Development of anti-poliovirus therapies to complement vaccination is an urgent priority. A number of antiviral drugs are in development. Recently we have developed human monoclonal antibodies that could be used for treatment of chronically infected individuals and emergency response to potential reappearance of polioviruses after eradciation.
The aim of this study was to characterize neutralizing activity of anti-poliovirus monoclonal antibody A12 against wild type, vaccine-derived, and drug-resistant poliovirus strains, evaluate in vivo pre-and post-exposure protective properties of the antibody against polioviruses of serotypes 1 and 2, and to determine whether it interferes with response to immunization with poliovirus vaccine.
Immunogenicity studies were performed in CD1 mice. Poliovirus neutralizing titers were determined in poliovirus microneutralization assay. Poliovirus immunization-challenge experiments were performed in poliovirus-susceptible TgPVR21 mice.
We show that monoclonal antibody A12 effectively neutralizes in vitro a broad range of Type 1 and Type 2 wild and vaccine-derived polioviruses, provides effective pre- and post-exposure protection of TgPVR21 mice from challenge with a lethal dose of poliovirus. Treatment of animals with the antibody concurrent with IPV immunization does not prevent immune response to the vaccine.
Anti-poliovirus antibody A12 effectively neutralizes a range of wild and VDPV strains and protects transgenic mice susceptible to poliovirus against lethal challenge upon pre- and post-exposure administration. This suggests that the antibodies could be used in combination with drugs and/or vaccine to improve their efficacy and prevent emergence of resistant variants, and provides a justification for initiating their clinical evaluation.
polio eradication; antiviral therapy; drug-resistance; chronic virus excretors; emergency prophylaxis
Many public health laboratories adopting the U.S. HIV laboratory testing algorithm do not have a nucleic acid test (NAT), which is needed when the third-or fourth-generation HIV screening immunoassay is reactive and the antibody-based supplemental test is non-reactive or indeterminate.
Among public health laboratories utilizing public health referral laboratories for NAT conducted as part of the algorithm, we evaluated the percentage of screening immunoassays needing NAT, the number of specimens not meeting APTIMA (NAT) specifications, time to APTIMA result, the proportion of acute infections (i.e., reactive APTIMA) among total infections, and screening immunoassay specificity.
From August 2012 to April 2013, 22 laboratories enrolled to receive free APTIMA (NAT) at New York or Florida public health referral laboratories. Data were analyzed for testing conducted until June 2013.
Results: Submitting laboratories conducted a median of 4,778 screening immunoassays; 0 to 1.3% (median 0.2%) needed NAT. Of 140 specimens received, 9 (6.4%) did not meet NAT specifications. The median time from specimen collection to reporting the 11 reactive NAT results was ten days, including six days from receipt in the submitting laboratory to shipment to the referral laboratory. Acute infections ranged from 0 to 12.5% (median 0%) of total infections. Third- and fourth-generation immunoassays met package insert specificity values.
Public health referral laboratories provide a feasible option for conducting NAT. Reducing the time from specimen collection to submission of specimens for NAT is an important step toward maximizing the public health impact of identifying acute infections.
HIV; algorithms; nucleic acid amplification test; diagnostic tests
Human herpesvirus 6 (HHV-6) has a unique ability to integrate into chromosomal telomeres. Vertical transmission via germ cell integration results in offspring with inherited chromosomally integrated (ci)HHV-6 in all nucleated cells, affecting ~1% of the population.
Inherited ciHHV-6 may be a direct or indirect mediator of human disease, but efficient identification of affected individuals is a fundamental roadblock to larger studies exploring the clinical importance of this condition.
A group testing strategy was designed to efficiently identify individuals with inherited ciHHV-6. DNA was extracted from 2496 cellular samples from hematopoietic cell transplant (HCT) donor–recipient pairs. Pools of 12 samples were screened for HHV-6 DNA with quantitative (q)PCR. Individual samples from high positive pools were tested with qPCR, and high positive individual samples were tested for inherited ciHHV-6 using droplet digital (dd)PCR to determine HHV-6 DNA copies/cellular genome.
Thirty-one pools had high positive HHV-6 DNA detection with >103 HHV-6 DNA copies/μg. Each pool had one sample with >104 copies/μg HHV-6 DNA. Inherited ciHHV-6 was confirmed by ddPCR in every high positive sample (>103 HHV-6 DNA copies/μg), yielding a prevalence of 1.5% in HCT recipients and 0.96% in donors. We performed 580 qPCR tests to screen 2496 samples for inherited ciHHV-6, a 77% reduction in testing.
Inherited ciHHV-6 can be efficiently identified by specimen pooling coupled with modern molecular techniques. This algorithm can be used to facilitate cost-effective identification of patients with inherited ciHHV-6, thereby removing a major hurdle for large-scale study of its clinical impact.
Herpes; PCR; HHV-6; Chromosomally integrated; Diagnostic; PCR
Crimean-Congo hemorrhagic fever (CCHF) is an expanding tick-borne hemorrhagic disease with increasing human and animal health impact. Immense knowledge was gained over the past 10 years mainly due to advances in molecular biology, but also driven by an increased global interest in CCHFV as an emerging/re-emerging zoonotic pathogen. In the present article we discuss the advances in research with focus on CCHF ecology, epidemiology, pathogenesis, diagnostics, prophylaxis and treatment. Despite tremendous achievements, future activities have to concentrate on the development of vaccines and antivirals/therapeutics to combat CCHF. Vector studies need to continue for better public and animal health preparedness and response. We conclude with a roadmap for future research priorities.
Crimean-Congo hemorrhagic fever; ecology; epidemiology
Human rhinovirus (HRV) is a major cause of influenza-like illness (ILI) in adults and children. Differences in disease severity by HRV species have been described among hospitalized patients with underlying illness. Less is known about the clinical and virologic characteristics of HRV infection among otherwise healthy populations, particularly adults.
To characterize molecular epidemiology of HRV and association between HRV species and clinical presentation and viral shedding.
Observational, prospective, facility-based study of ILI was conducted from February 2010 to April 2012. Collection of nasopharyngeal specimens, patient symptoms, and clinical information occurred on days 0, 3, 7, and 28. Patients recorded symptom severity daily for the first 7 days of illness in a symptom diary. HRV was identified by RT-PCR and genotyped for species determination. Cases who were co-infected with other viral respiratory pathogens were excluded from the analysis. We evaluated the associations between HRV species, clinical severity, and patterns of viral shedding.
Eighty-four HRV cases were identified and their isolates genotyped. Of these, 62 (74%) were >18y. Fifty-four were HRV-A, 11 HRV-B, and 19 HRV-C. HRV-C infection was more common among children than adults (59% vs. 10%, P<0.001). Among adults, HRV-A was associated with higher severity of upper respiratory symptoms compared to HRV-B (P=0.02), but no such association was found in children. In addition, adults shed HRV-A significantly longer than HRV-C (Ptrend=0.01).
Among otherwise healthy adults with HRV infection, we observed species-specific differences in respiratory symptom severity and duration of viral shedding.
rhinovirus; HRV genotypes; viral shedding; military
Dengue virus (DENV) infection is a significant risk to over a third of the human population that causes a wide spectrum of illness, ranging from sub-clinical disease to intermediate syndrome of vascular complications called Dengue Fever Complicated (DFC) and severe, dengue hemorrhagic fever (DHF). Methods for discriminating outcomes will impact clinical trials and understanding disease pathophysiology.
We integrated a proteomics discovery pipeline with a heuristics to develop a molecular classifier to identify an intermediate phenotype of DENV-3 infectious outcome.
121 differentially expressed proteins were identified in plasma from DHF vs dengue fever (DF), and informative candidates were selected using nonparametric statistics. These were combined with markers that measure complement activation, acute phase response, cellular leak, granulocyte differentiation and viral load. From this, we applied quantitative proteomics to select a 15 member panel of proteins that accurately predicted DF, DHF, and DFC using a Random Forest Classifier. The classifier primarily relied on acute phase (A2M), complement (CFD), platelet counts and cellular leak (TPM4) to produce an 86% accuracy of prediction with an area under the receiver operating curve of >0.9 for DHF and DFC vs DF.
Integrating discovery and heuristic approaches to sample distinct pathophysiological processes is a powerful approach in infectious disease. Early detection of intermediate outcomes of DENV-3 will speed clinical trials evaluating vaccines or drug interventions.
Dengue; biomarker pipeline; selected reaction monitoring; acute phase reaction
HTLV-1; Proviral load; HAM/TSP; Cut-off value; Diagnosis
We present a 17-year old girl with DOCK-8 deficiency, severe untreated oral HSV-1 infection and associated aggressive periodontitis. DOCK-8 deficiency is a primary immunodeficiency, caused by biallelicloss-of-function mutations in the DOCK8 gene, often leading to severe viral and fungal mucocutaneous infections. Nevertheless, to date DOCK8 has not been associated with severe periodontitis and inflammatory bone loss around teeth. Understanding whether DOCK8 deficiency or severe HSV-1 infection underlies susceptibility to periodontitis is central to this case and may provide insights into susceptibility factors for periodontitis in the general population. Our clinical and microbiological data suggest that severe HSV-1 infection is the driver of periodontal inflammation in this case.
DOCK8 deficiency; oral HSV-1; aggressive periodontitis
Next generation sequencing (NGS) allows the detection of minor variant HIV drug resistance mutations (DRMs). However data from new NGS platforms after Prevention-of-Mother-to Child-Transmission (PMTCT) regimen failure are limited.
To compare major and minor variant HIV DRMs with Illumina MiSeq and Life Technologies Ion Personal Genome machine (PGM) in infants infected despite a PMTCT regimen.
We conducted a cross-sectional study of NGS for detecting DRMs in infants infected despite a zidovudine (AZT) and Nevirapine (NVP) regimen, before initiation of combination antiretroviral therapy. Sequencing was performed on PCR products from plasma samples on PGM and MiSeq platforms. Bioinformatic analyses were undertaken using a codon-aware version of the Smith-Waterman mapping algorithm and a mixture multinomial error filtering statistical model.
Of 15 infants, tested at a median age of 3.4 months after birth, 2 (13%) had non-nucleoside reverse transcriptase inhibitor (NNRTI) DRMs (K103N and Y181C) by bulk sequencing, whereas PGM detected 4 (26%) and MiSeq 5 (30%). NGS enabled the detection of additional minor variant DRMs in the infant with K103N. Coverage and instrument quality scores were higher with MiSeq, increasing the confidence of minor variant calls.
NGS followed by bioinformatic analyses detected multiple minor variant DRMs in HIV-1 RT among infants where PMTCT failed. The high coverage of MiSeq and high read quality improved the confidence of identified DRMs and may make this platform ideal for minor variant detection.
Fourth-generation HIV assays detect both antigen and antibody, facilitating detection of acute/early HIV infection. The Bio-Rad GS HIV Combo Ag/Ab assay (Bio-Rad Combo) is an enzyme immunoassay that simultaneously detects HIV p24 antigen and antibodies to HIV-1 and HIV-2 in serum or plasma.
To evaluate the performance of the Bio-Rad Combo assay for detection of HIV infection in adults from Southern Africa.
Samples were obtained from adults in Soweto and Vulindlela, South Africa and Dar es Salaam, Tanzania (300 HIV-positive samples; 300 HIV-negative samples; 12 samples from individuals previously classified as having acute/early HIV infection). The samples were tested with the Bio-Rad Combo assay. Additional testing was performed to characterize the 12 acute/early samples.
All 300 HIV-positive samples were reactive using the Bio-Rad Combo assay; false positive test results were obtained for 10 (3.3%) of the HIV-negative samples (sensitivity: 100%, 95% confidence interval [CI]: 98.8–100%); specificity: 96.7%, 95% CI: 94.0–98.4%). The assay detected 10 of the 12 infections classified as acute/early. The two infections that were not detected had viral loads < 400 copies/mL; one of those samples contained antiretroviral drugs consistent with antiretroviral therapy.
The Bio-Rad Combo assay correctly classified the majority of study specimens. The specificity reported here may be higher than that seen in other settings, since HIV-negative samples were pre-screened using a different fourth-generation test. The assay also had high sensitivity for detection of acute/early infection. False-negative test results may be obtained in individuals who are virally suppressed.
Fourth-generation; HIV; Diagnosis; Africa; Enzyme immunoassay
Human rhinovirus (HRV) infections are highly prevalent, genetically diverse, and associated with both mild upper respiratory tract and more severe lower tract illnesses (LRTI).
To characterize the molecular epidemiology of HRV infections in young children seeking acute medical care.
Nasal swabs collected from symptomatic children <3 years of age receiving care in the Emergency and Urgent Care Departments at Seattle Children's Hospital were analyzed by a rapid polymerase chain reaction (PCR) system (FilmArray®) for multiple viruses including HRV/enterovirus. HRV-positive results were confirmed by laboratory-developed real-time reverse transcription PCR (LD-PCR). Clinical data were collected by chart review. A subset of samples was selected for sequencing using the 5’ noncoding region. Associations between LRTI and HRV species and genotypes were estimated using logistic regression analysis.
Of 595 samples with HRV/enterovirus detected by FilmArray, 474 (80%) were confirmed as HRV by LD-PCR. 211 (96%) of 218 selected samples were sequenced; HRV species A, B, and C were identified in 133 (63%), 6 (3%), and 72 (34%), respectively. LRTI was more common in HRVC than HRV-A illness episodes (adjusted OR [95% CI] 2.35[1.03-5.35). Specific HRV-A and HRV-C genotypes detected in multiple patients were associated with a greater proportion of LRTI episodes. In 18 patients with >1 HRV-positive illness episodes, a distinct genotype was detected in each.
Diverse HRV genotypes circulated among symptomatic children during the study period. We found an association between HRV-C infections and LRTI in this patient population and evidence of association between specific HRV genotypes and LRTI.
Human rhinovirus; emergency department; lower respiratory tract infection; HRV-C; genotyping
Methods for the longitudinal study of respiratory virus infections are cumbersome and limit our understanding of the natural history of these infections in solid organ transplant (SOT) recipients.
To assess the feasibility and patient acceptability of self-collected foam nasal swabs for detection of respiratory viruses in SOT recipients and to define the virologic and clinical course.
We prospectively monitored the course of symptomatic respiratory virus infection in 18 SOT patients (14 lung, 3 liver, and 1 kidney) using patient self-collected swabs.
The initial study sample was positive in 15 patients with the following respiratory viruses: rhinovirus (6), metapneumovirus (1), coronavirus (2), respiratory syncytial virus (2), parainfluenza virus (2), and influenza A virus (2). One hundred four weekly self-collected nasal swabs were obtained, with a median of 4 samples per patient (range 1–17). Median duration of viral detection was 21 days (range 4–77 days). Additional new respiratory viruses detected during follow-up of these 15 patients included rhinovirus (3), metapneumovirus (2), coronavirus (1), respiratory syncytial virus (1), parainfluenza virus (1), and adenovirus (1). Specimen collection compliance was good; 16/18 (89%) patients collected all required specimens and 79/86 (92%) follow-up specimens were obtained within the 7±3 day protocol-defined window. All participants agreed or strongly agreed that the procedure was comfortable, simple, and 13/14 (93%) were willing to participate in future studies using this procedure.
Self-collected nasal swabs provide a convenient, feasible, and patient-acceptable methodology for longitudinal monitoring of upper respiratory virus infection in SOT recipients.
•“Influenza D” virus was not detected in Scottish respiratory samples (n = 3000).•Influenza C virus infection was present in 0.2% of respiratory samples.•Six influenza C virus complete genomes were sequenced.•Influenza C isolates comprised multiple, reassortant lineages.
A newly proposed genus of influenza virus (influenza D) is associated with respiratory disease in pigs and cattle. The novel virus is most closely related to human influenza C virus and can infect ferrets but infection has not been reported in humans.
To ascertain if influenza D virus can be detected retrospectively in patient respiratory samples.
3300 human respiratory samples from Edinburgh, Scotland, covering the period 2006–2008, were screened in pools of 10 by RT-PCR using primers capable of detecting both influenza C and D viruses.
Influenza D was not detected in any sample. Influenza C was present in 6 samples (0.2%), compared with frequencies of 3.3% and 0.9% for influenza A and B viruses from RT-PCR testing of respiratory samples over the same period. Influenza C virus was detected in samples from individuals <2 years or >45 years old, with cases occurring throughout the year. Phylogenetic analysis of nearly complete sequences of all seven segments revealed the presence of multiple, reassortant lineages.
We were unable to detect viruses related to influenza D virus in human respiratory samples. Influenza C virus was less prevalent than influenza A and B viruses, was associated with mild disease in the young (<2 years) and old (>45 years) and comprised multiple, reassortant lineages. Inclusion of influenza C virus as part of a diagnostic testing panel for respiratory infections would be of limited additional value.
Influenza C virus; Respiratory disease
•A co-infection between influenza A/H3N2 and A/H1N1pdm09 was detected from a patient.•A reassortant A/H3N2 virus was isolated with a NS1 gene from A/H1N1pdm09.•The reassortant virus was viable and able to replicate in cell culture.
Despite annual co-circulation of different subtypes of seasonal influenza, co-infections between different viruses are rarely detected. These co-infections can result in the emergence of reassortant progeny.
We document the detection of an influenza co-infection, between influenza A/H3N2 with A/H1N1pdm09 viruses, which occurred in a 3 year old male in Cambodia during April 2014. Both viruses were detected in the patient at relatively high viral loads (as determined by real-time RT-PCR CT values), which is unusual for influenza co-infections. As reassortment can occur between co-infected influenza A strains we isolated plaque purified clonal viral populations from the clinical material of the patient infected with A/H3N2 and A/H1N1pdm09.
Complete genome sequences were completed for 7 clonal viruses to determine if any reassorted viruses were generated during the influenza virus co-infection. Although most of the viral sequences were consistent with wild-type A/H3N2 or A/H1N1pdm09, one reassortant A/H3N2 virus was isolated which contained an A/H1N1pdm09 NS1 gene fragment. The reassortant virus was viable and able to infect cells, as judged by successful passage in MDCK cells, achieving a TCID50 of 104/ml at passage number two. There is no evidence that the reassortant virus was transmitted further. The co-infection occurred during a period when co-circulation of A/H3N2 and A/H1N1pdm09 was detected in Cambodia.
It is unclear how often influenza co-infections occur, but laboratories should consider influenza co-infections during routine surveillance activities.
Influenza; Seasonal; Co-infection; A/H3N2; A/H1N1pdm09; Reassortment; Reassortant
Human adenoviruses (HAdV) are known opportunistic pathogens in hematopoietic stem cell transplant (SCT) recipients. The detection of HAdV infection in children after SCT has been implicated as a determinant of poor outcome but specific associations between HAdV species or individual HAdV types and disease are poorly understood.
Characterization of a HAdV-D strain isolated from multiple clinical specimens of an 11-year-old female recipient of a matched unrelated donor peripheral SCT for T-cell lymphoma and case report.
Archived HAdV PCR-positive plasma, urine, and stool specimens were processed for virus isolation and detailed molecular typing. Complete genomic sequencing was carried out on 2 isolates.
The patient tested positive for HAdV DNA by real-time PCR of a stool specimen at 44 days after initiation of a SCT conditioning regimen. In the subsequent 3 months, HAdV was detected in plasma, urine and stool specimens in association with symptoms of gastroenteritis and hemorrhagic cystitis. A novel HAdV-D with a HAdV20-like hexon gene was isolated from both urine and stool specimens. All isolates yielded identical restriction profiles with endonucleases BamHI, BglII, BstEII, HindIII, PstI and SmaI. Analysis of 2 complete genomic sequences further identified the virus as a novel intertypic recombinant HAdV-D (P20/H20/F42) closely related to HAdV42.
This case highlights the identification of a previously unknown HAdV-D from an immunocompromised host. In this patient, the course of adenovirus infection is compatible with reactivation of a latent virus or a primary opportunistic infection. Adenoviremia in this patient resolved without definitive adenovirus-directed antiviral therapy.
In January of 2008, during the peak of the rotavirus season in Guatemala, a gastroenteritis outbreak with high mortality among infants was reported in Guatemala. Despite extensive efforts, the investigation was limited by the lack of bulk stool specimens collected, particularly from the more severely dehydrated or deceased children.
We evaluated the diagnostic performance of rectal swab specimens compared with bulk stool for the detection of rotavirus and norovirus.
Patients with diarrhea (≥3 loose stools in 24 h) were enrolled through an ongoing surveillance system in Guatemala. From January through March 2009, we attempted to enroll 100 patients <5years old captured by the diarrhea surveillance, and collected paired bulk stool and rectal swabs specimens from them. Specimens were tested for norovirus using real-time reverse transcription-polymerase chain reaction and for rotavirus via enzyme immunoassay.
We enrolled 102 patients with paired specimens; 91% of 100 paired specimens tested for rotavirus yielded concordant results positive for rotavirus with a negativity rate of 83%. Among 100 paired specimens tested for norovirus, 86% were concordant norovirus detection and the negativity rate was 85%. The diagnostic performance for rotavirus and norovirus detection did not differ significantly between the two specimen types.
Testing of properly collected fecal specimens using rectal swabs may be a viable alternative to bulk stool for detection of rotavirus and norovirus, particularly during outbreaks where collection of bulk stool may be difficult.
Norovirus; Rotavirus; Diagnosis; Concordance; Surveillance; Guatemala
HSV-2 diagnosis is typically by viral culture, viral DNA amplification of lesion material or by serology in cases of subclinical presentation. These methods can be time consuming and expensive. The Uni-Gold™ HSV-2 Rapid is a fast, point-of-care diagnostic test that can be performed outside a full service laboratory.
To evaluate the ability of the Uni-Gold™ HSV-2 Rapid to correctly diagnose the presence or absence of anti-HSV-2 antibodies in patient serum samples in comparison to the University of Washington HSV Western blot (UWWB).
Sera from 100 adult patients in the USA were tested for HSV-2 specific antibodies by Uni-Gold™ HSV-2 Rapid and results were compared to those of the UWWB to determine the test’s sensitivity and specificity.
Of 18 patients seropositive for HSV-2 by UWWB, 17 were correctly identified as such by the Uni-Gold™ HSV-2 Rapid. Of 76 patients who were seronegative for HSV-2 by UWWB, 75 were correctly identified by the rapid test. Six sera had indeterminate results by UWWB. Sensitivity for the Uni-Gold™ HSV-2 Rapid was 94% and specificity was 99%.
The Uni-Gold™ HSV-2 Rapid had high sensitivity and specificity in a small sample of unselected, adults seeking care in the Seattle, USA area. An accurate, near-person test allows immediate counselling directed toward symptom recognition, treatment, and practices that can limit the risk of HSV-2 transmission.
Herpes Simplex Virus; Uni-Gold™ Rapid; HSV serology
Background and Objectives
Hepatitis C virus (HCV) RNA level in acute HCV infection is predictive of spontaneous clearance. This study assessed factors associated with HCV RNA levels during early acute infection among people who inject drugs with well-defined acute HCV infection.
Data were from International Collaboration of Incident HIV and Hepatitis C in Injecting Cohorts (InC3) Study, an international collaboration of nine prospective cohorts studying acute HCV infection. Individuals with available HCV RNA levels during early acute infection (first two months following infection) were included. The distribution of HCV RNA levels during early acute infection were compared by selected host and virological factors.
A total of 195 individuals were included. Median HCV RNA levels were significantly higher among individuals with interferon lambda 3 (IFNL3, formerly called IL28B) CC genotype compared to those with TT/CT genotype (6.28 vs. 5.39 log IU/mL, respectively; P=0.01). IFNL3 CC genotype was also associated with top tertile HCV RNA levels (≥6.3 IU/mL; vs. TT/CT genotype; adjusted Odds Ratio: 4.28; 95%CI: 2.01, 9.10; P<0.01).
This study indicates that IFNL3 CC genotype predicts higher HCV RNA levels in early acute HCV infection.
Viral load; acute HCV; IFNL3 genotype; IL28B genotype; Cohort study
A high prevalence of reactivation of hepatitis B has been documented among immunosuppressed individuals in the inactive phase of chronic hepatitis B; However, the proportion of and the risk factors for reactivation are largely unknown among non-immunosuppressed persons.
Estimate the incidence rate of and risk factors for hepatitis B reactivation in a population-based cohort of persons in the inactive phase of chronic hepatitis B in Alaska.
A cohort of 414 Alaska Native Persons in the inactive phase of hepatitis B (HBV DNA < 2000 IU/mL and normal alanine aminotransferase (ALT) for 12 months) was followed-up for 10 years. Reactivation of hepatitis B was defined as HBV DNA ≥ 2000 IU/mL and ALT ≥ 40 IU/L. Cox-proportional hazards regression models were used to identify factors associated with reactivation.
A total of 36 (9%) persons had reactivation during 2984 person-years of follow-up, with an annual incidence of 1.2%. Persons aged ≥50 years (1.8%) at study entry had the highest incidence rates of reactivation although incidence rates were not significantly different by age group. Risk factors for hepatitis B reactivation were male sex (Hazard Ratio (HR) = 2.41; 95% Confidence Interval (CI): 1.17–4.96), HBV DNA ≥ 1000 IU/mL at study entry (HR = 7.61; 95% CI: 2.81–20.6), and HBV genotype B (HR = 6.08; 95% CI: 1.32–28.0).
The incidence of hepatitis B reactivation was low during the 10 years of follow-up. However, given the higher risk of reactivation than their counterparts, males, and those with HBV DNA ≥ 1000 IU/mL need to be followed-up more frequently.
Hepatitis B; Reactivation of infection; Incidence; Risk factors
Rotaviruses are the major cause of severe dehydrating diarrhea in children throughout the world. Enzyme immunoassays (EIA) have been the standard method for detection of rotavirus in stool specimens since the 1980s. The World Health Organization (WHO) Rotavirus Surveillance Network has proposed including three EIA kits in the WHO-GSM (Global Management System/Système Mondial de Gestion ) catalogue for easy procurement of EIA kits by participating rotavirus surveillance network laboratories.
In this study, we conducted a comparative analysis of 3 commercially available enzyme immunoassay kits: PremierTM Rotaclone® (Meridian Bioscience, Inc.), ProSpecTTM (Oxoid, Ltd.) and RIDASCREEN® (R-biopharm AG) for rotavirus diagnostics.
Using reverse-transcriptase-PCR (RT-PCR) as the gold standard, the 3 EIA kits were evaluated by testing a stool panel consisting of 56 rotavirus-positive and 54 rotavirus negative samples.
The sensitivities of the PremierTM Rotaclone®, ProSpecTTM and RIDASCREEN® kits were 76.8%, 75% and 82.1% respectively, but did not differ significantly. The specificity of all the 3 kits was 100%. The use of RT-PCR as a gold standard lowered the observed sensitivity of all 3 EIA kits but helps to reduce equivocal results that can be seen when another EIA or other non-molecular methods are used as the reference assay in comparison studies.
Our study found that all three kits are suitable for use by rotavirus surveillance programs.
rotavirus; EIA; comparison; RT-PCR; sensitivity; specificity
Enteroviruses have been implicated in the etiology of type 1 diabetes, supported by immunoreactivity of enteroviral protein in islets, but presence of enteroviral genome has rarely been reported. Failure to detect enterovirus with RT-PCR has been attributed to the possible presence of PCR inhibitors and that only few cells are infected.
The aim of this study was to evaluate strategies for detection of enterovirus in human islets.
A scenario was modeled with defined infected islets among a large number of uninfected pancreatic cells and the sensitivity of immunohistochemistry and PCR for detection of enterovirus was evaluated.
Enterovirus was detected with PCR when only one single human islet, infected in vitro with a low dose of virus, was mixed with an uninfected pancreatic biopsy. Enterovirus could not be detected by immunohistochemistry under the same conditions, demonstrating the superior sensitivity of PCR also in pancreatic tissue with only a small fraction of infected cells. In addition, we demonstrate that pancreatic cell culture supernatant does not cause degradation of enterovirus at 37°C, indicating that under normal culture conditions released virus is readily detectable. Utilizing PCR, the pancreases of two organ donors that died at onset of type 1 diabetes were found negative for enterovirus genome despite islet cells being positive using immunohistochemistry.
These data suggest that PCR should be the preferred screening method for enterovirus in the pancreas and suggest cautious interpretation of immunostaining for enterovirus that cannot be confirmed with PCR.
Type 1 diabetes; etiology; pathogenesis; Coxsackievirus; VP1; infection; PCR; immunohistochemistry
Human herpesvirus 6 (HHV-6) is an opportunistic pathogen after hematopoietic cell transplantation (HCT) that is associated with central nervous system (CNS) dysfunction.
The aim of this study was to determine the frequency and significance of HHV-6 DNA detection in cerebrospinal fluid (CSF) after HCT.
We identified patients with HHV-6 DNA in CSF using quantitative PCR. Patients with neurologic symptoms and HHV-6 DNA in CSF without identification of an alternative etiology were categorized as having HHV-6 CNS dysfunction.
Among 3,902 allogeneic HCT recipients from 1998-2012, 51 of 124 tested patients had HHV-6 DNA in CSF; 37 met criteria for HHV-6 CNS dysfunction and 14 (27%) did not. Patients with an alternative diagnosis had longer time to HHV-6 detection and lower viral load in CSF. Six patients without HHV-6 CNS dysfunction were not treated and had no morbidity attributable to HHV-6. Kaplan-Meier analysis demonstrated poor overall survival among all patients. Variables associated with higher all-cause mortality in a multivariable Cox model included alternative diagnosis (adjusted hazard ratio [aHR], 8.4; 95% CI, 1.7-40.9; P = 0.009) and higher peak plasma viral load (log10 scale) (aHR, 1.4; 95% CI, 1.1-1.9; P = 0.01).
We identified a number of allogeneic HCT recipients with HHV-6 DNA in CSF who did not meet criteria for HHV-6 CNS dysfunction. All patients had poor survival. Whether CSF HHV-6 DNA detection in patients without associated CNS dysfunction independently contributes to mortality and warrants treatment is unclear; management of these patients warrants further investigation.
herpesvirus; hhv-6; transplant; encephalitis; CNS; neurologic
Carcinogenic human papillomaviruses can (HPV) cause cervical, vaginal, vulvar, penile, anal, and oropharyngeal cancers. Non-carcinogenic HPVs can cause anogenital warts and recurrent respiratory papillomatosis. Currently, few research laboratories propagate, isolate or generate papilloma virions. However, there have been questions about potential exposure and risk in this setting. In this brief note, we discuss the use of wild type and laboratory-generated virions in research laboratories, potential routes of laboratory exposure, and considerations for HPV vaccination of laboratory personnel.
Laboratory safety; human papillomavirus; HPV; HPV vaccines
An alternate HIV testing algorithm has been proposed which includes a fourth-generation immunoassay followed by an HIV-1/HIV-2 antibody differentiation supplemental test for reactive specimens and a nucleic acid test (NAT) for specimens with discordant results.
To evaluate the performance of five rapid tests (Alere Clearview, Bio-Rad Multispot, OraSure OraQuick, MedMira Reveal, and Trinity Biotech Unigold) as the supplemental antibody assay in the algorithm.
A total of 3273 serum and plasma specimens that were third- generation immunoassay repeatedly reactive and Western blot (WB) negative or indeterminate were tested with rapid tests and NAT. Specimens were classified by NAT 1) HIV-1 infected (NAT-reactive; n=184, 5.6%), 2) HIV-status unknown (NAT nonreactive; n=3078, 94.2%) or by Multispot 3) HIV-2 positive (n=5), 4) HIV-1 and HIV-2 positive (n=6). Excluding HIV-2 positive specimens, we calculated the proportion of reactive rapid tests among specimens with reactive and nonreactive NAT.
The proportion of infected specimens with reactive rapid test results and negative or indeterminate WB ranged from 30.4% (56) to 47.8% (88) depending on the rapid test. From 1% to 2% of NAT-negative specimens had reactive rapid test results.
In these diagnostically challenging specimens, all rapid tests identified infections that were missed by the Western blot, but only one FDA-approved rapid test could differentiate HIV-1 from HIV-2. Regardless of which rapid test is used as a supplemental test in the alternative algorithm, false-positive algorithm results (i.e., reactive screening and rapid test in uninfected person) may occur, which will need to be resolved during the baseline medical evaluation.