Declining incidence of hepatitis A in Amsterdam (The Netherlands), 1996-2011: second generation migrants still an important risk group for virus importation

Use of passive samplers as sewage surveillance tool to monitor a hepatitis A outbreak at a school in Amsterdam, the Netherlands, Oct 2022 - March 2023

BACKGROUND

Enteric hepatitis A virus (HAV) infections during childhood are often asymptomatic but may cause severe illness in adults. To improve public health surveillance we assessed the applicability of sewage monitoring during an HAV outbreak at a primary school.

METHODS

Between October 19 and December 27, 2022, five symptomatic HAV cases were notified to the Public Health Service Amsterdam; all attended the same primary school. Passive samplers, small absorbent tools, were deployed in sewage near the school from November 14, 2022, to March 22, 2023. The absorbents were subjected to RNA extraction, HAV PCR testing, and, if positive, sequencing. PCR and sequencing were also performed on plasma and feces samples of HAV cases.

RESULTS

In 22 out of 88 (25%) of sewage samples, HAV RNA was detected. All HAV-RNA-positive sewage samples until 8 February 2023 were subgenotype IB, matching the strain detected in all cases. Another strain of HAV (subgenotype IA) was detected in sewage from 15 February 2023 onwards, without associated cases.

CONCLUSIONS

Passive sampler-based sewage monitoring is an effective method to rapidly detect HAV shedding linked to diagnosed cases. It detects unnoticed viral infections and allows monitoring of outbreaks. This suggests that passive sampler-based monitoring is a promising tool supporting the public health response during HAV and other outbreaks.

Dengue, chikungunya and Zika virus infections among Dutch travellers to Suriname: a prospective study during the introduction of chikungunya and Zika virus, 2014 to 2017

BackgroundSuriname, a country endemic for dengue virus (DENV), is a popular destination for Dutch travellers visiting friends and relatives and tourist travellers. Chikungunya and Zika virus (CHIKV, ZIKV) were introduced in 2014 and 2015, respectively. Data on infection risks among travellers are limited.AimWe aimed to prospectively study incidence rate (IR) and determinants for DENV, ZIKV and CHIKV infection in adult travellers to Suriname from 2014 through 2017.MethodsParticipants kept a travel diary and were tested for anti-DENV, anti-ZIKV and anti-CHIKV IgG antibodies (Euroimmun). Selected samples were subjected to an in-house DENV and ZIKV PRNT50. The IR (infections/1,000 person-months of travel) and IR ratio and determinants for infection were calculated.ResultsTravel-acquired infections were found in 21 of 481 participants: 18 DENV, four ZIKV and two CHIKV, yielding an IR_DENV of 47.0 (95% CI: 29.6-74.6), IR_ZIKV of 11.6 (95% CI: 4.4-31.0) and IR_CHIKV of 5.6 (95% CI: 1.4-22.2)/1,000 person-months. In nine DENV and three ZIKV infected participants, infections were PRNT50-confirmed, yielding a lower IR_DENV of 23.3 (95% CI: 12.1-44.8) and an IR_ZIKV of 8.4 (95% CI: 2.7-26.1) per 1,000 person-months. Tourist travel was associated with DENV infection. ZIKV and CHIKV infections occurred soon after their reported introductions.ConclusionsDespite an overestimation of serologically confirmed infections, Dutch travellers to Suriname, especially tourists, are at substantial risk of DENV infection. As expected, the risk of contracting ZIKV and CHIKV was highest during outbreaks. Cross-reaction and potential cross-protection of anti-DENV and -ZIKV antibodies should be further explored.

Ethnic differences in hepatitis A and E virus seroprevalence in patients attending the Emergency Department, Paramaribo, Suriname

BACKGROUND

Hepatitis A virus (HAV) and hepatitis E virus (HEV) have enteric modes of transmission and are common causes of acute hepatitis in low- and middle-income countries. HEV is also characterised as a zoonotic infection and is prevalent in high-income countries. Data on HAV and HEV prevalence in Suriname, a middle-income country in South America, are scarce.

METHODS

Serum samples of 944 and 949 randomly selected patients attending the Emergency Department at the Academic Hospital of Paramaribo, the capital of Suriname, were analysed for anti-HAV antibodies (anti-HAV) and anti-HEV antibodies (anti-HEV), respectively. Determinants of anti-HAV and anti-HEV positive serology were evaluated using multivariable logistic regression.

RESULTS

Anti-HAV prevalence was 58.3% (95% CI 55.4 to 61.4%) and higher prevalence was independently associated with belonging to the Tribal or Indigenous population and older age. Anti-HEV prevalence was 3.7% (95% CI 2.6 to 5.0%) and higher prevalence was associated with Tribal and Creole ethnicity and older age.

CONCLUSIONS

In Suriname, exposure to HAV is consistent with a very low endemic country and exposure to HEV was rare. Both viruses were more prevalent in specific ethnic groups. As anti-HAVantibodies were less frequently found in younger individuals, they could be susceptible to potential HAV outbreaks and might require HAV vaccination.

Differences in Incidence of Acute Viral Hepatitis between Foreigners and Autochthonous Population in Italy

Background: In European countries, the prevalence of HBV and HCV in refugees and migrants tends to reflect the prevalence in their countries of origin. The aim of this study is to analyse acute viral hepatitis cases diagnosed in Italy among foreign citizens and to compare incidence rates in foreigners and Italians. Methods: We analysed the cases of each viral hepatitis type among foreigners. Standardised incidence rates were compared between natives and foreigners. Results: Between 2004 and 2019, 15,872 cases of acute viral hepatitis were notified by 10 Italian regions, 14.8% among foreign citizens. Until 2012, the percentage increased gradually, while a fluctuating trend set in from 2013 onwards; in 2019, 23.9% of cases were foreigners. Data from the SEIEVA surveillance show higher standardised incidence rates of hepatitis A and B among foreign citizens; no significant difference emerged between Italians and foreigners in terms of their hepatitis C incidence. Conclusions: foreign citizens have an increased incidence of hepatitis A and B. Regarding hepatitis A, vaccination is strongly recommended to foreigners travelling to their countries of origin. Screening tests for hepatitis B and C infection should be offered to newly arrived migrants from high prevalence countries, or having specific risk factors.

Two concurrent outbreaks of hepatitis A highlight the risk of infection for non-immune travellers to Morocco, January to June 2018

From January to June 2018, two ongoing hepatitis A outbreaks affected travellers returning from Morocco and cases in Europe without travel history, resulting in 163 patients in eight European countries. Most interviewed travel-related cases were unaware of the hepatitis A risk in Morocco. Molecular analysis revealed two distinct hepatitis A virus (HAV) strains (subgenotype IA DK2018_231; subgenotype IB V18-16428). Vaccination recommendations should be emphasised to increase awareness among non-immune travellers to Morocco and HAV-endemic countries.

Importation of travel-related infectious diseases is increasing in South Korea: An analysis of salmonellosis, shigellosis, malaria, and dengue surveillance data

BACKGROUND

International travel has an important role in transmission of emerging infectious diseases. We described the imported infectious diseases in Korea from 2003 to 2012, and to analyze association of travels with the change in the incidences.

METHODS

We used National Notifiable Disease Surveillance System to investigate the incidence of salmonellosis, shigellosis, malaria, and dengue. Data from Korea Tourism Organization was used to describe the inbound and outbound travelers by their age group, gender, and purpose of travel. We assessed association between international travel and the incidence of the infectious diseases, and seasonal variability.

RESULTS

Among 1849 imported cases, dengue comprised the largest number with 631 cases. The proportion of imported cases among total cases gradually increased from 4.1% in 2003 to 30.3% in 2012 (P < 0.001). There was a positive correlation between the number of travelers and the number of imported cases of shigellosis, dengue (P < 0.001), but not for malaria. Seasonal variability was observed for importation of salmonellosis, shigellosis and dengue fever (P = 0.005).

CONCLUSION

International travel was associated with the incidence of imported infectious diseases in Korea. Pre-travel consultation for international travelers planned to visit endemic area should be recommended strongly.

[Migrations in Latin American countries. Characteristics of the pediatric population]

INTRODUCTION

Migration is a growing phenomenon among Latin American countries (LAC) as well as others; however, scarce information is available studying its impact on paediatric groups and its association with socioeconomic variables.

OBJECTIVE

To study the association among socioeconomic variables and the immigration rate of paediatric population in LAC.

MATERIAL AND METHODS

Official rates of migration of LAC were obtained from: International Organization for Migration, Pan American Health Organization, and United Nations Development Programme. Demographic and socioeconomic information was also obtained for: gross domestic product (GDP), human development index (HDI), Gini coefficient of inequality (GC), alphabetization rate for adults (AA), net migration rate (NMR), and immigration of children<15 years (IM15). Description, linear correlations and analysis of differences between groups of countries were assessed.

RESULTS

The NMR was positive for Costa Rica, Panama, Venezuela, Chile and Argentina. No association among NMR and GDP, HDI, GC, AA was found. A correlation of IM15 was found with: GC (r=0.668, P=.01), with GDP (r=-0.720; P=.01), AA (r=-0.755; P=.01) and with HDI (r=-0.799; P=.01). Rate of IM15 was lower in LA countries with advanced/medium development (GDP>median) vs those with low development (Fisher, P<.0001).

CONCLUSIONS

There is a direct inverse association between GDP per capita, HDI, AA and GC and the proportion of each country IN15. We did not observe an association between NMR and HDI, AA, and GC. The health impact of these migrations should be analysed.

Risk of hepatitis A decreased among Dutch travelers to endemic regions in 2003 to 2011

We divided the number of travel-related hepatitis A cases notified in Dutch surveillance (2003-2011) by travel data obtained from an annual holiday survey to estimate the risk of hepatitis A among Dutch travelers. Of the 2,094 cases notified, 931 (44%) were imported. Morocco (n = 272, 29%), Turkey (n = 98, 11%), and Egypt (n = 87, 9%) accounted for the largest proportion of cases. Attack rates in returnees from high or intermediate endemic regions declined from 7.5 per 100,000 travelers (95% CI 6.7-8.4) in 2003-2005 to 3.5 (95% CI 3.0-4.0) in 2009-2011 (p < 0.01). Despite the decrease in risk, vaccination remains important, and routine risk monitoring should also be considered.

Seroprevalence of Helicobacter pylori and Hepatitis A Virus among Children in Rural Central Taiwan

Helicobacter pylori and hepatitis A virus (HAV) are thought to have similar routes of transmission and epidemiology. This study investigated the seroprevalence of these 2 pathogens among children in rural, central Taiwan. Serum samples were collected from 856 children between 2010 and 2012 and levels of anti-HAV and anti-H. pylori antibodies were measured by ELISA. Questionnaires were used to investigate possible risk factors. The overall H. pylori and HAV infection rates were 6% and 0.8%, respectively. There was a significant difference in H. pylori infection rates (P value=0.008), but not HAV infection rates, between different age groups. H. pylori infection rates were significantly higher in children whose mothers had lower education levels. In contrast, HAV infection rates were significantly higher in children whose fathers had lower education levels. The risk of HAV infection was also 14.20-fold higher in children whose family members had traveled to China or Southeast Asia. No significant correlation was found between H. pylori and HAV seropositivity. The seroprevalences of H. pylori and HAV were low in rural central Taiwan. Universal HAV vaccination is highly recommended to prevent outbreak due to low seroprevalence.

The financial crisis and the expected effects on vaccinations in Europe: a literature review

Starting in 2008 several European countries experienced a financial crisis. Historically, diseases whose prevention and treatment depend highly on the continuity of healthcare re-emerge during political and financial crises. Evidence suggests that the current financial crisis has had an impact on the health and welfare of Europeans and that population health status and morbidity as well as mortality patterns may change in the coming years. At the same time decisions about expenditure for health services may impact the ability of public health providers to respond. It is expected that the current crisis will further exacerbate socioeconomic and health inequalities and novel vulnerable groups will emerge in addition to existing ones. We review the available evidence and discuss how the current crisis may have an impact on vaccine-preventable diseases and influence vaccination coverage rates in Europe.

Evaluation of hepatitis A vaccine in post-exposure prophylaxis, The Netherlands, 2004-2012

BACKGROUND

The secondary attack rate of hepatitis A virus (HAV) among contacts of cases is up to 50%. Historically, contacts were offered immunoglobulin (IG, a human derived blood product) as post-exposure prophylaxis (PEP). Amid safety concerns about IG, HAV vaccine is increasingly recommended instead. Public health authorities' recommendations differ, particularly for healthy contacts ≥40 years old, where vaccine efficacy data is limited. We evaluated routine use of HAV vaccine as an alternative to immunoglobulin in PEP, in those considered at low risk of severe infection in the Netherlands.

METHODS

Household contacts of acute HAV cases notified in Amsterdam (2004-2012) were invited ≤14 days post-exposure, for baseline anti-HAV testing and PEP according to national guidelines: immunoglobulin if at risk of severe infection, or hepatitis A vaccine if healthy and at low risk (aged <30, or, 30-50 years and vaccinated <8 days post-exposure). Incidence of laboratory confirmed secondary infection in susceptible contacts was assessed 4-8 weeks post-exposure. In a vaccinated subgroup, relative risk (RR) of secondary infection with estimated using Poisson regression.

RESULTS

Of 547 contacts identified, 191 were susceptible to HAV. Per-protocol, 167 (87%) were vaccinated (mean:6.7 days post-exposure, standard deviation(sd)=3.3) and 24 (13%) were given immunoglobulin (mean: 9.7 days post-exposure, sd=2.8). At follow-up testing, 8/112 (7%) had a laboratory confirmed infection of whom 7 were symptomatic. All secondary infections occurred in vaccinated contacts, and half were >40 years of age. In healthy contacts vaccinated per-protocol ≤8 days post-exposure, RR(ref. ≤15 years) of secondary infection in those >40 years was 12.0 (95%CI:1.3-106.7).

CONCLUSIONS

Timely administration of HAV vaccine in PEP was feasible and the secondary attack rate was low in those <40 years. Internationally, upper age-limits for post-exposure vaccination vary. Pending larger studies, immunoglobulin should be considered PEP of choice in people >40 years of age and those vulnerable to severe disease.