Incidence Of Hepatitis A Virus Infection Research Articles

Hepatitis A virus infection.

Hepatitis A is a vaccine-preventable infection caused by the hepatitis A virus (HAV). Over 150 million new infections of hepatitis A occur annually. HAV causes an acute inflammatory reaction in the liver that usually resolves spontaneously without chronic sequelae. However, up to 20% of patients experience a prolonged or relapsed course and <1% experience acute liver failure. Host factors, such as immunological status, age, pregnancy and underlying hepatic diseases, can affect the severity of disease. Anti-HAV IgG antibodiesproduced in response to HAV infection persist for life and protect against re-infection; vaccine-induced antibodies against hepatitis A confer long-term protection. The WHO recommends vaccination for individuals at higher risk of infection and/or severe disease in countries with very low and low hepatitis A virus endemicity, and universal childhood vaccination in intermediate endemicity countries. To date, >25 countries worldwide have implemented such programmes, resulting in a reduction in the incidence of HAV infection. Improving hygiene and sanitation, rapid identification of outbreaks and fast and accurate intervention in outbreak control are essential to reducing HAV transmission.

Insight into an acute hepatitis A outbreak in Indiana.

Hepatitis A virus (HAV) infection causes an acute enteric hepatitis associated with substantial morbidity and mortality, particularly in older individuals. Incidence of HAV infection is low in the United States, mostly related to consumption of contaminated food. Starting in 2017, Indiana reported a large HAV outbreak. We sought to characterize the risk-exposures, clinical features and outcomes of HAV and examine the differences based on underlying cirrhosis and age. Adults ≥18years diagnosed with HAV between January 2017 and April 2019 at two large healthcare systems in Indiana were identified. Demographic data, risk-exposures, clinical features, laboratory data and clinical outcomes were collected for analysis. The HAV cohort constituted 264 individuals with mean age of 41-years, 62% male and 94% Caucasian. Risk-exposures identified were illicit drug use (74%), food-borne (15%), person-to-person (11%) and incarceration (11%). Mortality rate was 2%, acute liver failure (ALF) was seen in 4% and acute on chronic liver failure (ACLF) was seen in 30% (6 of 20 with underlying cirrhosis). Admission MELD score was the only factor associated with ALF [OR=1.17 (1.08-1.2), p<0.0001], on multivariable logistic regression analysis. Higher proportion of individuals with underlying cirrhosis developed acute kidney injury (AKI) (26% vs. 9%, p=0.03), ascites (45% vs. 11%, p<0.0001) and hepatic encephalopathy (35% vs. 4%, p<0.0001). In conclusion, illicit drug use was the predominant risk-exposure in the current HAV outbreak, which was associated with 2% mortality rate, and those with cirrhosis had worse outcomes (AKI, ascites and HE), of whom 30% developed ACLF.

Molecular epidemiology of hepatitis A outbreaks in two districts in Indonesia in 2018: Same subtype, but different strains.

The present study aimed to analyse molecular epidemiological data from hepatitis A virus (HAV) outbreaks in two affected areas. The association between the knowledge of hepatitis A and incidence of infection was also determined. Serum samples were obtained from 88 individuals with clinical manifestations of acute hepatitis in Lamongan (n=54) in January 2018 and Bangkalan (n=34) in March 2018. The outbreak investigation was started one day after the outbreaks were reported by the Public Health Offices in Lamongan and Bangkalan. Anti-HAV immunoglobulin M (IgM) and PCR amplification products of the VP1 capsid protein-P2A protease and VP1-VP3 junctions were analysed. Positive PCR products were sequenced, and a phylogenetic tree was constructed using Molecular Evolutionary Genetics Analysis X software. The control group comprised healthy students and staff members from the two affected areas. Thus, 172 responses from the control and hepatitis A case groups were analysed to assess the association between the students' knowledge level and the incidence of HAV infection. A total of 32 (59.25%) of the 54 individuals from Lamongan and 19 (55.9%) of the 34 participants from Bangkalan were positive for anti-HAV IgM; 26 PCR tests were positive in the VP3-VP1 and/or VP1-P2A junction, which were identified as HAV subgenotype IA. The subtype of HAV in the two areas was IA, similar to those identified previously, but the viruses did not originate from the same strain, as identified by multiple alignment. The knowledge level of the students and staff members in Lamongan studying and working at a half-day school exhibited a significant association with the incidence; however, no association was observed among the students in Bangkalan studying at a full-day school with a dormitory.

Trends in disease and complications of hepatitis A virus infection in the United States, 1999-2011: a new concern for adults.

In recent years, few US adults have had exposure and resultant immunity to hepatitis A virus (HAV). Further, persons with liver disease have an increased risk of adverse consequences if they are infected with HAV. This study used 1999-2011 National Notifiable Diseases Surveillance System and Multiple Cause of Death data to assess trends in the incidence of HAV infection, HAV-related hospitalization, and HAV-related mortality. During 1999-2011, the incidence of HAV infection declined from 6.0 cases/100 000 to 0.4 cases/100 000. Similar declines were seen by sex and age, but persons aged ≥80 years had the highest incidence of HAV infection in 2011 (0.8 cases/100 000). HAV-related hospitalizations increased from 7.3% in 1999 to 24.5% in 2011. The mean age of hospitalized cases increased from 36.0 years in 1999 to 45.1 years in 2011. While HAV-related mortality declined, the mean age at death among decedents with HAV infection increased from 48.0 years in 1999 to 76.2 years in 2011. The median age range of decedents who had HAV infection and a liver-related condition was 51.0 to 68.0 years. Although vaccine-preventable, HAV-related hospitalizations increased greatly, mostly among adults, and liver-related conditions were frequently reported among HAV-infected individuals who died. Public health efforts should focus on the need to assess protection from hepatitis A among adults, including those with liver disease.

Epidemiology and Prevention of Hepatitis A in Travelers

Hepatitis A is the second most common vaccine-preventable travel-associated infectious disease and hepatitis A virus (HAV) is the most common cause of viral hepatitis. The incidence of infection is closely related to sanitary conditions and the level of economic development. We evaluated HAV incidence, infection-related risk factors, and HAV vaccination rates in international travelers through retrospective analyses using major databases, such as CENTRAL, MEDLINE, EMBASE, and the current literature describing epidemiological data for HAV infection in recent years. We found that the incidence of HAV infection in developed countries is very low. As international travel increases, the incidence of hepatitis A among travelers remains high and likely leads to regional outbreaks. Travelers should visit the Centers for Disease Control and Prevention website or Infectious Disease Prevention Center of their countries to learn about the incidence of infectious diseases associated with their destination before going abroad to determine if they should be vaccinated.

Prevalence of antibodies against hepatitis A virus among children and adolescents in Germany

Since hepatitis A virus (HAV) infection during childhood is mostly asymptomatic, only seroprevalence studies can provide reliable information on incidence of HAV infection in children. The prevalence of anti-HAV antibodies was determined in sera taken in 2008 to 2010 from 1,645 children aged 0-17 years and in sera taken in 2010-2011 from 400 adult blood donors in Germany. For examination of trend over time, 715 sera collected between 1999 and 2006 from children at the age of 0-17 years within the federal state Thuringia were included. Antibody testing was carried out using the test kits ETI-AB-HAVK PLUS and ETI-HA-IGMK PLUS from DiaSorin. In children, the overall prevalence of antibodies was 10.8 %. After the seroprevalence declined from 8.8 % among the 0-2 year-olds to 2.4 % among the 3-4 year-olds, there was a significant increase to 20.5 % in the group of the 15-17 year-olds. Boys had with 12.7 % a significantly higher seroprevalence of anti-HAV antibodies compared to 8.8 % among girls. In adult blood donors, there was a HAV seroprevalence of 19.3 %. The likelihood of past infection or immunization within the age groups of children from 0 to 12 years differed significantly from that of adults. In conclusion, in Germany, only a small number of HAV infections occur in children, especially up to the age of 12 years. The proportion of susceptible children is greater than the proportion of susceptible adults. Thus, during outbreaks, the rate of infection among children would usually be higher than the rate among adults.

Hepatitis A virus infection during pregnancy in Korea: Hepatitis A infection on pregnant women

ObjectiveAlthough there is a large body of data on acute hepatitis A virus (HAV) worldwide, data regarding the occurrence of HAV during pregnancy is limited. It is commonly acknowledged that HAV is not associated with severe outcomes or complications during pregnancy. In contrast, there are several reported cases of vertical HAV transmission. Moreover, it has been recently reported that HAV infection during pregnancy is associated with gestational complications. In Korea, the incidence of HAV infection has increased from 317 cases in 2002 to 13,117 cases in 2009. However, HAV infection during pregnancy is rarely reported in Korea.MethodsThis study was conducted as a retrospective cohort series of pregnant women presenting to Korea University Medical Center between January 2000 and October 2009 in whom a diagnosis of HAV infection was made.ResultsDuring study period, there were 12 cases of HAV in pregnant women, including two cases with preterm contraction, two cases with cholestatic hepatitis, and one case with fetal ascites and intra-abdominal calcification.ConclusionHAV infection during pregnancy is associated with high prevalence of maternal and fetal complications. Because the incidence of HAV infection in women of reproductive age is increasing, a further focus on preventing HAV infection during pregnancy is warranted.

TIM-1, a novel allergy and asthma susceptibility gene

Atopic diseases, including asthma, allergic rhinitis, and atopic dermatitis, are caused by environmental factors in genetically predisposed individuals. Although the prevalence of these diseases has risen dramatically over the past two decades, it has been difficult to identify the underlying causes of these diseases due to the complex interplay between the genetic and environmental factors involved. Using a congenic mouse model of asthma, we simplified this complex trait and identified the novel T cell immunoglobulin domain, mucin-like domain (TIM) gene family, that encodes transmembrane proteins expressed by CD4 T cells. Recent studies demonstrate that the TIM family, particularly TIM-1, plays a critical role in immune responses that regulate the development of atopic diseases. In humans, certain polymorphic variants of TIM-1 are strongly associated with protection against atopy, and this association occurs only in individuals who have had past infection with hepatitis A virus (HAV). Since TIM-1 functions as the cellular receptor for HAV, activation of T cells through TIM-1 by HAV or by its natural ligand may affect T cell differentiation and the development of Th2-driven allergic inflammatory responses. Epidemiologically, HAV infection is associated with a reduced risk of developing atopy, and because the incidence of HAV infection has been significantly reduced in industrialized countries over the past 30 years, the discovery of a genetic interaction between HAV and TIM-1 provides the first molecular genetic evidence for the hygiene hypothesis.

Seasonal variation of hepatitis A virus infection in the city of Rio de Janeiro, Brazil.

Hepatitis A virus (HAV) infection constitutes a major public health problem in Brazil. The transmission of HAV is primarily by fecal-oral route so the water is an important vehicle of HAV dissemination. There is a great incidence of acute cases of hepatitis A in some areas of Brazil however the seasonal variation of these cases was not documented. The aim of this study was to determine the seasonality of HAV infection in Rio de Janeiro. From January 1999 to December 2001, 1731 blood samples were collected at the National Reference Center for Hepatitis Viruses in Brazil (NRCHV). These samples were tested by a commercial enzyme-immunoassay to detect anti-HAV IgM antibodies. Yearly positive rates were 33.74% in 1999, 32.19% in 2000, and 30.63% in 2001. A seasonal variation was recognized with the highest incidence in spring and summer. Furthermore a seasonal increase in incidence of HAV infection was found during the rainy season (December to March) because the index of rains is very high. It is concluded that HAV infections occur all year round with a peak during hot seasons with great number of rains.

Acute and chronic hepatitis: Working Group Report of the First World Congress of Pediatric Gastroenterology, Hepatology, and Nutrition.

Acute and chronic hepatitis: Working Group Report of the First World Congress of Pediatric Gastroenterology, Hepatology, and Nutrition.

Hepatitis A shifting epidemiology in Poland and Eastern Europe

The clinical morbidity of hepatitis A probably only represents 20% of cases of hepatitis A virus (HAV) infection. When it became possible to determine specific antibodies, a seroepidemiological survey of anti-HAV was undertaken in Poland, which showed that between 1979 and 1997 there was a shift in the peak age of infection from childhood to adulthood, concomitant with a substantial decline in the incidence of HAV infection. Data from the World Health Organization also indicate that there has also been a decline in the incidence of hepatitis A in Eastern European countries in general, over the 3 years from 1994 to 1996. The potential risk of epidemics still exists, however, when appropriate conditions are created. The available data show that fewer young people are becoming infected with HAV, and general preventive measures, including vaccination of children and high-risk groups (e.g. healthcare and childcare personnel and those living in ‘closed communities’) are needed to deal with HAV infections in Eastern Europe.