SINGAPORE – Singapore has stepped up surveillance of three potentially deadly diseases that have no approved vaccines or antiviral treatments, with medical practitioners required to report all cases to the authorities from Oct 31.
These diseases are Crimean-Congo haemorrhagic fever (CCHF), Lassa fever and Marburg virus disease (MVD).
The Communicable Diseases Agency (CDA) said it has been monitoring them for some time “as all three diseases are viral haemorrhagic fevers that can cause severe illness and have the potential for human-to-human transmission”.
The diseases could have fatality rates of up to 50%, according to the World Health Organization (WHO).
They will be added to the Infectious Diseases Act’s (IDA) list of infectious diseases, following the amendment of IDA and its related regulations in September by the Ministry of Health (MOH).
This means that all medical practitioners such as doctors, as well as clinical laboratories, are legally required to notify the authorities of all confirmed as well as suspected cases.
Although the risk posed by these diseases to Singapore remains low, the latest moves will ensure the nation is prepared to respond when necessary, said a CDA spokeswoman in response to queries from The Straits Times.
The notification of cases will support early detection and a timely public health response, which could include measures such as isolation of cases and activation of contact tracing, she added.
The WHO website states that there is currently no specific treatment or vaccine approved for any of the diseases, though there is ongoing vaccine development for Lassa fever and MVD.
Diseases with high fatality rates
The WHO information showed that fatality rates of the three diseases could go as high as 50%.
CCHF can cause severe viral haemorrhagic fever outbreaks, with a fatality rate of up to 40%.
It is transmitted primarily through tick bites, contact with infected livestock, as well as close contact with the blood, secretions or other bodily fluids of infected people.
There is sudden onset of symptoms, such as fever, muscle ache, dizziness, sore eyes and photophobia (sensitivity to light), as well as sharp mood swings and confusion. Severely ill patients may experience rapid kidney deterioration, sudden liver failure or pulmonary failure.
Lassa fever has an overall fatality rate of 1%, rising to at least 15% for those hospitalised with severe illness.
It is more concerning for pregnant women as foetal death rates can go beyond 80% in the third trimester and maternal death rates can exceed 30%.
The virus is mainly transmitted through food or items contaminated with rodent urine or faeces, and possibly human to human.
About 80% of those infected have no or mild symptoms such as sore throat, muscle pain, nausea, vomiting and diarrhoea.
Severe cases may suffer from facial swelling, fluid in the lung cavity, bleeding from the mouth, nose, vagina or gastrointestinal tract, and low blood pressure.
Even after recovery, up to 25% of patients reported sudden hearing loss, and most of them never regained their hearing.
As for MVD, the virus is transmitted by a type of fruit bat known as rousettus aegyptiacus or between people, and the average fatality rate is around 50%, said WHO.
Symptoms include sudden onset of high fever, severe headache, and muscle aches and pains. Some may experience bleeding from the nose, gums and vagina, as well as confusion, irritability and aggression.
The CDA spokeswoman said: “While there has been no change to the risk level from these three diseases, which currently remains low, they have been added to the IDA to strengthen our overall surveillance and preparedness efforts.”
She reiterated that CDA continuously monitors the global and local infectious disease situation, so as to detect and respond to infectious disease threats early.
“As part of our preparedness efforts, CDA periodically reviews and updates the list of infectious diseases under the IDA to ensure that Singapore remains ready to respond to infectious disease risks,” she said.
Asked whether Singapore’s current border control measures could keep these diseases at bay, she said the measures already cover detection.
These measures include the Electronic Health Declaration card, which requires incoming travellers, including returning residents, to declare their health status and travel history.
Medical assessment is also available at points of entry for travellers who show symptoms and have travelled to specific affected areas.
Number of dangerous infectious diseases rises to 8
The various legislative amendments made by MOH included amending the Second Schedule of the IDA, which pertains to the list of “dangerous infectious diseases”.
With the addition of the three diseases, the list will grow to a total of eight diseases.
The five dangerous diseases currently listed are Ebola, the Middle East respiratory syndrome coronavirus infection (MERS-CoV), plague, severe acute respiratory syndrome (SARS) and yellow fever.
CDA said its weekly bulletin will include the three newly listed diseases from November. The bulletin reports the number of new cases and polyclinic attendances for various infectious diseases in Singapore.
The previous amendment to the Second Schedule was in 2024, when Covid-19 was delisted as a dangerous infectious disease.