Novel Human Parechovirus 3 Diversity, Recombination, and Clinical Impact Across 7 Years: An Australian Story.

BACKGROUND: A novel human parechovirus 3 Australian recombinant (HPeV3-AR) strain emerged in 2013 and coincided with biennial outbreaks of sepsis-like illnesses in infants. We evaluated the molecular evolution of the HPeV3-AR strain and its association with severe HPeV infections. METHODS: HPeV3-positive samples collected from hospitalized infants aged 5-252 days in 2 Australian states (2013-2020) and from a community-based birth cohort (2010-2014) were sequenced. Coding regions were used to conduct phylogenetic and evolutionary analyses. A recombinant-specific polymerase chain reaction was designed and utilized to screen all clinical and community HPeV3-positive samples. RESULTS: Complete coding regions of 54 cases were obtained, which showed the HPeV3-AR strain progressively evolving, particularly in the 3' end of the nonstructural genes. The HPeV3-AR strain was not detected in the community birth cohort until the initial outbreak in late 2013. High-throughput screening showed that most (>75%) hospitalized HPeV3 cases involved the AR strain in the first 3 clinical outbreaks, with declining prevalence in the 2019-2020 season. The AR strain was not statistically associated with increased clinical severity among hospitalized infants. CONCLUSIONS: HPeV3-AR was the dominant strain during the study period. Increased hospital admissions may have been from a temporary fitness advantage and/or increased virulence.

From worst-case to reality - Case studies illustrating tiered refinement of consumer exposure to cosmetic ingredients.

Consumer exposure to cosmetic ingredients is estimated in a tiered manner. Simple Tier1 deterministic aggregate exposure modelling generates a worst case estimate of exposure. Tier1 assumes that a consumer uses all cosmetic products concomitantly daily, at maximum frequency, and products always contain the ingredient at the maximum allowed % w/w concentration. Refining exposure assessment from worst case to more realistic estimates uses evidence from surveys of actual use levels of ingredients and Tier2 probabilistic models, where distributions of consumer use data can be applied. In Tier2+ modelling, occurrence data provides evidence of products on the market actually containing the ingredient. Three case studies are presented using this tiered approach to illustrate progressive refinement. The scale of refinements from Tier1 to Tier2+ modelling for the ingredients, propyl paraben, benzoic acid and DMDM hydantoin were: 0.492 to 0.026; 1.93 to 0.042 and 1.61 to 0.027 mg/kg/day exposure dose. For propyl paraben, moving from Tier1 to Tier2+ represents a refinement from 49-fold to 3-fold overestimate of exposure when compared to a maximum estimate of 0.01 mg/kg/day exposure seen in human studies. Such refinements from worst case to realistic levels of exposure estimation can be critical in the demonstration of consumer safety.

Read-across and new approach methodologies applied in a 10-step framework for cosmetics safety assessment - A case study with parabens.

Parabens are esters of para-hydroxybenzoic acid that have been used as preservatives in many types of products for decades including agrochemicals, pharmaceuticals, food and cosmetics. This illustrative case study with propylparaben (PP) demonstrates a 10-step read-across (RAX) framework in practice. It aims at establishing a proof-of-concept for the value added by new approach methodologies (NAMs) in read-across (RAX) for use in a next-generation risk assessment (NGRA) in order to assess consumer safety after exposure to PP-containing cosmetics. In addition to structural and physico-chemical properties, in silico information, toxicogenomics, in vitro toxicodynamic, toxicokinetic data from PBK models, and bioactivity data are used to provide evidence of the chemical and biological similarity of PP and analogues and to establish potency trends for observed effects in vitro. The chemical category under consideration is short (C1-C4) linear chain n-alkyl parabens: methylparaben, ethylparaben, propylparaben and butylparaben. The goal of this case study is to illustrate how a practical framework for RAX can be used to fill a hypothetical data gap for reproductive toxicity of the target chemical PP.

Parechovirus A Infections in Healthy Australian Children During the First 2 Years of Life: A Community-based Longitudinal Birth Cohort Study.

BACKGROUND: Hospital-based studies identify parechovirus (PeV), primarily PeV-A3, as an important cause of severe infections in young children. However, few community-based studies have been published and the true PeV infection burden is unknown. We investigated PeV epidemiology in healthy children participating in a community-based, longitudinal birth cohort study. METHODS: Australian children (n = 158) enrolled in the Observational Research in Childhood Infectious Diseases (ORChID) study were followed from birth until their second birthday. Weekly stool and nasal swabs and daily symptom diaries were collected. Swabs were tested for PeV by reverse-transcription polymerase chain reaction and genotypes determined by subgenomic sequencing. Incidence rate, infection characteristics, clinical associations, and virus codetections were investigated. RESULTS: PeV was detected in 1423 of 11 124 (12.8%) and 17 of 8100 (0.2%) stool and nasal swabs, respectively. Major genotypes among the 306 infection episodes identified were PeV-A1 (47.9%), PeV-A6 (20.1%), and PeV-A3 (18.3%). The incidence rate was 144 episodes (95% confidence interval, 128-160) per 100 child-years. First infections appeared at a median age of 8 (interquartile range, 6.0-11.7) months. Annual seasonal peaks changing from PeV-A1 to PeV-A3 were observed. Infection was positively associated with age ≥6 months, summer season, nonexclusive breastfeeding at age <3 months, and formal childcare attendance before age 12 months. Sole PeV infections were either asymptomatic (38.4%) or mild (32.7%), while codetection with other viruses in stool swabs was common (64.4%). CONCLUSIONS: In contrast with hospital-based studies, this study showed that diverse and dynamically changing PeV genotypes circulate in the community causing mild or subclinical infections in children.Parechovirus can cause severe illnesses in children. However, studies focus mainly on hospitalized populations. True disease burden in the community remains largely unknown. From our community-based cohort, we found diverse parechovirus genotypes in the community, causing mild or subclinical infections in children. CLINICAL TRIALS REGISTRATION: NCT01304914.

Over-diagnosis of Rotavirus Infection in Infants Due to Detection of Vaccine Virus.

An accurate rotavirus diagnosis is important for clinical management and monitoring active disease and vaccine effectiveness. Between 2016-2018, rotavirus-positive results in our laboratory were from vaccine virus shedding in 71/152 (46.7%) infants with a request for rotavirus testing. Routine infant diagnostic testing should ideally distinguish vaccine from wild-type viruses.

Paediatric intensive care admissions during the 2015-2016 Queensland human parechovirus outbreak.

AIM: The human parechovirus (HPeV) has emerged as a pathogen causing sepsis-like presentations in young infants, but there is a lack of data on HPeV presentations requiring intensive care support. We aimed to characterise the clinical presentation, disease severity, management and outcome of a population-based cohort of children with microbiologically confirmed HPeV infection requiring admission to paediatric intensive care units (PICUs) in Queensland, Australia during a recent outbreak. METHODS: This was a multicentre retrospective study of children admitted to PICU between 1 January 2015 and 31 December 2016 with confirmed HPeV infection. RESULTS: Thirty infants (median age 20 days) with HPeV genotype 3 were admitted to PICU, representing 16% of all children with HPeV admitted to hospital and 6.4% of non-elective PICU admissions in children <1 year of age. Children requiring PICU admission were younger than children admitted to hospital (P = 0.001). Apnoea, haemodynamic instability with tachycardia and seizures represented the main reasons for PICU admission. Eleven children (37%) required mechanical ventilation for a median duration of 62 h, 22 (73%) received fluid boluses and 7 (23%) were treated with vasoactive agents for a median duration of 53 h. Median length of stay was 2.62 days. A total of 24 children (80%) fulfilled sepsis criteria, 14 (47%) severe sepsis and 7 (23%) septic shock criteria. Eight (27%) had abnormal brain magnetic resonance imaging. No patient died. CONCLUSIONS: We confirm that HPeV infection is an important cause of sepsis-like syndrome in infants with substantial associated morbidity. Optimal management and long-term outcomes require further investigation.

Seroprevalence of antibodies to primate erythroparvovirus 1 (B19V) in Australia.

BACKGROUD: Primate erythroparvovirus 1 (B19V) is a globally ubiquitous DNA virus. Infection results in a variety of clinical presentations including erythema infectiosum in children and arthralgia in adults. There is limited understanding of the seroprevalence of B19V antibodies in the Australian population and therefore of population-wide immunity. This study aimed to investigate the seroprevalence of B19V antibodies in an Australian blood donor cohort, along with a cohort from a paediatric population. METHODS: Age/sex/geographical location stratified plasma samples (n = 2221) were collected from Australian blood donors. Samples were also sourced from paediatric patients (n = 223) in Queensland. All samples were screened for B19V IgG using an indirect- enzyme-linked immunosorbent assay. RESULTS: Overall, 57.90% (95% CI: 55.94%-59.85%) of samples tested positive for B19V IgG, with the national age-standardized seroprevalence of B19V exposure in Australians aged 0 to 79 years estimated to be 54.41%. Increasing age (p < 0.001) and state of residence (p < 0.001) were independently associated with B19V exposure in blood donors, with the highest rates in donors from Tasmania (71.88%, 95% CI: 66.95%-76.80%) and donors aged 65-80 years (78.41%, 95% CI: 74.11%-82.71%). A seroprevalence of 52.04% (95% CI: 47.92%-56.15%) was reported in women of child-bearing age (16 to 44 years). Sex was not associated with exposure in blood donors (p = 0.547) or in children (p = 0.261) screened in this study. CONCLUSIONS: This study highlights a clear association between B19V exposure and increasing age, with over half of the Australian population likely to be immune to this virus. Differences in seroprevalence were also observed in donors residing in different states, with a higher prevalence reported in those from the southern states. The finding is consistent with previous studies, with higher rates observed in countries with a higher latitude. This study provides much needed insight into the prevalence of B19V exposure in the Australian population, which has implications for public health as well as transfusion and transplantation safety in Australia.

Streptococcus pneumoniae colonization of the nasopharynx is associated with increased severity during respiratory syncytial virus infection in young children.

BACKGROUND AND OBJECTIVE: Respiratory syncytial virus (RSV) is the most significant cause of acute respiratory infection (ARI) in early life. RSV and other respiratory viruses are known to stimulate substantial outgrowth of potentially pathogenic bacteria in the upper airways of young children. However, the clinical significance of interactions between viruses and bacteria is currently unclear. The present study aimed to clarify the effect of viral and bacterial co-detections on disease severity during paediatric ARI. METHODS: Nasopharyngeal aspirates from children under 2 years of age presenting with ARI to the emergency department were screened by quantitative PCR for 17 respiratory viruses and the bacterial pathogens Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis. Associations between pathogen detection and clinical measures of disease severity were investigated. RESULTS: RSV was the most common virus detected, present in 29 of 58 samples from children with ARI (50%). Detection of S. pneumoniae was significantly more frequent during RSV infections compared to other respiratory viruses (adjusted effect size: 1.8, P: 0.03), and co-detection of both pathogens was associated with higher clinical disease severity scores (adjusted effect size: 1.2, P: 0.03). CONCLUSION: Co-detection of RSV and S. pneumoniae in the nasopharynx was associated with more severe ARI, suggesting that S. pneumoniae colonization plays a pathogenic role in young children.

Comparing Polymerase Chain Reaction Testing of Nasopharyngeal Swab and Lower Respiratory Tract Specimens for the Diagnosis of Pneumocystis jirovecii Pneumonia.

Using nasopharyngeal (NP) swab samples instead of lower respiratory tract specimens for polymerase chain reaction (PCR) to diagnose Pneumocystis jirovecii pneumonia (PJP) may be better tolerated and improve diagnostic accessibility. In this 2-year Australian retrospective cohort study of patients with clinically suspected PJP, P jirovecii PCR on NP swab samples had perfect specificity but low sensitivity (0.66).

Profiling Risk Factors for Household and Community Spatiotemporal Clusters of Q Fever Notifications in Queensland between 2002 and 2017.

Q fever, caused by the bacterium Coxiella burnetii, is an important zoonotic disease worldwide. Australia has one of the highest reported incidences and seroprevalence of Q fever, and communities in the state of Queensland are at highest risk of exposure. Despite Australia's Q fever vaccination programs, the number of reported Q fever cases has remained stable for the last few years. The extent to which Q fever notifications cluster in circumscribed communities is not well understood. This study aimed to retrospectively explore and identify the spatiotemporal variation in Q fever household and community clusters in Queensland reported during 2002 to 2017, and quantify potential within cluster drivers. We used Q fever notification data held in the Queensland Notifiable Conditions System to explore the geographical clustering patterns of Q fever incidence, and identified and estimated community Q fever spatiotemporal clusters using SatScan, Boston, MA, USA. The association between Q fever household and community clusters, and demographic and socioeconomic characteristics was explored using the chi-squared statistical test and logistic regression analysis. From the total 2175 Q fever notifications included in our analysis, we found 356 Q fever hotspots at a mesh-block level. We identified that 8.2% of Q fever notifications belonged to a spatiotemporal cluster. Within the spatiotemporal Q fever clusters, we found 44 (61%) representing household clusters and 20 (27.8%) were statistically significant with an average cluster size of 3 km radius. Our multivariable model shows statistical differences between cases belonging to clusters in comparison with cases outside clusters based on the type of reported exposure. In conclusion, our results demonstrate that clusters of Q fever notifications are temporally stable and geographically circumscribed, indicating a persistent common exposure. Furthermore, within individuals in household and community clusters, abattoir exposure (a traditional occupational exposure) was rarely reported by individuals.

Discord between presence of follicular conjunctivitis and Chlamydia trachomatis infection in a single Torres Strait Island community: a cross-sectional survey.

OBJECTIVE: Recent surveys identified trachomatous inflammation - follicular (TF) at endemic levels in the Torres Strait Islands; however, local health staff do not report trachomatous trichiasis (TT) in adults. We undertook a cross-sectional survey involving eye examination and microbiological testing to better understand this disconnect. METHODS: We examined 169 of 207 (82%) residents and collected ocular swabs for polymerase chain reaction (PCR) testing for Chlamydia trachomatis. Other viral PCR tests and bacterial culture were also performed. RESULTS: TF prevalence in children aged 5-9 years was 23% (7/30). No ocular C. trachomatis was identified by PCR. For the 72 participants (43%) with follicles, bacterial culture was positive for 11 (15%) individuals. No individual had trachomatous trichiasis. CONCLUSIONS: Follicular conjunctivitis consistent with TF was prevalent but ocular C. trachomatis and cicatricial trachoma were absent. Non-chlamydial infections or environmental causes of follicular conjunctivitis may be causing TF in this community. IMPLICATIONS FOR PUBLIC HEALTH: In similar settings, reliance on simplified clinical assessment alone may lead to an overestimation of the public health problem posed by trachoma. Consideration should be given to incorporating C. trachomatis PCR, and in certain settings, a detailed clinical exam could be performed by an experienced ophthalmologist during prevalence surveys.

Assessment of dermal absorption of aluminium from a representative antiperspirant formulation using a (26Al)Al microtracer approach: a follow-up study in humans.

A follow-up study was performed in 12 healthy women to evaluate systemic exposure to aluminium following topical application of a representative antiperspirant formulation under real-life use conditions (part A) and to assess the local fate of topically applied aluminium by taking additional tape strips and skin biopsies (Part B). A simple roll-on formulation, containing the maximal possible radioactive dose, was prepared with [26Al] aluminium-labeled chlorohydrate (ACH). The microtracer of [26Al] was used to distinguish aluminium from the natural background, using accelerator mass spectrometry. [26Al] aluminiumcitrate was administered intravenously to estimate the dermal fraction absorbed. Despite the 25-fold increase of the topical dose compared with the previous study, only 12 blood samples gave results above the lower limit of quantitation (0.118 fg/mL). The most reliable estimates of the dermal fraction absorbed are derived from noncompartmental analysis with the urine data. By using the intravenous dose to normalize the urinary excretion to 100% bioavailability, the best estimate of the fraction absorbed of [26Al] from a topical application of [26Al]-aluminium-labeled chlorohydrate in an antiperspirant formulation was 0.00052%. Part B of the study demonstrated that the majority of the aluminium in the formulation remained associated with the external layers of the skin without penetration through the skin.

A real-time, quantitative PCR method using hydrolysis probes for the monitoring of Plasmodium falciparum load in experimentally infected human volunteers.

BACKGROUND: The accurate quantification of Plasmodium falciparum parasite numbers by PCR is an important tool for monitoring growth kinetics in subjects infected and subsequently treated with anti-malarial agents. METHODS: A real-time quantitative PCR (rt-qPCR) method using primers and a hydrolysis probe that targets the 18S rRNA gene was adapted and optimized to estimate parasite load in blood samples. Samples included laboratory prepared blood samples of varying parasite concentrations (6.4 × 10(5) to 6.4 parasites per 500 µl of packed red blood cells (500pRBC)) and blood samples collected from an experimentally infected human subject collected at 19 time points over 10 days. Sample preparation and extraction, detection chemistry, assay reproducibility, and limit of detection were compared to a previously published SYBR Green rt-qPCR used in a malaria vaccine clinical trial. RESULTS: Both the rt-qPCR hydrolysis probe assay and SYBR Green rt-qPCR provided a limit of detection of 6.4 × 10(1) parasites per 500pRBC. However non-specific amplification in the SYBR Green rt-qPCR assay led to either inaccurate estimation of parasite load at levels below 6.4 × 10(2) parasites per 500pRBC and to false-positive detection of parasites in negative samples. The rt-qPCR hydrolysis probe assay was specific and provided reliable quantification of parasitaemia down to 6.4 × 10(1) parasites per 500pRBC. Notably, 12 of the 19 consecutive samples collected from the experimentally infected subject were at or below 6.4 × 10(2) copies per 500pRBC. CONCLUSIONS: These results show that the hydrolysis probe rt-qPCR assay is superior to the SYBR Green rt-qPCR for the quantification of P. falciparum in human blood samples. The hydrolysis probe rt-qPCR is now in use in the Queensland paediatric infectious diseases laboratory (QPID) to monitor parasitaemia in experimentally-infected clinical trial subjects.

High coverage of diverse invasive meningococcal serogroup B strains by the 4-component vaccine 4CMenB in Australia, 2007-2011: Concordant predictions between MATS and genetic MATS.

Meningococcal serogroup B (MenB) accounts for an important proportion of invasive meningococcal disease (IMD). The 4-component vaccine against MenB (4CMenB) is composed of factor H binding protein (fHbp), neisserial heparin-binding antigen (NHBA), Neisseria adhesin A (NadA), and outer membrane vesicles of the New Zealand strain with Porin 1.4. A meningococcal antigen typing system (MATS) and a fully genomic approach, genetic MATS (gMATS), were developed to predict coverage of MenB strains by 4CMenB. We characterized 520 MenB invasive disease isolates collected over a 5-year period (January 2007-December 2011) from all Australian states/territories by multilocus sequence typing and estimated strain coverage by 4CMenB. The clonal complexes most frequently identified were ST-41/44 CC/Lineage 3 (39.4%) and ST-32 CC/ET-5 CC (23.7%). The overall MATS predicted coverage was 74.6% (95% coverage interval: 61.1%-85.6%). The overall gMATS prediction was 81.0% (lower-upper limit: 75.0-86.9%), showing 91.5% accuracy compared with MATS. Overall, 23.7% and 13.1% (MATS) and 26.0% and 14.0% (gMATS) of isolates were covered by at least 2 and 3 vaccine antigens, respectively, with fHbp and NHBA contributing the most to coverage. When stratified by year of isolate collection, state/territory and age group, MATS and gMATS strain coverage predictions were consistent across all strata. The high coverage predicted by MATS and gMATS indicates that 4CMenB vaccination may have an impact on the burden of MenB-caused IMD in Australia. gMATS can be used in the future to monitor variations in 4CMenB strain coverage over time and geographical areas even for non-culture confirmed IMD cases.

Contact allergy to hair colouring products. The cosmetovigilance experience of 4 companies (2003-2006).

The post-marketing undesirable events to hair colouring products in the European Union notified to the cosmetovigilance departments of four major cosmetic companies were analysed (2003-2006). The objective was to determine whether there was any time effect (trend to increase or decrease), country effect (significant difference between the countries included in the analysis) or product type effect (direct or oxidation), as well as to identify risk factors. Alleged undesirable events (UEvs, all notifications prior to causality assessment), were compared to the respective undesirable effects (UEfs, reasonably attributable to product use). A detailed analysis was performed on notifications with manifestations compatible with allergic contact dermatitis. No time effect of UEvs and UEfs was shown, for all hair-dye associated notifications and for allergic contact dermatitis, for all hair colouring products together and by product type. The incidence of allergic contact dermatitis to direct hair colouring products was lower for all four companies compared to oxidative hair dyes. The reporting rates of UEfs were statistically higher in the UK for one of four companies. Past history of black henna tattoos appeared as a major risk factor for seriousness of allergic contact reactions.

The improving state of Q fever surveillance. A review of Queensland notifications, 2003-2017.

Q fever is a notifiable zoonotic disease in Australia, caused by infection with Coxiella burnetii. This study has reviewed 2,838 Q fever notifications reported in Queensland between 2003 and 2017 presenting descriptive analyses, with counts, rates, and proportions. For this study period, Queensland accounted for 43% of the Australian national Q fever notifications. Enhanced surveillance follow-up of Q fever cases through Queensland Public Health Units was implemented in 2012, which improved the data collected for occupational risk exposures and animal contacts. For 2013-2017, forty-nine percent (377/774) of cases with an identifiable occupational group would be considered high risk for Q fever. The most common identifiable occupational group was agricultural/farming (31%). For the same period, at-risk environmental exposures were identified in 82% (961/1,170) of notifications; at-risk animal-related exposures were identified in 52% (612/1,170) of notifications; abattoir exposure was identified in 7% of notifications. This study has shown that the improved follow-up of Q fever cases since 2012 has been effective in the identification of possible exposure pathways for Q fever transmission. This improved surveillance has highlighted the need for further education and heightened awareness of Q fever risk for all people living in Queensland, not just those in previously-considered high risk occupations.

Unravelling animal exposure profiles of human Q fever cases in Queensland, Australia, using natural language processing.

Q fever, caused by the zoonotic bacterium Coxiella burnetii, is a globally distributed emerging infectious disease. Livestock are the most important zoonotic transmission sources, yet infection in people without livestock exposure is common. Identifying potential exposure pathways is necessary to design effective interventions and aid outbreak prevention. We used natural language processing and graphical network methods to provide insights into how Q fever notifications are associated with variation in patient occupations or lifestyles. Using an 18-year time-series of Q fever notifications in Queensland, Australia, we used topic models to test whether compositions of patient answers to follow-up exposure questionnaires varied between demographic groups or across geographical areas. To determine heterogeneity in possible zoonotic exposures, we explored patterns of livestock and game animal co-exposures using Markov Random Fields models. Finally, to identify possible correlates of Q fever case severity, we modelled patient probabilities of being hospitalized as a function of particular exposures. Different demographic groups consistently reported distinct sets of exposure terms and were concentrated in different areas of the state, suggesting the presence of multiple transmission pathways. Macropod exposure was commonly reported among Q fever cases, even when exposure to cattle, sheep or goats was absent. Males, older patients and those that reported macropod exposure were more likely to be hospitalized due to Q fever infection. Our study indicates that follow-up surveillance combined with text modelling is useful for unravelling exposure pathways in the battle to reduce Q fever incidence and associated morbidity.

Association between meteorological variations and activities of influenza A and B across different climate zones: a multi-region modelling analysis across the globe.

OBJECTIVE: To elucidate the effects of meteorological variations on the activity of influenza A and B in 11 sites across different climate regions. METHODS: Daily numbers of laboratory-confirmed influenza A and B cases from 2011-2015 were collected from study sites where the corresponding daily mean temperature, relative humidity, wind speed and daily precipitation amount were used for boosted regression trees analysis on the marginal associations and the interaction effects. RESULTS: Cold temperature was a major determinant that favored both influenza A and B in temperate and subtropical sites. Temperature-to-influenza A, but not influenza B, exhibited a U-shape association in subtropical and tropical sites. High relative humidity was also associated with influenza activities but was less consistent with influenza B activity. Compared with relative humidity, absolute humidity had a stronger association - it was negatively associated with influenza B activity in temperate zones, but was positively associated with both influenza A and B in subtropical and tropical zones. CONCLUSION: The association between meteorological factors and with influenza activity is virus type specific and climate dependent. The heavy influence of temperature on influenza activity across climate zones implies that global warming is likely to have an impact on the influenza burden.

Detection of human bocavirus in respiratory, fecal, and blood samples by real-time PCR.

Human bocavirus (HBoV) has been detected worldwide in respiratory samples. Two real-time PCR assays, targeting the non-structural protein (NP-1) and viral protein (VP-1) genes, were designed and validated to detect HBoV in patients with respiratory disease, gastroenteritis, or systemic illness. Sensitivity of the NP-1 and VP-1 assays were equal to the conventional PCR assay previously described by Allander et al. [2005: Proc Natl Acad Sci USA 102: 12891-12896] being 100%, and giving specificity of 94% and 93%, respectively. There was no cross-reaction identified with unrelated respiratory agents, or to human DNA. The limits of detection were 10 copies of genomic DNA equivalents per reaction for both assays. The assays were used to screen three different sample populations, combined nose, and throat swabs (n = 96) from children with acute respiratory disease, fecal samples (n = 375) from adults, and children with gastroenteritis and whole blood (n = 229) collected from 31 immunocompromised children taken over an 18-month period. In total 17 (18%) respiratory samples and 18 (4.8%) fecal samples were identified as having HBoV present. Of the pediatric whole blood specimens investigated, HBoV was detected in six (2.6%) samples from four patients. In summary, two real-time PCR assays targeting different genes were designed and validated for use as screening methods for the detection of HBoV. HBoV was found in three different specimen types: parent-collected combined nose-throat swabs, fecal samples collected from symptomatic individuals and whole blood from immunocompromised children.

Aggregate exposure modelling of vitamin A from cosmetic products, diet and food supplements.

Realism is important in estimating consumer exposure to a substance, especially when accounting for exposure from multiple sources. Humans are exposed to vitamin A from food, dietary supplements and cosmetics products. A probabilistic aggregate exposure model was developed for estimating exposure distributions to vitamin A (as retinol equivalents) in pre-/post-menopausal, and menopausal women in European and US populations. Data from large dietary surveys were used, together with realistic and extreme case scenarios of cosmetics product use (including occurrence data for vitamin A presence in 17 cosmetic products). Results of absorbed exposure estimates were expressed as µg/kg bw/day by incorporating dermal and oral bioavailability data. The mean and 95th percentile (P95) aggregate exposures were below the EU Tolerable Upper Intake Limit (3000 µg/day; 45 µg/kg/day internal exposure dose (IED)), providing positive assurances of safety. The major source of vitamin A exposure is the diet, with cosmetics providing only a small fraction of total exposure (2-5% at P95). In addition to providing a realistic assessment of total vitamin A exposure, this work provides a case study on how to approach future complex aggregate exposure questions.