A closer look at Zika

RoossinckThroughout Latin America and the Caribbean, Zika has been a reality for months, and now the continental United States is beginning to feel the impact. Given the potential for devastating birth defects, concern about rampant spread of the disease has been significant in recent months. Many experts now say Zika probably won’t spread in Rio this month, and transmission in the U.S. is likely to be offset by mosquito control. And yet, much remains unknown about the disease.

In Virus by Marilyn J. Roossinck, forthcoming later this month, the Zika virus is described as a linear, single component, single-stranded RNA of about 11,000 nucleotides, encoding ten proteins via a polyprotein. It is in the flaviviridae family and the flavivirus genus and tends to proliferate in tropical and subtropical climates south of the equator. Transmitted via mosquitos, it finds hosts in humans and other primates. Associated diseases include a mild fever and rash, with possible links to microcephaly and Guillain Barre syndrome. We do not yet have a vaccine.

Zika was first discovered in a Rhesus monkey and in mosquitos during routine surveillance of the Zika forest of Uganda in 1947 and 1948. The first human case of Zika was described in 1952, and over the course of the next few decades cases were seen in parts of central Africa, and later in Asia. Zika reached Brazil in 2015.

In the image below, Zika virus particles are in infected cells, viewed via transmission electron microscopy. The structured virus particles are colored in blue. Like other related viruses, the membrane proteins form a geometric structure.


Zika, p. 95

Virus by Marilyn Roossinck takes the reader on a fascinating journey through the history and current research on known viruses from around the world.

Marilyn J. Roossinck is professor of virus ecology in the Department of Plant Pathology and Environmental Microbiology at Pennsylvania State University. She lives in Bellefonte, Pennsylvania.