Effectiveness of containment strategies in preventing SARS-CoV-2 transmission.

BACKGROUND: Despite substantial resources deployed to curb SARS-CoV-2 transmission, controlling the COVID-19 pandemic has been a major challenge. New variants of the virus are frequently emerging leading to new waves of infection and re-introduction of control measures. In this study, we assessed the effectiveness of containment strategies implemented in the early phase of the pandemic. METHODS: Real-world data for COVID-19 cases was retrieved for the period Jan 1 to May 1, 2020 from a number of different sources, including PubMed, MEDLINE, Facebook, Epidemic Forecasting and Google Mobility Reports. We analyzed data for 18 countries/regions that deployed containment strategies such as travel restrictions, lockdowns, stay-at-home requests, school/public events closure, social distancing, and exposure history information management (digital contact tracing, DCT). Primary outcome measure was the change in the number of new cases over 30 days before and after deployment of a control measure. We also compared the effectiveness of centralized versus decentralized DCT. Time series data for COVID-19 were analyzed using Mann-Kendall (M-K) trend tests to investigate the impact of these measures on changes in the number of new cases. The rate of change in the number of new cases was compared using M-K z-values and Sen's slope. RESULTS: In spite of the widespread implementation of conventional strategies such as lockdowns, travel restrictions, social distancing, school closures, and stay-at-home requests, analysis revealed that these measures could not prevent the spread of the virus. However, countries which adopted DCT with centralized data storage were more likely to contain the spread. CONCLUSIONS: Centralized DCT was more effective in containing the spread of COVID-19. Early implementation of centralized DCT should be considered in future outbreaks. However, challenges such as public acceptance, data security and privacy concerns will need to be addressed.

Predictive model integrating dynamic parameters for massive blood transfusion in major trauma patients: The Dynamic MBT score.

BACKGROUND: Currently existing predictive models for massive blood transfusion in major trauma patients had limitations for sequential evaluation of patients and lack of dynamic parameters. OBJECTIVE: To establish a predictive model for predicting the need of massive blood transfusion major trauma patients, integrating dynamic parameters. DESIGN: Multi-center retrospective cohort study. SETTING: Four designated trauma centers in Hong Kong. METHODS: Trauma patients aged >12years were recruited from the trauma registries from 2005 to 2012. MBT was defined as delivery of ≥10units of packed red cells within 24h. Split sampling method was adopted for model building and validation. Multivariate logistic regression was adopted for model building, with weight assigned based on logarithmic of adjusted odds ratios. The performance of the dynamic MBT score (DMBT) was compared with the PWH score and the Trauma Associated Severe Hemorrhage (TASH) score in the validation data set. RESULTS: 4991 patients were included in the study. The DMBT was established with 8 parameters: systolic blood pressure, heart rate, hemoglobin, hemoglobin drop within the first 2h, INR, base deficit, unstable pelvic fracture and hemoperitoneum in radiological imaging. At cut-off score of 6 the DMBT achieved sensitivity of 78.2% and specificity of 89.2%. In the validation set, the AUCs of the DMBT, PWH score, and TASH score were 0.907, 0.844, and 0.867 respectively. CONCLUSIONS: The DMBT score allows both snapshot and sequential activation along the trauma care pathway and has better performance than the PWH score and TASH score.

A comparative analysis of behaviors and sexual affiliation networks among men who have sex with men in Hong Kong.

In Hong Kong, men who have sex with men (MSM) account for a significant proportion of HIV infections. While perceived as a hidden population, they constitute a distinct social network shaped by their differential use of unique channels for sex partnership. To characterize their pattern of connectivity and association with high-risk sexual behaviors, 311 MSM were recruited via saunas and the internet to participate in a questionnaire survey. Internet recruits were younger, and many (31/43) were solely reliant on the internet to seek sex partners, while visiting a similar number of venues as the sauna recruits (p = 0.98). Internet users generally had a high frequency of unprotected anal intercourse (UAI). MSM who had visited only a single venue reported more UAI with their regular partners (adjusted OR 6.86, 1.88-24.96) and sought fewer casual partners than those frequenting multiple venues (adjusted OR 0.33, 0.19-0.60). This study provides evidence for the heterogeneity of the sexual affiliation networks of MSM in Hong Kong. High HIV risk of UAI could be offset by fewer casual partners in certain venues, the implications of which would need to be explored in longitudinal studies. Methodologically, internet sampling was very efficient in identifying sex networking venues, while internet recruits gave a high retention rate for updating profiles. However, sampling at high centrality saunas did not necessarily identify the MSM-affiliating venues in the networks efficiently. The sampling strategy of MSM survey should therefore be objective-driven, which may differ for health message dissemination and social marketing, versus HIV surveillance or risk assessment.

A new perspective on sexual mixing among men who have sex with men by body image.

BACKGROUND: "Casual sex" is seldom as non-selective and random as it may sound. During each sexual encounter, people consciously and unconsciously seek their casual sex partners according to different attributes. Influential to a sexual network, research focusing on quantifying the effects of physical appearance on sexual network has been sparse. METHODS: We evaluated the application of Log odds score (LOD) to assess the mixing patterns of 326 men who have sex with men (MSM) in Hong Kong in their networking of casual sex partners by Body Image Type (BIT). This involved an analysis of 1,196 respondents-casual sex partner pairs. Seven BITs were used in the study: Bear, Chubby, Slender, Lean toned, Muscular, Average and Other. RESULTS: A hierarchical pattern was observed in the preference of MSM for casual sex partners by the latter's BIT. Overall, Muscular men were most preferred, followed by Lean toned while the least preferred was Slender, as illustrated by LOD going down along the hierarchy in the same direction. Marked avoidance was found between men who self-identified as Chubby and men of Other body type (within-group-LOD: 1.25-2.89; between-group-LOD: <-1). None of the respondents reported to have networked a man who self-identified as Average for casual sex. CONCLUSIONS: We have demonstrated the possibility of adopting a mathematical prototype to investigate the influence of BIT in a sexual network of MSM. Construction of matrix based on culture-specific BIT and cross-cultural comparisons would generate new knowledge on the mixing behaviors of MSM.

Outcome of severely injured trauma patients at a designated trauma centre in the Hong Kong Special Administrative Region.

BACKGROUND: The Hong Kong Special Administrative Region (HKSAR) of the People's Republic of China (PRC) has seen significant changes in its trauma service over the last ten years including the implementation of a regional trauma system. The author's institution is one of the five trauma centres designated in 2003. This article reports our initial clinical experience. METHODS: A prospective single-centre trauma registry from January 2004 to December 2008 was reviewed. The primary clinical outcome measure was hospital mortality. The Trauma and Injury Severity Score (TRISS) methodology was used for bench-marking with the North America Major Trauma Outcome Study (MTOS) database. RESULTS: There were 1451 patients. The majority (83.9%) suffered from blunt injury. The overall mortality rate was 7.8%. Severe injury, defined as the Injury Severity Score > 15, occurred in 22.5% of patients, and was associated with a mortality rate of 31.6%. A trend of progressive improvement was noted. The M-statistic was 0.99, indicating comparable case-mix with the MTOS. The Z- and W-statistics of each individual year revealed fewer, but not significantly so, number of survivors than expected. CONCLUSIONS: Trauma centre designation was feasible in the HKSAR and was associated with a gradual improvement in patient care. Trauma system implementation may be considered in regions equipped with the necessary socio-economic and organizational set-up.

Full genome analysis of an emerging cluster of human immunodeficiency virus type 1 subtype B infection in Hong Kong.

With considerable capacity for genetic diversification, new HIV-1 genotypes have been reported over the years. Three HIV-1 isolates previously genotyped as B using gag and env sequences were completely sequenced and reanalyzed. Several amino acid mutations were found in vif, rev, and nef genes but not in gag or env sequences. These alterations have not previously been reported in Hong Kong. The investigation of phylogenetic relatedness revealed that a region of the vif of the studied Hong Kong isolates subtype B cluster contains several subtype D signature amino acid residues. Several unique mutations on vif in these three isolates were also identified.

Self-assembling peptide nanofiber scaffold promotes the reconstruction of acutely injured brain.

Traumatic brain injury (TBI) or brain surgery may cause extensive loss of cerebral parenchyma. However, no strategy for reconstruction has been clinically effective. Our previous study had shown that self-assembling peptide nanofiber scaffold (SAPNS) can bridge the injured spinal cord, elicit axon regeneration, and eventually promote locomotor functional recovery. In the present study we investigated the effect of SAPNS for the reconstruction of acutely injured brain. The lesion cavity of the injured cortex was filled with SAPNS or saline immediately after surgically induced TBI, and the rats were killed 2 days, 2 weeks, or 6 weeks after the surgery for histology, immunohistochemistry, and TUNEL studies. Saline treatment in the control animals resulted in a large cavity in the injured brain, whereas no cavity of any significant size was found in the SAPNS-treated animals. Around the lesion site in control animals were many macrophages (ED1 positive) but few TUNEL-positive cells, indicating that the TBI caused secondary tissue loss mainly by means of necrosis, not apoptosis. In the SAPNS-treated animals the graft of SAPNS integrated well with the host tissue with no obvious gaps. Moreover, there were fewer astrocytes (GFAP positive) and macrophages (ED1 positive) around the lesion site in the SAPNS-treated animals than were found in the controls. Thus, SAPNS may help to reconstruct the acutely injured brain and reduce the glial reaction and inflammation in the surrounding brain tissue. FROM THE CLINICAL EDITOR: Self-assembling peptide nanofiber scaffold (SAPNS) was reported earlier to bridge the injured spinal cord, elicit axon regeneration, and promote locomotor recovery. In this study the effect of SAPNS for the reconstruction of acutely injured brain was investigated. In SAPNS-treated animals the graft integrated well with the host tissue with no obvious gaps. SAPNS may help to reconstruct the acutely injured brain and reduced the glial reaction and inflammation in the surrounding brain tissue.

Knowledge, acceptance and perception towards brainstem death among medical students in Hong Kong: a questionnaire survey on brainstem death.

BACKGROUND: Brainstem death (BSD), defined as the irreversible loss of consciousness, brainstem reflexes and the capacity to breathe, is not an uncommon scenario seen in the day to day practice of medical personnel. Upon the diagnosis of BSD, controversial issues of withdrawing life-supporting treatments and organ procuring for transplantation inevitably arise. This study evaluated the knowledge, acceptance and perception of BSD amongst medical students in Hong Kong. METHODS: A total of 126 medical students completed a self-administered questionnaire. Ten questions were used to assess their knowledge of BSD and this was correlated with their responses in three hypothetical vignettes. RESULTS: The mean score of the subjects' knowledge was 6.03 out of 10. Less than half (48.8%) of the subjects' knew that BSD is different from persistent vegetative state while 49.2% and 36.3% knew that BSD is accepted as death medically and legally in Hong Kong, respectively. When 'diagnosed' with BSD, 63.7%, 46.8% and 52.4% of the subjects would agree to the withdrawal of life-support from themselves, their most-loved one/family member and a stranger, respectively. Subjects with better knowledge and those who thought that doctors may tend to diagnose BSD to save resources or procure organs for transplantation were more ready to accept the withdrawal of life-support. CONCLUSIONS: We concluded that knowledge of BSD amongst medical students was unsatisfactory and that urgent actions should be taken to remedy the situation. A better knowledge of BSD positively influenced the decision-making on withdrawing life-support and that adequate information regarding the outcome of BSD should be provided. On the other hand, the perception of doctors' intentions behind diagnosing BSD has no direct influence on the decision-making. More emphasis is required on medical education, including a specific emphasis in the undergraduate lecture curriculum and bedside exposure to BSD diagnosis and subsequent counselling of patients' family members.

Characterization of murine interferon-alpha 12 (MuIFN-alpha12): biological activities and gene expression.

Interferon alpha (IFN-alpha) belongs to the type I interferon family and consists of multiple subtypes in many species. In the mouse, there are at least 14 IFN-alpha genes and 3 IFN-alpha pseudogenes, the most recently identified of which are murine interferon-alpha 12 (MuIFN-alpha12), MuIFN-alpha13 and MuIFN-alpha14. To further study the biological activities of MuIFN-alpha12, we have produced a recombinant MuIFN-alpha12 (rMuIFN-alpha12) protein using COS-1 cells. rMuIFN-alpha12 was found to inhibit the growth of murine myeloid leukemia JCS cells. Flow cytofluorometric analysis with propidium iodide staining showed that the growth inhibitory activity of rMuIFN-alpha12 may be caused by the induction of apoptosis. Flow cytofluorometric analysis also revealed that rMuIFN-alpha12 was able to up-regulate the expression of MHC-I on both JCS cells and primary macrophages. Functional studies indicated that a MuIFN-alpha12 transgene could induce an anti-viral state in L929 cells against Influenza A virus. Moreover, expression of MuIFN-alpha12 was not detectable by RT-PCR in untreated, Influenza A virus infected, polyI:polyC induced L929 cells, or in a wide range of normal murine tissues. Taken together, this data shows that MuIFN-alpha12 is a protein with all the biological traits of a type I IFN.