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Hepatitis CHepatitis C, although unrelated to hepatitis B, often causes similar symptoms. Estimates of the number of people in the UK who are chronically infected vary, but range from just under 200,000 people to nearly 450,000. The majority of those living with hepatitis C do not know they are infected. ขอขอบคุณ นายแพทย์ ศัลยวิทย์ จิตต์มิตรภาพ Transmission Hepatitis C is mostly transmitted by direct blood-to-blood contact. The most common route of transmission in the UK is by sharing equipment for injecting drug use, mainly via blood-contaminated needles and syringes, but sexual transmission does occur. The virus can survive in syringes and in tubs of lubricant for weeks. Sharing drug sniffing equipment (straws or banknotes) has also been shown to be a risk. Many people also contracted hepatitis C from being given blood products in a medical procedure before screening and sterilisation processes were introduced (September 1991 in the UK). Sexual transmission of hepatitis C is less common but does occur. It is more likely to happen if you also have another sexually transmitted infection (STI). Also, anal or rough sex is more likely to pass on the infection. Oral sex is of low risk. The virus is present in saliva, but kissing is not usually a risk unless both partners have cuts in the mouth or bleeding gums. In recent years, there has been a large increase in the number of HIV-positive gay men who have also become infected with hepatitis C through sexual transmission. There seems to be an association with rougher sex, with risk factors such as fisting, group sex and using recreational drugs during sex, but sometimes the only identifiable risk factor is unprotected anal sex. There is also evidence that some of the infections in HIV-positive gay men may be as a result of injecting drug use and other shared routes of drug taking. There is little evidence of sexual transmission of hepatitis C in heterosexuals. Mother-to-child transmission of hepatitis C is uncommon, but the risk is increased if the mother is also infected with HIV. A high hepatitis C viral load also increases the chance that a mother will pass on hepatitis C to her baby. As with HIV, a caesarean delivery reduces the chance of mother-to-child transmission of hepatitis C. Unlike hepatitis A and B, having hepatitis C once does not mean you are then immune from getting it again. It is also possible to be reinfected with a different strain of hepatitis C. Preventing hepatitis C When used correctly, condoms can reduce the risk of sexual transmission of hepatitis C, as well as HIV and other sexually transmitted infections. Some HIV-positive gay men try only to have unprotected sex with men who are also HIV-positive (‘serosorting’). However, because of the risk of contracting other sexually transmitted infections and hepatitis C, it is recommended that condoms should still be used even when a sexual partner is also HIV-positive. The use of gloves for fisting is also an effective method of prevention. In group sex situations, neither sex toys nor lubricants should be shared. Gloves and condoms should be changed between partners. Needles, syringes and other equipment used to inject drugs, and equipment used to sniff drugs such as straws or banknotes, should never be shared. Some studies have found a risk of passing on hepatitis C by breastfeeding, but the evidence is inconclusive. However, in the UK and other countries where safe alternatives to breast milk are available, all mothers with HIV should avoid breastfeeding. Sharing household items that may have any contact with blood, such as razors, toothbrushes and nail scissors, should be avoided. The hepatitis C virus can live outside the body much longer than HIV can. There is no risk of transmission through normal social contact, such as sharing crockery or cutlery, or touching someone with hepatitis C. Blood spills from someone with hepatitis C should be cleaned up using undiluted household bleach. Scratches, cuts and wounds should be carefully cleaned and covered with a waterproof dressing or plaster. Using non-sterile needles for piercings, acupuncture and tattooing is a transmission risk; new, sterile needles should be used. Symptoms Less than 5% of people experience symptoms when they are first infected with hepatitis C. When they do occur, symptoms can include jaundice, diarrhoea and feeling sick. Even if you do not have any symptoms, you can still pass the virus on to others. In the longer term, about half of people with hepatitis C will experience some symptoms. The most common ones are feeling generally unwell, extreme tiredness, weight loss, intolerance of alcohol and fatty food, and depression. Disease progression Only about 20% of people who have been infected with the hepatitis C virus appear to clear the virus naturally from their blood, whilst about 80% will develop chronic hepatitis C. Those with chronic infection will continue to be infectious and can pass on the virus to others. If a person continues to be infected over a number of years with the hepatitis C virus, they could develop the following complications: • Chronic liver inflammation. • Liver cirrhosi Patterns of disease vary from person to person. Some people never experience any of these complications but about a third of those with chronic infection will develop serious liver disease after 15 to 25 years of infection. The severity of disease can be affected by a number of factors. It is thought that it may take between 30 and 40 years for hepatitis C to cause cirrhosis - serious scarring to the liver. But men, people who drink alcohol, older people, and people with untreated HIV seem to have faster hepatitis C disease progression. Cardiovascular (heart) disease is an increasing concern for people with HIV. Because of effective treatment for HIV, many people are living longer. But this means an increased chance for some people that they will develop heart disease. This is now known to be caused by the effect of HIV itself. In addition, some anti-HIV drugs can cause physical changes that can contribute to heart disease. There’s now some evidence that people who are co-infected with hepatitis C may have an increased risk of cardiovascular disease. Your HIV clinic should monitor your blood fats, or lipids (cholesterol and triglycerides) to see if you are at risk of heart disease. In addition, there are higher rates of diabetes amongst people with hepatitis and HIV co-infection, a condition that may also contribute to heart disease. Diagnosing and monitoring hepatitis C Treatment for hepatitis C has the best chance of success if it is given soon after a person is infected with the virus. So if you’re at risk of hepatitis C it makes very good sense to be regularly tested for the infection. Ask staff at your HIV clinic about having these tests. A blood test can tell if you have been exposed to hepatitis C and have antibodies to it. You should be tested for hepatitis C at least once a year, and have more frequent tests if you are especially at risk of hepatitis C. A test is also available to measure hepatitis C viral load (called a PCR test). This can show if you are likely to clear hepatitis C naturally. Hepatitis C viral load is not an indicator of when to start treatment, but it can be used to indicate how long you should continue to take treatment against hepatitis C. If you have a very high hepatitis C viral load, you may require a longer course of treatment. Liver function tests, which measure levels of enzymes produced by your liver, can give an indication of whether or not hepatitis C has damaged your liver. However, some people with hepatitis C can have normal liver function tests, even though they have suffered significant liver damage. If the degree of liver damage you have suffered is unclear, then you may need to have a liver biopsy. This involves using a hollow needle to remove a small sample of the liver, which is checked under the microscope for signs of liver damage. Liver biopsies can also be used to help decide what kind of hepatitis C treatment you need and how long it should last for. Liver biopsies can be uncomfortable for some patients (although you will be given a local anaesthetic) and, very rarely, can cause bleeding or bile to leak from the liver. If you have haemophilia you may need to receive extra clotting factor before and after the biopsy, and a very small number of people with haemophilia may not be able to have a biopsy at all because of very low clotting factor levels. To minimise the risk of complications, some centres have started offering an alternative method called transjugular liver biopsy. This is a process by which the liver biopsy is carried out internally via a hollow wire. This wire is inserted through a large vein in the neck under X-ray guidance. The procedure reduces the risk of bleeding and other complications. Some doctors are also exploring the possibility of using a number of different blood tests that, viewed together, can give an accurate impression of liver function and damage, rather than using biopsies. Another method for assessing liver damage is elastography (FibroScan), which measures liver stiffness by using a vibration probe. This is a test very much like an ultrasound scan of the liver. Many centres are now offering this as an alternative to or as well as the liver biopsy for accurate and frequent monitoring for liver damage. How does HIV affect hepatitis C? It seems that people co-infected with untreated HIV and hepatitis C are more likely to develop liver damage than people infected only with hepatitis C. However, there is evidence that HIV treatment can slow hepatitis C disease progression. The effect of hepatitis C on HIV In countries in the UK, potent HIV treatment is widely availale and peiople are living longer, healthier lives with HIV. However, liver disease is now a major cause of hosiptal admission and death among HIV-positive people because of hepatitis and C liver-related problems. Having hepatitis C does not appear to significantly alter your chances of becoming ill due to HIV, developing AIDS, or dying of an AIDS-defining illness. HIV treatment if you have hepatitis C HIV treatment can be used safely and effectively if you have hepatitis C. It’s possible to treat both HIV and hepatitis C at the same time. If you are co-infected with hepatitis C, then you’re especially encouraged to start HIV treatment when your CD4 cell count is higher than in people without hepatitis. Reducing your HIV viral load appears to reduce the risk of hepatitisC, and of other HIV drugs such as - nevirapine (Viramune) - causing liver damage. Some anti-HIV drugs can cause liver side-effects. For instance, the older, and now rarely used, drugs ddI (didanosine, Videx) and d4T (stavudine, Zerit) have been associated with an increased risk of developing hepatic steatosis (‘fatty liver’), which is the accumulation of fat in the liver. You and your doctor should bear these factors in mind when selecting which anti-HIV drugs you are going to take, and careful monitoring of your liver after you start taking HIV treatment is strongly recommended. Personal health inquiries and information about STDs: these Channels Resources NAM |
