Discrimination between recent and non-recent HIV infections using routine diagnostic serological assays.

The suitability of routine diagnostic HIV assays to accurately discriminate between recent and non-recent HIV infections has not been fully investigated. The aim of this study was to compare an established HIV recency assay, the Sedia limiting antigen HIV avidity assay (LAg), with the diagnostic assays; Abbott ARCHITECT HIV Ag/Ab Combo and INNO-LIA HIV line assays. Samples from all new HIV diagnoses in Ireland from January to December 2016 (n = 455) were tested. An extended logistic regression model, the Spiegelhalter-Knill-Jones method, was utilised to establish a scoring system to predict recency of HIV infection. As proof of concept, 50 well-characterised samples were obtained from the CEPHIA repository whose stage of infection was blinded to the authors, which were tested and analysed. The proportion of samples that were determined as recent was 18.1% for LAg, 6.4% with the ARCHITECT, and 14.5% in the INNO-LIA assay. There was a significant correlation between the ARCHITECT S/CO values and the LAg results, r = 0.717, p < 0.001. ROC analysis revealed that an ARCHITECT S/CO < 250 had a sensitivity and specificity of 90.32% and 89.83%, respectively. Combining the Abbott ARCHITECT HIV Ag/Ab Combo assay and INNO-LIA HIV assays resulted in an observed risk of being recent of 100%. Analysis of the CEPHIA samples revealed a strong agreement between the LAg assay and the combination of routine assays (κ = 0.908, p < 0.001). Our findings provide evidence that assays routinely employed to diagnose and confirm HIV infection may be utilised to determine the recency of HIV infection.

Underreporting of viral encephalitis and viral meningitis, Ireland, 2005-2008.

Viral encephalitis (VE) and viral meningitis (VM) have been notifiable infectious diseases under surveillance in the Republic of Ireland since 1981. Laboratories have reported confirmed cases by detection of viral nucleic acid in cerebrospinal fluid since 2004. To determine the prevalence of these diseases in Ireland during 2005-2008, we analyzed 3 data sources: Hospital In-patient Enquiry data (from hospitalized following patients discharge) accessed through Health Intelligence Ireland, laboratory confirmations from the National Virus Reference Laboratory, and events from the Computerised Infectious Disease Reporting surveillance system. We found that the national surveillance system underestimates the incidence of these diseases in Ireland with a 10-fold higher VE hospitalization rate and 3-fold higher VM hospitalization rate than the reporting rate. Herpesviruses were responsible for most specified VE and enteroviruses for most specified VM from all 3 sources. Recommendations from this study have been implemented to improve the surveillance of these diseases in Ireland.

Molecular epidemiology of circulating measles virus in Ireland 2002-2007.

The molecular characterization of measles virus (MeV) is a valuable epidemiological tool to monitor virus transmission and to discriminate between imported and endemic infection. There has been significant immigration into Ireland in recent years and many individuals originate from regions of high measles incidence. Ireland has had a number of outbreaks of MeV which appear attributable to sub-optimal vaccine uptake and possibly imported strains as new genotypes have been identified in recent years. To ascertain any significant changes in circulating measles genotypes we investigated 65 confirmed measles cases between the years 2002 and 2007. The laboratory diagnosis of measles was confirmed by detection of measles-specific IgM in oral fluid in conjunction with a real-time polymerase chain reaction assay targeting the MeV hemagglutinin gene. Phylogenetic analysis based on the 3' hypervariable region of the nucleoprotein gene was performed and three genotypes, all within measles clade D, were found to be circulating during this time period. In 2002 and 2003, genotype D8 (n = 2) was observed whereas genotype D7 was dominant in 2003 (n = 31). A distinct change in the circulating MeV genotype and increased genetic diversity was observed between 2004 and 2007. All cases were within genotype D4 (n = 32) but were phylogenetically distinct from each other. These data provide important epidemiologic baseline information on MeV in Ireland and facilitates detailed examination of measles transmission.

HepSEQ: International Public Health Repository for Hepatitis B.

HepSEQ is a repository for an extensive library of public health and molecular data relating to hepatitis B virus (HBV) infection collected from international sources. It is hosted by the Centre for Infections, Health Protection Agency (HPA), England, United Kingdom. This repository has been developed as a web-enabled, quality-controlled database to act as a tool for surveillance, HBV case management and for research. The web front-end for the database system can be accessed from http://www.hpa-bioinfodatabases.org.uk/hepatitis_open/main.php. The format of the database system allows for comprehensive molecular, clinical and epidemiological data to be deposited into a functional database, to search and manipulate the stored data and to extract and visualize the information on epidemiological, virological, clinical, nucleotide sequence and mutational aspects of HBV infection through web front-end. Specific tools, built into the database, can be utilized to analyse deposited data and provide information on HBV genotype, identify mutations with known clinical significance (e.g. vaccine escape, precore and antiviral-resistant mutations) and carry out sequence homology searches against other deposited strains. Further mechanisms are also in place to allow specific tailored searches of the database to be undertaken.