Wastewater surveillance for early pathogen detection in Asia.

Wastewater surveillance (WS) has emerged as an important population-based surveillance tool for early pathogen detection to inform timely public health action. Despite global guidance to initiate WS programming in Asia, the priorities and needs in Asia remain poorly understood. To address this gap, we conducted a cross-sectional assessment of WS efforts in Asia.

Acute and Postacute Health Care Utilization and Costs After Dengue Infection: A Population-Based Cohort Study.

Background: Emerging evidence suggests that postacute sequelae may arise following dengue infection. There has been no quantification of the risk and burden of acute and postacute health care utilization and cost due to dengue.

Methods: We utilized national notification databases from Singapore to construct cohorts of adults first infected with dengue.

Characterization of post-acute multi-organ sequelae following dengue infection.

Objectives: Population-based cohort studies on long-term sequelae post-dengue are lacking, given dengue's disproportionate burden in tropical low- and middle-income countries with limited access to diagnostic testing and follow-up. We estimated the 300-day post-acute risk of new-incident multi-systemic complications after dengue infection.

Methods: National dengue registries and healthcare-claim databases in Singapore were utilized to build a retrospective population-based adult cohort with laboratory-confirmed dengue infection (1 January 2017-30 June 2023) and a cohort of uninfected controls.

Adjacent spillover efficacy of Wolbachia for control of dengue: emulation of a cluster randomised target trial.

Background: Matings between male Aedes aegypti mosquitoes infected with wAlbB strain of Wolbachia and wild-type females yield non-viable eggs, thereby suppressing Ae. aegypti abundance in the field. We evaluated the spillover efficacy of releasing wAlbB-infected Ae.

Zika virus: advancing a priority research agenda for preparedness and response.

The 2015-16 Zika virus epidemic emerged in the Americas and rapidly spread throughout the region and beyond, showing the epidemic potential of this mosquito-borne Orthoflavivirus and its capacity to cause severe congenital malformations and neurological sequelae. WHO declared the Zika virus epidemic a public health emergency of international concern in 2016. Despite this declaration, there are no licensed Zika virus vaccines, therapeutics, or diagnostic tests appropriate for routine antenatal screening.

Suppression of Aedes aegypti may not affect sympatric Aedes albopictus populations: findings from two years of entomological surveillance in Singapore.

Globally, multiple trials have successfully demonstrated the effectiveness of novel tools, such as the sterile and incompatible insect techniques, in suppressing Aedes aegypti populations. However, there is concern that Aedes albopictus, another arbovirus-competent vector, may occupy the niches vacated by Ae. aegypti in areas where these species occur in sympatry.

COMPARING DETECTIONS OF AEDES AEGYPTI FEMALES USING THREE TYPES OF AUTOCIDAL GRAVID TRAPS.

We compared the number of Aedes aegypti females per trap and the number of detections of this mosquito species per week during 8 wk in 3 types of autocidal gravid traps, the Centers for Disease Control and Prevention (CDC) Autocidal Gravid Ovitrap (AGO), Biogents Gravid Aedes Trap (GAT), and Singapore Gravitrap (SGT), in central Puerto Rico. These traps use the same principles for attracting gravid Ae. aegypti females as traditional ovitraps, such as dark colors, standing water, and decomposing plant materials.

Effectiveness of Wolbachia-mediated sterility coupled with sterile insect technique to suppress adult Aedes aegypti populations in Singapore: a synthetic control study.

Background: Incompatible insect technique (IIT) coupled with sterile insect technique (SIT) via the release of sterile male Wolbachia-infected mosquitoes is a promising tool for Aedes-borne disease control. Yet, real-world evidence on the suppressive effectiveness of IIT-SIT on mosquito abundance remains mostly limited to small semi-rural village and suburban localities over short trial durations. However, a large proportion of Aedes-borne diseases occur in dense, urban, and high-rise locations, limiting the applicability of previous studies for these settings with high disease burden.

Evaluating quasi-experimental approaches for estimating epidemiological efficacy of non-randomised field trials: applications in Wolbachia interventions for dengue.

Background: Wolbachia symbiosis in Aedes aegypti is an emerging biocontrol measure against dengue. However, assessing its real-world efficacy is challenging due to the non-randomised, field-based nature of most intervention studies. This research re-evaluates the spatial-temporal impact of Wolbachia interventions on dengue incidence using a large battery of quasi-experimental methods and assesses each method's validity.

Assessing Wolbachia-mediated sterility for dengue control: emulation of a cluster-randomized target trial in Singapore.

Background: Matings between male Aedes aegypti mosquitoes infected with wAlbB strain of Wolbachia and wildtype females yield non-viable eggs. We evaluated the efficacy of releasing wAlbB-infected Ae. aegypti male mosquitoes to suppress dengue.

Update to: Assessing the efficacy of male Wolbachia-infected mosquito deployments to reduce dengue incidence in Singapore.

Background: This trial is a parallel, two-arm, non-blinded cluster randomised controlled trial that is under way in Singapore, with the aim of measuring the efficacy of male Wolbachia-infected Aedes aegypti deployments in reducing dengue incidence in an endemic setting with all four dengue serotypes in circulation. The trial commenced in July 2022 and is expected to conclude in September 2024. The original study protocol was published in December 2022.

Dengue versus COVID-19: comparing the incidence of cardiovascular, neuropsychiatric and autoimmune complications.

Background: While persistence of chronic symptoms following dengue infection has been documented in small prospective cohorts, population-based studies are limited. The post-acute risk of new-incident multi-systemic complications following dengue infection was contrasted against that following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in a multi-ethnic adult Asian population.

Methods: National testing and healthcare claims that databases in Singapore were utilized to build a retrospective population-based adult cohort with laboratory-confirmed infection during overlapping waves of SARS-CoV-2 and dengue transmission (1 July 2021 to 31 October 2022).

Usefulness of aircraft and airport wastewater for monitoring multiple pathogens including SARS-CoV-2 variants.

Background: As global travel resumed in coronavirus disease 2019 (COVID-19) endemicity, the potential of aircraft wastewater monitoring to provide early warning of disease trends for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants and other infectious diseases, particularly at international air travel hubs, was recognized. We therefore assessed and compared the feasibility of testing wastewater from inbound aircraft and airport terminals for 18 pathogens including SARS-CoV-2 in Singapore, a popular travel hub in Asia.

Methods: Wastewater samples collected from inbound medium- and long-haul flights and airport terminals were tested for SARS-CoV-2.

Combining wastewater surveillance and case data in estimating the time-varying effective reproduction number.

Wastewater surveillance has been increasingly acknowledged as a useful tool for monitoring transmission dynamics of infections of public health concern, including the coronavirus disease (COVID-19). While a range of models have been proposed to estimate the time-varying effective reproduction number (R) utilizing clinical data, few have harnessed the viral concentration in wastewater samples to do so, leaving uncertainties about the potential precision gains with its use. In this study, we developed a Bayesian hierarchical model which simultaneously reconstructed the latent infection trajectory and estimated R.

Case report: Zika surveillance complemented with wastewater and mosquito testing.

Background: In June 2023, a local cluster of 15 Zika cases was reported in a neighbourhood in Northeastern Singapore. The last significant local transmission of Zika virus (ZIKV) with more than 450 cases was in 2016-2017. To monitor the situation and mitigate further transmission, case, entomological and wastewater-based surveillance were carried out.

Efficacy of Wolbachia-mediated sterility to reduce the incidence of dengue: a synthetic control study in Singapore.

Background: Due to the absence of available therapeutics and good vaccines, vector control solutions are needed to mitigate the spread of dengue. Matings between male Aedes aegypti mosquitoes infected with the wAlbB strain of Wolbachia and wildtype females yield non-viable eggs. We evaluated the efficacy of releasing wAlbB-infected A aegypti male mosquitoes to suppress dengue incidence.

Estimating COVID-19 cases on a university campus based on Wastewater Surveillance using machine learning regression models.

Wastewater Surveillance (WS) is a crucial tool in the management of COVID-19 pandemic. The surveillance is based on enumerating SARS-CoV-2 RNA concentrations in the community's sewage. In this study, we used WS data to develop a regression model for estimating the number of active COVID-19 cases on a university campus.

Screening for extended-spectrum beta-lactamase in recreational beach waters in Singapore.

As part of Singapore's One Health antimicrobial resistance (AMR) management, this work was designed to understand the AMR burden in recreational beach waters using extended-spectrum beta-lactamase (ESBL-EC) as an indicator. A total of 90 water samples were collected from six different recreational beaches over three different time periods. Only 28/90 (31.

Positive association of SARS-CoV-2 RNA concentrations in wastewater and reported COVID-19 cases in Singapore - A study across three populations.

Wastewater testing of SARS-CoV-2 has been adopted globally and has shown to be a useful, non-intrusive surveillance method for monitoring COVID-19 trends. In Singapore, wastewater surveillance has been widely implemented across various sites and has facilitated timely COVID-19 management and response. From April 2020 to February 2022, SARS-CoV-2 RNA concentrations in wastewater monitored across three populations, nationally, in the community, and in High Density Living Environments (HDLEs) were aggregated into indices and compared with reported COVID-19 cases and hospitalisations.

Characterization of size-differentiated airborne particulate matter collected from indoor environments of childcare facilities.

Inhalation of particulate matter (PM) present in indoor atmospheres has been associated with poor health and wellbeing of occupants. Here we report the characteristics of airborne PM collected from twenty-two air-conditioned childcare centres in Singapore. Airborne PM were collected using cascade impactors and characterized for morphology, elemental composition, endotoxin levels, ability to generate abiotic reactive oxygen species, and oxidative stress-dependent cytotoxicity in BEAS-2B cell lines.

Singapore's 5 decades of dengue prevention and control-Implications for global dengue control.

This paper summarises the lessons learnt in dengue epidemiology, risk factors, and prevention in Singapore over the last half a century, during which Singapore evolved from a city of 1.9 million people to a highly urban globalised city-state with a population of 5.6 million.

Genetic Diversity and Dispersal of DENGUE Virus among Three Main Island Groups of the Philippines during 2015-2017.

Dengue has been one of the major public health concerns in the Philippines for more than a century. The annual dengue case burden has been increasing in recent years, exceeding 200,000 in 2015 and 2019. However, there is limited information on the molecular epidemiology of dengue in the Philippines.