HCV antibody response and genotype distribution in different areas and races of China

Population dynamics of hepatitis C virus subtypes in injecting drug users on methadone maintenance treatment in China associated with economic and health reform

The extensive genetic heterogeneity of hepatitis C virus (HCV) requires in-depth understanding of the population dynamics of different viral subtypes for more effective control of epidemic outbreaks. We analysed HCV sequences data from 125 participants in Wuhan, China. These participants were newly infected by subtype 1b (n=13), 3a (n=15), 3b (n=50) and 6a (n=39) while on methadone maintenance treatment (MMT). Bayesian phylogenies and demographic histories were inferred for these subtypes. Participants infected with HCV-1b and 3a were clustered in well-supported monophyletic clades, indicating local subepidemics. Subtypes 3b and 6a strains were intermixed with other Chinese isolates, as well as isolates from other Asian countries, reflecting ongoing across geographic boundary transmissions. Subtypes 1b and 3a declined continuously during the past ten years, consistent with the health and economic reform in China, while subtype 3b showed ongoing exponential growth and 6a was characterized by several epidemic waves, possibly related to the recently growing number of travellers between China and other Asian countries. In conclusion, results of this study suggest that HCV subtype 3b and 6a subepidemics in China are currently not under control, and new epidemic waves may emerge given the rapid increase in international travelling following substantial economic growth.

The global burden of liver disease: the major impact of China

Liver disease is a major cause of illness and death worldwide. In China alone, liver diseases, primarily viral hepatitis (predominantly hepatitis B virus [HBV]), nonalcoholic fatty liver disease, and alcoholic liver disease, affect approximately 300 million people. The establishment of the Expanded Program on Immunization in 1992 has resulted in a substantial decline in the number of newly HBV-infected patients; however, the number of patients with alcoholic and nonalcoholic fatty liver diseases is rising at an alarming rate. Liver cancer, one of the most deadly cancers, is the second-most common cancer in China. Approximately 383,000 people die from liver cancer every year in China, which accounts for 51% of the deaths from liver cancer worldwide. Over the past 10 years, China has made some significant efforts to shed its "leader in liver diseases" title by investing large amounts of money in funding research, vaccines, and drug development for liver diseases and by recruiting many Western-trained hepatologists and scientists. Over the last two decades, hepatologists and scientists in China have made significant improvements in liver disease prevention, diagnosis, management, and therapy. They have been very active in liver disease research, as shown by the dramatic increase in the number of publications in Hepatology. Nevertheless, many challenges remain that must be tackled collaboratively. In this review, we discuss the epidemiology and characteristics of liver diseases and liver-related research in China.

Update on epidemiology of hepatitis B and C in China

A high rate of chronic hepatitis B virus (HBV) infection in China is mainly caused by perinatal or early childhood transmission. Administration of universal HBV vaccination in infants has led to a dramatic decrease in HBV epidemiology, with hepatitis B surface antigen (HBsAg) prevalence declining from 9.75% in 1992 to 7.18% in 2006. The major HBV genotypes are B and C, with B being more prevalent in the southern part and C more prevalent in the northern part of China. A national survey carried out in 1992 showed that the hepatitis C virus (HCV) infection rate was 3.20% in general population in China. After implementation of mandatory HCV screening for blood transfusion and other precautions to prevent blood-borne disease since 1993, the new cases of HCV infection associated with blood or blood product has become very rare. Although the anti-HCV prevalence would be much higher in high-risk groups, a survey carried in 2006 showed that the anti-HCV prevalence rate was only 0.43% in general population. This sharp decline in HCV infection rate was mainly due to stringent administration and monitoring of blood donors and blood products, but may also be related to the remarkably improved specificity of anti-HCV test. The predominant HCV genotype in China is genotype 1b (60-70%), and the host interleukin-28b rs12979860 CC genotype is very frequent in Chinese population (over 80%).

Ultrasound and infections on the Tibetan Plateau()

INTRODUCTION

The authors report on an ultrasound (US) outreach program for the nomadic people living in Yushu, a remote area of Qinghai, Tibet, People's Republic of China (PRC) about 4800 m above sea level. The program was carried out in cooperation with ROKPA INTERNATIONAL, a non-profit organization (NGO) that aims at helping the poorest peoples living in remote regions of the world.

MATERIALS AND METHODS

A hand-held US scanner (Sonosite 180 Plus, Sonosite Inc., Bothell, WA, USA) equipped with a 3.5-5 MHz convex probe was used at a local clinic for 21 days in 2007 and for 32 days in 2009.

RESULTS

A total of 1128 US examinations were performed (578 in 2007 and 550 in 2009). The main diagnoses were: Echinococcal cysts (66 cases; 6.23%) - Biliary tract and intrahepatic gallstones (10% of patients examined) - Ascariasis - Acute and chronic hepatitis, liver cirrhosis, abdominal masses - Abdominal tuberculosis - Miscellaneous (trophoblastic tumor, megacalicosis, splenomegaly in acute leukemia). After the first experience in 2007, collaboration with the local hospital was established for the treatment of patients affected by active echinococcal cysts using albendazole and puncture, aspiration and injection of scolicidal agent and re-aspiration (PAIR) and subsequent follow-up.

DISCUSSION AND CONCLUSIONS

US scanning was well accepted by the local population and allowed diagnosis, classification and choice of treatment of the echinococcal cysts according to recent criteria based on a stage-specific approach. Percutaneous treatment was also introduced, but more training of local healthcare providers is needed to secure continuation of this practice. Further experience may help improve the standard of health care services offered to the nomadic populations in this remote area.