Viral hepatitis A, active component, U.S. Armed Forces, 2007-2016

During 2007-2016, there were 237 incident diagnoses of acute hepatitis A, with an overall incidence rate of 1.88 cases per 100,000 person-years (p-yrs). Crude overall rates of hepatitis A were highest among service members in the youngest age group, those in healthcare occupations, and among Air Force and Navy members. Service members of "other" or unknown race/ethnicity and non-Hispanic black service members had higher overall incidence rates of hepatitis A, compared to their non-Hispanic white and Hispanic counterparts. Annual incidence rates of hepatitis A were relatively stable until 2012 when rates peaked at 2.94 per 100,000. Rates dipped to 1.41 per 100,000 p-yrs in 2015 and then increased to 2.22 per 100,000 p-yrs in 2016. During the 10-year period, annual rates among male service members were relatively stable. The low rates of acute hepatitis A among U.S. service members overall reflect the widespread use of the hepatitis A virus vaccine.

Viral Hepatitis Among Non-Hispanic Asian Adults in the United States, 2011-2014

Hepatitis A (HAV), B (HBV), and C (HCV) viruses are common types of viral hepatitis. HBV and HCV infection can lead to liver disease, cancer, and serious health consequences. HAV and HBV infections are high among Asian persons, especially those born outside the United States (1-3). This report provides 2011- 2014 National Health and Nutrition Examination Survey (NHANES) estimates on prevalence of antibody to HAV (from infection or immunization), past or current HBV infection, and current HCV infection, by race and Hispanic origin.

The role of ethnicity and travel on Hepatitis A vaccination coverage and disease incidence in Arizona at the United States-Mexico Border

BACKGROUND

Hepatitis A (HAV) incidence has decreased in the United States, yet regional disparities persist. The role of international travel has become increasingly important in HAV transmission. We compared the relative burden of HAV in border and non-border regions in Arizona and examined the role of travel in sustaining HAV transmission.

METHODS

HAV vaccination coverage was calculated by age and region, using Arizona State Immunization Information System data. Incidence, demographics, and risk factors of cases reported through Arizona's infectious disease surveillance system between 2006 and 2011 were analyzed.

RESULTS

Hepatitis A incidence was higher in the border region of Arizona. Compared with the rest of Arizona, one-dose coverage in children<15 years was lower in the border region until 2008. Second dose coverage was lower in the border region, particularly among Spanish speakers. International travel among cases was generally high; however, in the border region cases were more likely to visit Mexico or South/Central America (94% vs. 80%, P value = 0.01) and be Hispanic (68% vs. 42%, P value = 0.0003).

CONCLUSIONS

Rates of HAV continue to be higher in the Arizona border region; the risk appears particularly high among Hispanics with recent travel in the Americas. Border surveillance should be emphasized, along with vaccination of all travelers, to continue to decrease and control HAV.

Viral hepatitis A, active component, U.S. Armed Forces, 2000-2010

From 2000 to 2010, there were 214 incident diagnoses of acute hepatitis A among active component members of the U.S. Armed Forces; the crude overall incidence rate during the period was 1.37 per 100,000 person-years. Rates of incident diagnoses of acute hepatitis A were relatively low throughout the period and much lower than during the pre-vaccine era (1990-1996). There were disproportionate numbers of diagnoses of acute hepatitis A among service members born in countries endemic for the infection. The low rates of acute hepatitis A among U.S. military members overall reflect the widespread use of hepatitis A virus vaccine.

Hepatitis A outbreak in an Orthodox Jewish community in London, July 2010

A cluster of hepatitis A cases in the Orthodox Jewish community in London, United Kingdom in July 2010 has triggered extensive contact tracing and vaccination. Two primary cases imported from a common source in Israel and three secondary cases have resulted in immunisation of over 900 contacts to date. Rapid response by local public health, primary care services and a dedicated community health team, and active hepatitis A vaccination rather than immunoglobulin treatment were used to avert a larger outbreak.

Does the race or gender of hepatitis C infected patients influence physicians' assessment of hepatitis A and hepatitis B serologic status?

BACKGROUND

HCV infection with concurrent or superinfection with HAV or HBV has the potential to worsen the liver status of HCV-infected individuals. This study evaluates if patients' race or gender influenced whether HAV or HBV serologic status was determined for the purpose of providing immunization.

METHODS

Medical records of consecutive African-American and white patients referred for management of HCV were evaluated to determine whether the referring physicians had obtained HAV and HBV serology.

RESULTS

Race and gender analysis revealed a statistically significant difference (P < 0.0001) in HAV testing of African-American and white patients, a statistically significant difference in HAV (P < 0.0001) and HBV (P < 0.0001) testing of African-American and white men, and a statistically significant difference (P = 0.0026) in HBV testing of African-American and white women.

CONCLUSION

HCV-infected individuals were inconsistently tested for HAV and HBV. Patients' race, but not gender, had a significant impact upon whether HCV-infected individuals were tested for HAV and HBV.

Prevalence of antibodies against hepatitis A virus among the Kuikuro and Kaiabi Indians of Xingu National Park, Brazil

A seroprevalence study to detect total antibodies against Hepatitis A Virus was done with 220 samples from 589 Native Indians from Xingu National Park, Brazil, in five Kaiabi and Kuikuro villages, the most populous ethnic groups. Using a commercial immunoassay kit we detected 97.7% positive samples (95% Confidence Interval: 95%-99%). We noticed a precocious seroconversion, before the age of six years, when the disease is usually asymptomatic. These results are similar to those found in the literature in non-Indian population studies of the Northern, Northeastern and West Central regions of Brazil. They suggest that it is not necessary to introduce vaccination against Hepatitis A in these highly endemic populations.

Hepatitis and human immunodeficiency virus co-infection among injection drug users in Los Angeles County, California

This study examined the prevalence of hepatitis A (HAV), B (HBV), C (HCV), and Human Immunodeficiency Virus (HIV) co-infection among Injection Drug Users (IDUs) in Los Angeles County, California, and predictors of multiple infections in this population. Six hundred seventy-nine IDUs were recruited from October 2002 through June 2004. Participants completed questionnaires to elicit demographic, drug and sex risk information, and were tested for hepatitis A, B, C and HIV.A linear regression model predicting the total number of infections (0 to 4 possible) was constructed. Significant associations were found between HAV and HBV infection, HAV and HCV infection, and HBV and HCV infection. Predictors of total co-infections included age of first injection, lifetime years in jail, and Hispanic ethnicity. Latinos had the highest proportion of HAV and HBV co-infection with HCV. The total number of co-infections, especially those co-infected with all three of the hepatitis infections, was unexpectedly high.

Immunity to hepatitis A and hepatitis B in Indian and Chinese immigrants seen in a travel clinic in Massachusetts, United States

Immigrants to the United States from developing countries have a higher probability of previous infection with hepatitis A virus (HAV) and/or hepatitis B virus in their countries of origin. Prior knowledge of hepatitis A and B seroprevalence in this population may aid in determining the need for pretravel immunizations when these individuals travel to endemic regions. We conducted a retrospective analysis of hepatitis A and B serologies in a travel clinic population (from March 1999 through September 2002) to determine the seroprevalence in our predominantly highly educated foreign-born subjects. All our patients who had immigrated from China and India and who were older than 60 years (born on or before 1940) were immune to hepatitis A. The Indian and Chinese subjects who were anti-HAV positive were also significantly older than the anti-HAV negative group. In addition, in our Indian study group, the hepatitis A-seropositive individuals first left India at a significantly older age than the hepatitis A-seronegative group (mean age 22.7 years vs 11.4 years, p < 0.05). Our small sample size of Chinese subjects may not have permitted a statistically significant difference to be detected for hepatitis A seroprevalence and age at departure from their country of origin. These results have helped tailor our recommendations for pretravel immunizations for our groups of foreign-born individuals planning to visit endemic areas. Individuals born in China or India on or before 1940 are likely to have preexisting antibody to hepatitis A and probably do not need the vaccine when they travel. Younger individuals may elect to have a hepatitis A antibody titer checked before getting the vaccine.

Hepatitis A virus infection in the United States: serologic results from the Third National Health and Nutrition Examination Survey

To determine the prevalence of hepatitis A virus (HAV) infection in the general U.S. population, sera from participants in the Third National Health and Nutrition Examination Survey (NHANES III) conducted in 1988-1994 were tested for antibody to HAV (anti-HAV). Among 21,260 participants aged > or = 6 years tested, the overall prevalence of infection was 31.3%, and increased markedly with age. The age-adjusted prevalence was significantly higher among foreign- compared to U.S.-born participants, and was highest among Mexican-Americans and lowest among non-Hispanic whites. Among U.S.-born children, only Mexican-American ethnicity and income below the poverty level were associated with HAV infection in a multivariate model. During this period before hepatitis A vaccination, age, ethnicity and birthplace were the most important determinants of HAV infection in the United States.

United States epidemiology of hepatitis A: influenced by immigrants visiting friends and relatives in Mexico?

Among the industrialized nations, the United States annually receives the greatest number of immigrants as permanent residents. Immigrants from Mexico have represented the largest segment of the foreign-born population in recent decades, and continued growth of Mexican immigration is predicted for the decades ahead. The changing demographics of this population, including the emergence of new immigrant growth centers, will influence the future epidemiology of hepatitis A virus transmission in the United States. Travel home to the place of origin to visit friends and relatives (VFR) by both newly arrived and established Mexican immigrants constitutes a new group of travelers that now include intergenerational family units. Asymptomatic pediatric travelers-who acquire hepatitis A abroad and are infectious on return to American communities-contribute to the silent transmission of hepatitis A to playmates, caretakers, and contacts in households, daycare facilities, and elementary schools. Considering the expanded geographic distribution of Mexican immigrant settlement, the predicted increased diversity of pediatric populations in the United States over time, and the continued growth of VFR travel, a universal pediatric vaccine recommendation for hepatitis A immunization can help to prevent hepatitis A transmission in this country in the future.

Viral hepatitis in minority America

Viral hepatitis continues as an important public health concern in the United States. Available data indicate that acute and chronic viral hepatitis remains an important cause of morbidity and mortality in this country despite the availability of immunization for hepatitis A and B and pharmacologic therapy for chronic hepatitis B and C. Minority populations within the United States are disproportionately affected by acute and chronic viral hepatitis. Many diseases, for example, Barrett's esophagus, affect ethnic groups differently. Viral hepatitis A, B, and C may demonstrate ethnic variation with regard to their epidemiology, natural history, clinicopatholgic findings, complications, and treatment outcomes. This report will review the literature regarding these areas in hepatitis A, B, and C among the African American, Hispanic American, and Native American populations of the United States.

[Immunogenetic HLA markers of chronic viral hepatitis]

AIM

To study possible immunogenetic HLA markers of chronic viral hepatitides.

MATERIAL AND METHODS

Using the reaction of complement-dependent cytotoxicity by Terasaki, we analysed distribution of leukocytic HLA antigens (loci A, B and C) in 179 patients with chronic viral hepatitides B, C and D in Russians and Kazakhs living in the Astrakhan Region.

RESULTS

In the Russian population we discovered a significant positive association of CVHB with HLA-B18, HLA-B35, HLA-B40, HLA-Cw3 antigens, and negative one--with HLA-A2. In Kazakhs with CVHB there was a positive association with HLA-A3, HLA-B18 and negative one--with HLA-A11. Alleles HLA-A10, HLA-B35, HLA-B40 and HLA-Cw3 mark CVHC in Russians. HLA-Cw4 specificity acts as protector in development of chronic HCV-infection. A correlation was found between carriage of some specificities and haplotypes of HLA and activity of chronic HBV and HCV infection. A high risk of chronic delta infection in Russians is associated with HLA-B8 and HLA-B35, in Kazakhs--with HLA-B35 and HLA-D40. There are significant associations between CVHB, CVHC, chronic delta infection and some HLA haplotypes.

CONCLUSION

A universal role of HLA-B35 specificity in development of CVH irrespective of hepatotropic virus and patients' nationality is shown.

Impact of hepatitis A vaccination of Indigenous children on notifications of hepatitis A in north Queensland

OBJECTIVE

To describe the impact of a hepatitis A vaccination program for Indigenous children in north Queensland.

DESIGN

Enhanced surveillance of all notified cases of hepatitis A in north Queensland from 1996 to 2003.

SETTING

North Queensland; population, 596 500 people, including about 6900 Indigenous children aged under five years.

INTERVENTIONS

Hepatitis A vaccine was provided to Indigenous children in north Queensland from February 1999; two doses were recommended (at 18 months and 2 years of age), as was catch-up vaccination up to the sixth birthday.

RESULTS

In the 4 years 1996-1999, 787 cases of hepatitis A were notified in north Queensland, 237 (30%) of which were in Indigenous people. The average annual notification rates in Indigenous and non-Indigenous people during this period were 110 and 25 cases per 100 000 persons, respectively. In the first 4 years after introduction of the vaccination program (2000-2003), 66 cases of hepatitis A were notified. Only nine of the 66 (14%) were in Indigenous people. The average annual notification rates in Indigenous and non-Indigenous people in 2000-2003 were 4 and 2.5 cases per 100 000 persons, respectively.

CONCLUSION

Hepatitis A seems to have been eradicated from Indigenous communities in north Queensland very soon after the vaccination program began. The rapid decline in notifications in non-Indigenous as well as Indigenous people suggests the program quickly interrupted chains of transmission from Indigenous children to the broader community. To our knowledge this is the first evidence that a hepatitis A vaccination program targeting a high-risk population within a community can reduce disease in the broader community. Hepatitis A vaccine should be provided to other high-risk Indigenous children elsewhere in Australia.

Racial and ethnic differences in the seroprevalence of 6 infectious diseases in the United States: data from NHANES III, 1988-1994

OBJECTIVES

We examined racial/ethnic differences in the seroprevalence of selected infectious agents in analyses stratified according to risk categories to identify patterns and to determine whether demographic, socioeconomic, and behavioral characteristics explain these differences.

METHODS

We analyzed data from the third National Health and Nutrition Examination Survey, comparing differences among groups in regard to the prevalence of infection with hepatitis A, B, and C viruses, Toxoplasma gondii, Helicobacter pylori, and herpes simplex virus type 2.

RESULTS

Racial/ethnic differences were greater among those in the low-risk category. In the case of most infectious agents, odds associated with race/ethnicity were almost 2 times greater in that category than in the high-risk category.

CONCLUSIONS

Stratification and adjustment for socioeconomic factors reduced or eliminated racial/ethnic differences in the prevalence of infection in the high-risk but not the low-risk group, wherein race/ethnicity remained significant and might have been a surrogate for unmeasured risk factors.

Hepatitis A in Hispanic children who live along the United States-Mexico border: the role of international travel and food-borne exposures

OBJECTIVES

Hispanic children who live along the United States-Mexico border historically have had among the highest hepatitis A rates in the United States, but risk factors have not been well characterized. The objective of this study was to examine risk factors associated with acute hepatitis A virus (HAV) infection in Hispanic children who live along the United States-Mexico border in San Diego County, California.

METHODS

In this case-control study, hepatitis A cases among Hispanic children who were younger than 18 years reported from June 1998 through August 2000 were matched by age group and exposure period to Hispanic children who were susceptible to HAV infection. Participants and their families were interviewed about demographic information and potential sources of HAV infection, including attending child care, food and waterborne exposures, cross-border and other international travel, and travel-related activities.

RESULTS

Participants included 132 children with hepatitis A and 354 control subjects. The median age of study participants was 7 years (range: 1-17). Sixty-seven percent of case-patients traveled outside the United States during the incubation period, compared with 25% of the children without hepatitis A (odds ratio [OR]: 6.3; 95% confidence interval [CI]: 4.0-9.7); all children, except 1, had traveled to Mexico. In multivariate analysis, hepatitis A was associated with having eaten food from a taco stand or street food vendor (adjusted OR: 17.0; 95% CI: 4.1-71.1) and having eaten salad/lettuce (adjusted OR: 5.2; 95% CI: 1.3-20.1) during travel.

CONCLUSIONS

Hepatitis A among Hispanic children who live in an urban area of the United States-Mexico border is associated with cross-border travel to Mexico and food-borne exposures during travel. Travelers to areas where hepatitis A is endemic should receive hepatitis A vaccine before travel.

Immunity and exposure to hepatitis A virus in pre-adolescent children from a multi-ethnic inner city area

Seroprevalence data among ethnic minority groups within England and Wales are rare. An opportunistic approach was taken to test residual oral fluid, collected from pre-adolescent school children from an ethnically diverse region of northwest England, for anti-hepatitis A virus (HAV) IgG. Individual data on ethnicity and country of birth were also available. Of the 257 children who consented to participate, 62% were of South Asian ethnic origin. The overall seroprevalence was 18.8%, higher than 13.1% reported from a recent population-based survey in England and Wales among a mainly Caucasian population of the same age. The only factor significantly associated with HAV seropositivity in a multivariable logistic regression model was birth of the child abroad. Association with the place of birth of the child, but not that of the parent indicates that infection within this group occurs mainly abroad. Larger studies among ethnic minority groups are needed to investigate this claim further.

Promoting prevention of viral hepatitis in the African American community

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Hepatitis A vaccination among young African American men who have sex with men in the deep south: psychosocial predictors

Despite recommendations for vaccination against hepatitis A (HAV) of men who have sex with men (MSM), most remain unvaccinated. This study was designed to identify attitudes and beliefs associated with vaccination against HAV using a conventional outreach sample of African American MSM in Birmingham, Alabama. Of 107 participants, nearly 34% reported being vaccinated against HAV. Over half of the participants reported 10 or more different lifetime male sexual partners, and a third reported having had intercourse with females, as well as, males within the past 5 years. About 10% of the participants reported condom use over half of the time during oral intercourse, and 50% of the participants reported using a condom over half the time during anal intercourse. In multivariable analysis, predictors of HAV vaccination were a decreased perception of the practical barriers to HAV vaccination (odds ratio [OR], 0.05; 95% confidence interval [CI]: 0.01-0.18, P = 0.002); increased health provider communication (OR, 9.89; 95% CI: 2.74-35.65, P = 0.02); and increased perceived personal self-efficacy to complete the two-dose series (OR, 7.31; 95% CI: 2.38-22.45, P = 0.02). Our findings underscore the need to increase vaccination through innovative approaches to reduce perceived barriers to vaccination while increasing provider-patient communication and self-efficacy to complete the vaccine series.

Prevalence rates of viral hepatitis infections in refugee Kurds from Iraq and Turkey

BACKGROUND

Since little is known about the burden of viral hepatitis in Kurds, the prevalence of infection with hepatitis A virus (HAV), hepatitis E virus (HEV), hepatitis B virus (HBV) and hepatitis C virus (HCV) was investigated in a sample of refugee Kurds from Iraq and Turkey.

PATIENTS AND METHODS

A cross-sectional study was carried out. Serological markers to hepatitis viruses were determined for 1,005 subjects from all age-groups of which 36.6% were from Turkey and 63.4% from Iraq.

RESULTS

Overall seroprevalence for anti-HAV was 94.4% and 14.8% for anti-HEV. A significantly higher prevalence for anti-HEV was found among Iraqis (17.5%) compared to Turkish immigrants (10.0%). The prevalence of hepatitis B surface antigen (HBsAg) and total anti-HBc (core) was 6.8% and 35.6% in Turkish Kurds and 2.2% and 12.7% in Iraqis, respectively. Only 10% of children aged up to 10 years and 2.8% of subjects aged 11-20 years had been vaccinated against HBV, the majority of them coming from Iraq. One subject was confirmed as positive for anti-HCV (0.1%) and HCV-RNA and analysis showed a 4c/4d genotype.

CONCLUSION

This survey shows a high prevalence of enterically transmitted viral hepatitis in Kurds. HBV infection is moderately endemic, while the prevalence of HCV infection is low. There is a need for a universal immunization strategy for HBV in the Kurd population.

Seroprevalence of hepatitis A virus antibodies in Turkish and Moroccan children in Rotterdam

Seasonal fluctuations in hepatitis A have been observed in the Netherlands related to Turkish and Moroccan children after visiting their home countries. This study determined the prevalence and associated factors of hepatitis A virus (HAV) antibodies in Turkish and Moroccan children in Rotterdam. A random sample was taken of children in Rotterdam, aged 5-16 years, of Turkish and Moroccan origin, together with a random sample of native Dutch children aged 5-7 and 14-16 years. Blood was collected by finger prick on filter paper. IgG and IgM anti-HAV was detected by an enzyme-linked immunoassay (EIA). The 319 Turkish, 329 Moroccan, and 248 native Dutch children participated in the study. In Turkish children, IgG anti-HAV increased from 2.2% to 22.2% over the age groups. In Moroccan children, IgG anti-HAV increased from 10.2% to 57.7%. In native Dutch children, 0.8% had IgG anti-HAV in the youngest and 3.1% in the oldest age group. The percentage IgG-positive also having IgM anti-HAV was 21% in Turkish, and 41% in Moroccan children. No IgG-positive native Dutch children had IgM anti-HAV. The prevalence of IgG anti-HAV was associated with increased age, being Moroccan, longer stay in the country of origin before migrating to the Netherlands, and known contact to HAV. The majority of Turkish and Moroccan children aged 4-16 years in Rotterdam are not protected against HAV, but do have a high risk of becoming infected while visiting their native country. Active vaccination against HAV of these children is indicated, with as primary aim their own protection. Prevention of HAV-transmission in the general community should be seen as a secondary benefit. In addition, possible Dutch contacts of nonvaccinated Turkish and Moroccan children, such as day care workers and teachers, should also be vaccinated against HAV.

A study of hepatitis A seropositivity in Dallas County, Texas, 1998 through 1999

This paper provides background information on the epidemiology and a descriptive analysis of infection with hepatitis A virus in Dallas County, Texas, for 1998 and 1999. Reported cases were obtained from the Dallas County Health Department, and incidence rates per 100,000 population were calculated. Persons who tested seropositive for hepatitis A virus between January 1, 1998, and December 31, 1999, were included. Variables of interest included age, sex, race, and date of occurrence. The overall incidence rate of this infection in Dallas County for 1998 was 1.9 times higher than that of the United States; in 1999, the overall rate for Dallas County increased by more than 1.6 times. Rates were significantly higher among males, highest among Hispanics, and lowest among blacks for both years. Incidence rates among age groups varied between years by increasing in people 50 years and older from 1998 to 1999 as a result of a single cafeteria-related outbreak of 150 cases in March 1999. Infection with hepatitis A virus remains the most reported vaccine-preventable disease in the United States.

Changing scenario of hepatitis A virus and hepatitis E virus exposure among the primitive tribes of Andaman and Nicobar Islands, India over the 10-year period 1989-99

The Andaman and Nicobar Islands, Union Territory of India, are home to six primitive tribes. Studies carried out earlier among these tribes revealed very high rates of hepatitis B infection. We have now studied hepatitis A and E infection among them. A total of 951 serum samples were collected from four accessible tribes (Nicobarese, Shompens, Onges and Great Andamanese) and tested for antibodies against hepatitis A and E viruses. In addition, 240 serum samples collected a decade earlier from age-stratified Nicobarese were also screened. Hepatitis A virus (HAV) infection was found to be highly endemic among all the tribes, whereas hepatitis E virus (HEV) infection was common among the Nicobarese and Shompens. The age group-wise prevalence of these infections among the Nicobarese showed different patterns, HAV prevalence rising significantly from those aged 10 years and thereafter reaching a plateau, whereas HEV prevalence was found to be more evenly distributed over all age groups, but rising somewhat after 30 years of age. Over the last decade, the prevalence of HAV among the Nicobarese has declined slightly, particularly in those aged 10 years or less whereas HEV infection has more than doubled over all age ranges. Different HEV prevalence observed among the tribes could not be attributed to differences in sanitation or water supply. This fact and the different age-wise patterns of HAV and HEV prevalences is suggestive of different modes of transmission of HEV that are not shared. The highest rates for HEV were among those tribes which reared pigs suggesting that pigs might serve as reservoir of HEV. Further studies are needed, however, to validate these findings.

Seroprevalence of hepatitis A immunity in male genitourinary medicine clinic attenders: a case control study of heterosexual and homosexual men

OBJECTIVES

To compare the seroprevalence of hepatitis A in homosexual and heterosexual men to determine their susceptibility to infection and provide guidance for a policy on vaccination.

METHODS

A case-control study design was utilised to compare the risk factors associated with hepatitis A in homosexual and heterosexual men attending a city centre genitourinary medicine clinic. Demographic and sexual behavioural characteristics were included in univariate and multivariate models.

RESULTS

The overall seropositivity rate was 29% with no significant difference between homosexual and heterosexual men. Ethnicity and age were strongly associated with hepatitis A seropositivity in both homosexuals and heterosexuals. A history of sex in a sauna in homosexual men, and being born outside the United Kingdom for heterosexual men, was associated with hepatitis A seropositivity.

CONCLUSIONS

Targeted hepatitis A screening and vaccination of homosexual men attending UK genitourinary medicine clinics is not supported by the results of this study.

[Hepatitis A in Denmark. Notified cases 1996-1999]

INTRODUCTION

The aim of the study was to describe the incidence of hepatitis A in Denmark with the emphasis on the role of immigrants in relation to transmission and prevention of the disease.

METHOD

A retrospective study of notified cases of hepatitis A during the period, 1.1.1996-31.12.1999.

RESULTS

A total of 398 notified cases were examined, 45% of which occurred in immigrants. The average incidence per year was 13.2 per 100,000 for immigrants and 1.1 per 100,000 for Danes. The incidence for immigrants from Pakistan and Turkey was 4-5 times that for immigrants as a whole. The median age in immigrants was eight years and in Danes 29 years. Immigrants were hospitalised in 35% of the cases. Of children below ten years of age 31% were admitted. Danes were hospitalised in 43% of the cases, and of children below ten years of age 44% were admitted. Infection was acquired abroad for 71% of immigrants, 49% of whom visited Pakistan or Turkey. Of those infected in Denmark, person-to-person transmission was the most common mode of infection for both groups. Immigrants who had been travelling to endemic areas were involved in 21 of 34 outbreaks.

CONCLUSION

The incidence of hepatitis A in Denmark seems to relate highly to the children of immigrants, who come from high endemic areas. Vaccination of those above one year of age is recommended when travelling abroad if anticipated. Economic compensation could be considered.

Sources of infection among persons with acute hepatitis A and no identified risk factors during a sustained community-wide outbreak

CONTEXT

Hepatitis A is a common vaccine-preventable disease in the United States. Most cases occur during community-wide outbreaks, which can be difficult to control. Many case-patients have no identified source.

OBJECTIVE

To identify foodborne and household sources of hepatitis A during a community-wide outbreak.

DESIGN

Serologic and descriptive survey.

SETTING

Salt Lake County, Utah.

PARTICIPANTS

A total of 355 household contacts of 170 persons reported with hepatitis A during May 1996 to December 1996, who had no identified source of infection; and 730 food handlers working in establishments where case-patients had eaten.

MAIN OUTCOME MEASURE

Prevalence of immunoglobulin M antibodies to hepatitis A virus (IgM anti-HAV) among household and food service contacts.

RESULTS

Overall, 70 household contacts (20%) were IgM anti-HAV-positive, including 52% of children 3 to 5 years old and 30% of children <3 years old. In multivariate analysis, the presence of a child <3 years old (odds ratio [OR]: 8.8; 95% confidence limit [CL]: 2.1,36) and a delay of >/=14 days between illness onset and reporting (OR: 7. 9; 95% CL: 1.7,38) were associated with household transmission. Of 18 clusters of infections linked by transmission between households, 13 (72%) involved unrecognized infection among children <6 years old. No food handlers were IgM anti-HAV-positive.

CONCLUSION

During a community-wide outbreak, HAV infection among children was common, was frequently unrecognized, and may have been an important source of transmission within and between households. Transmission from commercial food establishments was uncommon. Ongoing vaccination of children may prevent future outbreaks.

Ethnic and geographic variations in the prevalence of hepatitis A, B and C among aboriginal villages in Hualien, Taiwan

BACKGROUND

Taiwan is endemic for viral hepatitis infections. A field survey was performed in the isolated aborigines in Hualien, eastern Taiwan, to investigate the geographic and ethnic variations in hepatitis epidemiology.

MATERIALS AND METHODS

From 1996 to 1998, blood was drawn from 1,748 subjects from two southern Ami and two northern Atayal villages for serum markers of hepatitis A, B and C.

RESULTS

Hepatitis A infection approached 100% in all groups. Hepatitis B infection and carrier rates were higher in the Atayal than in the Ami (92.3% vs. 49.1% and 20.8% vs. 5.3%; p<0.01). Hepatitis C infection rates were higher in three villages (27.5%, 20.1% and 25.4% vs. 3.6%; p<0.01). Hepatitis C infection increased with age (p<0.01) while hepatitis B infection did not.

CONCLUSION

Hepatitis A infected most aborigines before the age of 15 years. Hepatitis B seldom infected people after the age of 15 years, while hepatitis C continued to infect people who were older. Geographic factors are important for hepatitis C infection, whereas for hepatitis B infection, in addition ethnicity is also important.

Hepatitis A among health workers in Paris hospitals. Occupational Health Physicians of Paris Hospital (AP-HP)

To design a vaccination strategy against hepatitis A among hospital employees, we carried out a serological survey of hepatitis A virus (HAV) infection in 10 university hospitals in the Paris area. Subjects under 60 years of age were consecutively enrolled by occupational health services and tested for IgG to HAV by ELISA. Of the 1,516 subjects recruited, 926 were health workers (HW), 322 clerks, and 268 cooks or kitchen employees. Among HW and clerks the HAV seroprevalence was 53.8% (95% CI: 44.0-65.6), increasing with age and being higher among employees of African or Caribbean origin than those from Europe (83.6% vs 45.6%, P < .001). Age correlated closely with the duration of hospital work, so only age was taken into account for further analysis. The HAV seroprevalences among HW and clerks originating from Europe were close (46.8% vs 42.6%) and remained so after adjustment for age. HAV seroprevalences in HW caring for adults and those caring for children were also similar (45.2% vs 40.1%). Seroprevalence was higher in assistant nurses than in nurses (51.3% vs. 39.8%, P < .02). Among cooks and kitchen employees, 53.4% were HAV-seropositive. This study shows that hospital employees need not routinely be vaccinated against HAV; the decision should be taken by the occupational physician according to the type of work, but should be routine for cooks and kitchen employees. The need for prevaccinal screening for anti-HAV should be assessed in the light of employees' geographical origin and age.

Hepatitis A infections in Wisconsin: trends in incidence and factors affecting surveillance, 1986-1995

From January 1986 through December 1995, 4,143 cases of hepatitis A virus (HAV) infection were reported in Wisconsin. The annual hepatitis A incidence remained stable from 1986 through 1988, with a mean annual rate of 4.7 cases per 100,000 (endemic HAV incidence rate). During 1989-1993, the incidence of HAV infection increased with a peak in 1992 of 19 cases per 100,000 population. A large foodborne outbreak (1992) and community wide outbreaks among African American residents (1989-1993) and Native Americans residents (1991) were associated with these high rates of HAV infection. The community wide outbreaks affected different groups: among African Americans, incidence rates were highest in young adults 15-34 years old; among Native Americans rates were highest in children 5-14 years old. Approximately 2,343 (57%) patients had no apparent risk factor (e.g., international travel, contact with person with HAV infection) for acquiring HAV infection. Factors limiting control of HAV infection in Wisconsin included poor reporting by laboratories (only 19% of all reported cases were independently reported to the Wisconsin Division of Health by a laboratory and fewer than 50% of these reports were from private laboratories), incomplete reporting by Wisconsin physicians or designees (74% of cases confirmed in Wisconsin laboratories were reported in 1995), failure to submit follow-up case report forms (14% of cases), and a prolonged interval between diagnosis and follow-up (> or = 15 days for 610 cases). Efforts should be enhanced to improve the reporting of cases of HAV infection by private laboratories, particularly through the use of automated electronic reporting.

Epidemiological study of viral hepatitis types A, B, C, D and E among Inuits in West Greenland

A descriptive study was performed to evaluate the relative frequencies and molecular epidemiological features of viral hepatitis types A to E among the Inuit population in West Greenland. Serum samples were collected from 503 Inuits (186 males and 317 females; mean age 35 years; range 7-79 years) and were tested for markers of viral hepatitis infection. The hepatitis A prevalence averaged 54%, with a significant rise from 9% to 50% between the second and third decade of life. As for hepatitis B, 42% of the total study population showed serological evidence of current or past hepatitis B virus (HBV) infection and 7% were hepatitis B surface antigen (HBsAg) carriers. Among the carriers, 6% were also positive for hepatitis B e antigen (HBeAg), and HBV DNA could be detected in 49% of carriers by polymerase chain reaction. Typing of the HBV isolates revealed genomic group D in 83% (serotype ayw2) and group A in 17% (serotype adw 2). Less than 1% of the study population had antibodies to the hepatitis C virus. None were positive for HCV RNA. Serological evidence of hepatitis D infection was found in 7% of those with hepatitis B helper virus infection markers and in 40% of the HBsAg carriers. As for hepatitis E, 3% of the Inuits showed reactivity in an enzyme immunoassay that detected hepatitis E virus antibody. HEV RNA could not be detected.

Hepatitis A vaccination programs in communities with high rates of hepatitis A

In June 1995, the Public Health Service Advisory Committee on Immunization Practices (ACIP) issued recommendations about the use of hepatitis A vaccine for the prevention and control of hepatitis A. In communities with high rates of hepatitis A and periodic outbreaks, the ACIP recommends routine vaccination of young children and catch-up vaccination of previously unvaccinated older children. This report describes hepatitis A vaccination programs initiated to control ongoing outbreaks and prevent future outbreaks in two communities with high rates of hepatitis A. Preliminary epidemiologic data indicate that the program in one area may have decreased the magnitude and duration of a predicted outbreak. The incidence of hepatitis A in other areas will require long-term monitoring to determine the effect of the vaccination program .

The role of young children in a community-wide outbreak of hepatitis A

An Hasidic Jewish community has experienced recurrent hepatitis A outbreaks since 1980. To assess risk factors for illness during a 1985-6 outbreak, the authors reviewed case records and randomly selected 93 households for an interview and serologic survey. In the outbreak, 117 cases of hepatitis A were identified, with the highest attack rate (4.2%) among 3-5 year olds. Among the survey households, the presence of 3-5 year olds was the only risk factor that increased a household's risk of hepatitis A (indeterminant relative risk, P = 0.02). Furthermore, case households from the outbreak were more likely to have 3-5 years olds than were control households from the survey (odds ratio = 16.4, P < 0.001). Children 3-5 years old were more likely to have hepatitis A and may have been the most frequent transmitters of hepatitis A in this community. Hepatitis A vaccination of 3-5 year olds can protect this age group and might prevent future outbreaks in the community.

A program to control an outbreak of hepatitis A in Alaska by using an inactivated hepatitis A vaccine

OBJECTIVE

To stop an epidemic of hepatitis A in rural Alaska by mass immunization of susceptible persons with 1 dose of an inactivated hepatitis A vaccine.

DESIGN

Nonrandomized, uncontrolled trial. Hepatitis A vaccine was offered to all persons in susceptible age groups in villages with documented cases of hepatitis A. Immune globulin was not offered at the time of vaccination.

SETTING

Twenty-five rural communities located in interior Alaska and along the northwest coast of the Bering Sea and Arctic Ocean.

PARTICIPANTS

Persons without a history of acute hepatitis A in age groups selected by applying results of a previous serosurvey conducted on serum collected before the epidemic.

INTERVENTION

One dose of a formalin-inactivated hepatitis A vaccine was given to each participant. Adults 20 years of age and older received 1440 enzyme-linked immunosorbent assay units and persons younger than 20 years received 720 enzyme-linked immunosorbent assay units. Prevaccination and postvaccination levels of antibody to hepatitis A IgG were obtained from 136 participants.

MAIN OUTCOME MEASURES

An active surveillance system was established to detect persons with symptomatic illnesses compatible with hepatitis A; persons who met the illness criteria were tested for antibody to hepatitis A IgM. One area (the Kotzebue region), where all communities were offered vaccine, was selected for intensive surveillance and analysis.

RESULTS

During the 12-month period before the vaccine trial, 529 cases of icteric hepatitis A were reported, and 443 were confirmed to be positive for antibody to hepatitis A IgM. Hepatitis A vaccine was administered to 4930 persons, 3517 of whom were younger than 20 years. After vaccination began, 237 persons positive for antibody to hepatitis A IgM were identified during a 60-week surveillance period; 46 were vaccines and 191 were unvaccinated susceptible persons. In the Kotzebue region, in communities in which more than 80% of persons considered susceptible were vaccinated, the outbreak ceased in 4 to 8 weeks, whereas in 1 large community in which less than 50% of susceptible persons were vaccinated, the outbreak continued for more than 50 weeks. More than 90% of seronegative persons developed antibody to hepatitis A IgG 3 to 4 weeks after vaccination.

CONCLUSION

This trial suggested that by providing both short-term and long-term protection, hepatitis A vaccine used without immune globulin halted an established epidemic of hepatitis A in rural Alaska.

Should aboriginals in the "top end" of the Northern Territory be vaccinated against hepatitis A?

OBJECTIVE

To determine the level of immunity to hepatitis A virus infection in rural Australian Aboriginal populations in the "Top End" of the Northern Territory.

METHODS

A total of 344 sera, for which details of donors' age, sex and domicile were available, were collected and tested for hepatitis A total antibody in a delinked seroprevalence study.

RESULTS

Overall, 337/344 samples (97.97%) tested positive for hepatitis A total antibodies--18/20 samples (90%) in the 1-5 year age group; 85/88 (96.6%) in the 6-10 year age group; 98/98 (100%) in the 11-15 year age group; 32/33 (97.0%) in the 16-20 year age group and 104/105 (99%) in the older than 20 year age group.

CONCLUSION

Hepatitis A is hyperendemic in the rural Aboriginal communities studied and the virus is acquired predominantly in the first five years of life. Symptomatic hepatitis A infection is uncommon in this population. We suggest that hepatitis A vaccination for rural Aboriginal children is not indicated as it would not reduce clinical disease rates and may produce a cohort whose immunity could decrease over the following 10 years. Although vaccination is appropriate for non-immune individuals working in remote communities, emphasis must be placed on the inequities in health infrastructure and education underlying the high transmission rates in Aboriginal children.

Racial differences in the seroprevalence of hepatitis A virus infection in Natal/KwaZulu, South Africa

The age- and race-specific seroprevalence of hepatitis A virus (HAV) infection was determined by radioimmunoassay (RIA) in 786 subjects between the ages of 6 months to 60 years. More than 50% of African children were seropositive by the age of 5 years. In blood donors (17-60 years), 50% (93/187) of Whites, 67% (110/163) of Indians, 85% (117/137) of Coloureds, and 91% (115/127) of Africans were seropositive. There was a significant difference in the seroprevalence of HAV infection between White blood donors and blood donors from the other three racial groups [Coloureds (P < 0.0001), Africans (P < 0.0001), and Indians (P < 0.001)] and between Indians and Coloureds (P < 0.0001) and Indians and Africans (P < 0.0001). There was no significance difference in HAV infection between Coloureds and Africans (P < 0.200). Eighty-seven per cent (32/37) of rural Africans had previous infection. In the African population HAV infection is acquired in childhood. There are significant racial differences in the seroprevalence of HAV infection. The surveillance of HAV infection may be used as a valuable yardstick to monitor the changing standards of hygiene and socioeconomic conditions of a community in transition in South Africa and to make rational public health decisions regarding a hepatitis A vaccination policy.

Immunogenicity, safety and tolerability of varying doses and regimens of inactivated hepatitis A virus vaccine in Navajo children

The Navajo are known to be at high risk for hepatitis A virus (HAV) infection. This study investigated the safety and immunogenicity of an investigational, alum-adjuvanted, formalin-inactivated HAV vaccine (VAQTA) developed by Merck Research Laboratories in Navajo children. One hundred two of 212 children, ages 4 to 12 years, were HAV-seronegative (< 10 mIU/ml by an enhanced sensitivity modification of the HAVAB; Abbott). Ninety of these children received the HAV vaccine. Study participants were given vaccines containing various viral protein concentrations: Group A (n = 18), 6 units; Group B (n = 36), 13 units; and Group C (n = 36), 25 units HAV protein (1 unit approximately 1 ng viral protein antigen). Three-dose (0, 8, 24 weeks) and two-dose (0, 24 weeks) regimens were compared in subgroups within B and C. The vaccine was well-tolerated and there were no serious adverse reactions; no vaccinee developed hepatitis A. After 1 dose 82 to 100% of children seroconverted (> or = 10 mIU/ml, modified HAVAB; Abbott) and 100% seroconverted after 2 doses. After 1 dose the geometric mean titer for antibody was: Group A, 22 mIU/ml; Group B, 18 mIU/ml; and Group C, 38 mIU/ml. After 3 doses geometric mean titers increased to 10,106 mIU/ml in Group A, 7258 mIU/ml in Group B and 11,856 mIU/ml in Group C. Further field studies are indicated to evaluate its use in high risk populations, such as the Navajo.

The prevalence of antibodies to the hepatitis A virus in Owambo children

The prevalence of hepatitis A virus infection, in a population as well as the age at which it is usually acquired reflect the prevailing socio-economic conditions and standards of public hygiene. Infection occurs equally in both the sexes. Black Africans are known to have a high prevalence of hepatitis A virus infection and do acquire the infection early in life. This study documents the age-specific prevalence in Owambo children and confirms an equal sex distribution.

Sero-epidemiology of hepatitis A in black South African children

A community-based sero-epidemiological survey was undertaken to determine the age-specific prevalence rates of hepatitis A virus (HAV) infection in a representative sample of 782 urban black children aged from newborn to 13 years. Among children aged 0-5 months, the prevalence of anti-HAV was 68.8% (95% confidence interval (CI) 60.6-77.0%); this fell to a low of 2.5% (CI 0.1-4.9%) in those aged 6-11 months, implying the presence of maternal antibody in the first few months of life. By the age of 2 years, 51.2% (CI 45.7-56.7%) had anti-HAV, by age 4 the prevalence had risen to 81.4% (CI 75.5-87.3%) and by age 6, the prevalence of anti-HAV was almost 100% (CI 90.5-96.7%), reflecting the poor socio-economic and environmental conditions these children live in. The lowest prevalence of HAV infection among urban black South African children was during infancy, before the age at which the incidence rate rose sharply; e.g. 1 out of 5 children was already infected with HAV by its 2nd birthday. Vaccination in infancy will therefore have the biggest impact on the spread of HAV. However, before HAV vaccination in infancy is advocated, vaccine immunogenicity in infancy and the possible detrimental effect of maternal antibodies on the immunogenicity of the vaccine need clarification.

Changing seroepidemiology of hepatitis A virus infection between two regions in Taiwan differing in socioeconomic status

In Taiwan, hepatitis A virus (HAV) infection is hyperendemic, and prior to the late 1970s more than 85% of the population was infected by 15 years of age. In this study, the prevalence of HAV infection in two regions of Taiwan with differing standards of living is evaluated. Serum antibody to HAV (anti-HAV) was determined by enzyme immunoassay. A total of 4,218 subjects under the age of 16 years were enrolled. The first group of 1,581 subjects were residents of the prosperous western plain region where the socioeconomic status and living environment have improved greatly in the past 20 years; the second group of 2,637 subjects were aborigines inhabiting the eastern and central mountain regions where improvement in the standard of living lags far behind the western region. All serum samples were collected in 1991 except for 1,100 samples collected in 1989 from elementary and junior middle school students in Tainan city. The prevalence of HAV infection was 11.9% for the western region and 81.0% for the eastern and central regions. In the eastern and central regions, 80% of the subjects had been infected with HAV before the age of six years, in contrast to 0% in the western region. By the age of 13 years, only 6% of the subjects were infected in the western region; however 97% had been infected in the eastern and central regions. Among children under the age of 10 years, only 10.6% (10/94) of the IgM-anti-HAV positive cases had clinical symptoms. These findings indicate that HAV infection has a close relationship with socioeconomic status and environmental sanitation.

Risk of viral hepatitis among military personnel assigned to US Navy ships

A prevalence study of 2072 male US shipboard military personnel scheduled for deployment to South America/West Africa and the Mediterranean was conducted to determine whether serologic evidence of prior hepatitis A, B, or C infection is associated with exposure in foreign countries. There were 210 subjects (10.1%) who had antibodies to hepatitis A virus (anti-HAV), 76 (3.7%) to hepatitis B core antigen (anti-HBc), and 9 (0.4%) to hepatitis C virus (anti-HCV). By multivariate analysis, anti-HAV seropositivity was independently associated with age, non-white racial/ethnic groups, birth outside of the United States, and prior Caribbean deployment for less than 1 year. Anti-HBc seropositivity was independently associated with black and Filipino race/ethnicity, foreign birth, a history of a sexually transmitted disease, South Pacific/Indian Ocean deployment (less than 12 months), and South Pacific or Mediterranean duty for (greater than 1 year). No geographic risk factors were associated with anti-HCV positivity. These data indicate that military personnel deployed outside the United States are at increased risk of viral hepatitis infection and should be considered for vaccination.

Sociodemographic correlates of neutralizing poliovirus and hepatitis A virus antibodies as markers of different modes of acquiring immunity

The prevalence and sociodemographic correlates of antibodies against poliovirus and hepatitis A virus (HAV) were compared in a random sample of 457 military recruits in Israel inducted during 1987. Lower socioeconomic status (SES) was associated with a higher prevalence of anti-HAV antibodies (67.3 vs 32.5 percent), whereas the reverse was true for type 1 poliovirus (78.4 vs 89.5 percent). While the high prevalence of anti-HAV antibodies observed in the lower SES groups reflects considerable natural exposure to enteroviruses, immunity against poliovirus appears to be determined primarily by compliance with vaccination.

Sibship size as a risk factor for hepatitis A infection

Marked ethnic differences in the prevalence of anti-hepatitis A antibodies among Jews in Israel are only partly explained by variation in socioeconomic status. In this study, various sociodemographic variables were examined as possible correlates of anti-hepatitis A antibodies in a group of 552 Jewish males aged 25-44 years examined between January and April 1987. Among subjects aged 25-29 years, 41.5% of those of European and American origin had antibodies as compared with 88.5% of those of Asian and North African origin (p less than 0.0001), whereas by the age of 40-44 years, this difference had largely disappeared. In further univariate analysis, number of siblings, years of education, and number of children were also significantly associated with the presence of antibodies. When multiple logistic regression was used to control simultaneously for the effects of the other variables, sibship size emerged as the strongest correlate of anti-hepatitis A antibodies (p less than 0.0001), and it appears to explain a large part of the ethnic differences in antibody status. These findings provide strong evidence for the role of siblings in the spread of hepatitis A infection.

The 1985 national immunisation survey: hepatitis A

In April 1985 a national immunisation survey was carried out, during which sera were collected from approximately 3000 randomly selected children throughout New Zealand. The sample comprised approximately equal numbers of new school entrants (mean age 5 years), standard 3 pupils (mean age 10 years) and form 4 students (mean age 15 years). This collection of sera was tested for antibody to hepatitis A virus, a marker of past infection with this virus, by means of a sensitive ELISA test. Prevalence of infection was found to be less than 1% in the 5 year olds, about 3% in the 10 year olds, and about 9% in the 15 year olds. Amongst the 10 and 15 year olds, but not the 5 year olds, Maori children were approximately three times more likely to have been infected than European children. Children resident in the eastern part of the North Island had a higher risk of infection than other children, even after controlling for ethnic distribution.

Epidemiology of hepatitis A in children in Sweden 1979-1983

The incidence and transmission of hepatitis A in the Swedish child population was investigated for the period 1979-83. 47% (152/323) of the hepatitis A cases in children reported in Sweden 1979-83 occurred in children born to parents of foreign extraction. The annual incidence in Swedish children was extremely low (2/100,000) during this period, whereas the incidence was between 103 and 20 in children born to immigrants of Turkish, Yugoslavian, Asian or African extraction. A known transmission of hepatitis A to Swedish children occurred mainly from 3 sources; in 60 cases (35%) by exposure within the families; in 18 of these cases a family member had been abroad, visiting a country where hepatitis A is endemic; in 34 cases (20%) by exposure in a pre-school setting; and in 29 cases (17%) by exposure when travelling abroad. In 48 cases (28%) the exposure was unknown.