Maternal ZIKA virus infection linked to fetal and placental malformations, apart from Microcephaly.

The World Health Organization has declared the Zika virus an international public health emergency, with a prediction of about four million people being infected at the end of the year.

WHO has issued a travel warning for pregnant women advising them not to travel to areas with continuing outbreaks of Zika virus due to the potential risk of birth defects.

Sexual transmission appears to be more common than previously thought of. "Pregnant women whose sexual partners live in or travel to areas with Zika virus outbreaks should ensure safe sexual practices or abstain from sex for the duration of their pregnancy," the WHO said, based on advice from its Emergency Committee of independent experts.

According to a preliminary report of case series  from Rio de Janeiro, Brazil, published online March 4 issue of the New England Journal of Medicine, ZIKA is also linked to fetal death, placental insufficiency, IUGR and Nervous system malformation.

Dr. Patrícia Brasil, MD, the principal investigator of the study  “our findings provide further support for a link between maternal ZIKV infection and fetal and placental abnormalities that is not unlike that of other viruses that are known to cause congenital infections characterized by intrauterine growth restriction and placental insufficiency.”

In September, 2015 researchers in Brazil identified dengue like fever, which was later identified as ZIKV. In the same month the ZIKV was linked to microcepahy, cases in Brazil rocketed to 3,500 from 147, the average for the same time last year (2014).

The link was first detected when Brazilian health authorities found traces of the Zika virus in a deceased infant born with microcephaly or in amniotic fluid of mothers delivering microcephalic infants.

In the present study, the researchers enrolled pregnant women of any gestation, who presented with a rash that had developed within the previous 5 days. Out of 88 women, 72 (82%) women tested positive ZIKV in blood and/or urine by reverse-transcriptase polymerase chain reaction assays. The researchers followed the women prospectively with clinical examinations and serial ultrasound. All the study participants were generally healthy with no h/o congenital malformations.

Clinically the women presented with a macular or maculopapular rash, pruritus (94%) arthalgia (65%), conjuntival redness (58%). Fever was not a significant symptom with only one third of women reporting it.

All the ZIKV negative as well as positive women had ultrasound. USG showed abnormalities in 12 of ZIKV positive women while those women who are negative showed normal USG.  Sonographically detected abnormalities include:

• intrauterine growth restriction, with or without accompanying microcephaly(5)
• cerebral calcification (4)
• CNS alterations (n = 2)
• Oligohydramnios and anhydramnios (2)
• Abnormal arterial flow in the cerebral or umbilical arteries(4)
• additional malformations, including agenesis of the vermis, Blake’s pouch cyst, and potentially a club foot, in addition to cerebral calcifications, intrauterine growth restriction, and microcephaly(1)

Abnormalities were present in fetuses of women irrespective of there gestational age at ZIKV infection, although those women infected in first trimester show signs of insult during embryogenesis. CNS abnormalities seen in fetuses infected as late as 27 weeks.

Six live births and two still births occurred during the follow up and confirmed the Sonography findings.

The authors suggest that “many aspects of ZIKV infection are similar to those of rubella, particularly rash, arthralgias, pruritus, and lymphadenopathy in the mother without high fever.” But, it is worrisome that there is no population immunity for ZIKV as compared to rubella U.S. pandemic of 1959–1965, when only 17.5% of women of childbearing age lacked rubella antibodies.

In summary the study findings provide support to the hypothesis of link between maternal ZIKV infection and fetal and placental abnormalities. The women infected with ZIKV should be followed up closely with serial ultrasonography to evaluate for signs of placental insufficiency, given the risks of fetal death and intrauterine growth restriction.

References:

http://www.who.int/mediacentre/news/statements/2016/zika-ec/en

http://www.nejm.org/doi/full/10.1056/NEJMoa1602412?query=featured_home#t=articleDiscussion