The remaining 70% (55–85%) of persons will develop chronic HCV infection. Of those with chronic HCV infection, the risk of cirrhosis ranges between 15% and 30% within 20 years.
Hepatitis C is found worldwide. The most affected regions are the WHO Eastern Mediterranean Region and the WHO European Region, with an estimated prevalence in 2015 of 2.3% and 1.5% respectively. Prevalence of HCV infection in other WHO regions varies from 0.5% to 1.0%. Depending on the country, hepatitis C virus infection can be concentrated in certain populations. For example, 23% of new HCV infections and 33% of HCV mortality is attributable to injecting drug use. Yet, people who inject drugs and people in prisons are not often included in national responses.
In countries where infection control practices are or were historically insufficient, HCV infection is often widely distributed in the general population. There are multiple strains (or genotypes) of the HCV virus and their distribution varies by region. However, in many countries, the genotype distribution remains unknown.
The hepatitis C virus is a bloodborne virus. It is most commonly transmitted through:
- injecting drug use through the sharing of injection equipment;
- the reuse or inadequate sterilization of medical equipment, especially syringes and needles in healthcare settings;
- the transfusion of unscreened blood and blood products;
- sexual practices that lead to exposure to blood (for example, among men who have sex with men, particularly those with HIV infection or those taking pre-exposure prophylaxis against HIV infection).
HCV can also be transmitted sexually and can be passed from an infected mother to her baby; however, these modes of transmission are less common.
Hepatitis C is not spread through breast milk, food, water or casual contact such as hugging, kissing and sharing food or drinks with an infected person.
WHO estimates that in 2015, there were 1.75 million new HCV infections in the world (23.7 new HCV infections per 100 000 people).
The incubation period for hepatitis C ranges from 2 weeks to 6 months. Following initial infection, approximately 80% of people do not exhibit any symptoms. Those who are acutely symptomatic may exhibit fever, fatigue, decreased appetite, nausea, vomiting, abdominal pain, dark urine, grey-coloured faeces, joint pain and jaundice (yellowing of skin and the whites of the eyes).
Testing and diagnosis
Because new HCV infections are usually asymptomatic, few people are diagnosed when the infection is recent. In those people who go on to develop chronic HCV infection, the infection is also often undiagnosed because it remains asymptomatic until decades after infection when symptoms develop secondary to serious liver damage.
HCV infection is diagnosed in 2 steps:
- Testing for anti-HCV antibodies with a serological test identifies people who have been infected with the virus.
- If the test is positive for anti-HCV antibodies, a nucleic acid test for HCV ribonucleic acid (RNA) is needed to confirm chronic infection because about 30% of people infected with HCV spontaneously clear the infection by a strong immune response without the need for treatment. Although no longer infected, they will still test positive for anti-HCV antibodies.
After a person has been diagnosed with chronic HCV infection, they should have an assessment of the degree of liver damage (fibrosis and cirrhosis). This can be done by liver biopsy or through a variety of non-invasive tests.
The degree of liver damage is used to guide treatment decisions and management of the disease.
Early diagnosis can prevent health problems that may result from infection and prevent transmission of the virus. WHO recommends testing people who may be at increased risk of infection.
Populations at increased risk of HCV infection include:
- people who inject drugs;
- people in prisons and other closed settings;
- people who use drugs through other routes of administration (non-injecting);
- people who use intranasal drugs;
- recipients of infected blood products or invasive procedures in health-care facilities with inadequate infection control practices ;
- children born to mothers infected with HCV ;
- people with sexual partners who are HCV-infected;
- people with HIV infection;
- prisoners or previously incarcerated persons; and
- people who have had tattoos or piercings.
In settings with high HCV antibody seroprevalence in the general population (defined as >2% or >5% HCV antibody seroprevalence), WHO recommends that all adults have access to and be offered HCV testing with linkage to prevention, care and treatment services.
About 2.3 million people (6.2%) of the estimated 3.7 million living with HIV globally have serological evidence of past or present HCV infection. Chronic liver disease represents a major cause of morbidity and mortality among persons living with HIV globally.
66顺彩票appA new infection with HCV does not always require treatment, as the immune response in some people will clear the infection. However, when HCV infection becomes chronic, treatment is necessary. The goal of hepatitis C treatment is cure.
66顺彩票appWHO’s updated 2018 guidelines recommend therapy with pan-genotypic direct-acting antivirals (DAAs). DAAs can cure most persons with HCV infection, and treatment duration is short (usually 12 to 24 weeks), depending on the absence or presence of cirrhosis.
WHO recommends treating all persons with chronic HCV infection over the age of 12. Pan-genotypic DAAs 66顺彩票appremain expensive in many high- and upper-middle-income countries. However, prices have dropped dramatically in many countries (primarily low-income and lower middle-income countries), due to the introduction of generic versions of these medicines.
Access to HCV treatment is improving but remains too limited. In 2017, of the 71 million persons living with HCV infection globally, an estimated 19% (13.1 million) knew their diagnosis, and of those diagnosed with chronic HCV infection, around 5 million persons had been treated with DAAs by the end of 2017. Much more needs to be done in order for the world to achieve the 80% HCV treatment target by 2030.
There is no effective vaccine against hepatitis C, therefore prevention of HCV infection depends upon reducing the risk of exposure to the virus in health-care settings and in higher risk populations, for example, people who inject drugs and men who have sex with men, particularly those infected with HIV or those who are taking pre-exposure prophylaxis against HIV.
The following list provides a limited example of primary prevention interventions recommended by WHO:
- safe and appropriate use of health care injections;
- safe handling and disposal of sharps and waste;
- provision of comprehensive harm-reduction services to people who inject drugs including sterile injecting equipment and effective treatment of dependence;
- testing of donated blood for HBV and HCV (as well as HIV and syphilis);
- training of health personnel;
- prevention of exposure to blood during sex;
- hand hygiene, including surgical hand preparation, hand washing and use of gloves; and
- promotion of correct and consistent use of condoms.
For people infected with the hepatitis C virus, WHO recommends:
- education and counselling on options for care and treatment;
- immunization with the hepatitis A and B vaccines to prevent coinfection from these hepatitis viruses and to protect their liver;
- early and appropriate medical management including antiviral therapy; and
- regular monitoring for early diagnosis of chronic liver disease.
Screening, care and treatment of persons with hepatitis C infection
In July 2018, WHO updated its "Guidelines for the care and treatment of persons diagnosed with chronic hepatitis C virus infection".
These guidelines are intended for government officials to use as the basis for developing national hepatitis policies, plans and treatment gudelines. These include country programme managers and health-care prividers responsible for planning and implementing hepatitis care and treatment programmes, particularly in low- and middle-income countries.
Summary of key recommendations
1. Screening for alcohol use and counselling to reduce moderate and high levels of alcohol intake
An alcohol intake assessment is recommended for all persons with HCV virus infection followed by the offer of a behavioural alcohol reduction intervention for persons with moderate-to-high alcohol intake.
2. Assessing degree of liver fibrosis and cirrhosis
In resource-limited settings, the aminotransferase/platelet ratio index (APRI) or FIB4 tests should be used for the assessment of hepatic fibrosis rather than other non-invasive tests that require more resources such as elastography or fibrotest.
Recommendations on hepatitis C treatment
3. Assessing for treatment
All adults and children with chronic HCV infection should be assessed for antiviral treatment.
WHO recommends offering treatment to all individuals diagnosed with HCV infection who are 12 years of age or older, irrespective of disease stage.
WHO recommends the use of pan-genotypic DAA regimens for the treatment of persons with chronic HCV infection aged 18 years and above.
In adolescents aged 12-17 years or weighing at least 36 kg with chronic HCV infection, WHO recommends:
66顺彩票app• sofosbuvir/ledipasvir for 12 weeks in genotypes 1, 4, 5 and 6
• sofosbuvir/ribavirin for 12 weeks in genotype 2
• sofosbuvir/ribavirin for 24 weeks in genotype 3.
In children aged less than 12 years with chronic HCV infection, WHO recommends:
• deferring treatment until 12 years of age
• treatment with interferon-based regimens should no longer be used.
New highly effective short-course oral pan-genotypic DAA regimens are likely to become available for children under 12 years of age in late 2019 or 2020. This will provide an opportunity to advance treatment access and cure to a vulnerable group that will benefit from early treatment.
In May 2016, The World Health Assembly adopted the first “Global Health Sector Strategy on Viral Hepatitis, 2016-2021”. The strategy highlights the critical role of universal health coverage and sets targets that align with those of the Sustainable Development Goals. The strategy has a vision to eliminate viral hepatitis as a public health problem. This is encapsulated in the global targets to reduce new viral hepatitis infections by 90% and reduce deaths due to viral hepatitis by 65% by 2030. Actions to be taken by countries and the WHO Secretariat to reach these targets are outlined in the strategy.
WHO is working in the following areas to support countries in moving towards achieving the global hepatitis goals under the Sustainable Development Agenda 2030:
- raising awareness, promoting partnerships and mobilizing resources;
- formulating evidence-based policy and data for action;
- preventing transmission; and
- scaling up screening, care and treatment services.
Since 2011, together with national governments, civil society and partners, WHO has organized annual World Hepatitis Day campaigns (as 1 of its 9 flagship annual health campaigns) to increase awareness and understanding of viral hepatitis. The date of 28 July was chosen because it is the birthday of Nobel-prize winning scientist Dr Baruch Bloomberg, who discovered the hepatitis B virus and developed a diagnostic test and vaccine for the virus.
For World Hepatitis Day 2019, WHO is focusing on the theme “Invest in eliminating hepatitis” to highlight the need for increased domestic and international funding to scale up hepatitis prevention, testing and treatment services, in order to achieve the 2030 elimination targets.