Publications by authors named "Marcella Kong"

Refuse storage and collection systems are potential sources of food and harbourage areas for rodents which transmit pathogens. We examined the factors associated with rodent activity in public housing municipal waste collection premises in a highly urbanized city-state. We analysed data from April 2019 to March 2020 in mixed-effects logistic regression models to examine the independent factors associated with rodent activity in central refuse chute rooms (CRCs), individual refuse chute (IRC) bin chambers and bin centres.

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Japanese encephalitis virus (JEV) is an important arbovirus in Asia that can cause serious neurological disease. JEV is transmitted by mosquitoes in an enzootic cycle involving porcine and avian reservoirs, in which humans are accidental, dead-end hosts. JEV is currently not endemic in Singapore, after pig farming was abolished in 1992; the last known human case was reported in 2005.

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Wastewater-based surveillance has been widely used as a non-intrusive tool to monitor population-level transmission of COVID-19. Although various approaches are available to concentrate viruses from wastewater samples, scalable methods remain limited. Here, we sought to identify and evaluate SARS-CoV-2 virus concentration protocols for high-throughput wastewater testing.

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Wastewater-based surveillance for SARS-CoV-2 has been used for the early warning of transmission or objective trending of the population-level disease prevalence. Here, we describe a new use-case of conducting targeted wastewater surveillance to complement clinical testing for case identification in a small community at risk of COVID-19 transmission. On 2 July 2020, a cluster of COVID-19 cases in two unrelated households residing on different floors in the same stack of an apartment building was reported in Singapore.

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Fomite-mediated transmission has been identified as a possible route for the spread of COVID-19 disease caused by SARS-CoV-2. In healthcare settings, environmental contamination by SARS-CoV-2 has been found in patients' rooms and toilets. Here, we investigated environmental presence of SARS-CoV-2 in non-healthcare settings and assessed the efficacy of cleaning and disinfection in removing virus contamination.

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Background: Singapore used to report an annual average of 14 cases of Japanese encephalitis, but ever since the abolishment of pig farms in the early 1990s, the local incidence rate for Japanese encephalitis virus (JEV) infections has reduced drastically. Studies done in the early 2000s demonstrated the presence of JEV-specific antibodies in animals such as wild boars, dogs, chickens and goats on the offshore island and peripheral parts of the Singapore, indicative of prior JEV exposure. A JEV wildlife and sentinel chicken surveillance system was initiated in 2010 through to 2017 to study the animal host seroprofiles.

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