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Pandemics & Epidemics: A Topic & Resource Guide

Dengue and Zika: The Basics

view Zika virus, illustration

"Zika virus is shown in cross section at center left. On the outside, it includes envelope protein (red) and membrane protein (magenta) embedded in a lipid membrane (light purple). Inside, the RNA genome (yellow) is associated with capsid proteins (orange). The viruses are shown interacting with receptors on the cell surface (green) and are surrounded by blood plasma molecules at the top. Transmission of Zika virus is primarily through the bite of an infected Aedes species mosquito. Zika is generally asymptomatic, although some infected individuals may develop symptoms such as fever, rash, joint and muscle pain and conjunctivitis. It is possible for maternal-fetal transmission to occur, which can cause microcephaly and other severe brain defects in the developing fetus."

--Wellcome Collection,, Accessed April 6th, 2021, Creative Commons Attribution 4.0 International (CC BY 4.0),

Dengue and Severe Dengue

Dengue is a mosquito-borne viral infection that is common in warm, tropical climates. Infection is caused by any one of four closely related dengue viruses (called serotypes) and these can lead to a wide spectrum of symptoms, including some which are extremely mild (unnoticeable) to those that may require medical intervention and hospitalization. In severe cases, fatalities can occur. There is no treatment for the infection itself but the symptoms that a patient experiences can be managed....Earlier this year, WHO listed dengue as a potential threat among ten diseases for 2019 and current outbreaks in many countries confirm this observation. Dengue epidemics tend to have seasonal patterns, with transmission often peaking during and after rainy seasons.

---World Heath Organization,   accessed April 24, 2023

ZIKA Virus Disease

Zika virus is primarily transmitted by the bite of an infected mosquito from the Aedes genus, mainly Aedes aegypti, in tropical and subtropical regions. Aedes mosquitoes usually bite during the day, peaking during early morning and late afternoon/evening. This is the same mosquito that transmits dengue, chikungunya and yellow fever...Zika virus is also transmitted from mother to fetus during pregnancy, through sexual contact, transfusion of blood and blood products, and organ transplantation...In October 2015, Brazil reported an association between Zika virus infection and microcephaly. Outbreaks and evidence of transmission soon appeared throughout the Americas, Africa, and other regions of the world. To date, a total of 86 countries and territories have reported evidence of mosquito-transmitted Zika infection....No vaccine is yet available for the prevention or treatment of Zika virus infection. Development of a Zika vaccine remains an active area of research

---World Heath Organization,, accessed April 24, 2023


ZIKA Virus