While the global HCV infection rate is 3%, China’s infection rate is about 3.2%, which is slightly higher than the global infection rate. China is also one of the countries with the highest number of HCV infections in the world. Our study revealed the current status and characteristics of HCV infection in a general hospital featuring infectious diseases.
In this study, we compared the positivity rates of HCV antibodies among nine age groups. The highest positivity rate of 19.92% was observed in patients aged 0–2 years. The positivity rate was found to be significantly higher in this group than in the other age groups. Also, the mean value of antibodies in positive patients was found to be the highest. Further analysis revealed 262 positive HCV antibodies in the 0–2 years age group. Of these, 134 patients were younger than 7 days. Hence, we can infer that most pregnant women who came to our hospital were positive for HCV antibodies. The reason for the high HCV antibodies positive rate was that most newborns passively obtain HCV antibodies from their mothers. These antibodies were considered to exist until 18 months after birth [11–13]. Therefore, in babies less than 18 months, the HCV antibody test does not provide accurate information. In this scenario, the HCV-RNA test should be carried out to determine an active infection [14]. Similar to epidemiological surveys in the USA [15], the positivity rates of HCV antibodies were lowest in the 10–19 years age group. Additionally, our study demonstrated that 10–19-year-old patients with HCV infection showed the lowest mean values of HCV antibodies and HCV-RNA. However, whether this indicated the greater ability of patients aged 10–19 years to clear the HCV virus needs further investigation. The positivity rate of HCV antibodies in patients aged 10–59 years showed an increase with the increase in age, but in patients aged over 60 years, it showed a decreased value with age. This increase in positivity rate with age was consistent with previous research results [10, 16, 17]. Based on the same age range, the age distribution of HCV antibody-positive patients was further analyzed. Although HCV antibody-positive patients were distributed in all age groups, they were mainly concentrated among the 20–69 years age group. Of these, the number of patients was the largest in the group aged 50–59 years. In our study, both the positivity rate and the number of patients were significantly higher in those over the age of 40 than in those under 40 years (P < 0.001), which was consistent with previous studies [18, 19]. In China, the relevant documents on hepatitis C screening have revealed that all hospitalized patients over the age of 40 should be tested for HCV antibodies [4]. We speculated that the high rates and the number of positive HCV antibodies in Chinese patients over 40 years of age were due to the non-inclusion of HCV antibodies screening in the routine screening of blood donors before 1993. Since blood transmission is considered an important route of transmission for hepatitis C, blood donation before 1993 may have caused the large-scale transmission of hepatitis C. Additionally, older patients were often less educated with fewer opportunities to learn about the hepatitis C along with the lack of awareness of proactive hepatitis C screening. The antibody-positivity rate was found to be low in young people, which has proven the necessity of strict management of blood products and the implementation of hepatitis C prevention policy. The gradual decrease in the positivity rate in patients over 60 years of age may be attributed to the death of some patients due to HCV-related cirrhosis or hepatocellular carcinoma [20].
The detection of HCV antibodies can only be used as the basis for preliminary screening since HCV antibodies can still be positive in case of previous HCV infection, spontaneous virus clearance, or recovery after treatment. Therefore, further testing of HCV-RNA may be required. The positivity rate of HCV-RNA in our hospital was found to be much higher than that of the HCV antibodies, indicating that most patients only tested for HCV-RNA after the antibody test turned out to be positive. In this study, the HCV-RNA positivity rate increased with age, which was similar to findings observed in other studies [16, 19]. This may indicate that younger patients were more likely to be cured. Moreover, the positivity rate in patients over 40 years of age was significantly higher than in those under 40 (16.98 vs. 28.85%, P < 0.001), accounting for 71.63% of all HCV-RNA-positive patients. Hence, patients over 40 years were confirmed as the main population to screen for HCV infection and provide treatment.
In this study, the average positivity rate of HCV antibodies was higher in females than that in males (7.52% vs. 6.11%, P < 0.001). The comparison between the positivity rates of HCV antibodies in men and women of different ages showed significantly higher positivity in women of the 20–69 age group than in men belonging to the same age group. Also, no significant differences were observed in the remaining age groups. Studies have shown that the best critical value for predicting HCV-RNA positivity using HCV antibodies was higher in women than in men [16], which may indicate more false-positive results for HCV antibodies in women. Previous studies [16, 17, 20, 21] have shown conflicting conclusions in the comparison results of HCV antibodies and HCV-RNA-positivity rates between men and women. Although the specific reason for this is not clear, the differences might be related to the different survey populations, different lifestyles, and other reasons.
According to the relevant data, the HCV antibody-positivity rate in the general population of China was 0.6%, while in this study, the HCV antibody-positivity rate was found to be 6.78% between 2017 and 2020, which was about 11 times higher than that of the general population in China. This indicated that most patients coming to our hospital were already diagnosed with HCV or were in high-risk groups. Overall, the number of HCV antibody tests and positive people in our hospital decreased gradually from 2017 to 2020. Although the positivity rate changed a little, a downward trend was also observed. We speculated that the decrease in HCV antibody-positivity rate may not reflect the situation of HCV infection in China but could be likely related to people's lack of awareness of active HCV screening. The total number of HCV-RNA detection tests and positive population also decreased, showing an increasing trend in the positivity rates. Although the exact cause is not known, it could be related to the rate of diagnosis of HCV infection in our hospital.
Between 2017 and 2020, 100,692 inpatients were admitted to our hospital, and 60,211 patients were tested for HCV antibodies. The detection rate was 59.8%, which was consistent with other studies [10, 16]. Overall, the detection rate in the past four years has shown an upward trend, which is due to the recent attention and emphasis of China on hepatitis C. Successively, to promote its screening, various management measures have also been promulgated. Perhaps since our hospital was featured by infectious diseases with relatively several high-risk groups, including HIV-infected patients and their sexual partners or people with a history of high-risk sexual behavior, etc., the positivity rate of HCV antibodies in hospitalized patients was significantly higher than those in the other general hospitals. Liu Lili et al. [10] conducted statistical analyses on eight tertiary hospitals in different regions of China and found that the positivity rate of HCV antibodies was 0.88% in inpatients. However, the positivity rate of inpatients in our hospital was 5.24%, which was about 6 times higher than that in other general hospitals. The Chinese guidelines for the prevention and treatment of hepatitis C suggest that all patients with positive HCV-RNA should be treated irrespective of liver cirrhosis, chronic kidney disease, or extrahepatic manifestations [3]. Direct antiviral agents (DAA) can cure hepatitis C in only three months with fewer side effects. However, only about 50% of HCV antibody-positive patients were being tested for HCV-RNA, and even if diagnosed with HCV infection, only a minority received professional treatment [22]. A German study including 28,809 emergency patients showed that one-fifth of HCV-RNA-positive patients were previously unaware of their diagnosis [23]. Therefore, even with 100% sustained virological response (SVR), the total viral clearance rate in the infected population could still be very low.
Our findings showed a significantly higher positivity rate of HCV antibodies in our hospital than that in other general hospitals. We presumed that the other hospitals in China that feature infectious diseases share the characteristics of our hospital. Overall, we suggest that to eliminate hepatitis C in China, all hospitals featuring infectious diseases should enable HCV antibody-positive patients to test for HCV-RNA for further diagnosis and treatment.
To our knowledge, this is the first study of HCV-related data obtained from a hospital that features infectious diseases in China. The sample size was large, and the source of patients was also widely distributed. However, there were some shortcomings in our study. First, our data came from one hospital and did not include hospitals in other regions. Second, our study was retrospective. Hence, for our next study, we need to focus on further analysis of patients' HCV antibodies and HCV-RNA results with no lack of information on diagnosis rates and referral rates.