HCV can be transmitted through contact with blood (including through sexual contact if the two parties blood is mixed) and can also cross the placenta. Hepatitis C usually leads to chronic hepatitis, culminating in cirrhosis in some people. It usually remains asymptomatic for decades. Patients with hepatitis C are susceptible to severe hepatitis if they contract either hepatitis A or B, so all persons with hepatitis C should be immunized against hepatitis A and hepatitis B if they are not already immune, and avoid alcohol. HCV can lead to the development of hepatocellular carcinoma, however, only a minority of HCV-infected individuals develop cancer (1–4% annually), suggesting a complex interplay between viral gene expression and host and environmental factors to promote carcinogenesis. The risk is increased two-fold with active HBV coinfection and a 21% increase in mortality compared to those with latent HBV and HCV. HCV viral levels can be reduced to undetectable levels by a combination of interferon and the antiviral drug ribavirin. The genotype of the virus is the primary determinant of the rate of response to this treatment regimen, with genotype 1 being the most resistant.Hepatitis C is the most common chronic blood-borne infection in the United States. Hepatitis D
Hepatitis D is caused by the hepatitis D virus (HDV), or hepatitis delta virus; it belongs to the genus Deltavirus. HDV is similar to a satellite virus as it can only propagate in the presence of the hepatitis B virus, depending on the helper function of HBV for its replication and expression.
Cinchonism is a pathological condition caused by an overdose of quinine or its natural source, cinchona bark. Quinine and its derivatives are used medically to treat malaria and lupus erythematosus. In much smaller amounts, quinine is an ingredient of tonic drinks, acting as a bittering agent. Cinchonism can occur from therapeutic doses of quinine, either from one or several large doses. Quinidine (a Class 1A anti-arrhythmic) can also cause cinchonism symptoms to develop with as little as a single dose. Signs and symptoms
Signs and symptoms of mild cinchonism (which may occur from standard therapeutic doses of quinine) include flushed and sweaty skin, ringing of the ears (tinnitus), blurred vision, impaired hearing, confusion, reversible high-frequency hearing loss, headache, abdominal pain, rashes, drug-induced lichenoid reaction (lichenoid photosensitivity), vertigo, dizziness, nausea, vomiting and diarrhea. Large doses of quinine may lead to severe (but reversible) symptoms of cinchonism: skin rashes, deafness, somnolence, diminished visual acuity or blindness, anaphylactic shock, and disturbances in heart rhythm or conduction, and death from cardiotoxicity (damage to the heart). Quinine may also trigger a rare form of hypersensitivity reaction in malaria patients, termed blackwater fever, that results in massive hemolysis, hemoglobinemia, hemoglobinuria, and kidney failure. Most symptoms of cinchonism (except in severe cases) are reversible and disappear once quinine is withdrawn.