The Zika virus outbreak has caught the world’s attention specifically the chances of developing fetal microcephaly in pregnant women infected by the virus. The Zika virus comes from the family of Flavivirus’s and until very recently was thought to be mosquito born by a very specific type of mosquito called Aedes aegypti which can be found in the Pacific Islands, Latin America and in the USA.
The majority of patients infected with Zika virus remain asymptomatic.
A few develop mild flu-like generalised symptoms including fever, mayalgia, arthralgia a rash, possibly conjunctivitis. The disease usually abates in a week and hospitalisation or deaths are almost unheard of.
There has been limited data in pregnancy however since the outbreak health organisations throughtout the world are tripping over themselves trying to gauge as much as they can about the virus. There is conclusive evidence that pregnancy does not predispose a women to infection and that pregnant women do not become more unwell with the infection. It is however apparent that vertical transmission from mother to baby does occur during pregnancy and the number of cases of microcephaly in mothers who have been infected by the Zika virus is extremely high.
This has led to the US Centers for Disease Control and Prevention (CDC) to put together guidelines for the care of pregnant women during the current Zika virus outbreak.
The guidelines were published online on January 19 and appeared in Morbidity and Mortality Weekly Report, on 22 January, and followed a travel alert issued by the CDC. They advised that “who are or might become pregnant not to travel to 14 countries and territories in Central and South America and the Caribbean”.
A full list of countries where you might be at risk can be found here.: Areas with Zika
The advice of is that women contemplating a pregnancy should not travel to areas where Zika virus transmission is ongoing. Those who report such travel and experience fever, rash, muscle aches, or conjunctivitis during or within 2 weeks of travel should be tested for Zika virus infection, Maternal serum from symptomatic women can be tested using reverse-transcription polymerase chain reaction (RT-PCR) within 1 week of symptom onset. Antibody testing is not recommended 4 or more days after symptom onset, as there can be cross-reactivity to other flaviviruses (eg, dengue or yellow fever). Amniotic fluid can also be tested using RT-PCR, but the sensitivity and specificity are unknown at this time.
There is no currently commercial test available. Specimens have to be sent to Wellington for testing.
Recommendations include growth scans on a regular basis specifically checking for fetal growth and microcephaly.
Treatment recommendations include general symptomatic measures that are safe in pregnancy. As yet there is no effective antiviral treatment of the Zika virus.
It is expected that because of the frequency of travel between the Pacific Island and New Zealand that we are likely to see an increased amount of infections amongst travellers returning to New Zealand. At present it is not certain if transmission is on mosquito born but there is some suggestion that there may be human to human transmission as well.
According to the CDC, “During the current outbreak in Brazil, Zika virus RNA has been identified in tissues from several infants with microcephaly and from fetal losses in women infected during pregnancy”. Although there has been a significant number of babies born with microcephaly in Brazil, there has been no conclusive evidence that these cases have been associated with Zika virus infection and whether there is anything that might increase the risk to the foetus.
Studies are being commenced as a matter of urgency worldwide to determine more about the risks of a Zika virus infection during pregnancy. Of note is the fact that the the Zika virus may also be associated with Guillain-Barré syndrome.
We also need to be aware that a number of our high profile athletes as well as supporters will be travelling to Brazil during the 2016 Olympics and will need to be screened on their return and advised appropriately before travel.
The CDC has now issued a statement in its list of interim guidelines, that men with a pregnant partner should use a condom or abstain from sex if they have visited, or live in an area considered high risk for the Zika virus. These guidelines do not cover kissing only Penetrative sex.
This is based on evidence from only 3 cases, 1 of which a patient in Dallas Texas, contracted the Zika virus from a partner who had just returned from a known Zika area. The virus has been isolated from semen at least 2 weeks and up to 10 weeks after the onset of the illness. There is insufficient data on Urine and Saliva for any comment to be issued.
About the author – Naylin Appanna is a Gynaecologist with a special interest in Advanced Laparoscopic (Keyhole) surgery and Endometriosis. His philosophy is to create an educational environment to help patients understand their conditions and make informed decisions about their management. He has a number of educational videos on his website which are used by patients, Family doctors, nurses and educators.