By Madeleine Bushnell
In the pre-HAART (Highly Active Anti-Retro Viral) era the consequences of being co-infected with HIV and Hepatitis C (HCV) were often overshadowed by AIDS mortality. Before treatment for HIV existed, someone co-infected with the two viruses most likely experienced death due to AIDS before any noticeable damage had been sustained to their liver in relation to HCV. This is because in most cases the damage the immune system sustained from HIV occurs relatively quickly in comparison to the length of time it takes for HCV to cause critical liver deterioration. Symptoms related to HIV infection occur between one and ten years after the initial infection. HCV is commonly asymptomatic and can take up to forty years for someone to show symptoms of disease progression. Currently, an estimated 25% of all people living with HIV in the U.S. are co-infected with HCV.
Today there are 1.2 million people living with HIV and 4 million people living with HCV in the U.S. HIV and HCV share common routes of transmission, making co-infection a serious concern. HIV is contracted through infected blood, semen, vaginal fluid, and breast milk, and therefore is most commonly transmitted through unprotected sex, sharing needles, and mother to child contact. HCV is spread through blood and for this reason is not considered a sexually transmitted infection (STI). HCV infection usually occurs through sharing needles and drug injection equipment, although it can be transmitted from mother to child and, in rare cases, sexual activity. The manifestations of HCV and HIV co-infection vary in severity, but often include a combination of the following symptoms: fatigue, generalized weakness, liver pain, abdominal swelling, hives, joint pain, insomnia, and depression. Most of these symptoms overlap between the two diseases, causing exacerbated discomfort.
The highest numbers of new HIV and HCV co-infections occur among individuals who inject drugs. This is because blood is a common route of transmission for both viruses. Fifty to ninety percent of all people living with HIV who inject drugs also are infected with HCV. The longer someone has been injecting drugs, the greater the likelihood of contracting both viruses. By the time an individual has been injecting drugs for five years, the chance of having contracted HCV is 50-80%, which in turn lowers one’s immune system function and increases one’s risk of becoming infected with HIV.
HIV and HCV affect each other’s viral progression, causing a complex relationship between the two viruses. A weakened immune system caused by HIV infection can create an increase in HCV particles in one’s bloodstream (the viral load), which in turn leads to an accelerated progression of HCV related liver disease. The higher the viral load, the more infectious the person, which can increase HCV transmission via routes not usually attainable by the virus. This includes a heightened propensity for the virus to spread during sexual contact and from mother to child during birth. Research pertaining to the effect HCV has on the progression of HIV in the body is not as well understood. Several studies conducted point to a more rapid progression to an AIDS diagnosis. Evidence also suggests that HAART may be less effective in recovering immune system function for people who experience HCV and HIV co-infection.
Treatment for HIV and HCV co-infection is challenging because of the high number of pills, possible drug interactions, over-lapping drug toxicities, and high cost. Many doctors will defer HCV treatment for someone who is experiencing no to moderate liver function impairment. This is because HAART is not only effective at combating HIV, but also has been shown to positively influence HCV infection by decreasing the viral load. HAART can be extremely hard on the liver; therefore drug-induced liver injury is far more common in co-infected patients receiving HIV treatment than it is for their HIV mono-infected counterparts. Despite the limitations of treatment for co-infection, discovering both viruses at an early stage and implementing an effective treatment plan can greatly influence the quality and length of life.