Overseas Travel Deferral Criteria
Our priority is always to provide the safest possible blood to all patients in need. Overseas travel to an area with a risk of insect-borne or animal-borne infections can result in infections that may be transmitted through blood transfusion by asymptomatic donors.
Our areas of concern related to infection risks with overseas travel are:
- Chikungunya fever
- Variant Creutzfeldt-Jakob Disease [vCJD or Mad Cow disease]
- West Nile Virus
- Chagas Disease
- Zika Virus
The overseas travel deferral measures that we have adopted are in line with international guidelines and best practices in blood banking. We will continue to closely monitor scientific developments in blood screening that may enable us to review these precautionary measures from time to time.
Chikungunya (CHIKV) fever is caused by Chikungunya virus (of the family Togaviridae) transmitted by Aedes mosquitos. The symptoms of CHIKV infection are similar to dengue fever, with an acute fever lasting 2 to 5 days, associated with prolonged muscle and joint pains.
Click here to learn more about CHIKV.
Theoretically, the virus can spread through transfusion, tissue or organ transplant, although to date, there has been no report of CHIKV infection from blood transfusion. The incubation period (from infection to first symptoms appearing) is usually 3 to 7 days but it can range from 2 to 12 days. There is currently no suitable blood donor screening test available for CHIKV infection.
To ensure our blood supply is free of CHIKV, donors who have travelled to CHIKV endemic regions within the last 2 weeks and have had fever or flu symptoms including joint pain, must not donate for at least 3 weeks upon return.
Click here for the latest list of CHIKV endemic areas.
Malaria is caused by Plasmodia, a parasitic infection transmitted through the bite of an infected Anopheles mosquito. Malaria can also be transmitted by blood transfusion and organ transplants. Click here for more information about malaria. The incubation period for malaria is typically 4 weeks for falciparum malaria, and typically 4 to 8 weeks for vivax malaria.
However, symptoms of malaria (such as fever, vomiting, headache, dark urine) can occur as early as a week after infection and even up to a year after exposure in an area with malaria. Persons who have had malaria can also be re-infected more than once, and can have relapses, depending on the malaria type and treatment.
To ensure our blood supply is free of malaria, we test the blood of donors if they previously resided in a malaria endemic area in the past or visited a malaria endemic area in the past 12 months, since they may have been infected or exposed to malaria. Donors who return less than 4 months from a malaria endemic area will be deferred from blood donation for at least 4 months from the day they left the area. The deferral period enables us to reliably test for malaria in the donated blood as it takes about 4 months for the body to develop antibody after exposure. “The above advice on travel to malaria endemic areas applies only to those who stayed in a malaria endemic area “overnight” (meaning they spent at least one night in a malaria endemic area). Donors who visited a malaria endemic area for a short “day trip” (that is, the visit was only during the daytime) are not considered to be at risk and can donate as per normal (whole blood and apheresis plasma and platelets). Donors are welcome to call the blood bank and speak to our medical staff if they have questions regarding our donor criteria for travel to malaria endemic areas or if they are unsure whether the place you have visited is considered malaria endemic.”
The malaria endemic areas* in the commonly visited countries include:
- Bangladesh (All areas except Dhaka)
- Cambodia (All areas except Angkor Wat, Phnom Penh and Lake Tonle Sap)
- India (All areas except elevated areas above 2,000m)
- Indonesia (All rural areas of Kalimantan, Nusa Tenggara, Sulawesi, and Sumatra; Batam, Bintan, and all areas of eastern Indonesia)
- Laos (All areas except Vientiane)
- Malaysia (All rural areas of Sabah and Sarawak; to a lesser extent in rural areas of Peninsular Malaysia)
- Myanmar (All areas at altitude below 1000m which includes Yangon, Mandalay and Bagan)
- Thailand (All rural areas except the cities of Bangkok, Chiang Mai, Chiang Rai, Koh Phangan, Koh Samui, Pattaya, Phang Nga and Phuket)
- Vietnam (All rural areas except the Red River Delta and cities such as Da Nang, Haiphong, Hanoi, Ho Chi Minh City, Nhra Trang, and Qui Nhon)
First-time donors with a history of malaria, as well as regular donors whose blood are tested positive for malaria, will be deferred indefinitely. Persons who have had malaria may still carry a low level of parasites in their body although they have recovered and display no symptoms.
Donors' blood donations will be tested if they have:
- Visited a malaria endemic area in the last 12 months
- Lived in a malaria endemic area for more than 6 months continuously
For the latest list of malaria endemic areas, please click here.
- Adapted from 2016 CDC Health Information for International Travel (commonly called the Yellow Book)
Variant Creutzfeldt-Jakob disease (vCJD) is a rare but fatal human neurodegenerative condition. As with the Creutzfeldt-Jakob disease, vCJD is classified as a Transmissible Spongiform Encephalopathy (TSE) because of the characteristic spongy degeneration of the brain and its ability to be transmitted.
In contrast to the traditional forms of CJD, vCJD has affected younger patients (average age of 29 years, as opposed to 65 years), and has a relatively longer duration of illness (median of 14 months as opposed to 4.5 months). vCJD is strongly linked to exposure, probably through food, to a TSE of cattle called Bovine Spongiform Encephalopathy (BSE).
Click here to learn more about vCJD.
HSA has adopted the policy of excluding donors from the United Kingdom (UK) and most European countries due to the incidence of endogenous human clinical vCJD (“Mad Cow Disease”) infections and outbreaks of vCJD in their cattle industry.
Donors will not be eligible to donate blood if they have:
- Visited or lived in the United Kingdom (England, Northern Ireland, Scotland, Wales, the Isle of Man or the Channel Island) between 1980 and 1996 for a cumulative period of 3 months or longer
- Visited or lived in France since 1980 for a cumulative period of 5 years or longer
- Received a transfusion of blood or blood components in France or the United Kingdom since 1980
Donors who have lived in other European countries (excluding France and UK) for 5 years or more are advised to donate only plasma via apheresis procedure.
These precautionary deferral measures have been adopted by Singapore as well as many other countries such as the USA, Australia, New Zealand, Japan and Hong Kong. There is currently no reliable screening test for vCJD in the blood. As vCJD has been reported to be transmitted through blood transfusion in at least 3 cases in the UK, we have decided to adopt these stringent precautions in the interests of blood safety for our patients.
West Nile Virus (WNV) is an arthropod-borne virus of the family Flaviviridae. It mainly infects birds, but humans can be infected through the bite of an infected Culex mosquito. The incubation period is about 3 to 14 days. Most of the infected patients are asymptomatic. Some may present as mild fever with flu-like symptoms. Rarely, it may present as meningitis or encephalitis.
Click here to learn more about WNV.
Persons considered to be at risk of WNV infection are those who have travelled to areas with risk of WNV transmission, including Greece, the USA and Canada, in the past 28 days. Hence, donors who have travelled to these countries in the last 4 weeks and have had fever should not donate blood for at least 3 weeks upon return.
Chagas disease is widely endemic throughout Central and South America, and Mexico, where the main mode of transmission is exposure to infected triatomine (or reduviid) bugs. Most infections are asymptomatic or cause non-specific, flu-like symptoms and are not diagnosed. Chagas disease can cause serious complications of the heart and gastrointestinal tract in approximately 30 per cent of infected individuals. Donors who were diagnosed to have Chagas disease are deferred permanently. Since screening tests for donors are not available, donors with an identified risk of Chagas disease should be permanently deferred. Risk factors include:
- Donors born in South America or Central America and Mexico
- Donors whose mother was born in South America or Central America and Mexico
- Those who have received blood transfusion in South America or Central America and Mexico
- Those who have lived or worked in rural subsistence farming communities in South America or Central America and Mexico for a continuous period of four weeks or more
The Health Sciences Authority is taking additional precautionary measures to reduce the risk of Zika virus entering Singapore’s blood supply. Donors who have visited countries with ongoing outbreaks will be deferred from blood donation for 28 days after leaving the area. Currently, the risk of acquiring Zika virus infection through a blood transfusion remains low in Singapore.
Please refer to the table on Ministry of Health website under Countries with Ongoing Outbreaks for the list of affected countries:
Zika virus infection is a mosquito-borne viral infection that is spreading rapidly in many areas such as Central America, South America, and the Caribbean. As Zika virus can be present in the blood of an infected person who has no symptoms of illness, there is concern that Zika virus can be transmitted by blood transfusion.
With this additional deferral criteria, we anticipate a reduction in the number of eligible blood donors. Hence, we would like to urge eligible blood donors to continue to come forward and help patients in need. Donors are also encouraged to either donate before they travel or return for donation after their travel deferral period, to help maintain a healthy blood supply in Singapore.
Thank you for your understanding and support in ensuring a safe and sustainable blood supply for patients in Singapore.