Zika Virus: Overview
How is the Zika Virus Spread?
The Zika virus is transmitted to humans by the bite of an infected Aedes mosquito (Aedes aegypti and Aedes albopictus are the common species found locally). A mosquito is infected when it takes a blood meal from a Zika-infected person and later transmits the virus to other people it bites.
What Treatments are Available for the Virus?
There is no known vaccine or specific treatment against the Zika virus. Treatment is directed at alleviating symptoms.
Which are the Vulnerable Groups?
While there is currently no evidence that pregnant women are more likely to get Zika virus infection, the consequences can be more serious if a pregnant woman is infected, as the Zika virus infection can cause microcephaly in a small number of unborn foetus of pregnant women. Hence, pregnant women ought to take added precautions undertaking strict protection against mosquito bites.
Pregnant women who develop symptoms of Zika such as fever and rash should consult their doctors for testing for Zika infection.
Those without these symptoms but who are concerned that they have been infected with the Zika virus should consult and follow the advice of their doctors regarding monitoring of the pregnancy.
Pregnant women should adopt safe sexual practices (e.g. consistent and correct use of condoms during sex) or consider abstinence for at least eight weeks if there is a possibility that their sexual partners may have Zika infection. People diagnosed with Zika should adopt safer sex practices or consider abstinence for at least six months.
Which Countries are Affected?
Sporadic cases of local Zika virus infection have been detected in several countries in Southeast Asia, including Cambodia, Indonesia, Philippines, Malaysia (Sabah), Vietnam, Lao People’s Democratic Republic and Thailand previously. According to Gov.sg, as of 4 May 2018, there are no active Zika clusters in Singapore.
Zika in Singapore
On 28 August 2016, the Ministry of Health (MOH) confirmed localised community spread of Zika virus infection in Singapore. Given that the Zika virus is spread by the Aedes mosquito vector, MOH cannot rule out further community transmission in Singapore, since some of those tested positive also live or work in other parts of Singapore. As such, vector control remains the mainstay in reducing the spread of Zika.
Singapore’s Health Sciences Authority has since June 2016 been working with the National Public Health Laboratory (NPHL) to provide Zika-tested red blood cells to pregnant women who require non-emergency red blood cell transfusions.
It is critical that the community join in the fight by taking immediate action to prevent mosquito breeding with the 5-step Mozzie Wipeout weekly.
Zika and Pregnancy
If a Woman who is Not Pregnant is Infected with Zika Virus, will her Future Pregnancies be At Risk?
Zika virus infection does not pose a risk of birth defects for future pregnancies.
Are There Tests to Determine if a Pregnant Woman is Infected with Zika?
Currently, the only reliable test available for Zika is the reverse transcriptase-polymerase chain reaction (RT-PCR) test which looks for genetic material of the virus in blood or urine. However, RT-PCR test is only able to detect Zika infection in blood within five to seven days of onset of symptoms and in urine within 14 days of onset. Therefore, the time window in which a pregnant woman can be tested using RT-PCR is very small. At present, there is no reliable serological test (which looks for antibodies in the blood) for Zika.
If I am Pregnant and my Male Partner Tests Positive for Zika, do I Need to Get Tested if I Do Not Have Any Symptoms?
If you have had sexual intercourse with your partner, you should consult a doctor and inform him/her of possible exposure to Zika so that he/she can arrange for Zika testing.
If I am Pregnant and Asymptomatic, but Worried About Possible Exposure to Zika, Where Should I Go to Get Tested?
The World Health Organisation’s May 2016 guidelines do not recommend routine Zika testing for asymptomatic pregnant women. If you are concerned, you should discuss this with your doctor.
Should a Woman who is Pregnant get Regular Blood/Urine Tests for Zika, to Make Sure She is Not Infected?
No, unless she has symptoms of possible Zika virus infection (fever and rash and other symptoms such as red eyes or joint pain).
Is it Safe for Pregnant Women to Use Insect Repellent?
Yes, insect repellents sold in Singapore are safe for use for pregnant women.
You can also prevent mosquito bites by wearing long, covered clothing, and sleeping under mosquito nets or in rooms with wire-mesh screens or air-conditioned rooms to keep out mosquitoes.
If I am Pregnant and Have Recently Visited a Zika-affected Area in Singapore, What Should I Do?
There is no need to see your doctor, if you are well. You should continue to take strict precautions against mosquito bites. If you have symptoms of possible Zika virus infection (fever and rash and other symptoms such as red eyes or joint pain), you should seek medical attention immediately, and consult your Obstetrics and Gynecology (O&G) doctor.
If my Female Partner is Pregnant and I Test Positive for Zika, What Should I Do?
You should practise safe sex through the correct and consistent use of condoms, or abstinence, for at least the whole duration of your female partner’s pregnancy.
If I am Pregnant and Live, Work or Study in a Zika-affected Area in Singapore, What Should I Do?
You should take steps to prevent mosquito bites and consult a doctor if you develop a fever, rash and/or other symptoms such as red eyes or joint pain after possible exposure to Zika. You should tell the doctor where you live, work or study.
If I am Pregnant and my Blood Tests Positive for Zika, Will I Need to be Hospitalised and For How Long?
You will be referred to a public hospital for management and followed up by an O&G doctor.
If I am Pregnant and Positive for Zika Virus Infection, Will my Baby Have Microcephaly?
Currently, even if a pregnant woman is confirmed to be infected with Zika virus, there is no test that will predict the future occurrence of microcephaly. We advise that you follow-up closely with your doctor.
If a Pregnant Woman is Positive for Zika Virus Infection, Should She Consider Termination of Pregnancy?
A pregnant patient with confirmed Zika infection will be arranged for admission to a public hospital with a referral to an O&G doctor for further management. Serial ultrasounds and amniotic fluid testing may be considered after the potential risks and interpretation of results are discussed. The termination of pregnancy is a personal choice which should be carefully made by the parents in consultation with their doctor.
Can Mothers with Zika Infection Breastfeed Their Baby?
Zika virus has been detected in breast milk but there is currently no evidence that the virus is transmitted to babies through breastfeeding.
Zika and Microcephaly
What is Microcephaly?
Microcephaly is a congenital condition in which the head size is very much smaller than usual for a baby of the same age, race and sex.
Microcephaly can be caused by a variety of genetic and environmental factors, such as Down syndrome, exposure to drugs, alcohol or other toxins in the womb; rubella and a few other infections during pregnancy.
There is no specific treatment for this condition. Infants with microcephaly showing developmental delay might benefit from early intervention programmes or developmental, physical and occupational therapy, as well as interdisciplinary programmes.
Does Zika Cause Microcephaly?
There is evidence that Zika can cause microcephaly.
What is the Impact of Microcephaly on an Infant?
Microcephaly can be an isolated condition, meaning that it can occur with no other major birth defects, or it can occur in combination with other birth defects. Infants with microcephaly may have concurrent disabilities.
Different symptoms and signals associated with microcephaly (very small head, difficulty feeding, high-pitched crying, fits, stiffness of arms and legs, developmental delays and disabilities, among others) have been described.
Infants with suspected microcephaly should be evaluated by a healthcare professional. In addition to clinical evaluation, neuroimaging tests to evaluate possible structural deformities may be required.
What Exactly Does the Risk of Microcephaly (From Zika Virus) Entail?
As studies are still ongoing, the risk of microcephaly from Zika virus infection is still not clear. Currently, even if a pregnant mother is confirmed to be infected with Zika virus, there is no test that will predict the future occurrence of microcephaly. Close follow-up by healthcare professionals will be required.
Can Microcephaly be Picked up Through Prenatal Screening? If So, What Options are Available to Pregnant Women if it is Detected?
Microcephaly may be picked up during prenatal screening, such as through ultrasound of the foetus. However, not all cases may be picked up in the early stages of pregnancy (i.e. within the first trimester). Some may not be diagnosed until after late in the pregnancy or after the birth of the child. This is similar to other congenital conditions, such as Down syndrome. Similarly, a small head measured on ultrasound does not necessarily confirm the diagnosis of microcephaly. A significant proportion of foetuses with small heads on ultrasound turn out to be neuro-developmentally normal.
If this condition is picked up through prenatal screening, the parents should consult with their healthcare professional on their options.
Can Amniocentesis Tests be Used to Detect Zika Virus Infection in the Foetus?
If the woman is not known to be infected with Zika virus, amniocentesis is not recommended for detecting Zika virus infection in the foetus. If the woman is confirmed to be positive for Zika, the O&G doctor will assess and counsel her on the pros and cons of doing such a test.
I Think my Child’s Head is Smaller than Usual. Does S/he Have Microcephaly?
Having a seemingly smaller head may not mean that your child has microcephaly. Just as importantly, having a small head does not automatically mean that the child will have developmental concerns. The child should be evaluated by a healthcare professional. More tests may be needed to determine if there are any issues of concern.
Can Microcephaly be Treated? What Support can be Provided to a Child Born with Microcephaly?
Treatment and support depend on whether the child has any disabilities and if so, the type and degree of disability. Treatment and support will include rehabilitative measures which may include environmental stimulation, physiotherapy, speech therapy and occupational therapy.
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