Mongolia is one of the highest hepatitis A, C, B and D infection incidence country in the world. Acute hepatitis B is a self-limited disease and most patients with acute hepatitis would recover in six months after the Hepatitis B virus (HBV) infection [1-3]. Previous studies have shown that HBV surface antigen (HBsAg) prevalence is 11.8% of the unvaccinated population, 9-10% of healthy individuals, 40% of patients with liver cirrhosis and 34.4% of patients with HCC in Mongolia [4-6].
Hepatitis Delta virus (HDV), the smallest RNA virus mammalians, is known as a mutant virus that requires HBsAg for its replication and assembly . HBV infection can be acquired by either co-infection (exposed HBV and HDV) or super-infection (to people who have chronic infection with HBV) . HDV infection causes a more aggressive form of viral hepatitis with rapid progression of liver disease than HBV mono-infection does. Chronicity rate is established, HDV has been described as the most severe form of viral hepatitis, with progression to cirrhosis in 10-15% of patients within 2 years and in 70-80% of patients within 5-10 years [9, 10]. Anti-HDV prevalence is 33-66% of HBsAg carriers, 82% of patients with end-stage of liver diseases and 6.1% of children in Mongolia [11-13]. One third of HBsAg carriers were co-infected with HDV. Therefore, we performed the present study to investigate the recent clinical and laboratory features of adult patients with acute viral hepatitis B and delta infection progressing to chronic infection.
Material and methods
A total of 182 patients with acute hepatitis B (AHB) and acute hepatitis Delta (AHD) were enrolled and followed-up 12 months in this study. They admitted to the acute viral hepatitis unit at National Center for Communicable Diseases between January 2016 and January 2018.
All participants provided written informed consent and the study had been fully explained and agreed. The study protocol was approved by the Medical Ethics Committee of the Mongolian National Health Sciences University (No. 2017/3-201702).
All laboratory tests were performed using standardized laboratory procedures at the Department of Laboratory of NCCD. Serum alanine aminotransaminase (ALT), aspartate aminotransferase (AST), albumin (ALB), total bilirubin (TBIL) and total protein (TP) were evaluated using an automatic analyzer (COBAS® INTEGRA400 plus, Roche Diagnostics, Germany). All serum samples were analyzed using commercial ELISA kits for detection of HBsAg, anti-HDV, HBeAg, anti-HBe, anti-HBc IgM, anti-HBs, anti-HDV and anti-HDV IgM (Wantai, Beijing) following the manufacturer’s instructions.
The Ethical Review Committee of Mongolian National University of Medical Sciences approved the current study protocol and the written consent forms were obtained from all subjects’ prior blood sampling (2017/3-201702).
All statistical analyses were performed using a standard software package (Stata, version 12.0; StataCorp). Continuous variables were summarized as mean and standard deviation, and categorical data were expressed as a percentage. Differences in variables were analyzed using Student’s t-test and one way ANOVA. Categorical dated were evaluated by the Chisquared test. A two-tailed p<0.05 was considered statistically significant.
The aim of the study was to determine the clinical and laboratory features and the rate of development to chronic infection in patients with acute hepatitis B and delta infection in Mongolia.
Out of 182 hospitalized patients aged between 16-55 years, 59.3% were male. 105 patients were diagnosed with acute hepatitis B, 5 patients were diagnosed with HBV/HDV co-infection, and 72 patients were diagnosed with acute HBV/HDV superinfection. The mean age was 25.2±6.1 years in AHB group. 30±7.6 years in HBV/HDV super-infection group and 28.4±2.2 years in HBV/HDV co-infection Age of patients with HBV/HDV super-infection was slightly older, comparing to patients with AHB (mean age: 30 vs 25.2, p=0.0001).
Mean hospitalization days was 24.1±7.8 in AHB, 27.6±11.7 in HBV/HDV super-infection and 28±13 in HBV/HDV co-infection group (p=0.03). The hospitalization day of HBV/HDV was longer than AHB (p=0.05), also clinical course was more severe (10.5 vs 20.8%, p=0.03).
Comparing clinical manifestations in AHB and HBV/HDV co and super-infection groups
The main clinical manifestations included abdominal pain, loss of appetite, vomiting and fatigue were predominant in all 3 groups (Table 1). Jaundice was observed in 96.2% of patients with AHB, 100% of patients with HBV/HDV co-infection, and 95.8% of patients with HBV/HDV super-infection. There was no significant difference between the groups during the admission period. Symptoms resolved 100% of the patients with AHB within 6 months and 95.8% of the patients with HBV/ HDV super-infection resolved by the final follow-up. Fatigue and abdominal bloating were reported in 4.2% of patients with HBV/HDV super-infection.
Comparing laboratory tests in AHB and HBV/HDV co and super-infection groups
The comparison of mean values of laboratory and serology tests were shown in tables 2 and 3. Patients with HBV/HDV coinfection exhibited higher initial total bilirubin, ALT and AST levels, compared to patients with AHB and HBV/HDV superinfection.
At the time of admission, there were no significant differences in bilirubin, AST, ALT and albumin levels among the 3 groups. From the analysis of liver function, bilirubin levels were 7.7 times higher than normal in AHB, HBV/HDV superinfection, and 9.9 times higher in HBV/HDV co-infection group. Also, ALT levels in AHB, HBV/HDV co-infection and HBV/HDV super-infection were 35 times, 35 times, 86 times higher than the normal range, respectively (p=0.12).
At the time of admission, the HBsAg positivity rate was 100% in all groups. All patients with acute hepatitis B and HBV/HDV co-infection had positive IgM anti-HBc. Patients with AHB were 100% seropositive HBsAg and anti-HBcIgM. 25.7% of them were seropositive for HBeAg. The seropositive rate of HBsAg, anti-HDV, anti-HDVIgM and HBeAg among patients with HBV/HDV super-infection were 100, 63.9, 78.9 and 13.9%, respectively. Patients with HBV/HDV co-infection were 100% seropositive HBsAg and anti-HBcIgM, 50% of them were seropositive for HBeAg seromarker. HBeAg positive proportion (50 vs 13.9%) was greater in the HBV/HDV co-infection group than in the HBV/HDV super-infection group (p=0.28).
At the final follow-up, patients with HBV/HDV super-infection had significantly higher total bilirubin (9.6±4.6, 7.9±4.6 and 8.5±2.8; p=0.04), ALT (85.5±125.8, 18.2±36 vs 13.8±6.5; p=0.0001) and AST (63.4±67.1, 18.9±19.2 vs 19.7±9.6; p=0.0001) compared with AHB and HBV/HDV co-infection groups. There were significant differences in bilirubin, ALT, AST and AST/ALT levels between the three groups. Serum platelet level was significantly lower in HBV/HDV co and super-infected patients than AHB patients (179.1±49.3×109/L, 171±57.3 vs 222.5±68.6×109/L; p=0.000).
At the final follow-up, the HBsAg positivity rate was significantly higher in HBV/HDV super-infection patients than in AHB and HBV/HDV co-infection patients (94.4%, 40 vs 6.7%, p=0.0000). The HBsAg seroconversion rate of AHB, HBV/HDV super-infection and HBV/HDV co-infection were 60%, 1.4 and 40%, respectively. 96.2% of the patients with AHB, 52.4% of patients with HBV/HDV super-infection and 50% of patients with HBV/HDV co-infection were HBV-DNA undetected at final follow-up. In serological tests, the anti-HDV positivity rate was 4.8% in the final follow-up in patients with acute HBV infection.
We performed the present study to investigate the recent clinical and laboratory features of patients with acute hepatitis B and D in Mongolia. The HBV infection rate has been declined significantly since the National vaccination program against HBV, which was introduced in 1991. The WHO supported a series of national serological surveys and found that Mongolia had reached its regional goal, with 96% of children fully vaccinated as of 2009 . Also the Mongolian government has launched the Viral Hepatitis Prevention, Control and Elimination Program to reduce the burden of viral hepatitis related liver cirrhosis and hepatocellular carcinoma. The incidence of the acute hepatitis B per 10000 populations was decreased from 3.4 in 2000 to 0.7 in 2019 [4, 14]. For acute hepatitis D, the incidence per 10000 population was decreased from 0.4 in 2009 to 0.2 in 2019 .
In our study, patients between the age of 16-55 were conducted, 59.3% were male. Our results suggest that HBV/HDV super-infection patients were older compared to AHB patients (p=0.0001).
The clinical course of HBV/HDV co-infection may range from self-limited hepatitis to severe or fulminant hepatitis. The outcome is complete recovery and in only 2% of cases, it may progress to chronicity . In super-infection, pre-existing HBV infection plays a major role in most patients developed severe acute hepatitis and further developed chronic liver disease including liver cirrhosis and hepatocellular carcinoma .
In the present study, 99.5% of the patients were symptomatic, the main clinical manifestation included abdominal pain, loss of appetite, vomiting and fatigue, no significant difference between groups at the admission time. In patients with AHB and HBV/HDV co-infection, the clinical symptoms completely disappeared and liver function tests returned to normal. Fatigue and abdominal bloating were reported in 4.2% of patients with HBV/HDV super-infection. As previously described, patients with acute hepatitis B present symptoms such as nausea, abdominal pain, fever, jaundice and vomiting. In general, the symptoms of AHB clear after one to three months, although some people find that the fatigue persists for longer [2, 3].
O. Baatarkhuu et al. reported that acute hepatitis B and D were diagnosed in 40.7% and 14.7% of patients with acute viral hepatitis. 21% of the patients had a dual infection .
In our study, there was significant difference in the levels of serum bilirubin, ALT and AST between patients with AHB, HBV/HDV co-infection and HBV/HDV super-infection at the final follow-up.
Table 1. Comparison of clinical symptoms between the groups
Table 2. Comparison of baseline laboratory tests in study groups
Table 3. Comparison of final follow-up laboratory tests in study groups
In patients with HBV/HDV super-infection, the recovery of clinical symptoms was 95.8%, and changes in liver function tests were statistically significantly different compared with other groups ALT (85.5±125.8, 18.2±36 vs 13.8±6.5, p=0.0001), AST (63.4±67.1, 18.9±19.2 vs 19.7±9.6, p=0.0001) at the final follow-up. More patients in the HBV/HDV super-infection group had persistent abnormal liver function test, progressed chronic hepatitis, and the difference was statistically significant. 96.2% of the patients with AHB, 52.4% of patients with HBV/HDV super-infection and 50% of patients with HBV/HDV co-infection were undetectable HBV-DNA at final follow-up.
Hepatitis D virus infection is associated with progression to severe liver disease. More than half (54%) of the patients suffering from acute HDV infection develop chronicity, and the majority (76%) of these chronically infected patients progress to liver cirrhosis .
The chronicity rate was significantly higher in HBV/HDV super-infection patients than in AHB and HBV/HDV co-infection patients. At the final follow-up, the HBsAg positivity rate was significantly higher in HBV/HDV super-infection patients than in AHB and HBV/HDV co-infection patients (94.4%, 40 vs 6.7%, p=0.0000). The HBsAg seroconversion rate of AHB, HBV/ HDV super-infection and HBV/HDV co-infection were 60%, 1.4 and 40%, respectively.
Other studies reported rates of 0.2% in Greece, 1% in Japan, 2.7% in Taiwan, 10.4% in Alaskan Inuit and 8.1% in Germany [18-23]. A study of the clinical course of acute HBV infection in China, 76.8% had icteric and the main symptoms were fatigue and gastrointestinal symptoms. In a one-year follow-up, 110 out of 118 patients had HBsAg seroconversion, and 8 cases developed into chronic HBV infection .
Another study of acute HBV in Brazil conducted, between 1999 and 2007, 103 cases of acute HBV infection were reported, of which 74.8% were male and 74.8% were 20-49 years old. In a study of the prognosis of these patients, 71.8% were completely cured, 14.1% had developed a chronic HBV infection, and 14.1% died .
6.7% of patients with acute hepatitis B virus infection, 40% of patients with HBV/HDV co-infection and 93.3% of patients with HBV/HDV super-infection developed a chronic infection. In patients with AHB and HBV/HDV co-infection, the clinical symptoms and liver function tests were completely cleared. However, in patients with HBV/HDV, liver function test findings were twice as high as normal.