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As it rapidly spreads, the Zika virus could already be appearing in countries that are popular travel destinations. With summertime coming and international vacationing increasing, this viral phenomenon will meet travelers head-on.
In 1947, in an overgrown tropical forest near Entebbe in Uganda, Zika was first isolated. The Aedes, a genus of mosquitoes, was identified as its carrier. Originally relegated to areas of Africa, Southeast Asia, and the Pacific Islands, a case involving the Zika virus was identified in Brazil in early 2015.
Zika, spread through transmission by these infected mosquitoes, is now appearing in North America. The species Aedes aegypti is one such vector, or transmitter. This mosquito species, found in North America, is active mainly for a few hours before both the rising and the setting of the sun. Yet, even as of early February this year, the Zika virus had become nationally ‘notifiable’ by the Centers for Disease Control (CDC). In the most recent data, from March 30, 2016, cases had been identified in 41 states and in Washington, D.C., including states on both coasts, Hawaii, and inland east of the Rockies.
The Zika virus could be rapidly spreading to locations otherwise thought safe. On April 7, 2016, the Caribbean Public Health Ministry was reported by Reuters to have confirmed two cases in St. Lucia. Neither of the people diagnosed with the ailment were noted to have traveled to any country already affected by the outbreak.
It appears that humans are also now transmitting it to each other. As with other blood-borne pathogens, this virus can be transmitted by transfusion. The CDC has also reported that men can transmit it to their sexual partners through semen. The virus appears to live longer in semen than in blood. How long it stays alive there is subject to additional research. Zika has managed to unite both mosquitoes and humans in its transmission.
The Zika viral symptoms are similar to those of Dengue fever and include headaches, joint and muscle aches, fatigue, and skin rashes. The transmission by mosquitoes puts both Dengue and Zika into the arbovirus category. Both can also both be transmitted by the same Aedes carrier. In addition to these seemingly flu-like symptoms, another possibly more unsettling result of infection by Zika, called microcephaly, may exist.
Microcephaly occurs when the human head at birth is smaller than normal, because the brain has stopped growing as a result of genetic abnormalities. This potential link to microcephaly was discussed in the New England Journal of Medicine. The lack of any cure for it is what makes Zika such a sinister virus and a cause for vigilance in its prevention.
“Mounting evidence supports a link between Zika and microcephaly, and possibly other problems such as miscarriage,” said Dr. Denise Jamieson, co-lead of the Pregnancy and Birth Defects Team of the CDC’s Zika Virus Response Team, during a March 25, 2016, news conference. Such is the nature of this birth defect that Pope Francis, the spiritual leader of an estimated 1.16 billion Roman Catholics, has advised that pregnancy prevention is a “lesser evil” than abortion for women.
Recent preventive guidelines have been established to avoid both mosquito and human transmission. Travelers in areas where Zika has been identified are encouraged to wear long-sleeved clothing and use window screens or netting to keep mosquitoes out. EPA-registered insect repellent has been suggested for outdoor use, or, as an alternative, it is recommended that people stay inside in an air-conditioned environment. Condom usage during sex with pregnant women has been advised.
When traveling to these Zika-identified areas, or when having sex with a person who has recently returned from such a place, prudence and vigilance are the watchwords. Reuters reported that South Korea identified its first confirmed case of the virus during mid-March 2016. The rapid spread of Zika virus could also imperil Olympic athletes and visitors to the games in Rio de Janeiro this summer.
By Bob Reinhard
The New England Journal of Medicine: Zika Virus and Microcephaly
Vatican News: Interview with the Pope on his return flight from Mexico
National Institute of Neurological Disorders and Stroke: Microcephaly Information Page
Centers for Disease Control (CDC): Zika virus disease in the United States, 2015–2016
CDC: Zika Virus Prevention
CDC: Detection of Zika Virus in Semen – Atkinson B, Hearn P, Afrough B, Lumley S, Carter D, Aarons EJ, et al. Detection of Zika virus in semen [letter]. Emerg Infect Dis. 2016 May [March 29, 2016]
CDC: Viral Hemorrhagic Fevers: Flaviviridae
CDC: Transmission & Risks
CDC: About Zika Virus Disease
CDC: Dengue and the Aedes aegypti mosquito
DMC Harper University Hospital – Hutzel Women’s Hospital: CDC Sets New Guidelines on Sex After Zika Exposure
Department of Health and Human Services: Disaster Information Management Research Center: Zika Virus
World Health Organization: Media Center: Zika Virus
State of California Health and Human Services Agency: Aedes aegypti (Yellow Fever Mosquito) Fact Sheet
Reuters: South Korea confirms first case of Zika virus
Reuters: St. Lucia confirms first two case of Zika, contracted locally.
Photo Courtesy of Sanofi Pasteur’s Flickr Page – Creative Commons License