Multiple introductions of monkeypox virus to Ireland during the international mpox outbreak, May 2022 to October 2023.

BackgroundMpox, caused by monkeypox virus (MPXV), was considered a rare zoonotic disease before May 2022, when a global epidemic of cases in non-endemic countries led to the declaration of a Public Health Emergency of International Concern. Cases of mpox in Ireland, a country without previous mpox reports, could reflect extended local transmission or multiple epidemiological introductions.AimTo elucidate the origins and molecular characteristics of MPXV circulating in Ireland between May 2022 and October 2023.MethodsWhole genome sequencing of MPXV from 75% of all Irish mpox cases (182/242) was performed and compared to sequences retrieved from public databases (n = 3,362). Bayesian approaches were used to infer divergence time between sequences from different subclades and evaluate putative importation events from other countries.ResultsOf 242 detected mpox cases, 99% were males (median age: 35 years; range: 15-60). All 182 analysed genomes were assigned to Clade IIb and, presence of 12 distinguishable subclades suggests multiple introductions into Ireland. Estimation of time to divergence of subclades further supports the hypothesis for multiple importation events from numerous countries, indicative of extended and sustained international spread of mpox. Further analysis of sequences revealed that 92% of nucleotide mutations were from cytosine to thymine (or from guanine to adenine), leading to a high number of non-synonymous mutations across subclades; mutations associated with tecovirimat resistance were not observed.ConclusionWe provide insights into the international transmission dynamics supporting multiple introductions of MPXV into Ireland. Such information supported the implementation of evidence-informed public health control measures.

WireSafeTM - A pilot study of a novel safety engineered device designed to prevent guidewire retention and reduce sharps injuries during central venous catheter insertion.

Background: Guidewire retention and sharps injury during central venous catheter insertion are errors that cause patient and healthcare professional harm. The WireSafeTM is a novel procedure safety pack engineered to prevent guidewire retention and sharps injury during central venous catheter insertion. This is a pilot study aimed to determine its acceptability, usability and safety during clinical practice. Methods: An observational time and motion study was conducted comparing central venous catheter insertion and sharps disposal practice using standard versus WireSafeTM techniques. One-year following implementation, a structured survey was conducted to determine clinician opinion and experiences of using the WireSafeTM. Results: 15 procedures were observed using standard practice and 16 using the WireSafeTM technique. The WireSafeTM technique decreased the time taken from removal of the guidewire to disposal of sharps (standard 11.4 ± 5.6 min vs WireSafeTM 8.7 ± 1.4 min, p = 0.035), as well as total procedure time (standard 16 ± 7 min vs WireSafeTM 14.2 ± 2 min, p = 0.17), although this latter trend did not reach significance. Clinicians frequently practiced unsafe behaviour during sharps disposal in the standard group (53%), but when using the WireSafeTM technique, 100% exhibited safe practice by transferring sharps to the bin inside the sealed WireSafeTM box. One-year following implementation, 20 clinicians participated in the structured survey. Clinicians across three different departments used the WireSafeTM in varying clinical situations and reported that its use for central line insertion was either easier (10/20) or no different (10/20) compared to standard practice. All clinicians (20/20) felt that the WireSafeTM reduced the risk of guidewire retention and all stated that they approved of the WireSafeTM technique, and supported its use for convenience and safety benefits. Conclusion: Utilising the WireSafeTM for central line insertion facilitated earlier and safer sharps disposal, and the device was well supported by clinicians for its convenience and safety benefits.

Adeno-Associated Virus 2 and Human Adenovirus F41 in Wastewater during Outbreak of Severe Acute Hepatitis in Children, Ireland.

During April-July 2022, outbreaks of severe acute hepatitis of unknown etiology (SAHUE) were reported in 35 countries. Five percent of cases required liver transplantation, and 22 patients died. Viral metagenomic studies of clinical samples from SAHUE cases showed a correlation with human adenovirus F type 41 (HAdV-F41) and adeno-associated virus type 2 (AAV2). To explore the association between those DNA viruses and SAHUE in children in Ireland, we quantified HAdV-F41 and AAV2 in samples collected from a wastewater treatment plant serving 40% of Ireland's population. We noted a high correlation between HAdV-F41 and AAV2 circulation in the community and SAHUE clinical cases. Next-generation sequencing of the adenovirus hexon in wastewater demonstrated HAdV-F41 was the predominant HAdV type circulating. Our environmental analysis showed increased HAdV-F41 and AAV2 prevalence in the community during the SAHUE outbreak. Our findings highlight how wastewater sampling could aid in surveillance for respiratory adenovirus species.

The Association between Therapeutic Alliance and Parental Health Outcomes following a Child's Death in the Pediatric Intensive Care Unit.

Therapeutic alliance reflects the strength and quality of the physician-patient/family relationship. We investigated the association between therapeutic alliance and bereaved parents' mental health and perceived overall health following their child's death in a pediatric intensive care unit (PICU). Bereaved parents were surveyed 6 months after their child's death in a PICU affiliated with the Collaborative Pediatric Critical Care Research Network. Parents were evaluated for complicated grief, depression, and post-traumatic stress using the Inventory of Complicated Grief (ICG), the Patient Health Questionnaire (PHQ-8), and the Short Post-Traumatic Stress Disorder Rating Interview (SPRINT), respectively. Overall health was evaluated using a single item. Therapeutic alliance between parents and their deceased child's PICU physicians was assessed using the Human Connection scale (HCS). Two hundred and thirty-five parents of 158 deceased children completed surveys. Mean ICG score was 34.4 ± 14.9 with 142 (60.4%) parents screening positive for complicated grief. Mean PHQ-8 score was 9.1 ± 6.2 with 102 (43.4%) screening positive for at least moderate depression. Mean SPRINT score was 14.6 ± 8.2 with 122 (51.9%) screening positive for post-traumatic stress disorder. Overall health was perceived as fair for 47 (20.0%) parents and poor for 10 (4.3%). Using multivariable modeling, higher HCS score (greater therapeutic alliance) was significantly associated with lower (better) ICG score (-0.23, 95% CI -0.42, -0.04, p = 0.018). HCS score was not significantly associated with PHQ-8, SPRINT, or overall health scores. We conclude that bereaved parents experience a high level of adverse mental health symptoms including complicated grief, depression, and post-traumatic stress symptoms. Greater therapeutic alliance with PICU physicians may lessen symptoms of complicated grief during bereavement.

SARS-CoV-2 variant trends in Ireland: Wastewater-based epidemiology and clinical surveillance.

SARS-CoV-2 RNA quantification in wastewater is an important tool for monitoring the prevalence of COVID-19 disease on a community scale which complements case-based surveillance systems. As novel variants of concern (VOCs) emerge there is also a need to identify the primary circulating variants in a community, accomplished to date by sequencing clinical samples. Quantifying variants in wastewater offers a cost-effective means to augment these sequencing efforts. In this study, SARS-CoV-2 N1 RNA concentrations and daily loadings were determined and compared to case-based data collected as part of a national surveillance programme to determine the validity of wastewater surveillance to monitor infection spread in the greater Dublin area. Further, sequencing of clinical samples was conducted to determine the primary SARS-CoV-2 lineages circulating in Dublin. Finally, digital PCR was employed to determine whether SARS-CoV-2 VOCs, Alpha and Delta, were quantifiable from wastewater. No lead or lag time was observed between SARS-CoV-2 wastewater and case-based data and SARS-CoV-2 trends in Dublin wastewater significantly correlated with the notification of confirmed cases through case-based surveillance preceding collection with a 5-day average. This demonstrates that viral RNA in Dublin's wastewater mirrors the spread of infection in the community. Clinical sequence data demonstrated that increased COVID-19 cases during Ireland's third wave coincided with the introduction of the Alpha variant, while the fourth wave coincided with increased prevalence of the Delta variant. Interestingly, the Alpha variant was detected in Dublin wastewater prior to the first genome being sequenced from clinical samples, while the Delta variant was identified at the same time in clinical and wastewater samples. This work demonstrates the validity of wastewater surveillance for monitoring SARS-CoV-2 infections and also highlights its effectiveness in identifying circulating variants which may prove useful when sequencing capacity is limited.

Transmission of SARS-CoV-2 arising from international flights arriving in Ireland in December 2020: a descriptive analysis using national surveillance data.

OBJECTIVES: There is limited evidence on the risk of in-flight transmission of SARS-CoV-2. This study estimated the extent of in-flight SARS-CoV-2 transmission on international flights arriving in Ireland during December 2020. STUDY DESIGN: This was a cross-sectional analysis. METHODS: National surveillance data identified all notified cases of COVID-19 who were infectious while travelling on international flights to Ireland during December 2020. Close contacts of cases were tested for SARS-CoV-2, and the results were collated to estimate the pooled secondary attack rate across all flights. Laboratory and epidemiological data were obtained from the Health Service Executive Covid Care Tracker, a national database of COVID-19 cases in Ireland. RESULTS: A total of 165 infectious cases of COVID-19 were identified on 134 incoming flights; 40.0% were symptomatic on board. There were 2099 flight close contacts identified, of whom 40.9% had results of a SARS-CoV-2 polymerase chain reaction test within 14 days of arrival. The pooled secondary attack rate for these contacts was 7.0% and was higher among those on flights of ≥5-hour duration (P = 0.008). More than half (59.1%) of close contacts had no SARS-CoV-2 test result recorded; the reasons included incorrect or absent contact details (26.5%) and no response when contacted (17.8%). CONCLUSIONS: In this national study investigating transmission of SARS-CoV-2 from international flights arriving into Ireland, the pooled secondary attack rate was 7.0%. International travel is likely to have contributed to the third wave of SARS-CoV-2 infections in Ireland in early 2021. Application of non-pharmaceutical interventions remains central to mitigating the risk of in-flight transmission.

Fetal Deaths in Ireland Due to SARS-CoV-2 Placentitis Caused by SARS-CoV-2 Alpha.

CONTEXT.­: A severe third wave of COVID-19 disease affected Ireland in the first 3 months of 2021. In this wave, 1 second-trimester miscarriage and 6 stillbirths were observed in the Irish population because of placental insufficiency as a result of SARS-CoV-2 placentitis. This observation was at odds with the country's previous experience with COVID-19 disease in pregnant mothers. OBJECTIVE.­: To describe the clinical and pathologic features of these pregnancy losses. DESIGN.­: Retrospective review of clinical and pathologic data of cases of second-trimester miscarriage, stillbirth, or neonatal death identified by perinatal pathologists as being due to SARS-CoV-2 placentitis during the third wave of COVID-19 in Ireland. RESULTS.­: Clinical and pathologic data were available for review in 6 pregnancies. Sequencing or genotyping of the virus identified SARS-CoV-2 alpha (B.1.1.7) in all cases. Three of the 6 cases had maternal thrombocytopenia, and fetal growth restriction was not prominent, suggesting a rapidly progressive placental disease. CONCLUSIONS.­: The identification of SARS-CoV-2 alpha in all these cases suggests that the emergence of the variant was associated with an increased risk of fetal death due to SARS-CoV-2 placentitis when compared with the original virus. Maternal thrombocytopenia may have potential as a clinical marker of placentitis, but other inflammatory markers need investigation. Three of the 6 women had been assessed for reduced fetal movements in hospital some days before the fetal deaths actually occurred; this could suggest that there may be a window for intervention in some cases.

Re-emergence of enterovirus D68 in Europe after easing the COVID-19 lockdown, September 2021.

We report a rapid increase in enterovirus D68 (EV-D68) infections, with 139 cases reported from eight European countries between 31 July and 14 October 2021. This upsurge is in line with the seasonality of EV-D68 and was presumably stimulated by the widespread reopening after COVID-19 lockdown. Most cases were identified in September, but more are to be expected in the coming months. Reinforcement of clinical awareness, diagnostic capacities and surveillance of EV-D68 is urgently needed in Europe.

Genomic epidemiological analysis of SARS-CoV-2 household transmission.

Family clusters have contributed significantly to the onward spread of SARS-CoV-2. However, the dynamics of viral transmission in this setting remain incompletely understood. We describe the clinical and viral-phylogenetic characteristics of a family cluster of SARS-CoV-2 infections with a high attack rate, and explore how whole-genome sequencing (WGS) can inform outbreak investigations in this context. In this cluster, the first symptomatic case was a 22-month-old infant who developed rhinorrhoea and sneezing 2 days prior to attending a family gathering. Subsequently, seven family members in attendance at this event were diagnosed with SARS-CoV-2 infections, including the infant described. WGS revealed indistinguishable SARS-CoV-2 genomes recovered from the adults at the gathering, which were closely related genetically to B.1 lineage viruses circulating in the local community. However, a divergent viral sub-lineage was recovered from the infant and another child, each harbouring a distinguishing spike substitution (N30S). This suggested that the infant was unlikely to be the primary case, despite displaying symptoms first, and additional analysis of her nasopharyngeal swab revealed a picornavirus co-infection to account for her early symptoms. Our findings demonstrate how WGS can elucidate the transmission dynamics of SARS-CoV-2 infections within household clusters and provide useful information to support outbreak investigations. Additionally, our description of SARS-CoV-2 viral lineages and notable variants circulating in Ireland to date provides an important genomic-epidemiological baseline in the context of vaccine introduction.

Molecular Epidemiology and Evolutionary Trajectory of Emerging Echovirus 30, Europe.

In 2018, an upsurge in echovirus 30 (E30) infections was reported in Europe. We conducted a large-scale epidemiologic and evolutionary study of 1,329 E30 strains collected in 22 countries in Europe during 2016-2018. Most E30 cases affected persons 0-4 years of age (29%) and 25-34 years of age (27%). Sequences were divided into 6 genetic clades (G1-G6). Most (53%) sequences belonged to G1, followed by G6 (23%), G2 (17%), G4 (4%), G3 (0.3%), and G5 (0.2%). Each clade encompassed unique individual recombinant forms; G1 and G4 displayed >2 unique recombinant forms. Rapid turnover of new clades and recombinant forms occurred over time. Clades G1 and G6 dominated in 2018, suggesting the E30 upsurge was caused by emergence of 2 distinct clades circulating in Europe. Investigation into the mechanisms behind the rapid turnover of E30 is crucial for clarifying the epidemiology and evolution of these enterovirus infections.

HSP25 Vaccination Attenuates Atherogenesis via Upregulation of LDLR Expression, Lowering of PCSK9 Levels and Curbing of Inflammation.

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Humidicare - an implementation study of a novel HME safety device designed to prevent ventilator circuit occlusion due to inadvertent dual humidification.

Mechanical ventilation bypasses the protective mechanisms of the upper respiratory tract which are designed to heat and humidify inspired air to 37 °C and 44 mg H2O/L respectively. Artificial humidification systems are therefore incorporated into ventilation circuits to condition cold and dry medical gases before they reach the lower respiratory tract and cause patient harm. Commonly either a heat and moisture exchanger (HME) or a heated humidifier (HH) are utilised for this purpose, however the inadvertent simultaneous use of both devices within the same circuit can cause critical airway occlusion within 24 h. The Humidicare HME (Medovate, Cambridge, UK) is a safety engineered temperature-dependent warning system designed to activate when inadvertently placed into a warm circuit containing a HH. This study aimed to determine the efficacy of the Humidicare HME warning system in simulated clinical conditions. The threshold temperature for activation of the device was determined in a digital incubator, and the device was tested for efficacy with a HH present or absent from the breathing circuit. The device performed reliably and activated rapidly when required across all simulations. The Humidicare HME warning system is a simple and unobtrusive device which can effectively alert the operator to the error of dual humidification.

Treating COVID-19 in the nursing home setting: an integrated approach for a complex and susceptible cohort.

Our patient, a nursing home resident, was reviewed by our frailty outreach service in November 2020. She initially was diagnosed with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in September 2020 during an outbreak in her nursing home. On this occasion, she again tested positive for SARS-CoV-2. Our case report describes the resident's poor immune response indicated by a low IgG level after her initial COVID infection as well as reinfection with a 'non-variant' SARS-CoV-2 lineage (B.1.177). The case describes the importance of integration of community and secondary care. The nursing home received close monitoring and nurse supervision for the detection of potential deterioration of the patient. Exit-seeking behaviour by nursing home residents was limited effectively. The issues of low immune response to COVID-19 in older people and the emergence of variants of concern will continue to pose a threat to this susceptible group.

A bedside rescue method for retrieving retained guidewires: The 'Suck Out' technique.

BACKGROUND: Central venous catheter guidewire retention is classed as a 'never event' in the United Kingdom, with the potential for significant patient harm. If the retained guidewire remains within the central venous catheter lumen, bedside techniques may facilitate guidewire retrieval. However, these techniques may be ineffective if the guidewire has already passed below skin level. We investigated a novel 'suck out' technique for bedside guidewire retrieval and compared this against traditional retrieval methods. METHODS: Simulation 1: in a benchtop model, seven different central venous catheters had their corresponding guidewire placed in the last 2 cm of the catheter tip which was immersed horizontally in fluid. A 50-mL syringe was attached to the distal lumen central venous catheter hub and suction applied for 5 s, and the distance of guidewire retraction was recorded. Simulation 2: a central venous catheter guidewire was intentionally retained within the catheter at either 5 cm above or below skin level in a pigskin model. Simple catheter withdrawal, catheter clamping withdrawal and the 'suck out' method were compared for efficacy using Fisher's exact test. RESULTS: Simulation 1: retained guidewires were retracted by 13 cm on average. Simulation 2: when guidewires were retained 5 cm above skin level, all retrieval methods were 100% effective; however, when retained 5 cm below skin level, simple catheter withdrawal was ineffective, clamping and withdrawal was only 10% effective and the 'suck out' technique was 90% effective (p < 0.001). CONCLUSION: The 'suck out' technique can effectively retract guidewires retained within central venous catheter lumens and demonstrates superiority over traditional methods of retained guidewire extraction in simulated models.

Group A Rotavirus Detection and Genotype Distribution before and after Introduction of a National Immunisation Programme in Ireland: 2015-2019.

Immunisation against rotavirus infection was introduced into Ireland in December 2016. We report on the viruses causing gastroenteritis before (2015-2016) and after (2017-2019) implementation of the Rotarix vaccine, as well as changes in the diversity of circulating rotavirus genotypes. Samples from patients aged ≤ 5 years (n = 11,800) were received at the National Virus Reference Laboratory, Dublin, and tested by real-time RT-PCR for rotavirus, Rotarix, norovirus, sapovirus, astrovirus, and enteric adenovirus. Rotavirus genotyping was performed either by multiplex or hemi-nested RT-PCR, and a subset was characterised by sequence analysis. Rotavirus detection decreased by 91% in children aged 0-12 months between 2015/16 and 2018/19. Rotarix was detected in 10% of those eligible for the vaccine and was not found in those aged >7 months. Rotavirus typically peaks in March-May, but following vaccination, the seasonality became less defined. In 2015-16, G1P[8] was the most common genotype circulating; however, in 2019 G2P[4] was detected more often. Following the introduction of Rotarix, a reduction in numbers of rotavirus infections occurred, coinciding with an increase in genotype diversity, along with the first recorded detection of an equine-like G3 strain in Ireland.

Improving preparedness to respond to cross-border hepatitis A outbreaks in the European Union/European Economic Area: towards comparable sequencing of hepatitis A virus.

IntroductionSequence-based typing of hepatitis A virus (HAV) is important for outbreak detection, investigation and surveillance. In 2013, sequencing was central to resolving a large European Union (EU)-wide outbreak related to frozen berries. However, as the sequenced HAV genome regions were only partly comparable between countries, results were not always conclusive.AimThe objective was to gather information on HAV surveillance and sequencing in EU/European Economic Area (EEA) countries to find ways to harmonise their procedures, for improvement of cross-border outbreak responses.MethodsIn 2014, the European Centre for Disease Prevention and Control (ECDC) conducted a survey on HAV surveillance practices in EU/EEA countries. The survey enquired whether a referral system for confirming primary diagnostics of hepatitis A existed as well as a central collection/storage of hepatitis A cases' samples for typing. Questions on HAV sequencing procedures were also asked. Based on the results, an expert consultation proposed harmonised procedures for cross-border outbreak response, in particular regarding sequencing. In 2016, a follow-up survey assessed uptake of suggested methods.ResultsOf 31 EU/EEA countries, 23 (2014) and 27 (2016) participated. Numbers of countries with central collection and storage of HAV positive samples and of those performing sequencing increased from 12 to 15 and 12 to 14 respectively in 2016, with all countries typing an overlapping fragment of 218 nt. However, variation existed in the sequenced genomic regions and their lengths.ConclusionsWhile HAV sequences in EU/EEA countries are comparable for surveillance, collaboration in sharing and comparing these can be further strengthened.

20,000 years of societal vulnerability and adaptation to climate change in southwest Asia.

The Fertile Crescent, its hilly flanks and surrounding drylands has been a critical region for studying how climate has influenced societal change, and this review focuses on the region over the last 20,000 years. The complex social, economic, and environmental landscapes in the region today are not new phenomena and understanding their interactions requires a nuanced, multidisciplinary understanding of the past. This review builds on a history of collaboration between the social and natural palaeoscience disciplines. We provide a multidisciplinary, multiscalar perspective on the relevance of past climate, environmental, and archaeological research in assessing present day vulnerabilities and risks for the populations of southwest Asia. We discuss the complexity of palaeoclimatic data interpretation, particularly in relation to hydrology, and provide an overview of key time periods of palaeoclimatic interest. We discuss the critical role that vegetation plays in the human-climate-environment nexus and discuss the implications of the available palaeoclimate and archaeological data, and their interpretation, for palaeonarratives of the region, both climatically and socially. We also provide an overview of how modelling can improve our understanding of past climate impacts and associated change in risk to societies. We conclude by looking to future work, and identify themes of "scale" and "seasonality" as still requiring further focus. We suggest that by appreciating a given locale's place in the regional hydroscape, be it an archaeological site or palaeoenvironmental archive, more robust links to climate can be made where appropriate and interpretations drawn will demand the resolution of factors acting across multiple scales. This article is categorized under:Human Water > Water as Imagined and RepresentedScience of Water > Water and Environmental ChangeWater and Life > Nature of Freshwater Ecosystems.

Hepatitis A outbreak disproportionately affecting men who have sex with men (MSM) in the European Union and European Economic Area, June 2016 to May 2017.

Between 1 June 2016 and 31 May 2017, 17 European Union (EU) and European Economic Area countries reported 4,096 cases associated with a multi-country hepatitis A (HA) outbreak. Molecular analysis identified three co-circulating hepatitis A virus (HAV) strains of genotype IA: VRD_521_2016, V16-25801 and RIVM-HAV16-090. We categorised cases as confirmed, probable or possible, according to the EU outbreak case definitions. Confirmed cases were infected with one of the three outbreak strains. We investigated case characteristics and strain-specific risk factors for transmission. A total of 1,400 (34%) cases were confirmed; VRD_521_2016 and RIVM-HAV16-090 accounted for 92% of these. Among confirmed cases with available epidemiological data, 92% (361/393) were unvaccinated, 43% (83/195) travelled to Spain during the incubation period and 84% (565/676) identified as men who have sex with men (MSM). Results depict an HA outbreak of multiple HAV strains, within a cross-European population, that was particularly driven by transmission between non-immune MSM engaging in high-risk sexual behaviour. The most effective preventive measure to curb this outbreak is HAV vaccination of MSM, supplemented by primary prevention campaigns that target the MSM population and promote protective sexual behaviour.

Heat shock protein-27 and sex-selective regulation of muscarinic and proteinase-activated receptor 2-mediated vasodilatation: differential sensitivity to endothelial NOS inhibition.

BACKGROUND AND PURPOSE: Previously, we demonstrated that exogenous heat shock protein 27 (HSP27/gene, HSPB1) treatment of human endothelial progenitor cells (EPCs) increases the synthesis and secretion of VEGF, improves EPC-migration/re-endothelialization and decreases neo-intima formation, suggesting a role for HSPB1 in regulating EPC function. We hypothesized that HSPB1 also affects mature endothelial cells (ECs) to alter EC-mediated vasoreactivity in vivo. Our work focused on endothelial NOS (eNOS)/NO-dependent relaxation induced by ACh and the coagulation pathway-activated receptor, proteinase-activated receptor 2 (PAR2). EXPERIMENTAL APPROACH: Aorta rings from male and female wild-type, HSPB1-null and HSPB1 overexpressing (HSPB1o/e) mice were contracted with phenylephrine, and NOS-dependent relaxation responses to ACh and PAR2 agonist, 2-furoyl-LIGRLO-NH2 , were measured without and with L-NAME and ODQ, either alone or in combination to block NO synthesis/action. Tissues from female HSPB1-null mice were treated in vitro with recombinant HSP27 and then used for bioassay as above. Furthermore, oestrogen-specific effects were evaluated using a bioassay of aorta isolated from ovariectomized mice. KEY RESULTS: Relative to males, HSPB1-null female mice exhibited an increased L-NAME-resistant relaxation induced by activation of either PAR2 or muscarinic ACh receptors that was blocked in the concurrent presence of both L-NAME and ODQ. mRNAs (qPCR) for eNOS and ODQ-sensitive guanylyl-cyclase were increased in females versus males. Treatment of isolated aorta tissue with HSPB1 improved tissue responsiveness in the presence of L-NAME. Ovariectomy did not affect NO sensitivity, supporting an oestrogen-independent role for HSPB1. CONCLUSIONS AND IMPLICATIONS: HSPB1 can regulate intact vascular endothelial function to affect NO-mediated vascular relaxation, especially in females.