Welcome to this month’s High Five at Altmetric. On a monthly basis, my High Five posts examine a selection of the most popular research papers Altmetric has seen attention for that month. This month, we are paying special attention to research papers on the topic of Zika.
An Emerging Zika Pandemic
“The Zika virus (ZIKV), a flavivirus related to yellow fever, dengue, West Nile, and Japanese encephalitis, originated in the Zika forest in Uganda and was discovered in a rhesus monkey in 1947.” – Lucey & Gostin, 2016
Our first High Five paper is a viewpoint published in the Journal of the American Medical Association in late January, 2016. Daniel Lucey and Lawrence Gostin write that Zika “now has ‘explosive’ pandemic potential, with outbreaks in Africa, Southeast Asia, the Pacific Islands, and the Americas.” The virus is spread by the Aedes species mosquito.
“Zika virus infection usually is asymptomatic or causes mild illness, such as fever, rash, muscle/joint pain, and conjunctivitis; severe disease and fatalities are uncommon. Health authorities, however, are investigating severe clinical manifestations, including neurological and autoimmune-like illness, particularly Guillain-Barré syndrome (GBS) and congenital neurological malformations. Most concerning is a possible association between Zika virus and microcephaly in Brazil and, retrospectively, in French Polynesia.” – Lucey & Gostin, 2016
The viewpoint was picked up by over 100 news outlets and shared hundreds of times on social media this month.
“Public health officials are particularly worried that Zika leads to a condition known as microcephaly, in which infants are born with abnormally small heads and damaged brains. Although researchers have not conclusively identified Zika as the cause, the number of babies born in Brazil with microcephaly has risen sharply along with the spread of the virus.” – Kate Thomas, New York Times
Zika Association with Microcephaly
Our next High Five paper and one of the most popular research papers according to Altmetric data this month was a brief report published on February 10 in the New England Journal of Medicine, “Zika Virus Associated with Microcephaly.” Over 60 news outlets picked up the report. The report also received thousands of mentions on Twitter and other social media sites.
The New England Journal of Medicine article presents a case report of a 25-year-old previously healthy European woman who presented with high fever, musculoskeletal pain and a rash while pregnant. Ultrasound tests later revealed fetal microcephaly (a head circumference below the second percentile for gestation) and brain disease. Following a termination of the pregnancy at the mother’s request, researchers discovered remnants of Zika virus in a fetal brain sample.
“This case shows severe fetal brain injury associated with ZIKV infection […] Recently, ZIKV was found in amniotic fluid of two fetuses that were found to have microcephaly, which was consistent with intrauterine transmission of the virus.” – Mlakar et al. 2016
“Researchers have, for example, been able to recover the entire Zika virus genome (about 11,000 bases long) from the brain tissue of an aborted fetus with microcephaly; using electron microscopy, they could also see virus particles in the brain. […] This one case report doesn’t prove anything, but it does associate the presence of the virus with microcephaly, and is strong evidence that it can be transmitted across the placenta.” – Sim Shuzhen, Asian Scientist Magazine
Donald McNeil Jr. writes for New York Times:
“Researchers in Brazil are investigating thousands of reports of microcephalic births. While there is no solid proof that Zika virus is the cause, virologists studying the outbreak strongly suspect it.” – Zika May Increase Risk of Mental Illness, Researchers Say
Detection of Zika Virus
Other Zika-related research reports popular in the media this month according to Altmetric data include our next two High Five papers on the detection of Zika virus. In a Feb. 2016 Lancet Infectious Diseases article, “Detection and sequencing of Zika virus from amniotic fluid of fetuses with microcephaly in Brazil: a case study,” researchers document the detection and sequencing of a Zika virus genome in the amniotic fluid of two pregnant women whose fetuses were diagnosed with microcephaly. They write that these findings “strengthen the putative association between Zika virus and cases of microcephaly in neonates in Brazil.” In a Jan. 2016 article published in the Journal of Clinical Virology, researchers report an increased rate of Zika virus detection using saliva samples compared to blood samples. They write that the saliva-based detection method may be preferred when blood is difficult to collect, for example with sick children and newborns.
Both research reports were picked up by dozens of news outlets, while hundreds of users mentioned the amniotic fluid detection case study on Twitter and Facebook. Business Insider headlined “Scientists just found another critical piece of evidence that links Zika to a disturbing birth defect.”
“The findings still do not prove that Zika causes babies in the womb to develop microcephaly – a condition resulting in small heads and potential neurological damage – but it makes the link increasingly plausible.” – Sarah Boseley, The Guardian
- Why It’s So Hard To Prove Zika Is Causing Birth Defects, by Christie Aschwanden, FiveThirtyEight
- What we need to find out about Zika and pregnancy, by Wellcome Trust
- How Much Do We Really Know About the Relationship Between Zika Virus and Birth Defects? By Francie Diep, Pacific Standard
Transmission of Zika – Not Just Mosquitoes
Our final High Five paper, published in JAMA Ophthalmology in Feb. 2016, presents findings of ocular (related to the eye) abnormalities, lesions for example, in infants with microcephaly with a presumed diagnosis of congenital Zika virus. Based on the observational study, the researchers conclude that “[c]ongenital infection due to presumed ZIKV exposure is associated with vision-threatening findings, which include bilateral macular and perimacular lesions as well as optic nerve abnormalities in most cases.” Over 50 news outlets mentioned the study.
The New York Times headlined, “Study in brazil links Zika virus to eye damage in babies.”
“The study described damage to the retina or optic nerve in 10 of 29 newborns examined at Roberto Santos General Hospital in Salvador, Brazil. All the infants were presumed to have been infected with the Zika virus and had small heads, a condition called microcephaly. Other causes of the defect, like infection with rubella or toxoplasmosis, were ruled out.”
The New York Times article does acknowledge important limitations of the study, including a small sample from only one hospital. But researchers like Dr. Rebecca Christofferson, an assistant professor who studies infectious disease transmission including transmission of Zika virus at Louisiana State University, are quicker to point out that more research is needed to characterize not only the link between Zika infection and microcephaly, but basic characteristics of the virus itself and its transmission cycle.
I asked Christofferson what Zika research papers she had seen get big media play in the last few months and if there were other research papers she thought the media should instead be focusing more attention on.
“Until this outbreak, there wasn’t much out there about Zika compared to other similar pathogens,” Christofferson wrote in an e-mail correspondence. “One thing that has surprised me is the seeming lack of retrospective literature study. For example, it was frustrating that sexual transmission was touted as a new phenomenon when there were two compelling studies out there that supported this (Musso 2015, Foy 2011).”
“The headlines from the media, and sometimes the content of the articles themselves, make it seem like the scientific field has reached an evidence-based consensus on Zika virus. This is not the case. The disconnect is that the scientific community is scrambling to be able to investigate this virus and the outbreak (often relying on funding mechanisms that often take months) and results are coming slowly (with the exception of case reports). The media, however, presents these breadcrumbs, sometimes out of proportion, so it can seem like we are learning much more, much faster than we are.” – Dr. Rebecca Christofferson, E-mail Q&A
Christofferson says that while the link to microcephaly and the risk to unborn children should be investigated, there is also a need for basic virological studies characterizing this virus, such as which mosquitoes can carry the virus and how sexual transmission contributes to the whole transmission cycle of the virus.
“Most of what is coming out from this outbreak so far are case reports and observational studies that, while important and informative, cannot tease apart the other potentially confounding factors associated with this outbreak,” Christofferson wrote. “While very much needed, the basic research that can answer many of these questions takes time to do. So the basic research is still in the pipelines, but I hope the media tunes in to see what I and other laboratories can discern in the near future.”
How will media coverage of Zika research play out in the coming months and years? Will basic virological studies receive the same attention as case studies on the potential association of the virus with microcephaly?
Upcoming webinar: examining the recent resurgence of Zika research
Wednesday April 20th, 3pm GMT
The recent outbreak of the Zika virus has led to an intensification in the publication and real-world use of the related research data. In this webinar, Ben McLeish shows how altmetrics indicators have made it possible to quickly identify and monitor these developments. Ben will discuss how old articles on mosquitos have resurfaced with a new and distinct level of attention, and how new research in 2016 has been picked up rapidly, sometimes within days or weeks, within policy documents authored to fight the Zika outbreak.