What you need to know about Zika Virus Outbreak (SQ-4)
The WHO (World Health Organization) has declared Zika virus a public health emergency of international concern, mainly because of the virus’s suspected association with microcephaly, a neurological birth defect. And then you hear that the government of El Salvador is advising the women in the country against pregnancy until 2018, a strange recommendation indeed, but it only underscores the seriousness of the Zika outbreak and the underlying complications, no matter the debate on its origins.
Mosquito-borne Zika virus is rampant in many parts of the Americas and the Caribbean and, according to WHO, as many as four million people could be infected by the end of the year. Right now, Brazil is the epicentre for the Zika virus infection, with the country experiencing the largest known eruption so far.
What is Zika Virus?
Zika is a RNA virus that is primarily spread by the bite of the infected mosquito from Aedes genus, mainly Aedes aegypti, that thrive in hot tropical and subtropical regions. It is the same mosquito that transmits Chikungunya, dengue fever and yellow fever.
Here is a quick run-down on Aedes aegypti mosquito:
- Aggressively active at dawn and dusk; usually bites during daytime, and late afternoon and evening hours.
- Only female mosquitoes bite.
- Feeds intermittently and bites more than one person during their feeding period, making the infection spread faster
- The eggs can survive up to one year without water. When they get access to water, even small puddles of standing water is enough, eggs mature into mosquitoes.
- Can’t fly more than 400 meters, so it can’t travel from region to region
- Found both indoors and outdoors
Mosquitoes become infected with Zika virus when they bite an infected person, and then transmit it to other people. However, with new cases being reported, other possible modes of transmission are also emerging and scientists believe that in addition to being spread by infected mosquitoes, transmissions through sexual contact and blood transfusions can’t be ruled out  . Zika virus can also be transmitted from an expecting mother to the baby in the womb. With the latest Zika outbreak in the Americas, scientists are putting renewed energy and focus on understanding the virus in terms of what other possible ways it can spread, and if the infection can cause any other serious complication besides what are currently known.
Zika Virus Infection Symptoms and Complications
The infection causes symptoms in only one in five people. A vast majority of people infected with Zika virus don’t have any indications and in those who do, the most common symptoms are fever, itchy red rash, headache, joint and muscle pains, and conjunctivitis (inflamed red eyes). People usually recover within a time frame of 2 to 7 days, and death is very rare. With these mild symptoms and no potential threat to life, what makes Zika virus an international health scare? Unfortunately, exposure to Zika virus is associated with two quite rare but severe complications.
Researchers believe that Zika virus may have a causal link with microcephaly, a rare condition where babies are born with unusually small heads, and often with damaged brains. While health experts have yet to establish a connection between Zika and microcephaly, the evidence is growing strong. Since the start of the Zika pandemic, about 4,000 infants in Brazil have been born with this birth defect, a number that is 20 times higher than expected. Whether Zika actually causes this birth defect, or how the virus enters the placenta and cause damage to the brain of the foetus is not known yet. Experts are also not clear at what stage of pregnancy the risks are greatest. However, the first trimester is considered as the most dangerous time as this may be when some women may not be aware they are pregnant.
Some new findings may hold the key to the possible effects of Zika Virus on the growing foetal brain. In a case study recently published in The New England Journal of Medicine (February 10, 2016), Slovenian researchers report finding the traces of ZIKV in the brain tissue of a foetus whose mother who was living in Brazil when she became pregnant before she returned to Slovenia late into her pregnancy. The mother had suffered Zika symptoms at the end of her 1st trimester. While ultrasounds performed in the second-trimester didn't reveal anything suspicious, the third-trimester scan showed massive damage to the foetal brain. The scientists found an extremely abnormal brain — that was not only unusually small but lacked the usual crinkly neural folds. Although it may not be a conclusive proof of Zika as the possible cause of increase in microcephaly, it still adds to the existing clues.
As WHO Director-General Margaret Chan puts it in a statement "Although a causal link between Zika infection in pregnancy and microcephaly has not, and I must emphasize, has not been established, the circumstantial evidence is suggestive and extremely worrisome."
Zika virus infection is also complicated by its possible association with Guillain-Barre Syndrome (GBS), a rare autoimmune disease, often triggered by infections. Here, the body’s immune system launches an attack on parts of the peripheral nervous system – resulting in muscle weakness, tingling sensations and in some cases paralysis. These symptoms may last a few weeks or several months. Fortunately, GBS is a very rare complication and most people fully recover from GBS. (Severe cases are rare, but in some of the most severe cases, some people may suffer a permanent damage with total paralysis.) While the link between this neurological and auto-immune complication is not yet established, the Zika virus outbreak in French Polynesia during 2013 did witness a surge in Guillain-Barre Syndrome cases.
How to protect against Zika Virus?
Currently, there is no vaccine or treatment for Zika virus. You can only take preventive measures that may help in protecting you from contracting the infection .
- Since pregnant women are more at risk due to the potential damage to the brain of an unborn baby and it is not possible to completely avoid getting mosquito bites, The Centers for Disease Control and Prevention (CDC) has warned pregnant women against traveling to countries and territories where the Zika outbreak is rampant. CDC has issued travel alerts for such places where the Zika virus is in full swing.
- Avoid nonessential travel.
- When travelling to the countries rampant with Zika outbreak, people are advised to avoid or minimize mosquito bites by:
- Staying in air-conditioned rooms or with rooms that have window and door screens.
- Sleeping under mosquito nets
- Using EPA registered insect repellents at all times, and especially when going outdoors.
- Covering the body as much as possible by wearing long sleeved shirts, full pants, closed shoes and hats.
- Keep your surroundings clean and empty or cover containers that can collect water such as buckets, flower pots or used tyres. Such places are perfect breeding ground for the mosquitoes. (Our water purification capsules will quickly kill mosquito larvae when added to water where the larvae are present. It will also ensure no future larvae hatch when used regularly.)
- Pregnant women who are coming back from affected areas should be tested for Zika; especially if they have flu-like symptoms. If you are pregnant and you believe your male partner may be at the risk of getting Zika, use condoms or refrain from sexual contact. Most importantly, talk to your doctor. Here is an interim guide from CDC for Pregnant Women during a Zika virus outbreak.
There is no widely available test to detect Zika virus infection. However, a blood sample can be sent to a specialized lab within the first week of infection where sophisticated tests like serology and polymerase chain reaction (PCR) can be helpful in detecting the infection. There is a major limitation, as it is closely related to infections such as dengue fever, chikungunya and yellow fever, and may cross-react with antibody tests for these viruses and give a false positive.
How to treat Zika?
What if you are diagnosed with Zika virus? While there is no vaccine or any other FDA approved medicine available to treat Zika virus infections, you can manage the symptoms by getting good rest and drinking plenty of fluids to prevent dehydration. While NSAD drugs like aspirin are to be avoided, one can take acetaminophen for fever and joint pain. Also make sure you take measures to prevent transmitting the virus to other people.
- Donald G. Mcneil Jr., Catherine Saint Louis and Nicholas St. Fleur. Short Answers to Hard Questions About Zika Virus. The New York Times. February 2016.
- Ashley Welch. Red Cross: Wait to donate blood after visiting Zika areas. CBS News. February 2016.
- Prevention. Centres of Disease Control and prevention.