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Zika is a virus from the same genus as dengue fever (Flavivirus). It is transmitted by the mosquitoes Aedes aegypti and A. albopictus, present in tropical and subtropical regions around the world, and has attracted attention after a 2015 and 2016 outbreak in the Americas.
The Zika virus was first isolated in Africa in 1947, but the first known human infection was in Federated States of Micronesia on Yap Island in 2007. It has probably arrived in Brazil during the 2014 World Cup, brought by a tourist. Due to the abundance of the Aedes mosquito, it has found fertile ground and spread through the continent.
While Zika virus has mild symptoms, many times not experienced at all, it is thought to be related to birth defects such as microcephaly, which causes babies to be born with small heads. The disorder may lead to developmental delays and intellectual deficits, although damage may be reduced with early stimulation.
The evidence for Zika causing birth defects comes from the surge of microcephaly in babies whose mothers were infected by Zika in 2015 and 2016. In previous years, there were around 150 cases of microcephaly, a number that soared to thousands after the outbreak. Since the virus gained notoriety recently, it is not yet scientifically known how Zika infects the fetus. Its mechanism is still being studied and some discoveries have already been made, such as the presence of the virus in the placenta, identified by Brazilian researchers in January 2016.
El Salvador has advised women to not get pregnant until 2018, but at the same time offers no family planning to its people, imprisoning women for miscarriages. Many of the Latin American countries do not allow abortions, leading to a debate whether it should be legalized for microcephaly cases, following a recommendation from the United Nations. As of 2016, Latin American Catholic bishops have begun to reiterate their opposition to birth control and abortion in all cases. Bishop Leonardo Ulrich Steiner, the secretary general of the National Council of Bishops of Brazil, instead urged couples to use
Vatican roulette natural family planning.
Although mainly spread by the Aedes aegypti mosquito, it is probable that Zika is sexually transmitted. In 2008, an American biologist contracted the disease after studying mosquitoes in Senegal and transmitted it to his wife after unprotected intercourse. Since then, the virus has been found in semen and new cases of sexual transmission were registered in 2016. Both sexual and human-to-human blood transmissions have been reported.
Furthermore, Zika virus was found by Brazilian researchers in other body fluids, such as saliva and urine.
Since its outbreak, Zika virus has been the subject of conspiracy theories. One of them claims microcephaly is caused not by Zika virus, but by the rubella vaccine. However, this vaccine is contraindicated for pregnant women and thus was never distributed to them. Moreover, there is no link between vaccines and microcephaly.
Another conspiracy theory blames genetically modified mosquitoes for causing the Zika outbreak. Not only is this far from the truth, it's the polar opposite of the truth. Defective male GM mosquitoes were released in some regions of Brazil in order to decrease the Aedes aegypti population. These males contained genes that, without laboratory conditions, could only produce male offspring. The males would mate with wild females, and the next generation would be virtually all male, and there would be little third generation. For those that weren't aware, male mosquitoes don't bite. Other mosquitoes were released carrying the Wolbachia bacteria, which makes them unable to spread diseases.
- Gilda Grard, et al. "Zika virus in Gabon (Central Africa) – 2007: A new threat from Aedes albopictus?" PLOS Neglected Tropical Diseases 6 February 2014;8(2):e2681. doi: 10.1371/journal.pntd.0002681
- Zika Virus Outbreak on Yap Island, Federated States of Micronesia by Mark R. Duffy, et al. (2009) N. Engl. J. Med. 360: 2536-2543. DOI: 10.1056/NEJMoa0805715.
- Catholic Leaders Say Zika Doesn’t Change Ban on Contraception by Laurie Goodstein (Feb. 13, 2016) New York Times.
- Zika virus Centers for Disease Control.