Changes in the seroprevalence of IgG anti-hepatitis A virus between 2001 and 2013: experience at a single center in Korea

BACKGROUND/AIMS: The incidence of symptomatic hepatitis A reportedly increased among 20- to 40-year-old Korean during the late 2000s. Vaccination against hepatitis A was commenced in the late 1990s and was extended to children aged <10 years. In the present study we analyzed the changes in the seroprevalence of IgG anti-hepatitis A virus (HAV) over the past 13 years. METHODS: Overall, 4903 subjects who visited our hospital between January 2001 and December 2013 were studied. The seroprevalence of IgG anti-HAV was analyzed according to age and sex. In addition, the seroprevalence of IgG anti-HAV was compared among 12 age groups and among the following time periods: early 2000s (2001-2003), mid-to-late 2000s (2006-2008), and early 2010s (2011-2013). The chi-square test for trend was used for statistical analysis. RESULTS: The seroprevalence of IgG anti-HAV did not differ significantly between the sexes. Furthermore, compared to the seroprevalence of IgG anti-HAV in the early 2000s and mid-to-late 2000s, that in the early 2010s was markedly increased among individuals aged 1-14 years and decreased among those aged 25-44 years (P<0.01). We also found that the seroprevalence of IgG anti-HAV in individuals aged 25-44 years in the early 2010s was lower than that in the early 2000s and mid-to-late 2000s. CONCLUSIONS: The number of symptomatic HAV infection cases in Korea is decreasing, but the seroprevalence of IgG anti-HAV is low in the active population.

Seroprevalence of IgG Anti-HAV in Hospital Employees below 40 Years Old / 대한소화기학회지

BACKGROUND/AIMS: Hepatitis A is an acute infectious disease transmitted by fecal-oral route. As the incidence of hepatitis A has been increased in Gwangju and Chonnam province of Korea recently, the number of hepatitis A patients in hospital employees has also increased. Thus, we investigated the seroprevalence of IgG anti-HAV in hospital employees below 40 years old. METHODS: We analysed the seroprevalence of anti-HAV IgG from 1,002 Chonnam national university hospital empolyees (men: 190, women: 812) who were below 40 years old. The age group was divided by 5 years; 21-25 years old 199 (19.9%), 26-30 years old 426 (42.5%), 31-35 years old 215 (21.5%), 36-40 years old 162 (16.1%). RESULTS: Overall seropositive rate of IgG anti-HAV was 32.8% (329/1,002). The seropositive rate of men was 40.5% (77/190) and that of women was 31.0% (252/812). The seropositive rates of each age group were 1.5% (3/199) in 21-25 years old, 21.6% (92/426) in 26-30 years old, 48.4% (104/215) in 31-35 years old, and 80.2% (130/162) in 36-40 years old. The seropositivity rate of the high risk group (doctors, nurses, technicians) was 28.9% (234/809). CONCLUSIONS: The seropositive rate of IgG anti-HAV was the lowest in early twenties of hospital employees and below 50% in early thirties. Therefore, hepatitis A vaccination may be warranted in the hospital empolyees below the early thirties.

Comparison of Recent IgG Anti-HAV Prevalence between Two Hospitals in Seoul and Gyeonggi area / 대한간학회지

BACKGROUND/AIMS: Recently, the incidence of acute hepatitis A has increased nationwide and is related to the low rate of IgG anti-HAV. This study compared the prevalence of IgG anti-HAV in two university hospitals located in a large city and in a small city including a rural region according to age, gender, and the year of diagnosis. METHODS: IgG anti-HAV was measured in a total of 4299 patients, who visited Seoul or Guri Hanyang University Hospital between January 2002 and December 2006. RESULTS: The positive rates of the antibody in Seoul and Guri hospitals were 52.7% vs 57.1% in under the age of 1, 40.7% vs 42.2% in age of 1 to 4, 31.8% vs 30.3% in age of 5 to 9, 24.8% vs 27.1% in age of 10 to 14, 11.6% vs 18.2% in age of 15 to 19, 23.0% vs 20.3% in age of 20 to 24, 40.5% vs 42.9% in age of 25 to 29, 67.5% vs 75.0% in age of 30 to 34, 86.5% vs 88.1% in age of 35 to 39, 95.3% vs 93.6% in age of 40 to 44, 97.0% vs 98.7% in age of 45 to 49, and 98.5% vs 98.6% in patients who were more than 50, respectively. The positive rates of the antibody were not significantly different between two sites according to each age group and gender. CONCLUSIONS: The results confirmed the low rates of IgG anti-HAV, particularly in the ages of 10-24 that match the age group of recently increased incidence of acute hepatitis A nationwide. Therefore, measurement of the antibody and vaccination should be considered in this age group.