Zika Virus: An International Public Health Emergency

mosquito

Some researchers believe that one out of every two human beings to have ever lived on planet gearth was killed as a result of the lethal effect of Malaria. Once contracted, the parasite (Plasmodium falciparum) can cause anemia, hypoglycemia, or cerebral malaria, leaving the victim subject to an almost certain death if left untreated. Transmitted by the mosquito, Malaria is undoubtedly one of the most detrimental diseases on the planet, despite that fact that it is now highly preventable with use antimalarial medicines and mosquito nets. In 2015, an estimated 438,000 deaths were as a result of Malaria contraction, and this, by many, was seen as a noteworthy victory as these figures illustrate a 60% reduction in Malaria mortality rates since 2000, although there is still a long way to go.

However, with the optimistic news comes devastating new observations from the victims of a rapidly spreading mosquito-borne virus named Zika.

With the first isolated case identified in the Zika forest, Uganda, the Zika virus has always been present, with regular cases being reported in Africa and Asia. Spread by the common Aedes mosquito, the virus had never been recorded in the Western Hemisphere as of 2013. However, last May (2015) is when the virus is said to have began spreading rapidly in this region following the first outbreak in Brazil, South America.                                             With an incubation period that could vary between about 3-12 days, it has been thought that the virus poses no severe risk to victims, as an infected person typically illustrates very mild symptoms, with 80% of infected people demonstrating no symptoms at all.

This viewpoint has been dramatically changed following the most recent statistics in relation to pregnant victims of the virus, with data that has left scientists darting for as much information about the virus as possible.                                                                       In 2014, there were about 150 recorded cases of babies born with microcephaly in Brazil, while in 2015, almost 4,000 mothers bore children diagnosed with the condition in the country. The possibility that the Zika virus in pregnant women leads to  the birth of newborns with microcephaly emerged in October when a surge in babies with the condition was noted after the majority of women who bore infants that had the condition illustrated presence of the Zika virus in their RNA. Although it must be noted that other factors may be contributing to the rise as well as the fact that the number of reported cases increases when more people are alerted to a potential health crisis. However, as of now, evidence suggests the number of pregnant women infected with the Zika virus correlates with the number of microcephaly cases and this has been declared as a public health emergency of international concern (WHO, 1/02/16).

data

A condition that causes an infants head to be relatively smaller than expected, the congenital disorder sees many babies miss most of their development goals that track healthy progress, illustrating that children with the condition have brains that have not developed effectively in the womb. The possibility that the Zika virus could be causing a rise in this condition is harrowing enough to lead health officials to warn women in the affected areas not to conceive for the time being.

Leading scientists and researchers in Britain form the organisation ‘Oxitec’ and they are a company that has developed a genetically modified line of the Aedes Aegypti mosquito, the mosquito species that carries dengue fever, chikungunya as well as the Zika virus. The company plans to release genetically modified mosquitoes in Brazil in the wake of the severe concern over the zika virus and its probably detrimental effect. It would be a programme in which Oxitec would release genetically modified male mosquitoes into the wild, where the male mosquitoes would mate with females, leaving the females capable of laying eggs that would hatch larvae which would die before adulthood. Trials illustrate that this would supposedly reduce the wild Aedes population in Brazil by about 90%. However evidence suggest that it would be an ineffective project as large measures would need to be taken to ensure that there is a sufficient amount of GMO mosquitoes to be released, in order to ensure that the genetically modified trait is spread widely throughout the wild mosquitoes population in Brazil in order for the project to work productively and to prevent the gene from fading in the population of mosquitoes.

A more effective and advanced research project in progress is the CRISPR gene drive programme in which a new gene preventing the transmission of a virus would be inserted into the mosquitoes genetic sequence. The gene would then code for the production of an enzyme that is able to effectively identify unmodified copies of the gene and so when the modified chromosome pairs with an unmodified chromosome, the enzyme is able to target the unmodified section and clip it out of the gene sequence, leving the cell to repair the chromosome using the modified chromosome as a template. In this way, each mosqitoes holding the gene will have two copies of it and therefore effectively pass the gene on to its offspring without the risk of the gene disappearing from the wild mosquito population. Although presenting a highly effective and promising possibility, the CRISPR gene drive modification programme, as well as Oxitec’s genetically modified line of the Aedes, as powerful and impatful programmes, erect uneasiness around the virtue and ethics of the plans.

Would it be right for whole populations of mosquito to be genetically modified by us, altering the natural and original sequence of a the Aedes mosquito genome? Or are we just hurtling into new, unfamiliar and precarious territory? Could wiping out the majority of the Aedes population with Oxitec’s programme be seen as a heinous and destructive act in hindsight, with devastating effects that we are currently unaware of? It is impossible to forecast the effects of releasing genetically modified mosquitoes into the wild population. Currently, the present is the most perceptible thing to us, and with the spike in microcephaly cases and no available vaccine against the Zika virus, the choices we make as a society are momentous.

 

Sources:

http://www.cdc.gov/zika/

http://www.youtube.com/watch?v=JUlGN5XJ5dc

http://bit.ly/1POrNjA

http://www.youtube.com/watch?v=rNEPTxWNadg

http://bit.ly/1Q4LPAt

http://nyti.ms/1POs4Dd

http://n.pr/1nxV5WX

http://to.pbs.org/1PK4D7I

http://bit.ly/1WVJkWI

http://bit.ly/23CkEaf

 

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