Editor’s note: This story has been updated since it was originally published on January 29
Zika virus was a dark disease until recently, especially in the Americas. But now it has “spread explosively” throughout the New World, according to the World Health Organization (WHO) has declared an Zika global public health emergency .
Zika could infect up to 4 million people by the end of 2016, according to the director general of wHO, Margaret Chan, who says the virus has been “a slight threat to one of alarming proportions.” Although Zika has been known to science for seven decades, it is only now seen as a major threat to public health because of its relationship with birth defects and other serious health problems.
The sudden outbreak of the Zika America has left many governments struggling to catch up – and many people ask what they can do to prevent the virus. Following are brief answers to some of the most vital issues and irritants, about Zika are presented:
The Zika virus was discovered in a small forest of Uganda ago almost 70 years. (Photo: Rod Waddington / Flickr)
Where do Zika?
Zika is a flavivirus related to the virus behind the yellow fever, dengue fever, West Nile encephalitis and Japanese. It is named by Zika Forest in Uganda, where it was first identified in a monkey in 1947. It is endemic to Africa, and is likely to spread to Asia 50 years ago, but for decades only sporadic human cases were reported.
the first documented Zika outbreak occurred in 2007, on the island of Yap in the Federated States of Micronesia. The virus then spread to other islands in the South Pacific, helped by the lack of immunity among the population of that region. more than 30 other countries and territories and
[19459017-ItwasconfirmedforthefirsttimeinBrazilinMay2015andsincethenithasspreadrapidlythroughoutthecountry] Aedes aegypti mosquitoes are the main vector for the Zika virus. (Photo: Luis Robayo / AFP / Getty Images)
How is it spread?
Zika is transmitted by infected Aedes mosquitoes as Aedes aegypti and Aedes albopictus , also known as Asian tiger mosquito. These two species evolved in Africa and Asia, respectively, but are now common in warm, humid climates worldwide. They often live near buildings in urban areas and are usually active during the day, with a peak biting periods in the early morning and evening.
The virus can also be transmitted from a pregnant mother her baby during pregnancy or around the time of birth, according to the US Centers for Disease Control and Prevention (CDC), although it is not clear how often that happens. It is suspected spread through blood transfusion and sexual transmission , too; the latter is allegedly responsible for the first case US Zika transmission .
What are the symptoms?
Only one in five people infected with Zika virus will get sick, according to the CDC , and even then the symptoms are usually mild. Common symptoms include low-grade fever, rash, joint pain, headache and conjunctivitis. The incubation period of Zika is typically two to seven days, which means symptoms should appear within a week of the bite of an infected mosquito.
Hospitalization is rare, but Zika can still be dangerous in ways that are not immediately obvious. It has been associated with the syndrome Guillain-Barre syndrome , for example, an immune disorder that can cause paralysis. A study published in February 2016 strengthened the link, finding that 39 people in French Polynesia developed Guillain-Barre syndrome within six days after a Zika infection. That makes it “the first study that provides evidence of Zika virus infection causing Guillain-Barre syndrome,” the authors write in the journal The Lancet.
How babies affected?
After 2015 the arrival of Zika in Brazil, doctors began to notice an increase in cases of microcephaly , a birth defect It characterized by a head undersized and incomplete brain development. Brazil typically has about 150 reports of microcephaly per year, but the country is now investigating nearly 4,000 cases from 2015 to 20 times the normal amount. The connection is not widely reported until October, and since then the prospect of microcephaly Zika has become so feared diseases much more deadly.
This association is not yet well understood, and scientists can not say with certainty whether Zika causes of microcephaly. The increase in cases is certainly alarming, but microcephaly can be caused by a wide range of genetic, environmental and infectious factors.
A causal relationship is “strongly suspected” according to Chan, in part because research It shows that the virus can cross the placenta and enter the amniotic fluid. However, more research to prove Zika is responsible for the current crisis is needed.
If there is a link to microcephaly, why not noticed much earlier, in Africa or Asia? That’s still a bit of a mystery, but it could be because there are more immunity in populations in the Americas where the virus is a newcomer. Moreover, given relative softness of Zika, has faced less scrutiny than some other diseases transmitted by insects.
This map shows the countries and territories of the Zika virus transmission assets, as of 29 February 2016. (image: CDC )
which countries have you?
Zika finally spread locally in all countries of America, except for two: Canada and Chile, whose climates are less propitious for Aedes aegypti . Not the transmission of Zika virus now active in the following places: CDC:
- American Samoa
- Cape Verde
- Costa Rica
- Dominican republic
- El Salvador
- French Guiana
- Puerto Rico
- San Martin
- Saint Vincent and the Grenadines
- Sint Maarten
- Trinidad and Tobago
- US Virgin Islands
Because of the potential risk to newborns, the CDC recommends that women who are pregnant, in any quarter, “consider postponing travel to any area where Zika virus transmission is ongoing.” If you have to travel to one of these places, the CDC advised to consult a doctor first and strictly following the necessary steps to prevent mosquito bites .
And because of the possibility of Zika is spread through blood transfusions, the American Red Cross has issued a statement asking people to avoid blood donation for at least 28 days after traveling to Mexico, the Caribbean, Central America and the South. If Zika like symptoms occur within 14 days of blood donation, notify the Red Cross immediately so you can put the blood in quarantine.
Is there a vaccine or a cure?
No. There is no vaccine or specific medicine for Zika virus infection, and the CDC does not recommend any specific antiviral treatment. For now, doctors can only provide supportive care and treat the symptoms. Patients should get plenty of rest, stay hydrated and possibly take acetaminophen for pain or fever, but should avoid aspirin and other nonsteroidal antiinflammatory drugs (NSAIDs).
Is there a test for to diagnose?
No diagnostic tests commercially available for Zika , according to the CDC, and its close relationship with dengue and yellow fever makes it prone to cross-reaction with antibody tests for flavivirus. Testing can be done in the Arbovirus Diagnostic Laboratory, CDC, however, and some state health departments.
If a pregnant woman may have been exposed to Zika, what should you do?
The cast interim CDC guidelines for this scenario, on January 19, although like much of the advice of the agency so far, is subject to change as more information comes in
Clinicians should ask all pregnant recent travel, the CDC says, and proof Zika should be performed on any who reported two or more symptoms Zika -. or whose ultrasounds show signs of microcephaly – less than two weeks of traveling to an affected country. (It is worth noting Most infected people have no symptoms, however, and it is unclear whether fetuses are still at risk in that case.)
“In pregnant women with laboratory evidence of infection the Zika virus, “the guidelines added:” ultrasound examination standard should be considered to control the growth of the fetus and anatomy and referral to a maternal-fetal medicine or infectious disease specialist with experience in pregnancy recommends treatment. ” It is working to develop better Zika tests, and to expand the capacity of testing of state health departments.
What if someone gets pregnant after visit a affected country?
This is another of the many unknowns, but according to the CDC, Zika normally happens only “a few days to a week” inside the human body. “The virus does not cause infections in a baby conceived after the virus is removed from the blood,” says the agency in a Questions about pregnancy and Zika . “There is currently no evidence that Zika virus infection poses a risk of birth defects in future pregnancies.” Still, he adds that a woman contemplating pregnancy who has recently recovered from Zika “should consult your health care professional after recovery.”
climate change is involved?
Like the time, it is difficult to link any outbreak of the specific disease to the general climatic trends. But as with storms and droughts, climate change is expected favor certain insect-borne diseases as Zika, favoring the mosquitoes that spread.
climate change can not be to blame for Zika reach the Americas, but by the expansion of tropical and subtropical biomes where Aedes mosquitoes thrive, the disease could worsen now that he’s here. transmitted by mosquitoes all diseases depend on their hosts to move, so their fate depends on things that affect the mosquito population – that is, the density of people, the amount of rain and length summer in a given area. Rising temperatures extend the growing season for mosquitoes, which can also mature and reproduce faster in hot, wetter climate.
As Chelsea Harvey reports in the Washington Post, however, the relationship between climate and mosquito-borne diseases is not necessarily as simple as it seems. “With warming, we change our behavior,” University of Arizona epidemiologist Heidi Brown says Harvey. “We could leave before we could go out at different times of day People who work outdoors, people do not work outdoors, if we run out of air conditioning and stay indoors -. It is a combination of these things. “
What can you do to stop it?
Scientists and health officials around the world are competing to answer this question, both in trying to defeat Zika himself and trying to predict its spread. Private companies are also pitching in – Google, meanwhile, has donated $ 1 million to the efforts of Zika against UNICEF and establish a volunteer team of engineers, designers and scientists data to help UNICEF “build a platform to process data from different sources (ie, time and travel patterns) in order to visualize possible outbreaks.”
While the search for a vaccine or treatment continues, the best way to avoid Zika is to avoid places with active transmission. That does not help people living in those places, however, and may be only a matter of time before the virus is installed in parts of southern US “The best way to prevent mosquito-borne diseases,” the CDC says, “is to avoid being bitten.”
The first step bites limit mosquitoes is to limit mosquitoes , which means limiting the standing water where they breed. (Researchers are still studying more drastic measures, such as the release of genetically modified mosquitoes to curb wild populations.)
- Wear long-sleeved shirts and long pants.
- Stay in air-conditioned places or use window and door screens to keep mosquitoes out.
- use registered by EPA insect repellent . All insect repellents EPA registered are evaluated to determine efficacy.
- Always follow the instructions on the product label.
- reapplying insect repellent as indicated.
- Do not spray repellent on the skin under clothing.
- If you are using sunscreen, apply sunscreen before applying insect repellent.
- Do not use insect repellent on infants younger than 2 months old.
- dress your child in clothes that cover arms and legs, or …
- cradle cover, stroller and baby carrier with a mosquito net.
- Do not apply repellent to the hands, eyes, mouth of a child or irritated skin.
- Adults. Spray insect repellent on your hands and then apply to the face of a child
- treat clothing and gear with permethrin or buy items treated with permethrin.
- treated protective clothing remains after multiple washes. See product label to know how long protection.
- If treatment of articles yourself, follow the product instructions carefully.
- Do not use permethrin directly to skin. They are intended to clothing.
- sleep under a mosquito net if overseas or abroad and can not protect themselves from mosquito bites.