Overview and StatisticsWhat are the case definitions for reportable hepatitis C virus (HCV) infections?Case definitions have been developed by CDC, in collaboration with the Council of State and Territorial Epidemiologists, to provide uniform clinical and laboratory-testing criteria for the identification and reporting of nationally notifiable infectious diseases. Case definitions for acute hepatitis C and chronic hepatitis C are available. Show
How many new HCV infections occur annually in the United States?In 2019, a total of 4,136 cases of acute hepatitis C were reported to CDC (2). After adjusting for under-ascertainment and under-reporting, an estimated 57,500 acute hepatitis C cases occurred in 2019. More information on hepatitis C surveillance is available from CDC. What is the prevalence of chronic hepatitis C infection in the United States?An estimated 2.4 million people in the United States were living with hepatitis C during 2013–2016 (3). Who is at risk for hepatitis C infection?The following people are at increased risk for hepatitis C:
Is it possible for someone to become infected with HCV and then spontaneously clear the infection?Yes. Recent data reveal that up to approximately half of people who test anti-HCV positive do not have current chronic infection (1), indicating they may have experienced spontaneous clearance after acute infection. Only those with current infection as evidenced by a positive HCV RNA test need treatment. Factors that are predictive of spontaneous clearance of HCV include having jaundice, elevated ALT level, and hepatitis B virus surface antigen (HBsAg) positivity; younger age, being female; being infected with HCV genotype 1; and having certain host genetic polymorphisms, most notably those near the IL28B gene (6,7). What is the likelihood of HCV infection becoming chronicMore than half of people who become infected with HCV will develop chronic infection (6,7). Why do most people remain chronically infected with HCV?A person infected with HCV mounts an immune response to the virus, but replication of the virus during infection can result in changes that evade the immune response. This may explain how the virus establishes and maintains chronicity (7). What are the chances of someone with HCV infection developing cirrhosis or liver cancer?Of every 100 people infected with HCV, approximately 5–25 will develop cirrhosis within 10–20 years. Patients who develop cirrhosis have a 1%–4% annual risk of developing hepatocellular carcinoma and a 3%–6% annual risk of hepatic decompensation; for the latter patients, the risk of death in the following year is 15%–20% (7). Who is more likely to develop cirrhosis after becoming infected with HCV?Rates of progression to cirrhosis are increased in the presence of a variety of factors, including
How many different genotypes of HCV exist?Seven HCV genotypes and 67 subtypes have been identified (9). Which HCV genotypes are found in the United States?Genotypes 1a, 1b, 2, and 3 are the most common HCV genotypes in the United States (10,11,12). Can superinfection with more than one HCV genotype occur?Superinfection is possible if risk behaviors for HCV infection (e.g., injection-drug use) continue; however, superinfection does not appear to complicate decisions regarding treatment, because HCV antivirals with pan-genotypic activity are available. Can people become infected with a different strain of HCV after they have cleared the initial infection?Yes. Prior infection with HCV does not protect against later infection with the same or different genotypes of the virus. This is because people infected with HCV typically have an ineffective immune response due to changes in the virus during infection. Is hepatitis C a common cause for liver transplantation?Yes. Chronic liver disease and liver cancer caused by chronic HCV infection are a common reason for liver transplants in the United States (13,14). How many deaths can be attributed to chronic HCV infection?In 2018, a total of 15,713 U.S. death certificates had hepatitis C recorded as an underlying or contributing cause of death (2). This number is considered a conservative estimate; data indicate that most people who die from hepatitis C lack documentation of HCV infection on their death certificates (15). Is there a hepatitis C vaccine?Development of a vaccine for hepatitis C has been challenging, because the virus has multiple genotypes and subtypes and mutates rapidly, allowing it to evade the immune system. However, novel vaccine candidates based on advanced molecular technology have been explored (16). Transmission and SymptomsHow is HCV transmitted?HCV is transmitted primarily through parenteral exposures to infectious blood or body fluids that contain blood. Possible exposures include
Although less frequent, HCV can also be spread through:
What is the prevalence of hepatitis C among people who inject drugs (PWID)?No nationwide seroprevalence surveys targeting PWID have been conducted in the United States, and estimates based on smaller surveys in regional and metropolitan areas vary considerably. A 2017 review estimated an overall hepatitis C prevalence of about 53% among PWID in the United States, which varies from state to state (range: 38.1%–68.0%) (17). Is non-injection cocaine use associated with HCV transmission?Possibly. Limited epidemiologic data suggest an additional risk from non-injection (snorted or smoked) use of cocaine, but this risk is difficult to differentiate from associated injection-drug use and sex with HCV-infected partners. What is the risk of acquiring hepatitis C from transfused blood or blood products in the United States?Now that more advanced screening tests for hepatitis C are used in blood banks, the risk of transmission to recipients of blood or blood products is considered extremely rare, at <1 case per 2 million units transfused. Before 1992 (the year that blood screening became available), blood transfusion was a leading cause of hepatitis C virus transmission (18,19). Can hepatitis C be spread during medical or dental procedures?As long as Standard Precautions and other infection-control practices are consistently implemented, medical and dental procedures performed in the United States generally do not pose a risk for the spread of hepatitis C. However, hepatitis C can be spread in health-care settings when injection equipment, such as syringes, is shared between patients or when injectable medications or intravenous solutions are mishandled and become contaminated with blood. Health-care personnel should understand and adhere to Standard Precautions, which include maintaining injection safety practices aimed at reducing bloodborne pathogen risks for patients and health-care personnel. Cases of suspected health-care-associated HCV infection should be reported to state and local public health authorities for prompt investigation and response. Do hepatitis C outbreaks occur in health care settings?Yes. Hepatitis C can be spread in health-care settings (20,21) when Standard Precautions and other infection-control practices are not consistently implemented. In the United States, health-care-associated transmission of hepatitis C has been associated with inadequate infection prevention practices during inpatient care, outpatient care, and hemodialysis. These infection control breaches have included reuse of syringes and other failures of aseptic technique, contamination of multidose vials, and inadequate cleaning of equipment. Diversion of controlled substances for illicit use has also been associated with outbreaks (22). Often, health-care-associated outbreaks are first detected by astute clinicians who find new infections in people without risk factors and then report cases to public health authorities. Can hepatitis C be spread within a household?Yes; however, transmission between household members does not occur very often. If hepatitis C is spread within a household, it is most likely a result of direct (i.e., parenteral or percutaneous) exposure to the blood of an infected household member. What are the signs and symptoms of acute HCV infection?People with newly acquired HCV infection usually are asymptomatic or have mild symptoms that are unlikely to prompt a visit to a health-care professional. When symptoms do occur, they can include:
How soon after exposure to HCV do symptoms appear?In those people who do develop symptoms, the average period from exposure to symptom onset is 2–12 weeks (range: 2–26 weeks) (13, 14). What are the signs and symptoms of chronic HCV infection?Most people with chronic HCV infection are asymptomatic or have non-specific symptoms such as chronic fatigue and depression. Many eventually develop chronic liver disease, which can range from mild to severe, including cirrhosis and liver cancer. Chronic liver disease in HCV-infected people is usually insidious, progressing slowly without any signs or symptoms for several decades. In fact, HCV infection is often not recognized until asymptomatic people are identified as HCV-positive when screened for blood donation or when elevated alanine aminotransferase (ALT, a liver enzyme) levels are detected during routine examinations. What are the extrahepatic manifestations of chronic HCV infection?Some people with chronic HCV infection develop medical conditions due to hepatitis C that are not limited to the liver. Such conditions can include:
Testing and DiagnosisWho should be tested for HCV infection?CDC now recommends universal hepatitis C screening for all U.S. adults and all pregnant women during every pregnancy, except in settings where the prevalence of HCV infection is <0.1% (see How should providers determine hepatitis C prevalence?). This includes
Who should be tested for HCV on a routine basis?Routine periodic testing is recommended for people with ongoing risk factors, while risk factors persist, including those who currently inject drugs and share needles, syringes, or other drug preparation equipment, along with people who have certain medical conditions (e.g., people who ever received maintenance hemodialysis). Testing of people at risk should occur regardless of setting prevalence. How should providers determine hepatitis C prevalence to inform testing within their practices?In the absence of hepatitis C prevalence data in a particular practice or patient catchment area, providers and program directors should immediately begin screening all adults and all pregnant women during each pregnancy for HCV infection. To determine the baseline prevalence, providers and program directors are encouraged to consult CDC or their state and local health departments to determine a reasonable estimate in their setting or a methodology for determining how many people they need to screen before confidently being able to establish that the prevalence is below 0.1%. See CDC’s hepatitis C testing guidelines for detailed information on calculating prevalence in a health-care setting. What blood tests are used to detect HCV infection?Several blood tests can detect HCV infection, including:
How do I interpret the different tests for HCV infection?A table on the interpretation of results of tests for HCV infection and further actions is available at https://www.cdc.gov/hepatitis/HCV/PDFs/hcv_graph.pdfpdf icon. Is an algorithm for hepatitis C diagnosis available?A flow chart that outlines the serologic testing process beginning with HCV antibody testing is available at https://www.cdc.gov/hepatitis/HCV/PDFs/hcv_flow.pdfpdf icon. How soon after exposure to HCV can HCV antibodies be detected?Anti-HCV seroconversion occurs an average of 8–11 weeks after exposure (25,26,27,28,29,30), although cases of delayed seroconversion have been documented in people who are immunosuppressed (e.g., those with HIV infection) (31,32). How soon after exposure to HCV can HCV RNA be detected?People with recently acquired acute infection typically have detectable HCV RNA levels as early as 1–2 weeks after exposure to the virus (26). Is an HCV antibody (anti-HCV) test sufficient to diagnose current HCV infection?No. The anti-HCV test only provides information about past exposure to HCV. A negative anti-HCV result indicates that a patient has never been exposed to the virus, and therefore the anti-HCV test is only used to rule out HCV infection. If a person tests positive for HCV antibodies, hepatitis C testing is not considered complete unless the initial positive anti-HCV test is followed by a test for HCV RNA as per CDC guidelines. A positive test for HCV RNA is needed before a patient can be diagnosed with current HCV and begin receiving treatment. Ideally, positive antibody tests are “reflexed” to an HCV RNA test automatically from the same blood sample. However, reflex testing is not possible in every laboratory or clinical setting. Is someone with a positive anti-HCV test still at risk for hepatitis C?Yes. A person with a positive anti-HCV test is susceptible to future HCV infections. People with ongoing risk factors, such as those who currently inject drugs and those who have previously tested anti-HCV positive and HCV RNA negative, should receive periodic HCV RNA testing. Under what circumstances might a false-negative HCV antibody (anti-HCV) test result occur, even when a person has been exposed to HCV?People who have been very recently infected with HCV might not yet have developed antibody levels high enough to be detected by the anti-HCV test. The window period for acute HCV infection before the detection of antibodies averages 8 to 11 weeks, with a reported range of 2 weeks to 6 months. In addition, some people might lack the immune response necessary to develop detectable antibodies within this time range (31,32). In these people, virologic testing (e.g., PCR for HCV RNA) can be considered. Can a patient have a normal liver enzyme (e.g., ALT) level and still have chronic hepatitis C?Yes. It is common for patients with chronic hepatitis C to have fluctuating liver enzyme levels, with periodic returns to normal or near normal levels. Liver enzyme levels can remain normal for over a year despite chronic liver disease (28). Where can I learn more about hepatitis C serology?CDC offers an online training that covers the serology of acute and chronic hepatitis C and other types of viral hepatitis. Management and TreatmentWhat should a provider do for a patient with confirmed HCV infection?CDC recommends that people who are diagnosed with hepatitis C be provided
More information on recommendations for testing, management, and treating hepatitis C are available from CDC and the American Association for the Study of Liver Diseases and the Infectious Diseases Society of Americaexternal icon. What advice and messages should be given to patients diagnosed with hepatitis C?Providers should talk to their patients about
Which types of health-care providers can effectively manage patients with hepatitis C?Given that hepatitis C treatment has been simplified, many types of providers can effectively manage HCV-infected patients, including internal medicine and family practice physicians, nurse practitioners, physician assistants, and pharmacists (33). Specialists (e.g., infectious-disease physicians, gastroenterologists, pediatricians, and hepatologists) may be more appropriate when managing children with hepatitis C and patients who have certain HCV-related sequelae or advanced disease, including those requiring a liver transplant. What resources are available to providers who wish to manage treatment for patients with hepatitis C?Primary-care and other types of providers wishing to manage treatment for patients with hepatitis C can learn from the Project ECHOexternal icon model of hepatitis C treatment delivery. AASLD/IDSA also have published guidance for the management of patients with hepatitis C. external icon Is routine HCV genotyping required when managing a person with hepatitis C?Not usually. With the advent of hepatitis C therapies that are effective against many genotypes, genotyping is no longer required prior to treatment initiation. However, pre-treatment genotyping continues to be recommended for patients with evidence of cirrhosis and/or past unsuccessful hepatitis C treatment, because this knowledge can help tailor treatment regimens and improve patient outcomes. Should people with hepatitis C be restricted from working in certain occupations or settings?No one should be excluded from work, school, play, child-care, or other settings on the basis of their infection status (see CDC’s recommendations for prevention and control of HCV infection). There is no evidence that hepatitis C can be transmitted from food handlers, teachers, or other service providers in the absence of blood-to-blood contact. Should patients with acute hepatitis C receive treatment?With the exception of pregnant women and children under 3 years of age, people with acute hepatitis C (i.e., those with measurable HCV RNA) should be treated for their infection. There is no need to wait for potential spontaneous viral resolution. For more information about management of people diagnosed with acute HCV infection, see http://www.hcvguidelines.orgexternal icon. What is the treatment for chronic hepatitis C?Over 90% of people infected with hepatitis C virus (HCV) can be cured of their infection, regardless of HCV genotype, with 8–12 weeks of oral therapy (34). To provide health-care professionals with timely guidance as new therapies are available and integrated into hepatitis C treatment regimens, the Infectious Diseases Society of America (IDSA) and American Association for the Study of Liver Diseases (AASLD), in collaboration with the International Antiviral Society–USA (IAS–USA), developed evidence-based, expert-developed recommendations for hepatitis C management. These recommendations are available at http://www.hcvguidelines.orgexternal icon. Are patients undergoing treatment for hepatitis C at risk for reactivation of an existing hepatitis B virus (HBV) infection? How are these patients managed?Yes. HBV reactivation has recently been reported in co-infected patients receiving direct acting antiviral (DAA) therapy for hepatitis C virus (HCV) infection. Therefore, all patients initiating HCV DAA therapy should be tested for HBV with HBsAg, anti-HBs, and anti-HBc. People testing positive for HBsAg and/or anti-HBc should be monitored while receiving HCV treatment. More information about treating HBV/HCV co-infected patients can be found on these sites: http://hcvguidelines.orgexternal icon and https://www.aasld.org/publications/practice-guidelines-0external icon. For more information on HBV reactivation, see the American Gastroenterological Association’s Hepatitis B Reactivation During Immunosuppressive Drug Therapyexternal icon. Hepatitis C and Health-care PersonnelHow can health-care personnel avoid exposure to HCV?Avoiding occupational exposure to blood is the primary way to prevent transmission of bloodborne illnesses among health-care personnel. To promote blood safety in the workplace, health-care personnel should consult infectious-disease control guidance from the National Institute for Occupational Safety and Health and from CDC. Depending on the medical procedure involved, Standard Precautions may include the appropriate use of personal protective equipment (e.g., gloves, masks, and protective eyewear). What is the risk of acquiring hepatitis C after being accidentally exposed to HCV-contaminated blood or body fluids in the workplace?Although sharps injuries have decreased in recent decades due to improved prevention measures, they continue to occur, placing health-care personnel at risk for several bloodborne pathogens like hepatitis C. A recent analysis of several studies revealed an overall 0.2% risk for infection among those exposed to HCV-antibody-positive blood through needlestick or sharps injuries (35). Updated guidelines for management and treatment of hepatitis Cexternal icon are available to provide guidance for health-care personnel who become infected via exposure to contaminated blood at the workplace. Other than needlesticks, do other exposures (like splashes to the eye) place health-care personnel at risk for hepatitis C?Although a few cases of hepatitis C virus transmission via blood splash to the eye have been reported, the risk for such transmission is extremely low (35,36). In a report of U.S. data from 2002–2015, no HCV transmission occurred among 458 health care personnel with mucous membrane exposure (35). However, it was unknown whether the HCV-antibody-positive patients had current infection at the time of exposure. Should HCV-infected health-care personnel be restricted in their work?Most health-care personnel infected with HCV need not modify their professional duties based on infection status, because the risk of transmission from an infected health-care provider to a patient is very low. Specific guidance for providers that perform certain types of surgery that may pose a risk of bloodborne virus transmission based on HCV RNA level is available from the Society for Health care Epidemiology of Americapdf iconexternal icon (SHEA) (37). All health-care personnel, including those who are HCV positive, should follow a strict aseptic technique as described by the National Institute for Occupational Safety and Health and the CDC, including appropriate hand hygiene, use of protective barriers, and safe injection practices. Note that all people with HCV infection are recommended to receive curative treatment (www.hcvguidelines.orgexternal icon). How are health-care personnel managed after being exposed to the blood of an infected patient?CDC does not recommend postexposure prophylaxis (PEP) for health-care personnel exposed to hepatitis C virus (HCV)-contaminated blood (25, 38, 43). Instead, the source patient in question should be tested for HCV RNA or hepatitis C antibodies pdf icon[PDF – 177 KB](43). Baseline testing of the source patient and the health-care personnel should be done as soon as possible (preferably within 48 hours) after the exposure. For health-care workers exposed to a patient testing positive for hepatitis C infection, or whose status remains unknown, management should be guided by CDC’s testing algorithm pdf icon[PDF – 177 KB](43). Health-care workers who become infected with HCV should be referred for care consistent with current AASLD/IDSA guidelines external iconfor evaluation and treatment of all persons with acute or chronic HCV infection. Questions and Answers regarding updated CDC guidance published July 24, 2020: Testing and Clinical Management of Health Care Personnel Potentially Exposed to Hepatitis C Virus — CDC Guidance, United States, 2020 MMWR Recommend Rep 2020;69(No. RR-6):1–8 Pregnancy and Hepatitis CShould pregnant women be tested for HCV antibodies?Yes. All pregnant women should be screened for anti-HCV during each pregnancy, except in settings where the prevalence of HCV infection (HCV RNA‑positivity) is <0.1% (see How is HCV prevalence determined?). Pregnant women with known risk factors should be tested during each pregnancy, regardless of setting prevalence. Any pregnant women testing positive for anti-HCV should receive a PCR test for HCV RNA to determine current infection status. Can a mother with hepatitis C infect her infant during birth?The overall risk of an infected mother transmitting HCV to her infant is approximately 4%–8% per pregnancy (39). Transmission occurs during pregnancy or childbirth, and no prophylaxis is available to protect the newborn from infection. The risk is significantly higher if the mother has a high HCV viral load, or is coinfected with HIV with which the rate of transmission ranges from 8%–15% (39). Most infants infected with HCV at birth have no symptoms. Should a woman with hepatitis C be advised against breastfeeding?No. There is no evidence that breastfeeding spreads hepatitis C. Currently, both the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists support breastfeeding in HCV-infected women (40,41). Not enough information is available regarding the risks of transmission through breastfeeding by infected mothers with cracked or bleeding nipples. However, because HCV is a bloodborne infection, if a mother with hepatitis C has cracked or bleeding nipples, she should stop nursing temporarily until her nipples heal (41). When should children born to HCV-infected mothers be tested to see if they were infected at birth?According to guidelinesexternal icon from the Infectious Diseases Society of America (IDSA) and the American Association for the Study of Liver Disease (AASLD), children should be tested for HCV antibodies (anti-HCV) no sooner than age 18 months because anti-HCV from the mother might last until this age. If diagnosis is desired before the child reaches 18 months, testing for HCV RNA can be performed at or after the infant’s first well-child visit at age 1–2 months. HCV RNA testing should then be repeated at a subsequent visit, independent of the initial HCV RNA test result (42). References
What classification of drug allergy would be described as an immune system reaction to injected proteins used to treat immune conditions?Serum sickness is a reaction that is similar to an allergy. The immune system reacts to medicines that contain proteins used to treat immune conditions.
What client is most likely to have impaired drug metabolism?Elderly and pediatric patients are particularly vulnerable to ADRs because drugs are less likely to be studied extensively in these extremes of age, and drug absorption and metabolism are more variable and less predictable in both of these groups.
What changes due to aging in the geriatric client may affect excretion and promote accumulation of drugs in the body?Increased Sensitivity to Many Drugs: The problems of decreased body size, altered body composition (more fat, less water), and decreased liver and kidney function cause many drugs to accumulate in older people's bodies at dangerously higher levels and for longer times than in younger people.
Which client is most likely to experience the benefits of the placebo effect?3 People who are highly motivated and expect the treatment to work may be more likely to experience a placebo effect. A prescribing physician's enthusiasm for treatment can even impact how a patient responds.
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