and South Korea) by 2040; and two (Saudi Arabia and Taiwan) by 2050. The remaining twenty-seven countries are not expected to achieve this elimination before 2050. Compared to progress in 2017, South Korea is no longer on track to eliminate HCV by 2030, three countries (Canada, Germany, and Sweden) are now on track, and most countries (thirty in total) saw no change.

The authors conclude that assuming high-income countries will maintain current levels of diagnosis and treatment, only 24% are on track to eliminate HCV by 2030, and 60% are off track by at least twenty years. If current levels of diagnosis

also discusses.

(8–12 weeks).

targets.

few side effects, and pangenotypic action.

forty-five high-income countries between 2017 and 2019.