Jeff Connell

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections in health care workers (HCWs): guidelines for prevention of transmission of HBV and HCV from HCW to patients

The transmission of viral hepatitis from health care workers (HCW) to patients is of worldwide concern. Since the introduction of serologic testing in the 1970s there have been over 45 reports of hepatitis B virus (HBV) transmission from HCW to patients, which have resulted in more than 400 infected patients. In addition there are six published reports of transmissions of hepatitis C virus (HCV) from HCW to patients resulting in the infection of 14 patients. Additional HCV cases are known of in the US and UK, but unpublished. At present the guidelines for preventing HCW to patient transmission of viral hepatitis vary greatly between countries. It was our aim to reach a Europe-wide consensus on this issue. In order to do this, experts in blood-borne infection, from 16 countries, were questioned on their national protocols. The replies given by participating countries formed the basis of a discussion document. This paper was then discussed at a meeting with each of the participating countries in order to reach a Europe-wide consensus on the identification of infected HCWs, protection of susceptible HCWs, management and treatment options for the infected HCW. The results of that process are discussed and recommendations formed. The guidelines produced aim to reduce the risk of transmission from infected HCWs to patients. The document is designed to complement existing guidelines or form the basis for the development of new guidelines. This guidance is applicable to all HCWs who perform EPP, whether newly appointed or already in post.

Development of a real-time RT-PCR for the detection of Swine-lineage Influenza A (H1N1) virus infections

Abstract Background A novel influenza A virus, subtype H1N1 of swine-lineage (H1N1 swl) has transmitted rapidly to many regions of the world with evidence of sustained transmission within some countries. Rapid detection and differentiation from seasonal influenza is essential to instigate appropriate patient and public health management and for disease surveillance. Objectives To develop a rapid and sensitive real-time reverse transcriptase polymerase chain reaction (rtRT-PCR) for confirmation of H1N1 swl. Study design A one-step rtRT-PCR approach was employed to target the matrix gene of the novel influenza A/H1N1 swl and validated against a panel of seasonal influenza A (H1N1 and H3N2), swine influenza A/H1N1 and avian influenza A/H5N1 viruses. The assay following validation was then used prospectively to detect H1N1 swl positive specimens from the recent outbreaks in the UK and the Republic of Ireland. Results The one-step H1N1 swl matrix rtRT-PCR successfully detected H1N1 swl clinical specimens and did not cross-react with seasonal influenza A, subtypes H1N1 and H3N2 viruses and swine influenza A (H1N1). The H1N1 swl matrix assay did cross react with H5N1. The H1N1 swl matrix assay was then compared to two other assays using a dilution series and a panel of untyped influenza A positive clinical samples. These experiments found the assay to have a comparable sensitivity to the established universal influenza A rtRT-PCR and was more sensitive than the H1N1 swl specific assay that targeted the H1 region. Conclusions The results demonstrate that the rtRT-PCR is sensitive and should be used alongside existing universal influenza A assays to rapidly detect the novel H1N1 swl virus.

Deaths associated with human adenovirus-14p1 infections, Europe, 2009-2010.

Human adenovirus (HAdV) serotype 14 is rarely identified. However, an emerging variant, termed HAdV-14p1, recently has been described in the United States in association with outbreaks of acute respiratory disease with high rates of illness and death. We retrospectively analyzed specimens confirmed positive for HAdV by immunofluorescence, virus culture, or real-time PCR during July 1, 2009-July 31, 2010, and describe 9 cases of HAdV-14p1 infection with characteristic mutations in the fiber and E1A genes that are phylogenetically indistinguishable from the viruses previously detected in the United States. Three patients died; 2 were immunocompromised, and 1 was an immunocompetent adult. We propose that surveillance should be increased for HAdV-14p1 and recommend that this virus be considered in the differential diagnosis of sudden-onset acute respiratory disease, particularly fatal infections, for which an etiology is not clear.

Rapid molecular detection of the H275Y oseltamivir resistance gene mutation in circulating influenza A (H1N1) viruses.

Abstract In early 2008, drug susceptibility surveillance of influenza viruses in Europe revealed that some influenza A viruses (subtype H1N1) circulating during the winter season of 2007 and 2008 were resistant to the neuraminidase inhibitor, oseltamivir. This resistance arises due to a histidine to tyrosine substitution in the neuraminidase active site (H275Y in N1 nomenclature). Current methods to detect this mutation involve an end-point reverse transcription polymerase chain reaction followed by nucleotide sequencing. While accurate, this approach has the limitation of being time-consuming, labour-intensive and expensive. Herein we describe a one-step allelic discrimination assay which rapidly (2h) detects this resistance mutation. The sensitivity of the assay was as low as 10 copies per reaction and is capable of detecting the antiviral resistance mutation in a mixture of wild type H275 and mutant H275Y targets.

Suboptimal Measles-Mumps-Rubella Vaccination Coverage Facilitates an Imported Measles Outbreak in Ireland

The year 2000 saw a dramatic increase in the incidence of measles infections in Ireland, with >1500 cases documented. Initial cases were reported from an area of Dublin with low vaccine uptake and a large immigrant population. Molecular epidemiologic findings revealed that the strain of measles virus responsible for this outbreak was the genotype D2 strain, which is closely related to strains initially identified in South Africa. It is suggested that suboptimal vaccine uptake facilitated the spread of imported measles infection.

A Multicentre Molecular Analysis of Hepatitis B and Blood-Borne Virus Coinfections in Viet Nam

Hepatitis B (HBV) infection is endemic in Viet Nam, with up to 8.4 million individuals estimated to be chronically infected. We describe results of a large, multicentre seroepidemiological and molecular study of the prevalence of HBV infection and blood-borne viral coinfections in Viet Nam. Individuals with varying risk factors for infection (n = 8654) were recruited from five centres; Ha Noi, Hai Phong, Da Nang, Khanh Hoa and Can Tho. A mean prevalence rate of 10.7% was observed and levels of HBsAg were significantly higher in injecting drug users (IDUs) (17.4%, n = 174/1000) and dialysis patients (14.3%, n = 82/575) than in lower-risk groups (9.4%; p<0.001). Coinfection with HIV was seen in 28% of HBV-infected IDUs (n = 49/174) and 15.2% of commercial sex workers (CSWs; n = 15/99). HCV infection was present in 89.8% of the HBV-HIV coinfected IDUs (n = 44/49) and 40% of HBV-HIV coinfected CSWs (n = 16/40). Anti-HDV was detected in 10.7% (n = 34/318) of HBsAg positive individuals. Phylogenetic analysis of HBV S gene (n = 187) showed a predominance of genotype B4 (82.6%); genotypes C1 (14.6%), B2 (2.7%) and C5 (0.5%) were also identified. The precore mutation G1896A was identified in 35% of all specimens, and was more frequently observed in genotype B (41%) than genotype C (3%; p<0.0001). In the immunodominant ‘a’ region of the surface gene, point mutations were identified in 31% (n = 58/187) of sequences, and 2.2% (n = 4/187) and 5.3% (n = 10/187) specimens contained the major vaccine escape mutations G145A/R and P120L/Q/S/T, respectively. 368 HBsAg positive individuals were genotyped for the IL28B SNP rs12979860 and no significant association between the IL28B SNP and clearance of HBsAg, HBV viral load or HBeAg was observed. This study confirms the high prevalence of HBV infection in Viet Nam and also highlights the significant levels of blood-borne virus coinfections, which have important implications for hepatitis-related morbidity and development of effective management strategies.

Hepatitis C virus in Vietnam: high prevalence of infection in dialysis and multi-transfused patients involving diverse and novel virus variants.

Hepatitis C virus (HCV) is a genetically diverse pathogen infecting approximately 2–3% of the worlds population. Herein, we describe results of a large, multicentre serological and molecular epidemiological study cataloguing the prevalence and genetic diversity of HCV in five regions of Vietnam; Ha Noi, Hai Phong, Da Nang, Khanh Hoa and Can Tho. Individuals (n = 8654) with varying risk factors for infection were analysed for the presence of HCV Ab/Ag and, in a subset of positive specimens, for HCV RNA levels (n = 475) and genotype (n = 282). In lower risk individuals, including voluntary blood donors, military recruits and pregnant women, the prevalence of infection was 0.5% (n = 26/5250). Prevalence rates were significantly higher (p<0.001) in intravenous drug users (IDUs; 55.6%, n = 556/1000), dialysis patients (26.6%, n = 153/575) commercial sex workers (CSWs; 8.7%, n = 87/1000), and recipients of multiple blood transfusions (6.0%, n = 32/529). The prevalence of HCV in dialysis patients varied but remained high in all regions (11–43%) and was associated with the receipt of blood transfusions [OR: 2.08 (1.85–2.34), p = 0.001], time from first transfusion [OR: 1.07 (1.01–1.13), p = 0.023], duration of dialysis [OR: 1.31 (1.19–1.43), p<0.001] and male gender [OR: 1.60 (1.06–2.41), p = 0.026]. Phylogenetic analysis revealed high genetic diversity, particularly amongst dialysis and multi-transfused patients, identifying subtypes 1a (33%), 1b (27%), 2a (0.4%), 3a (0.7%), 3b (1.1%), 6a (18.8%), 6e (6.0%), 6h (4.6%), 6l (6.4%) and 2 clusters of novel genotype 6 variants (2.1%). HCV genotype 1 predominated in Vietnam (60%, n = 169/282) but the proportion of infections attributable to genotype 1 varied between regions and risk groups and, in the Southern part of Vietnam, genotype 6 viruses dominated in dialysis and multi-transfused patients (73.9%). This study confirms a high prevalence of HCV infection in Vietnamese IDUs and, notably, reveals high levels of HCV infection associated with dialysis and blood transfusion.

A low density oligonucleotide microarray for the detection of viral and atypical bacterial respiratory pathogens.

Abstract Acute respiratory tract infections are a major cause of morbidity and mortality worldwide and exert a considerable economic burden on healthcare systems. Acute respiratory tract infections of the upper and lower respiratory tract are caused by a wide variety of viral and bacterial pathogens, which require comprehensive laboratory investigations. Conventional serological and immunofluorescence-based diagnostic methods for acute respiratory tract infections lack sensitivity when compared to polymerase chain reaction (PCR)-based approaches and the development of new diagnostic methodologies is required, to provide accurate, sensitive and rapid diagnoses. In the present study, a PCR-based low density oligonucleotide microarray was developed for the detection of 16 viral and two atypical bacterial pathogens. The performance of this DNA microarray-based analysis exhibited comparable sensitivities and specificities to multiplex real-time reverse transcription polymerase chain reactions (rtPCRs) confirming the potential diagnostic utility of the method. In contrast to routine multiplex PCR, the microarray incorporates an intrinsic redundancy as multiple and non-identical probes per target on the array allow direct intra-assay confirmation of positives. This study demonstrates that microarray technology provides a viable alternative to conventional serological-based approaches and multiplex PCR for pathogen identification in acute respiratory tract infections.

Molecular Epidemiological Evaluation of the Recent Resurgence in Mumps Virus Infections in Ireland

ABSTRACT Mumps is a vaccine-preventable disease; however, outbreaks have been reported in a number of countries with childhood immunization programs, particularly among young adults at the tertiary stage of education. We have retrospectively investigated the epidemiological, virological, and serological factors associated with mumps cases identified in Ireland from 2004 to 2009. Genetic analysis of mumps virus strain variability demonstrated that a single genotype, genotype G, was circulating, and it was also detected in cerebrospinal fluid samples obtained from patients with meningitis. We observed that younger individuals were disproportionately affected with neurological sequelae following mumps virus infection, and the average age of patients with mumps virus RNA detected in cerebrospinal fluid was 19.25 years (median, 19 years; range, 14 to 24 years). Our analysis showed a 4-fold rise in mumps cases in 2008-2009 and an increased incidence in infection in those ≥30 years of age. Over a 6-year period (2004 to 2009), a total of 7,805 serum samples were investigated; of this number, 1,813 (23%) were positive for mumps virus-specific IgM. We observed a strong bias for acute mumps virus infection in males compared to females (P < 10−32) that was independent of vaccination status.

Determination of the burden of hepatitis C virus infection in Ireland

Information on the burden of hepatitis C virus (HCV) disease is needed to inform policy decisions on primary and secondary prevention. Specimen-based laboratory data (1989-2004) were converted to person-based data and combined with notification data (2004-2009) to describe the burden of HCV infection in Ireland. More than 10,000 people were confirmed as HCV infected in 1989-2004, with the numbers peaking in 2000. The predominant genotypes were 1 (55%) and 3 (39%). Drug use was the most likely risk factor in 80%, with receipt of blood or blood products in 16%. It is estimated that 20 000-50,000 people in Ireland are chronically infected with HCV, a population prevalence of 0·5-1·2%, which is similar to other countries in Northern Europe. This is the first published estimate of the number of chronic HCV infections in Ireland. These data will be of value in health service planning and will contribute to the understanding of HCV infection in Europe.