The Zika virus is causing international concern due to its rapid spread across the globe and potential connection to a microcephaly, a neurological birth disorder. According to World Health Organization (W.H.O.), the aggressive daytime biting Aedes aegypti mosquito has transmitted the virus to over 29 countries. W.H.O. has declared it a “public health emergency of international concern” and has suggested pregnant women not travel to countries already affected by the virus.
Zika virus belongs to the same flavivirus family as dengue, yellow fever and West Nile, but has many unique qualities that set it apart from its flavivirus counterparts. It is not an airborne virus, so it cannot spread like the common cold. However, Zika virus can stay in the blood stream for up to a week, during which it can be spread through blood transfusions and sexual contact. Infected individuals exhibit relatively mild symptoms including fever, muscle pain, red eyes and skin rash.
Zika has come into the spotlight due to an alarming connection between its outbreak and a drastic increase in microcephaly. Microcephaly is a complex neurological disorder that causes newborns to be born with abnormally small heads. The infection rate of Zika in Brazil has increased and the rate of microcephaly in regions of infection has skyrocketed as well. Though the increase in microcephaly and infection rate of Zika could be coincidental, there has been
Zika virus found in the umbilical cord blood of fetuses, indicating that Zika virus is capable of vertical transmission through the mother to the fetus.
A company in India had been working on developing a vaccine for Zika virus even before the outbreak occurred. Now, due to the W.H.O.’s recent announcement regarding Zika virus, the race is on to develop a vaccine for this virus.
“A vaccine tries to create an inert substance that cannot propagate that will then activate appropriate cells against the virus and hopefully intercept it at the correct point in its cycle,” Duane Sears, immunology professor in the Molecular, Cellular and Developmental Biology Department, said.
Though there has been little research conducted on how the Zika virus causes microcephaly, Sears has a possible explanation.
“There is a newly discovered lymphatic route in the brain, and it would be interesting to know whether that is the way the virus [gets into the brain]. Presumably, the virus is affecting something in the neural tissue development in the brain and knowing how it gets there is going to be the key so [the vaccine] can intervene the process by targeting the structure in the virus that is critical for transfer for one place to another,” Sears said.
Genetically modified male Aedes aegypti mosquitos, called OX513A, and dubbed “mutant mosquito” by critics, pass down a lethal gene that causes its offspring to die. Females only mate once, so this genetic modification is used to slow down the population growth of mosquitos. Field trials of OX513A in Brazil have been seen to be hugely successful in reducing the target population to below the level needed to transmit disease. This technology is still being researched in order to combat Zika virus.
Though the spread of the Zika virus has been devastating in Brazil, officials do not predict that the virus will have a significant effect in the United States. Sports Illustrated reported that the Director of the National Institutes for Allergies and Infectious Diseases at the National Institutes of Health stated, “there will be some unfortunate cases, but nothing of the magnitude that the poor Brazilians are going through.”
All people in the United States affected by the virus have traveled to Brazil or another affected area, or have had sexual contact with someone who was infected. The United States does not have a history of spreading mosquito-borne viruses as rapidly as other countries, mostly due to difference in climates. Mosquitos thrive in tropical areas, and they tend to dislike cooler temperatures. Due to the cooler temperatures in much of the United States, the number of mosquitos is lower, so there is less of a chance of the spread of Zika virus. Another factor in the lack of mosquito borne illnesses is the population density in the United States is much lower than in Brazil, so people tend to live further apart from each other. An infected mosquito cannot bite as many people in a short amount of time.
As of right now, many people are concerned with how the outbreak of Zika in Brazil will impact the upcoming Olympics in Rio de Jeneiro. Thus far, the International Olympic Committee president, Thomas Bach, is not expecting the virus to cause any significant issue with the Olympics.
A version of this story appeared on p. 14 of the Thursday, Feb. 18 print edition of the Daily Nexus.
Interesting that a vaccine was already in the works. Why is this virus causing so much trouble suddenly if its been around awhile? Nice article.