Pediatric migration and hepatitis A risk in host population

Immunization Against Hepatitis A in Migrant Children: Three Vaccination Strategies, A Retrospective Study

BACKGROUND

Hepatitis A is endemic in many countries. Swiss guidelines recommend vaccinating patients native from endemic areas. In Geneva's Children's hospital, migrant children are screened and vaccinated if seronegative. Because hepatitis A's prevalence is decreasing worldwide, more children are seronegative at arrival, highlighting the need for immunization in medical centers and refugee camps and questioning the benefits of systematic serology. Other Swiss hospitals vaccinate regardless of serostatus. This study's aim is to assess migrant children's immunity according to origin and age, and the cost-effectiveness of different immunization strategies.

METHODS

We retrospectively analyzed 329 children's serostatus (1-16 years of age) between 2012 and 2015, using enzyme-linked fluorescent assay method. Serology and vaccine costs were based on local prices. Groups were compared with χ test and the age-seropositivity relationship was studied with linear regression.

RESULTS

The predominant regions were the Eastern Mediterranean and European Regions with mostly negative serologies (71% and 83%) and the African Region with mostly positive serologies (79%). Immunity varied depending on birth country. Regardless of region, seropositivity increased with age (P < 0.001). The most cost-effective vaccination strategy was an individualized approach based on age and origin, reducing costs by 2% compared with serology-guided immunization and by 17% compared with systematic vaccination.

CONCLUSIONS

Many migrant children >5 years old are seronegative and at risk of clinical infection. They need to be immunized. New guidelines according to age and origin should be defined to reduce immunization costs. We recommend systematic vaccination for patients <5 years old or native from low endemicity areas (≤25.7% of seropositivity). For the others, we propose serology-based vaccination.

Analysis of genetic and serology of hepatitis A virus infection during and after outbreak in two junior high schools in Surabaya, Indonesia

Outbreaks of hepatitis A have occurred in some cities in Indonesia. In Surabaya, the capital city of East Java province, Indonesia, hepatitis A outbreaks have been reported since2013, with a marked increase in the number of cases in 2015. The aim of the present study was to analyze the genetic and serology of acute symptomatic cases (early infection) during a hepatitis A outbreak and asymptomatic cases after the outbreak in two junior high schools in Surabaya in 2015 to 2016. Students with acute symptomatic hepatitis A during the outbreak and other students who were asymptomatic 3 to 4 months after the outbreak were enrolled. Asymptomatic students had no symptoms from the outbreak until they were enrolled. Sera were collected to identify anti-hepatitis A virus (HAV) IgM (by enzyme-linked immunosorbent assay) and HAV genetic variations/genotypes (using polymerase chain reaction [PCR]-sequencing and phylogenetic analysis). A total of 33 (97.1%) out of 34 sera of students with acute symptoms were positive for anti-HAV IgM and 18% of them were positive by PCR, identified as HAV subgenotype IA. No prominent amino acid variations were observed from reported HAV sequences from Indonesia. Among 38 sera of asymptomatic students, most (55.3%) were positive for anti-HAV IgM, while none were positive by PCR. In conclusion, HAV-IA was the only subgenotype identified in acute symptomatic cases during the outbreak. The percentage of HAV-specific IgM-positive cases was very high among acute symptomatic students, but that was also high among asymptomatic students, which might contribute as the important source of infection during the outbreak.

Hepatitis a screening for internationally adopted children from hepatitis A endemic countries

Screening for hepatitis A virus (HAV) infection is not currently routinely recommended in internationally adopted children. International adoptees seen at the University of Minnesota International Adoption Clinic from 2006 to 2010 were assessed for acute HAV infection (positive HAV immunoglobulin M). Thirty of the 656 children screened (4.6%) were acutely HAV infected. HAV-infected children emigrated from Ethiopia (16), Guatemala (4), China (2), Colombia (2), Haiti (2), Philippines (2), Liberia (1), and Nepal (1). Infection was most frequent among children younger than 2 years (6.7%). No symptoms distinguished children with acute HAV infection from uninfected children. HAV infection caused significant social disruption, including separation of children from their ill adoptive parents during the initial weeks postarrival, a period important for postadoption adjustment and attachment. All international adoptees arriving from countries with high or intermediate HAV endemicity should be screened for HAV infection on arrival to the United States.

An outbreak of hepatitis A among primary and secondary contacts of an international adoptee

The Advisory Committee on Immunization Practices recommends that susceptible people traveling to developing countries receive hepatitis A vaccine or immune globulin prior to departure. Until 2009, the recommendations did not address non-traveling family members or other close contacts of international adoptees. We report an outbreak of hepatitis A in 2008 that occurred in Maine. Eight members of an extended family developed hepatitis A following the arrival of an asymptomatic infant from Ethiopia who was brought to the United States by an adoption agency. Two children in the family attended an elementary school where five additional cases of hepatitis A were subsequently identified. Only three (1%) of 208 students at the school had previously been immunized against hepatitis A. This outbreak highlights the need to immunize household members and other close contacts of families adopting children from countries where hepatitis A is endemic, as well as all children at one year of age.

Molecular characterization of hepatitis A virus isolated from acute gastroenteritis patients in the Seoul region of Korea

Hepatitis A virus (HAV) is a major public health problem throughout the world. As a result of declining HAV endemic in Korea, an increasing number of children and adolescents have become susceptible to HAV infection. HAV is related with sanitation conditions of the environment and is transmitted via the fecal-oral route, either through person-to-person contact or by contaminated water and food. The present study has been carried out to determine the phylogenetic analysis and circulating patterns of HAV strains detected from hospitalized patients with acute gastroenteritis (AGE) in the Seoul region of Korea. In total, 2,782 stool specimens from hospitalized patients with AGE collected in October 2006 to September 2007 in Seoul were tested for HAV. A pair comparison of the nucleic acid sequence of a 159-bp base region at the putative VP1/2A junction of 85 Seoul isolates revealed that the most common HAV strain circulating in the region during 2006-2007 was subgenotype IA. HAV phylogenetic studies can provide important information on the genetic characteristics of HAV from AGE patients who may subsequently become the source of infection in Korea.

Early infection and asymptomatic spread of hepatitis A virus in a public child care center in Rio de Janeiro, Brazil: should attending children under two years of age be vaccinated?

A cross-sectional study was conducted in order to identify hepatitis A virus (HAV) serological markers in 418 individuals (mean age, 16.4 years; range, 1 month-80 years) at a public child care center in Rio de Janeiro, Brazil, as well as to analyze risk factors and determine circulating genotypes. Serum samples were tested using an enzyme immunoassay. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect and characterize HAV RNA, and sequencing was performed. Anti-HAV antibodies and IgM anti-HAV antibodies were detected, respectively, in 89.5% (374/418) and 10.5% (44/418) of the individuals tested. Acute HAV infection in children was independently correlated with crawling (p < 0.05). In 56.8% (25/44) of the IgM anti-HAV-positive individuals and in 33.3% (5/15) of the IgM anti-HAV-negative individuals presenting clinical symptoms, HAV RNA was detected. Phylogenetic analysis revealed co-circulation of subgenotypes IA and IB in 93.3% (28/30) of the amplified samples. In present study, we verify that 79% (30/38) of children IgM anti-HAV-positive were asymptomatic. In child care centers, this asymptomatic spread is a more serious problem, promoting the infection of young children, who rarely show signs of infection. Therefore, vaccinating children below the age of two might prevent the asymptomatic spread of hepatitis A.

Changing travel-related global epidemiology of hepatitis A

Hepatitis A is highly endemic in many emerging cultures. Despite the availability of safe and effective vaccines and some improvements in sanitation in developing countries, hepatitis A remains a significant cause of morbidity for nonimmune travelers visiting such destinations. All are at risk, including short-term vacationers or business travelers who stay in deluxe accommodations. This may have considerable implications on public health. Hepatitis A vaccination programs for travelers have not proven to be effective, since many visitors to destinations at risk (e.g., Mexico) fail to consult health professionals prior to departure. Because 50% of the US population has an anticipated lifetime risk for exposure, universal immunization against hepatitis A should be considered.

Hepatitis A outbreaks--methods of intervention in South-East Asian countries

INTRODUCTION

In many Asian countries, improved hygiene standards and socio-economic conditions have led to a reduction in exposure to the hepatitis A virus (HAV) in childhood. However, the persistence of circulating HAV may lead to hepatitis A outbreaks, particularly in adolescents and adults. In other countries and specific areas, where socio-economic conditions have not improved as markedly, HAV endemicity remains medium-to-high. A systematic approach to outbreak control is therefore urgently needed.

METHODS

The Steering Committee for Prevention and Control of Infectious Diseases reviewed reports on recent hepatitis A outbreaks in South-East Asian countries and determined that there is no systematic regional plan for the containment of such outbreaks. By contrast, on reviewing reports on outbreaks in several North American and European countries, it was found that the most important elements of successful outbreak control are a plan of action, rapid and widespread communication, public education and vaccination of household contacts to prevent secondary cases.

RESULTS

This investigation proposes an outbreak control programme consisting of six key stages -- initiation, planning, set-up, implementation, vaccination of at-risk populations and evaluation. Outbreak control requires the formation of an outbreak management team, plus a task force to implement intervention and educate the public. The vaccination of family members and close contacts is a central element of the programme.

CONCLUSION

This model programme for hepatitis A outbreak control provides a framework for action in countries and specific areas where the disease remains a problem.

Risk groups for hepatitis A virus infection

We report the conduct and results of a systematic search for evidence of risk of infection with hepatitis A virus (HAV) among blood transfusion recipients, travellers, the military, healthcare workers, sewage workers, foodhandlers, day care assistants, institutionalised subjects, blood transfusion recipients, drug addicts, homosexuals, prisoners and other risk groups such a liver transplantees. We report our recommendations for the use of the HAV vaccine in these groups.

The role of vaccine in controlling hepatitis A epidemics

We report the conduct and results of a review of recent literature to describe various types of epidemics and outbreaks in Italy or countries with similar epidemiological profiles and to assess vaccine use in outbreak situations. We identified three scenarios most likely to occur in Italy: outbreaks occurring in small closed communities (nursery or a primary school), outbreaks in communities of limited dimensions (small towns or villages) and open community settings in which epidemics occur at regular intervals (person-to-person transmission). In closed communities we recommend vaccination of family members and school personnel living or working in close proximity to the index case as well as classmates. We also recommend vaccination when there is a proof of secondary transmission within the community. In small open communities we recommend vaccination of more susceptible age groups such as children and adolescents. For large open communities the only practicable alternative strategy is vaccination of close family contacts of acute cases couple with non-immunity boosting control measures.

Posttravel hepatitis A: probable acquisition from an asymptomatic adopted child

We report a case of acute hepatitis A in an adoptive parent that was probably acquired from a recently adopted child with asymptomatic, active infection. Prospective adoptive parents should be protected against hepatitis A because of potential exposure during travel and the risk of unrecognized active infection in adopted children.