Molecular detection and sequence analysis of porcine circovirus type 3 in sow sera from farms with prolonged histories of reproductive problems in Hunan, China.

A newly emerging porcine circovirus, designated PCV3, has been reported in various countries (USA, Poland, South Korea and China) since 2017. Its presence may be associated with porcine dermatitis and nephropathy syndrome (PDNS), reproductive failure, and multisystem inflammation. In this study, we report identification of PCV3 in cases of reproductive failure in various regions in Hunan, China. From January 2015 to December 2016, sera were collected from 190 sows from seven farms with reproductive problems. Specifically, 85 samples were from sows with a history of reproductive failure, whereas the remaining 105 were from healthy sows. The PCV3-positive rate was significantly higher in sows with reproductive failure (45.9%) than in healthy sows (21.9%), based on quantitative PCR (qPCR) assays. Although phylogenetic analysis based on the cap gene suggested that these PCV3 isolates belonged to the clade PCV3a, amino acid sequence variations in the Cap protein still occurred among these isolates, and these might have contributed to antigenic alterations of the Cap protein, based on the Jameson-Wolf antigenic index. Finally, we concluded that PCV3 was circulating in sows in Hunan province, China. However, the association of PCV3 with reproductive failure in sows and its potential for vertical transmission need to be studied further.

Mapping infectious disease hospital surge threats to lessons learnt in Singapore: a systems analysis and development of a framework to inform how to DECIDE on planning and response strategies.

BACKGROUND: Hospital usage and service demand during an Infectious Disease (ID) outbreak can tax the health system in different ways. Herein we conceptualize hospital surge elements, and lessons learnt from such events, to help build appropriately matched responses to future ID surge threats. METHODS: We used the Interpretive Descriptive qualitative approach. Interviews (n = 35) were conducted with governance and public health specialists; hospital based staff; and General Practitioners. Key policy literature in tandem with the interview data were used to iteratively generate a Hospital ID Surge framework. We anchored our narrative account within this framework, which is used to structure our analysis. RESULTS: A spectrum of surge threats from combinations of capacity (for crowding) and capability (for treatment complexity) demands were identified. Starting with the Pyramid scenario, or an influx of high screening rates flooding Emergency Departments, alongside fewer and manageable admissions; the Reverse-Pyramid occurs when few cases are screened and admitted but those that are, are complex; during a 'Black' scenario, the system is overburdened by both crowding and complexity. The Singapore hospital system is highly adapted to crowding, functioning remarkably well at constant near-full capacity in Peacetime and resilient to Endemic surges. We catalogue 26 strategies from lessons learnt relating to staffing, space, supplies and systems, crystalizing institutional memory. The DECIDE model advocates linking these strategies to types of surge threats and offers a step-by-step guide for coordinating outbreak planning and response. CONCLUSIONS: Lack of a shared definition and decision making of surge threats had rendered the procedures somewhat duplicative. This burden was paradoxically exacerbated by a health system that highly prizes planning and forward thinking, but worked largely in silo until an ID crisis hit. Many such lessons can be put into play to further strengthen our current hospital governance and adapted to more diverse settings.

Comparing patient and healthcare worker experiences during a dengue outbreak in Singapore: understanding the patient journey and the introduction of a point-of-care test (POCT) toward better care delivery.

BACKGROUND: In the aftermath of an upsurge in the number of dengue cases in 2013 and 2014, the SD BIOLINE Dengue Duo rapid diagnostic Point-of-Care Test (POCT) kit was introduced in Tan Tock Seng Hospital, Singapore in June 2013. It is known that the success of POCT usage is contingent on its implementation within the health system. We evaluated health services delivery and the Dengue Duo rapid diagnostic test kit application in Singapore from healthcare workers' perspectives and patient experiences of dengue at surge times. METHODS: Focus group discussions were conducted with dengue patients, from before and after the POCT implementation period. In-depth interviews with semi-structured components with healthcare workers were carried out. A patient centred process mapping technique was used for evaluation, which mapped the patient's journey and was mirrored from the healthcare worker's perspective. RESULTS: Patients and healthcare workers confirmed a wide range of symptoms in adults, making it challenging to determine diagnosis. There were multiple routes to help seeking, and no 'typical patient journey', with patients either presenting directly to the hospital emergency department, or being referred there by a primary care provider. Patients groups diagnosed before and after POCT implementation expressed some differences between speed of diagnoses and attitudes of doctors, yet shared negative feelings about waiting times and a lack of communication and poor information delivery. However, the POCT did not in its current implementation do much to help waiting times. Healthcare workers expressed that public perceptions of dengue in recent years was a major factor in changing patient management, and that the POCT kit was helpful in improving the speed and accuracy of diagnoses. CONCLUSIONS: Health service delivery for dengue patients in Singapore was overall perceived to be of an acceptable clinical standard, which was enhanced by the introduction of the POCT. However, improvements can be focused on Adapting to outbreaks by reducing and rendering Waiting experiences more comfortable; Advancing education about symptom recognition, while also Recognising better communication strategies; and Expanding follow-up care options. This is presented as the Dengue AWARE model of care delivery.

Engineering the male-specificity of Fab against SDM antigen by chain shuffling.

High-titer serologically detected male (SDM) antibody fragments are essential for specific binding to the SDM antigen and promoting its application. The A8 clone previously obtained from an original phage antibody library was further affinity-matured by light- and high-chain shuffling respectively, to generate the end product B9 clone. The binding capacity of B9 phage Fabs to male splenocytes doubled the value of its parental A8 clone (determined using ELISA). Based on immunofluorescent staining, B9-Fabs mainly bound to the surface antigen of male splenocytes and recognized testicular cells. The resulting B9-Fabs detected a single protein (approximately 40 kDa determined using Western blot analysis of male splenocytes and testis); its high SDM antigen binding ability might have been because of mutation sites and varied lengths of the amino acid sequences in the complementarity determining regions-3 of the κ and Fd chains. The new recombinant clones of Fab that were phage-enhanced using chain shuffling were candidate molecules for investigating molecular mechanisms of SDM antigens specific binding and applications.