Wednesday, July 19, 2017

HEPATITIS C

Hepatitis C is an infectious disease caused by the hepatitis C virus (HCV). This disease primarily infects the liver and in its early stages, it has very few symptoms. Patients may present with a fever, abdominal pain and mild jaundice (yellowish tinge in the skin). In the majority of the patients with the acute infection, the virus will persist in the liver and over many years, progress to cirrhosis of the liver.

HCV is spread by blood-to-blood contact, caused by intravenous drug use, poorly sterilized medical equipment, needlestick injuries in healthcare workers and blood transfusions. It can also spread during childbirth, from an infected mother to her baby.

HCV is a global health problem, with approximately 143 million people (2%) infected with this disease. It is most common in Africa and Central and East Asia. In 2015, approximately 167,000 deaths due to HCV related liver cancer and 326,000 deaths from HCV related cirrhosis occurred worldwide.

In the US, HCV is prevalent in approximately 2 % of the population, almost 3.5 million people. Approximately, 15,800 deaths in 2008 were due to HCV. According to the CDC, almost 30,500 newly infected patients were found in 2014. 70 % of the HCV patients in the US are caused by genotype 1 and 40 to 70 % patients who are infected are unaware of their HCV status.

Diagnosis of HCV is by detecting antibodies to HCV. If this is positive, a confirmatory test with an immunoassay as well as the viral load is determined. The viral load is determined by checking the HCV RNA. Liver enzymes initially run a variable course but gradually begin to rise at seven weeks after infection. The degree of liver damage can be assessed by doing a liver biopsy.

Routine screening is currently not recommended by the CDC except for those born between 1945 to 1965. Screening is recommended in those with higher risk for HCV such as injection drug users, those who received blood transfusions prior to 1992, those on hemodialysis, incarcerated individuals or those with tattoos.

Treatment consists of antiviral medications, recommended especially for patients at risk for complications, based on the degree of liver scarring. The regimen recommended depends on the type of HCV, known as the genotype, with which a person is infected. Prior to 2011, there were only two drugs that were available, pegylated interferon (PEG-IFN) and ribavirin. These drugs are now less commonly used because of their side effects and also because the newer medications are more effective with less side effects, albeit more expensive.

Boceprevir (victrelis)and telaprevir (incivek)were introduced in 2011 as protease inhibitors. They act by stopping viral reproduction and were approved for patients infected with HCV genotype 1, given mainly in combination with PEG-IFN and ribavirin.
Simeprevir (olysio) was introduced in 2013 as a once daily protease inhibitor. It is used in combination with sofosbuvir (sovaldi) and approved for HCV genotype 1.
Sofosbuvir can also be used for genotypes 1, 2, 3 and 4. This is a once daily medication and is a polymerase inhibitor, blocking a specific protein in the virus that it needs o grow.

Ledipasvir and sofosbuvir combination drug (harvoni) was introduced in 2014 for patients with genotype 1 and was found to cure 94 % patients in 12 weeks. It has now been approved for genotypes 4, 5, 6 and in patients co-infected with HIV. With ribavirin, it has been approved for use in patients who have undergone liver transplantation.

Multiple other combinations of newer drugs have been introduced and continue to be developed.

Liver transplantation is the treatment option for patients who have chronic HCV and have decompensated cirrhosis. The virus does recur after transplantation and causes cirrhosis in almost 30 % patients within 5 years.

Alternative treatment options include milk thistle, ginseng and colloidal silver have not shown to be effective in the treatment of HCV.


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