Severe Respiratory Illness Associated with Human Metapneumovirus in Nursing Home, New Mexico, USA

Whole genome sequencing and evolution analyses of Human metapneumovirus

Human metapneumovirus (HMPV) is a major pathogen of acute respiratory tract infections (ARTIs) in children. Whole genome sequence analyses could help understand the evolution and transmission events of this virus. In this study, we sequenced HMPV whole genomes to improve the identification of molecular epidemiology in Beijing, China. Nasopharyngeal aspirates of hospitalized children aged < 14 years old with ARTIs were screened for HMPV infection using qPCR. Fourteen pairs of overlapping primers were used to amplify whole genome sequences of HMPV from positive samples with high viral loads. The epidemiology of HMPV was analysed and 27 HMPV whole genome sequences were obtained. Sequence identity and the positional entropy analyses showed that most regions of HMPV genome are conserved, whereas the G gene contained many variations. Phylogenetic analysis identified 25 HMPV sequences that belonged to a newly defined subtype A2b1; G gene sequences from 24 of these contained a 111-nucleotide duplication. HMPV is an important respiratory pathogen in paediatric patients. The new subtype A2b1 with a 111-nucleotide duplication has become predominate in Beijing, China.

Outbreak Response Capacity Assessments and Improvements Among Public Health Department Health Care-Associated Infection Programs-United States, 2015-2017

CONTEXT

The Centers for Disease Control and Prevention awarded $85 million to health care-associated infection and antibiotic resistance (HAI/AR) programs in March 2015 as part of Infection Control Assessment and Response (ICAR) activities in the Epidemiology and Laboratory Capacity cooperative agreement Domestic Ebola Supplement.

PROGRAM

One goal of this funding was to assess and improve program capacity to respond to potential health care outbreaks (eg, HAI clusters). All 55 funded programs (in 49 state and 6 local health departments) participated.

IMPLEMENTATION

The Centers for Disease Control and Prevention developed guidance and tools for HAI/AR programs to document relevant response capacities, assess policies, and measure progress. HAI/AR programs completed an interim assessment in 2016 and a final progress report in 2017.

EVALUATION

During the project period, 78% (n = 43) of the programs developed new investigation tools, 85% (n = 47) trained staff on outbreak response, and 96% (n = 53) of the programs reported hiring staff to assist with outbreak response activities. Staffing and expertise to support HAI outbreak response increased substantially among awardees reporting staffing limitations on the interim assessment, including in domains such as on-site infection control assessment (n = 20; 83%), laboratory capacity (n = 20; 91%), and data management/analytics (n = 14; 67%). By 2017, reporting requirements in 100% of the programs addressed possible HAI/AR outbreaks; 93% (n = 51) also addressed sentinel events such as identification of novel AR threats. More than 90% (n = 50) of programs enhanced capacities for tracking response activities; in 2016, these systems captured 6665 events (range, 3-1379; median = 46). Health departments also reported wide-ranging efforts to engage regulatory, public health, and health care partners to improve HAI/AR outbreak reporting and investigation.

DISCUSSION

Broad capacity for responding to HAI/AR outbreaks was enhanced using Ebola ICAR supplemental funding. As response activities expand, health department programs will be challenged to continue building expertise, reporting infrastructure, investigation resources, and effective relations with health care partners.

Barriers and facilitators to person-centred infection prevention and control: results of a survey about the Dementia Isolation Toolkit

Background

People working in long-term care homes (LTCH) face difficult decisions balancing the risk of infection spread with the hardship imposed on residents by infection control and prevention (ICP) measures. The Dementia Isolation Toolkit (DIT) was developed to address the gap in ethical guidance on how to safely and effectively isolate people living with dementia while supporting their personhood. In this observational study, we report the results of a survey of LTCH staff on barriers and facilitators regarding isolating residents, and the impact of the DIT on staff moral distress.

Methods

We completed an online cross-sectional survey. Participants (n = 207) were staff working on-site in LTCH in Ontario, Canada since March 1, 2020, with direct or indirect experience with the isolation of residents. LTCH staff were recruited through provincial LTCH organizations, social media, and the DIT website. Survey results were summarized, and three groups compared, those: (1) unfamiliar with, (2) familiar with, and (3) users of the DIT.

Results

61% of respondents identified distress of LTCH staff about the harmful effects of isolation on residents as a major barrier to effective isolation. Facilitators for isolation included delivery of 1:1 activity in the resident’s room (81%) and designating essential caregivers to provide support (67%). Almost all respondents (84%) reported an increase in moral distress. DIT users were less likely to report an impact of moral distress on job satisfaction (odds ratio (OR) 0.41, 95% CI 0.19-0.87) with 48% of users reporting the DIT was helpful in reducing their level of moral distress.

Conclusions

Isolation as an ICP measure in LTCH environments creates moral distress among staff which is a barrier to its effectiveness. ICP guidance to LTCH would be strengthened by the inclusion of a dementia-specific ethical framework that addresses how to minimize the harms of isolation on both residents and staff.

A Study of Universal Severe Acute Respiratory Syndrome Coronavirus 2 RNA Testing Among Residents and Staff in a Large Group of Care Homes in South London

Background

Care homes have experienced a high number of COVID-19 related deaths of residents since the onset of the pandemic. However, up to May 2020, there has been a lack of information about the extent of SARS-CoV-2 infection in residents and staff in care homes and limited testing in this setting.

Results

Overall, the point prevalence of SARS-CoV-2 infection was 6.5% with a higher rate in residents (9.0%) than in staff (4.7%). A key finding was the high proportion of asymptomatic infection detected in staff (69%) and residents (51%) with evidence of under-detection of symptoms by care home staff.

Conclusions

The high proportion of asymptomatic infection combined with under detection of symptoms by care home staff indicates that offering a test to all residents and staff in care homes with rapid reporting of results would assist accurate identification of infected individuals, facilitating prompt infection prevention and control action.

Methods

Combined nose and throat swab testing for SARS-CoV-2 RNA was carried out in 2455 residents and staff across 37 care homes in the London Borough of Bromley across a three-week period. Results were reported within 24 hours of sample delivery and data were collected on the presence or absence of symptoms.

Severe Human Metapneumovirus and Group A Streptococcus Pneumonia in an Immunocompetent Adult

An immunocompetent adult with asthma developed severe human metapneumovirus (HMPV) illness complicated by group A Streptococcus coinfection, progressing to acute respiratory distress syndrome and shock. Several coworkers had less severe HMPV infection. HMPV can cause severe respiratory illness in healthy adults and should be considered as a potential cause of community respiratory outbreaks.

Antibody recognition of the Pneumovirus fusion protein trimer interface

Human metapneumovirus (hMPV) is a leading cause of viral respiratory infection in children, and can cause severe lower respiratory tract infection in infants, the elderly, and immunocompromised patients. However, there remain no licensed vaccines or specific treatments for hMPV infection. Although the hMPV fusion (F) protein is the sole target of neutralizing antibodies, the immunological properties of hMPV F remain poorly understood. To further define the humoral immune response to the hMPV F protein, we isolated two new human monoclonal antibodies (mAbs), MPV458 and MPV465. Both mAbs are neutralizing in vitro and were determined to target a unique antigenic site using competitive biolayer interferometry. We determined both MPV458 and MPV465 have higher affinity for monomeric hMPV F than trimeric hMPV F. MPV458 was co-crystallized with hMPV F, and the mAb primarily interacts with an alpha helix on the F2 region of the hMPV F protein. Surprisingly, the major epitope for MPV458 lies within the trimeric interface of the hMPV F protein, suggesting significant breathing of the hMPV F protein must occur for host immune recognition of the novel epitope. In addition, significant glycan interactions were observed with a somatically mutated light chain framework residue. The data presented identifies a novel epitope on the hMPV F protein for epitope-based vaccine design, and illustrates a new mechanism for human antibody neutralization of viral glycoproteins.

Prevalence of Antibodies to SARS-CoV-2 in Italian Adults and Associated Risk Factors

We aimed to assess the prevalence of and factors associated with anti- severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) positivity in a large population of adult volunteers from five administrative departments of the Liguria and Lombardia regions. A total of 3609 individuals were included in this analysis. Participants were tested for anti-SARS-CoV-2 antibodies [Immunoglobulin G (IgG) and M (IgM) class antibodies] at three private laboratories (Istituto Diganostico Varelli, Medical Center, and Casa della Salute di Genova). Demographic data, occupational or private exposure to SARS-CoV-2-infected patients, and prior medical history consistent with SARS-CoV-2 infection were collected according to a preplanned analysis. The overall seroprevalence of anti-SARS-CoV-2 antibodies (IgG and/or IgM) was 11.0% [398/3609; confidence interval (CI) 10.0%–12.1%]. Seroprevalence was higher in female inmates than in male inmates (12.5% vs. 9.2%, respectively, p = 0.002), with the highest rate observed among adults aged >55 years (13.2%). A generalized estimating equations model showed that the main risk factors associated with SARS-CoV-2 seroprevalence were the following: an occupational exposure to the virus [Odd ratio (OR) = 2.36; 95% CI 1.59–3.50, p = 0.001], being a long-term care facility resident (OR = 4.53; 95% CI 3.19–6.45, p = 0.001), and reporting previous symptoms of influenza-like illness (OR = 4.86; 95% CI 3.75–6.30, p = 0.001) or loss of sense of smell or taste (OR = 41.00; 95% CI 18.94–88.71, p = 0.001). In conclusion, we found a high prevalence (11.0%) of SARS-CoV-2 infection that is significantly associated with residing in long-term care facilities or occupational exposure to the virus. These findings warrant further investigation into SARS-CoV-2 antibody prevalence among the Italian population.

A Potent Neutralizing Site III-Specific Human Antibody Neutralizes Human Metapneumovirus In Vivo

Human metapneumovirus (hMPV) is a leading cause of viral lower respiratory tract infection in children. The sole target of neutralizing antibodies targeting hMPV is the fusion (F) protein, a class I viral fusion protein mediating virus-cell membrane fusion. There have been several monoclonal antibodies (mAbs) isolated that neutralize hMPV; however, determining the antigenic sites on the hMPV F protein mediating such neutralizing antibody generation would assist efforts for effective vaccine design. In this report, the isolation and characterization of four new human mAbs, termed MPV196, MPV201, MPV314, and MPV364, are described. Among the four mAbs, MPV364 was found to be the most potent neutralizing mAb in vitro Binding studies with monomeric and trimeric hMPV F revealed that MPV364 had the weakest binding affinity for monomeric hMPV F compared to the other three mAbs, yet binding experiments with trimeric hMPV F showed limited differences in binding affinity, suggesting that MPV364 targets an antigenic site incorporating two protomers. Epitope binning studies showed that MPV364 targets antigenic site III on the hMPV F protein and competes for binding with previously discovered mAbs MPE8 and 25P13, both of which cross-react with the respiratory syncytial virus (RSV) F protein. However, MPV364 does not cross-react with the RSV F protein, and the competition profile suggests that it binds to the hMPV F protein in a binding pose slightly shifted from mAbs MPE8 and 25P13. MPV364 was further assessed in vivo and was shown to substantially reduce viral replication in the lungs of BALB/c mice. Overall, these data reveal a new binding region near antigenic site III of the hMPV F protein that elicits potent neutralizing hMPV F-specific mAbs and provide a new panel of neutralizing mAbs that are candidates for therapeutic development.IMPORTANCE Recent progress in understanding the human immune response to respiratory syncytial virus has paved the way for new vaccine antigens and therapeutics to prevent and treat disease. Progress toward understanding the immune response to human metapneumovirus (hMPV) has lagged behind, although hMPV is a leading cause of lower respiratory tract infection in children. In this report, we advanced the field by isolating a panel of human mAbs to the hMPV F protein. One potent neutralizing mAb, MPV364, targets antigenic site III on the hMPV F protein and incorporates two protomers into its epitope yet is unique from previously discovered site III mAbs, as it does not cross-react with the RSV F protein. We further examined MPV364 in vivo and found that it limits viral replication in BALB/c mice. Altogether, these data provide new mAb candidates for therapeutic development and provide insights into hMPV vaccine development.