Journal of Clinical Virology - Volume 82 - Supplement 1 - September 2016

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S80 Abstracts / Journal of Clinical Virology 82S (2016) S1–S142
Aim: To present, as preliminary results of the NSS, the
seroprevalence of IgG antibodies to hepatitis A virus in a
population-based cross-sectional study of Lisbon region residents.
Materials and methods: Sample size was estimated based
on seroprevalence data from the previous NSS, sample has been
equally distributed by gender and assuming at least a precision of
5% and a design effect of 1.5. Serum samples from 304 participants,
153 of them females (50.3%), aged 15 years or more, resident in
NUTII area geographically corresponding to Lisbon region, were
tested for IgG antibodies to HAV (anti-HAV IgG), using ARCHI-
TECT HAVAb-IgGTM (Abbott), a chemiluminescent microparticle
immunoassay (CMIA). Study participant’s demographic data were
collect using a questionnaire and were registered in a database.
Statistical analysis was performed using the Chi-square test with a
significance level of 5%.
Results: Anti-HAV IgG antibodies were detected in 149 samples
representing an overall seroprevalence of 49.0% (CI 95%: 43.3–54.8).
Stratification by gender, age group and country of birth showed
no significant difference in seroprevalence distribution by sex
(male = 53.6% vs female = 44.4%; p = 0.136). By age group the sero-
prevalence ranged between 30.1% for 20–29 y/o age group to 87.5%
for ≥ 55 y/o age group (p < 0.001); a higher seroprevalence was
observed in individuals born outsideWHO European region (n = 15;
12/15 born in African countries) – 80.0% vs 46.6% (p = 0.024).
Discussion and conclusion: Our results are in accordance with
previous NSS findings and other published studies from same geo-
graphical region. A high seroprevalence of anti-HAV IgG in older
individuals was expected and is explained by a more extended
period of virus exposure, including infancy and youth lived in a
period of higher hepatitis A incidence. Although tests to detect anti-
HVA IgG do not differentiate between post infection and vaccine
induced antibodies, vaccination rate is not expected to be high in
adults. Information concerning the low immunity rates at younger
ages and consequent susceptibility to HAV infection is of particular
relevance in times were travelling to highly endemic areas is more
frequent. Inmost of African countries HAV incidence is known to be
high which explains the findings for Africa born participants. Gen-
der similarity for HAV antibodies prevalence has been consistently
described showing a similar transmission pattern.
The NSS 2015–2016 is still ongoing and samples from further
regions and age groups are being collected and studied. At the end
this study will enable to establish Portugal’s resident population
immunity/susceptibility profile for HAV.
Abstract no: 331
Presentation at ESCV 2016: Poster 119
Single-step hepatitis C testing: Simplifying the
clinical pathway from primary care to specialist
services
Melinda Munang ∗, Carol Atherton ,
Mohamed Elshabrawy moona Tahir
Ras Smit , Sowsan Atabani
1 Department of Infection, Heart of England NHS
Foundation Trust, United Kingdom
2 National Infection Service, Public Health England
Birmingham Laboratory, United Kingdom
3 Health Protection, Public Health England West
Midlands, United Kingdom
Background: Direct acting antivirals have revolutionised treat-
ment opportunities for patients with hepatitis C virus (HCV)
infection. Accessing treatment requires timely diagnosis but preva-
lent laboratory testing algorithms in the United Kingdom require
two consecutive blood draws (1) serum for anti-HCV antibodies (2)
whole blood for HCV RNA. This 2-step process may increase attri-
tion rates in the clinical pathway for HCV-infected patients. At the
same time, recent advances in laboratorymethods now enable RNA
extraction directly from serum making single-step testing on one
blood draw possible.
Objective: To compare 2-step versus single-step HCV testing
in terms of completion of testing algorithm and referral rates to
specialist services.
Design: Uncontrolled before and after study of patients tested
for HCV infection in primary care (December 2013 to April 2016).
From 1 March 2015 samples with a first detection of anti-HCV anti-
body were simultaneously tested for HCV RNA.
Results: The prevalence of anti-HCV antibody positivity was
similar throughout the study period (3.1% (141/4525) during 2-step
testing and 2.8% (115/4151) during single-step testing). Completion
of HCV testing for antibody positive samples with RNA confirma-
tion was 70% with 2-step testing while only a single specimen was
inhibitory in single-step testing. The overall proportion of patients
with detectable HCVRNAwas 53% (112/213) of whom13% (15/112)
were previously knowndiagnoses. For thosewith a first diagnosis of
active HCV infection, although there was no statistical difference in
referral rates to specialist services (88% (44/50) in single-step test-
ing versus 92% (43/47) in 2-step testing, P = 0.55) there was a trend
towards shorter time fromfirst blood draw to specialist assessment
with single-step testing (median time 80 days (interquartile range,
IQR 63–116) versus 140 days (IQR 56–272), P = 0.06). In addition
there were fewer unnecessary referrals to specialist services for
patients with no evidence of active infection although this differ-
encewas not statistically significant (6% (3/53) in single step testing
versus 16% (7/43) in 2-step testing, P = 0.09).
Conclusions: Referral rates for specialist assessment and treat-
ment are high once diagnosis of active HCV infection is made.
However, 30% of HCV antibody-positive patients have unknown
infection status. This attrition rate from missed diagnoses is elim-
inated by single-step testing. Based on this quality improvement,
avoidance of repeat blood draws for patients and cost-savings from
unnecessary specialist assessment single-step HCV testing should
be standard of care in the HCV clinical pathway.
Abstract no: 339
Presentation at ESCV 2016: Poster 120
HEPATITIS E – Reaction or unspecific reaction?
Hanne Thang Vestergaard ∗,
Charlotte Svaerke Joergensen , Peter Ott ,
Anders Frische
1 Statens Serum Institut, Denmark
2 Aarhus University Hospital, Denmark
Background:Hepatitis E (HEV) is not endemic in Denmark, yet a
substantial proportion of HEV patients have no travel history. Most
Danish HEV cases are serologically diagnosed. Especially among
elderly patients with competing diseases, the clinical interpreta-
tion can be difficult if a simultaneous fecal sample is PCR negative.
Reactivation among transplantation patients is well recognized
while possible recurrence among immunocompetent patients is
still debated
Question: We want to identify if patients presently investigated
for HEV have encountered HEV earlier in life, and whether the cur-
rent reaction can be due to a reactivation of the virus? To answer
the question concerning reactivation, we will test a number of sam-