Use of a digital contact tracing system in Singapore to mitigate COVID-19 spread.

BACKGROUND: Contact tracing has been essential to reducing spread of COVID-19. Singapore leveraged technology to assist with contact tracing efforts using a Bluetooth-based app and token platform called 'TraceTogether'. METHODS: We reviewed the impact of this system during the country's Delta and Omicron waves (24 August 2021 to 17 February 2022) to identify differences in number of close contacts and time savings between full automation using TraceTogether alone as compared to manual contact tracing supplemented by TraceTogether. Characteristics of digital contact tracing app or token users were reviewed. Thereafter, the number of close contacts identified by manual and digital contact tracing methods, and the number of confirmed COVID-19 cases among contacts were analysed. The difference in time taken for identification of close contacts was also determined. FINDINGS: Adoption rate for TraceTogether was high, with 93.3% of cases having a registered device. There was a 9.8 h (34.9%) reduction in time savings for close contacts to be informed using TraceTogether alone compared to manual contact tracing supplemented by TraceTogether. The proportion of close contacts automatically identified through TraceTogether alone and turned positive was 3.6%. For those identified through manual contact tracing supplemented by TraceTogether, this proportion was 12.5% and 6.2% for those served quarantine orders and health risk warnings respectively. INTERPRETATION: The high adoption rate of 'TraceTogether' suggest that digital solutions remain a promising option to improve contact tracing in future epidemics. This may have been through its concurrent use with vaccine differentiated public health measures and policies which engender public trust. There is future potential for utilising such technology in managing communicable diseases to achieve good public health outcomes.

The first imported case of monkeypox in Singapore during the 2022 outbreak - Reflections and lessons.

On June 21, 2022, Singapore reported its second ever case of imported monkeypox and first linked to the ongoing multi-country outbreak that has since been declared a public health emergency of international concern. There was quick initiation of public health measures including identification and quarantine of contacts, with post-exposure smallpox vaccination.

Does self-initiated sit-to-stand training with an assistive device regain the independence of sit-to-stand in stroke patient? A single-blinded randomized controlled trial.

BACKGROUND: It is unknown whether self-initiated sit-to-stand training with an assistive device is effective to regain the independence of sit-to-stand in stroke survivors. OBJECTIVE: To compare the effectiveness of self-initiated sit-to-stand training with an assistive device with manual sit-to-stand training. DESIGN: Parallel randomized controlled, assessor-blinded trial between January 2015 and May 2018. Randomization was performed by drawing lots to allocate treatment groups. SETTING: A rehabilitation hospital in Hong Kong. PARTICIPANTS: 69 participants in medical wards with unilateral hemiparetic stroke. A total of 52 participants fulfilled the study requirements. INTERVENTION: Ten sessions of intervention with conventional physiotherapy program followed, by self-initiated sit-to-stand training with an assistive device, or by manual sit-to-stand training. MAIN OUTCOME MEASURE: Number of participants regained the independence of sit-to-stand, sit-to-stand test from the Balance master® and Five-repetition sit-to-stand test. RESULTS: 69 participants (intervention, n = 36; control, n = 33) were randomized (mean age, 69.8 years (SD: 10.6), mean post-stroke days 18.6 (SD: 16.0)). Seventeen participants had not completed 10 sessions of training, leaving 52 (n = 26; n = 26) participants for per protocol analysis. Eighteen participants in the intervention group and 10 participants in the control group had regained the independence of sit-to-stand (Phi and Cramer's V: -0.31 and 0.31). The participants in the intervention group were faster to complete the Five-repetition sit-to-stand test than the control group (32.7 sec (SD: 1.93) versus 48.4 sec (SD, 6.8); 95% confidence interval, -30.8 to -0.7; p < 0.05). No adverse side effects occurred during and after the training across groups. CONCLUSIONS: Self-initiated sit-to-stand training with an assistive device may have positive effects on speeding up regaining the independence of sit-to-stand on sub-acute stroke survivors.

Assessment of the risk posed to Singapore by the emergence of artemisinin-resistant malaria in the Greater Mekong Subregion.

OBJECTIVE: To assess the public health risk to Singapore posed by the emergence of artemisinin-resistant (ART-R) malaria in the Greater Mekong Subregion (GMS). METHODS: We assessed the likelihood of importation of drug-resistant malaria into Singapore and the impact on public health of its subsequent secondary spread in Singapore. Literature on the epidemiology and contextual factors associated with ART-R malaria was reviewed. The epidemiology of malaria cases in Singapore was analysed. The vulnerability and receptivity of Singapore were examined, including the connectivity with countries reporting ART-R malaria, as well as the preparedness of Singaporean health authorities. Sources of information include international journals, World Health Organization guidelines, data from the Singapore Ministry of Health and National Public Health Laboratory of the National Centre for Infectious Diseases, and the International Air Transport Association. RESULTS: The importation of ART-R malaria into Singapore is possible given the close proximity and significant travel volume between Singapore and the GMS countries reporting artemisinin resistance. Singapore's vulnerability is further enhanced by the presence of foreign workers from neighbouring endemic countries. Nonetheless, the overall likelihood of such an event is low based on the rarity and decreasing trend of imported malaria incidence.​: With the presence of Anopheles vectors in Singapore, imported cases of drug-resistant malaria could cause secondary transmission. Nevertheless, the risk of sustained spread is likely to be mitigated by the comprehensive surveillance and control system in place for both infected vectors and human cases. DISCUSSION: This risk assessment highlights the need for a continued high degree of vigilance of ART-R malaria locally and globally to minimize the risk and public health impact of drug-resistant malaria in Singapore.

Inferring who-infected-whom-where in the 2016 Zika outbreak in Singapore-a spatio-temporal model.

Singapore experienced its first known Zika outbreak in 2016. Given the lack of herd immunity, the suitability of the climate for pathogen transmission, and the year-round presence of the vector- Aedes aegypti-Zika had the potential to become endemic, like dengue. Guillain-Barré syndrome and microcephaly are severe complications associated elsewhere with Zika and the risk of these complications makes understanding its spread imperative. We investigated the spatio-temporal spread of locally transmitted Zika in Singapore and assessed the relevance of non-residential transmission of Zika virus infections, by inferring the possible infection tree (i.e. who-infected-whom-where) and comparing inferences using geographically resolved data on cases' home, their work, or their home and work. We developed a spatio-temporal model using time of onset and both addresses of the Zika-confirmed cases between July and September 2016 to estimate the infection tree using Bayesian data augmentation. Workplaces were involved in a considerable fraction (64.2%) of infections, and homes and workplaces may be distant relative to the scale of transmission, allowing ambulant infected persons may act as the 'vector' infecting distant parts of the country. Contact tracing is a challenge for mosquito-borne diseases, but inferring the geographically structured transmission tree sheds light on the spatial transmission of Zika to immunologically naive regions of the country.

Fatal Case of Diphtheria and Risk for Reemergence, Singapore.

We report a fatal autochthonous diphtheria case in a migrant worker in Singapore. This case highlights the risk for individual cases in undervaccinated subpopulations, despite high vaccination coverage in the general population. Prompt implementation of public health measures and maintaining immunization coverage are critical to prevent reemergence of diphtheria.

Selection and Short-Term Outcomes of Living Kidney Donors in Singapore - An Analysis of the Donor Care Registry.

INTRODUCTION: Transplant rates in Singapore have been falling and there is limited information on baseline characteristics and clinical outcomes of living kidney donors nationally. This study aimed to determine the safety of living kidney donor transplant in Singapore by exploring the proportion of donors that meets international selection guidelines and describing short-term clinical outcomes. MATERIALS AND METHODS: We analysed 472 donors who underwent nephrectomies from 1 January 2010 to 31 December 2014 from the Donor Care Registry. We described donor characteristics against 5 international guidelines and measured post-nephrectomy outcomes in 150 local donors for up to 24 months. A multivariate analysis was performed to determine the baseline variables associated with poorer outcomes. RESULTS: There were more foreign than local donors, with differences in gender and hospital types. Selection was generally aligned with international recommendations although 3.0% (using the Chronic Kidney Disease Epidemiology [CKD-EPI] equation) to 8.5% (using radionuclide and creatinine clearance methods) of donors had inappropriate baseline estimated glomerular filtration rates (eGFR) forage. Post-procedure, many foreign donors were lost to follow-up. Over 24 months, eGFR decreased by 33.8% from baseline before recovering gradually to 29.6%. During this period, only 2 donors were admitted for renal or urological conditions and there were no cases of end-stage renal failure or deaths. A lower baseline eGFR (HR: 1.05; 95% Cl, 1.02 to 1.09) and older age (HR: 1.04; 95% Cl, 1.00 to 1.08) were associated with a post-nephrectomy eGFR of less than 60 mL/kg/1.73 m2. CONCLUSION: Kidney donation is safe in Singapore. Donor selection is in keeping with international guidelines and short-term outcomes are comparable to other cohorts.

An economic analysis of varicella immunization in the Singapore military.

BACKGROUND: Varicella outbreaks occur frequently in closed environments such as those of militaries. This paper compares the economic outcomes of varicella vaccination in enlisted servicemen without prior reported varicella infection or vaccination. METHODS: We analyzed the economic outcomes of a varicella vaccination program on all enlisted servicemen without prior reported varicella infection or vaccination in the Singapore Armed Forces (SAF) between December 11, 2010 - December 20, 2013, compared with the previous program of varicella vaccination only for selected personnel between December 1, 2007 - December 10, 2010. RESULTS: In the at-risk population of all active SAF servicemen, the program of varicella vaccination for all servicemen without prior reported varicella infection or vaccination upon enlistment would save 72.0 work days per 1000 (95 % CI: 61.2 - 82.9), valued at SG$6,544 per 1000 (95 % CI: 6,524 - 6,564), i.e., costing SG$91.5 per work day saved (95 % CI: 78.7 - 107.3). This also results in a reduction of 2.7 varicella cases per 1000 and 5.43 outbreaks per 10000, or a total savings of SG$1,695 per 1000 (95 % CI: -2,730 - 6,834), taking into account the cost of work days lost over a three-year period, compared with the previous regime of vaccinations only for selected individuals. CONCLUSION: The varicella vaccination strategy targeting all enlisted servicemen without prior reported varicella infection or vaccination is able to prevent varicella infections and outbreaks, thus reducing absenteeism and days lost.