WHO addresses Zika fears as more microcephaly findings surface

Dengue patient
Dengue patient

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The World Health Organization (WHO) today released a comprehensive backgrounder on Zika virus issues related to childbearing-age women, covering reports of sexual transmission and contraception resources, as researchers promised open data sharing and reported new Zika-related microcephaly findings.

So far this week the number of Zika-affected countries and territories in the Americas has remained stable at 26, but global health officials expect the outbreak to expand, even to parts of the continental United States.

In a risk assessment update earlier this week, the European Centre for Disease Prevention and Control (ECDC) said 21 countries are experiencing increasing or widespread transmission, most of them in the Americas.

WHO urges caution for pregnant women

The WHO, in a question-and-answer backgrounder, said suspicions about a Zika-link to Brazil's rise in microcephaly have raised understandable concerns in women, especially those who are pregnant or considering becoming pregnant.

It addressed many of the breaking developments regarding Zika infections, including another report of sexual transmission. The WHO said more research is needed to pin down how commonly sexual transmission occurs, and in the meanwhile, all men and women living in or visiting Zika-affected countries—especially pregnant women and their partners—should practice safe sex, including correct and consistent condom use.

The agency said it doesn't recommend any travel restrictions, but said pregnant women and those planning pregnancies should determine the risks they are willing to take by keeping informed and consulting with health providers before and after travel.

It advised pregnant women with Zika virus infections to see their health providers, adding that WHO recommendations are under development.

Postponing pregnancy because of microcephaly concerns is a personal decision, but the WHO said women should have access to a full range of contraception options.

Women who are worried enough to consider terminating their pregnancies should be aware that most women in Zika-affected areas will give birth to normal infants, but it added that early ultrasound doesn't reliably predict microcephaly except in extreme cases. Those who opt to end their pregnancies should have access to safe options, accurate information, and counseling to the extent possible under national laws, according to the WHO.

Abortion issues related to Zika virus came up during a US House committee hearing today, when some Republican lawmakers asked Tom Frieden, MD, MPH, director of the Centers for Disease Control and Prevention (CDC), whether any of President Obama's requested $1.8 billion in emergency funds would go toward the procedure, Stat news reported. He assured legislators that wouldn’t happen.

An open research declaration

Thirty-three of the world’s major medical groups and journals signed a statement committing to open data sharing in Zika virus and future public health emergencies, according to a statement today posted on the Wellcome Trust Web site. Signatories include the CDC and the National Institutes of Health (NIH).

The group said the statement is designed to ensure that information useful for battling the Zika virus outbreak is shared with the international community free of charge as soon as possible. Several of the signatories were medical journals, which are assuring researchers that early release of findings won't preclude subsequent journal publication.

Jeremy Farrar, MD, PhD, the Wellcome Trust's director, said in the statement that research is a key component of any global health emergency, especially with all the questions surrounding the Zika virus. "It’s critical that as results become available they are shared rapidly in a way that is equitable, ethical and transparent," he said. "This will ensure that the knowledge gained is turned quickly into health interventions that can have an impact on the epidemic."

The WHO on Feb 4 put out a call for open data sharing regarding Zika research and has established a portal for submissions and publication on its home page. Six papers have already been posted on the site.

More Zika detections in microcephaly

In new Zika research developments in other publications, Brazilian scientists and their collaborators at the CDC reported evidence of Zika virus in brain and placental tissue from two babies born with microcephaly who died soon after birth and two early-pregnancy miscarriages. The team published its findings in an early online edition of Morbidity and Mortality Weekly Report.

In all four instances the mothers had clinical signs of Zika infection during the first pregnancy trimester. Test methods included an assay the CDC developed for tissue testing. The tests showed viral RNA and antigens in brain tissue from the microcephalic infants and in placental tissues from the early miscarriages. Researchers concluded that brain and early gestational placental samples might be the best tissues for postmortem viral detection.

In a separate report, Slovenian researchers reporting in the New England Journal of Medicine today described microcephaly and Zika virus findings in the brain tissue of a fetus examined after a woman with a suspected earlier infection requested that her pregnancy be terminated.

The woman was in Brazil doing volunteer work and got pregnant in February 2015; she got sick with Zika virus symptoms during her 13th week of gestation. Her initial ultrasound in Brazil was normal, but a follow-up at 29 weeks gestation after she returned to Europe showed abnormalities.

The next ultrasound showed several abnormalities, including evidence of microcephaly and brain calcifications. Based on the prognosis, the woman requested that her pregnancy be terminated. On autopsy, reverse-transcriptase polymerase chain reaction testing and electron microscopy confirmed Zika virus in brain tissue.

The researchers said the virus wasn't found in other fetal organs, which raises the possibility of strong neurotropism of Zika virus.

In an accompanying editorial, three Boston-based experts wrote that the findings don't constitute absolute proof that Zika virus causes microcephaly, but when rare, devastating, and untreatable illness manifestations surface, clinicians must rely on a combination of scientific and epidemiologic evidence. "And the evidence in this case report makes the link stronger." 

See also:

Feb 8 ECDC updated Zika virus risk assessment

Feb 10 WHO Q and A on women's issues regarding microcephaly and Zika infection

Feb 10 Stat news story

House committee hearing background materials

Feb 10 Wellcome Trust Zika virus data sharing joint declaration

WHO Zika virus data sharing portal

Feb 10 MMWR report

Feb 10 N Engl J Med case report on Zika virus and microcephaly

Feb 10 N Engl J Med editorial

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