Tests and diagnosis (MEDICALNEWSTODAY)

HCV is often overlooked or mistaken for a less severe viral illness. It is rare for the infection to be diagnosed during the acute phase.

The immune system of a person infected with HCV responds to the infection and, in only 20 percent of cases, will clear the virus without assistance. The remaining 80 percent of cases will turn chronic, and it can become possible to spread HCV to others without knowing.

Screening tests are available for people the CDC have determined are at risk. People can test for HCV using a simple blood test called an HCV antibody screen.

There is a rapid test approved by the Food and Drug Administration (FDA) that provides results in 20 minutes. Otherwise, the blood is drawn from a vein and processed at a lab. A negative test means that the person has not been exposed. A positive test means that the person has been exposed to HCV, but does not necessarily prove ongoing infection.

All positive HCV antibody results will lead to a second blood test called HCV RNA (PCR). This test will demonstrate whether the virus is still present. A person with a positive PCR should see a liver specialist or a provider trained to treat HCV. It is important to note that the positive antibody test will always remain positive, whether or not the virus is still present. Once the chronic infection is confirmed, the genotype of the virus is established by testing. This will determine the percentile cure rate, the length of treatment, and the preferred medications.

In some instances, a liver biopsy may be recommended for grading the severity of the disease, staging the degree of fibrosis, and evaluating the extent of liver damage.