Image courtesy of The Telegraph
The World Health Organization (WHO) has declared the spreading outbreak of the mosquito-borne Zika virus a "public health emergency of international concern," and estimates 3 - 4 million people across the Americas will be infected with the virus in 2016. “The level of alarm is extremely high," said Margaret Chan, MD, the WHO director general.
This concern is not based on the Zika virus causing a life-threatening infection. In fact, if you catch Zika virus, you might not have any symptoms at all. If you do, you’ll likely feel mildly unwell for a few days with a little fever and maybe a rash, joint pain, and red eyes, and recover fully in two days to a week.
Researchers have noted an increase in Guillain-Barre syndrome cases in areas of the world that have experienced Zika outbreaks – and some reports of increased cases of this neurological disorder are now being possibly linked to infection with the virus, according to the Pan American Health Organization. Guillain-Barre is a usually temporary condition with symptoms marked by mild weakness and tingling that, rarely, causes paralysis (people typically recover) and, even more rarely, fatalities.
The biggest worry so far about Zika infection is the possible consequences for expectant moms, or women trying to get pregnant, especially if they travel to areas where the infection occurs. Evidence is mounting that infection with the Zika virus can cause a potentially life-wrecking birth defect in a baby – the heartbreaking abnormality known as microcephaly, marked by a smaller-than-normal head and brain. Children with microcephaly may also have facial distortions, seizures, difficulties with coordination and balance, impaired thinking abilities, and other neurological abnormalities.
Microcephaly is usually rare and caused primarily by genetic abnormalities so the unusual number of children, over 3,500, born with microcephaly after a major Zika virus outbreak in Brazil last year raised red flags in the medical community about a probable cause-and-effect connection.
“Astute clinicians in Brazil recognized that they were seeing more and more infants with microcephaly and reported this to public health authorities in Brazil,” Andi L. Shane, MD, associate professor of pediatric infectious disease and global health and Marcus professor of hospital epidemiology and infection control at Emory University School of Medicine and Children’s Healthcare of Atlanta, explained. “The public health authorities began an investigation and requested help from the Centers for Disease Control and Prevention (CDC), the Pan American Health Organization, and the WHO.”
The result was the current global effort to track and halt outbreaks of the infection.
The Zika virus is known to be spreading quickly, and Zika infections have been confirmed in more than 20 countries within South and Central America, including two U.S. territories – Puerto Rico and the U.S. Virgin Islands. It’s also found in the Pacific Islands and parts of Africa. Fewer than 40 cases of Zika have been confirmed in the continental U.S. so far, involving people in 11 states and Washington, D.C., according to the CDC.
All Zika-infected Americans were thought to have contracted the virus from mosquito bites while traveling outside of the U.S. But now there is one confirmed case of sexual transmission of Zika. In Texas, a man who had apparently contracted the infection while in Venezuela, infected his partner who had not been outside the U.S.
Body fluids, including blood, have been known to transmit the virus, although this scenario is rare. The virus survives in blood for about a week, and scientists are studying how long Zika lives in semen, according to CDC Director Tom Frieden.
The CDC is advising the use of condoms to prevent sexual transmission of Zika from an infected partner. This is especially important for women who are pregnant or may become pregnant, according to the CDC. In addition, the American Red Cross is now urging all prospective blood donors who have returned from countries where they could have been exposed to the virus to wait at least 28 days before donating blood.
“Blood borne and sexual transmission are potential ways that Zika could be transmitted,” said Emory’s Shane. “However, the most important way to acquire Zika is via the bite of a species of mosquito carrying Zika virus.”
It’s possible, and even likely, there will be limited Zika outbreaks in the U.S. this year, according to Anne Schuchat, MD, principal deputy director of the CDC. The southern states may be at greatest risk because that’s where Aedes aegypti mosquitoes, the kind that carry the virus, are common.
The best way to protect yourself from infection, no matter where you live, is to use common sense measures, according to Shane. First and foremost, avoid exposure to mosquitoes. Pregnant women in particular should avoid travel to areas where there is active transmission of Zika virus.
If you must be in an area where you could be exposed to mosquitoes, Shane advises keeping bare skin covered, sleeping under a mosquito net, and using an insect repellent containing DEET.
“DEET is safe,” she said. “When used as directed, insect repellent is the best way to protect yourself from mosquito bites – even children and pregnant women should protect themselves with DEET insect repellents. Higher percentages of active ingredient provide longer lasting protection.”
Contact your doctor if you have a fever, rash, and red eyes and have traveled to a place where Zika virus is being transmitted – a blood test can tell if you are infected. “A pregnant woman who has traveled to a setting where there is active transmission should discuss testing and monitoring with her obstetrician,” Shane said. “However, healthy, exposed people do not need to be tested if they do not have symptoms.”
If a woman is pregnant and learns she is infected with the virus, the odds of whether she will have a baby with microcephaly are not known. “Large population based studies would have to be conducted to accurately assess this number. Some epidemiologists are modeling this possibility, but there is still so much that is unknown, that this is difficult to predict,” Shane explained. “As with any infection during pregnancy, communication with an obstetrician and a maternal fetal medical specialist is recommended for a pregnant woman with Zika.”
A consortium of scientists is now working to develop a Zika vaccine that protects against the virus. In the meantime, public health measures are being put in place internationally to swiftly recognize Zika cases and prevent the spread of the disease by controlling mosquitoes with pesticide and eliminating habitats where the insects breed.
“The Zika outbreak illustrates the importance of public health, once again,” said Shane. “Funding is needed consistently to support surveillance and data gathering at times when there are and are not infections so that we have good baseline data as a comparison when an outbreak occurs.”
On a local level, once the weather warms, you can help fight Zika by reducing mosquito populations in your yard and neighborhood with DIY methods. For example, the Environmental Protection Agency advises covering or removing containers such as buckets and flower pots that hold water where mosquitoes can breed, using screens on open windows, and consistently wearing mosquito repellant when outdoors.
The WHO and the CDC offer frequently updated information on the Zika virus. Also check out the CDC’s Zika Travel Information page for the latest updates on areas where there are current outbreaks of the virus.
February 04, 2016
Christopher Nystuen, MD, MBA