Keeping yellow fever out of S’pore is one top priority for new Communicable Diseases Agency

SINGAPORE – While Singapore is free of yellow fever now, the country is still under threat from the viral disease, which like dengue is transmitted by the Aedes mosquito.

Mr Pream Raj, acting director of Contact and Environmental Diseases, Border and Travel Health at the new Communicable Diseases Agency (CDA), flagged the danger posed by yellow fever, and said Singapore has to do a lot more to prevent its potential introduction and spread here.

Yellow fever is a mosquito-borne acute haemorrhagic fever that can result in death. It poses a significant threat to global health security due to its high impact and potential for international spread.

Endemic in the tropical regions of South America and sub-Saharan Africa, yellow fever is estimated to cause up to 60,000 deaths worldwide every year.

In an interview with reporters on Nov 6, ahead of the official launch of CDA on Nov 12, Mr Pream gave the example of how Singapore is managing the threat of yellow fever to illustrate the work of the agency, which

was set up in April

and is the point agency to safeguard the country against infectious disease threats.

He highlighted the difficulty of managing the Aedes population in Singapore, as the country’s tropical climate and urban environment provide ample breeding habitats.

“This makes it extremely dangerous should yellow fever be brought into the country... so, what we want to do is to prevent the disease from taking root here,” he said.

Mr Pream’s team looks at travel health to ensure that residents of Singapore, who are travelling abroad, have the necessary information and know what measures to take to protect themselves, so that they do not get infected while abroad or bring any infectious diseases back.

Travel health refers to public health measures and guidance for travellers to prevent infectious diseases, including health screenings, vaccinations and risk assessments before and after international travel.

CDA manages the risks associated with international travel and trade hubs through services such as pre-travel consultations.

People travelling to countries where yellow fever is endemic – such as Ethiopia, Rwanda, Uganda, Brazil, Peru and Venezuela – need to get vaccinated at least 10 days before the trip to be protected against this mosquito-borne virus.

Returning travellers who are identified at the borders with symptoms of yellow fever will be referred to the hospital, Mr Pream said.

Those who return from places where the disease is endemic and fail to produce a valid yellow fever vaccination certificate can be quarantined in a government quarantine facility, even if they do not show symptoms, he added.

“For yellow fever, they cannot be quarantined at home because it’s a mosquito-borne disease, and we do not want them to have any exposure to the vector,” he said.

Another team under Mr Pream’s charge looks at all the border health measures in terms of policies and strategies to prevent the transmission of diseases into Singapore.

“A lot of the focus will be on our points of entry – the airport, the seaport and land checkpoints, where we can identify cases early and respond (accordingly) to prevent any spread of diseases of concern within Singapore,” he said.

Mr Pream said this is done via the electronic health declaration card, which all incoming Singaporeans and foreigners have to fill in to declare symptoms and travel history.

Passengers who meet certain criteria will be flagged, and immigration officers will help verify if their declaration was wrongly filled. If it is accurate, the traveller will be referred to medical service providers at the borders.

Those who test positive for diseases will be admitted to a medical facility. At the same time, a chain of other responses is triggered, including the disease teams looking at what control measures need to be put in place.

Mr Pream’s team also handles contact and environmental diseases, which include those that are endemic to Singapore, such as melioidosis, a bacterial infection caused by contaminated soil and water; and infectious diseases such as the Ebola and Marburg viruses that are transmitted from bats.

“We look at that aspect from the angle of disease surveillance response,” he said.

The various methods used include analysing data, conducting public health surveillance and monitoring programmes.

These help the agency detect outbreaks early, track disease trends, and inform public health policy and control strategies.

Mr Pream said no one agency was tasked to lead a border health response in a crisis until CDA was set up.

Now, there is a dedicated health agency to steer the nation’s public health defences.

“It benefits us because there’s coherence, there’s leadership that provides (strategic) guidance on what we all need to focus on, albeit public border health, laboratory and surveillance,” he said.

“The next key advantage here is speed, because we are all under one agency now, we do not go through various coordination meetings.

“Under one agency, we can all focus, so from the time when we first detect the disease to response time, we are much quicker,” he added.

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How Singapore prevents yellow fever from spreading in the country

Singapore may not have a single case of yellow fever owing to its stringent measures at its checkpoints, but its risk is real. A mosquito-borne acute haemorrhagic fever, it is transmitted by the Aedes mosquito, the same vector that transmits dengue fever. To prevent the disease from taking root here, the Communicable Diseases Agency (CDA) border health team has taken steps to keep it out.

1. Aedes mosquito

2. Yellow fever vaccine

3. At the borders

If travellers are identified at the borders as having symptoms of yellow fever, they will be referred to a hospital. But if they are asymptomatic and are within the six-day window period, which refers to the maximum incubation period of the virus, they will be quarantined at a government quarantine facility.

Quarantine facilities