All you need to know about Zika virus

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Zika virus is spreading in America at an explosive rate overwhelming millions of people with fear, especially pregnant women. Since the outbreak of Zika virus, thousands of babies are being born with abnormally small heads, a condition known as microcephaly.

Here are answers to some of the questions that you probably have in mind after watching the breaking news regarding the outbreak of Zika virus in Brazil.

What is Zika virus infection and what are Zika affected areas?

Zika virus infection in human originates from a bite of an infected Aedes mosquito, which results in muscle pain, conjunctivitis, rash and mild fever.

This virus was spotted for the first time in 1947 in Uganda in the forest called Zika forest. After its first discovery, it had only remained in Africa with some small amount of occurrences in Asia. A major outbreak has been recorded on the island of Yap in the year 2007. 75% of their population was reported to be infected.

WHO was notified by Chile on 3rd March, 2014 regarding cases of transmission of Zika virus at Easter Island, where the virus persisted and was detected till June 2014.

It had never been noticed in the western hemisphere. It was in May 2015 that the public health authorities of Brazil detected and reported the presence the of Zika virus in the north-east part of the country. Other countries and regions of America have confirmed occurrences of Zika virus cases since October, 2015.

Very few people had immune defences to fight this virus which is the reason it is spreading so fast. Millions of people specifically in the tropical regions of America are now infected by it. In majority of the cases, this infection shows no symptoms or any lasting arm. The main area of focus is when pregnant women become infected by it, they go through a temporary paralysis. This infection has in particular a relation with brain damage and abnormally small heads in newborn babies. Pregnant women in such areas should be tested for this infection.

According to WHO (World Health Organization), as many as 4 million people are predicted to be infected by the Zika virus by the end of this year keeping in mind the alarming speed at which it is spreading. Pregnant women are strongly advised not to travel to about two dozen countries especially Latin and Caribbean America where it is spreading at a fast pace.

Zika virus and pregnancy

Serious birth defect of brain  called microcepahly has been reported along with other poor pregnancy results in mothers afflicted with Zika virus infection during pregnancy. Microcephaly is a brain defect in which the baby’s head is abnormally small as compared to normal babies. Knowledge regarding relationship between Zika and pregnancy results are limited and still in the process of being researched upon. CDC has recommended special precautions for pregnant women till the relationship becomes more clear. All women are strongly advised to get ultrasound scans while some should get blood tests done.

Generally speaking, if pregnant women have visited Zika prevalent areas, they should go see a health care provider. If they have faced any symptoms of this infection such as joint pain, blood shot eyes, rash or fever, on their trip, they should get a blood test done to check for the virus. This recommendation remains controversial. The reason is that many infected women show no symptoms at all. 80 percent of the infected women have no feelings of being ill with no signs of their baby being hurt as well. When CDC and state health departments issued guidelines, the laboratory back then were not able enough to test each and every pregnant woman to have visited the Caribbean and Latin America in the last nine months along with pregnant woman in Puerto Rico.

Getting blood tests done doesn’t give a clear picture either. It is only reassuring if the tests a done one week after the infection. Test for antibodies may be effective, but it may not show you false positive results in case the woman is suffering from dengue or yellow fever.

According to CDC, if pregnant women have visited Zika prevalent areas,  they should  get ultrasound scans done even if they have got blood tests done. Ultrasound scans enable checking out if the fetuses show any signs of calcification of the skull or microcephaly. But the bad news is that even an ultrasound is unable to detect microcephaly if you get it done before the end of the second trimester.

However, amniocentesis can help test the fluid present around the fetus to check for Zika virus. In amniocentesis, the amniotic sac is pierced with the needle, which is why it is a bit risky and is not advised much.

What are the zika virus symptoms?

Some of the most common symptoms that Zika virus infection causes are skin rash (exanthema), muscle or joint pain, mild fever, normally causes conjunctivitis too and general malaise that starts after 2 to 7 days of infected mosquito bite.

Out of every 4 infected people, one will go through the symptoms of this disease. For people who do go through the symptoms, it lasts for  2 to 7 days and is normally mild. The symptoms encountered are very similar to the ones people face when infected by chikungunya or dengue, which are also caused by an infected mosquito. Autoimmune and neurological complications are rare, but have been faced by infected people during the occurrences of Zika virus infection in Polynesia and the most recent outbreak in Brazil. It will be possible to be more aware of its symptoms and complications associated with the infection as the virus spreads in America.

Zika Virus symptoms
Source: medicalnewstoday.com

How is Zika virus transmitted? 

The transmission of Zika virus takes place when an infected Aedes mosquito bites a person. It is the very same mosquito that is also responsible for transmitting chikungunya and dengue.

This mosquito can breed in a pool of water even if it is the size of a bottle cap. They usually bite in the daytime. Aedes Aegypti is the yellow fever mosquito who has been known to spread most Zika cases. This mosquito is commonly found in the United States in regions like Florida, Hawaii and along the Gulf coast. They have also been noticed in the north in Washington D.C particularly in hot weather.

Aedes albopictus, an Asian tiger mosquito is also known to transmit his virus, but to a lesser extent. This mosquito is found in Chicago and New York in hot weather.

Apart from being transmitted by mosquitoes, it is also known to be transmitted by sex.

Can it be transmitted through blood or sexual contact? 

Generally, Zika virus requires a carrier (vector) in order to be transmitted to people and in this virus’s case, it is the mosquito. Zika virus has also been found in semen, which means that it can be transmitted sexually. However, only one such case has been heard of and not confirmed.

Another mode of transmission of this virus is the blood, but this is rarer mode. If the instructions for safe transfusion of blood is followed, this is very unlikely to happen. For instance, making sure that the volunteer donor is healthy before blood transfusion.

Can it be transmitted from mother to child?

There isn’t much information regarding transmission of this virus from the mother to the baby during childbirth or pregnancy. Other vector borne viruses like chikungunya and dengue has confirmed cases of perinatal transmission. Recently, studies are being carried out regarding the possibility of  its transmission from the mother to the child and its impact on the baby.

Can it cause death?

This virus is new to America. Demographically and geographically this virus haven’t presented itself so much. None of the cases testify that it can result in death. It is not lethal, but there are some cases that showed critical complications and serious manifestations in people infected by it which eventually caused their death.

Who is at risk of Zika virus infection? 

Whoever lives in the place where this infected mosquito exists and anyone who has not been infected by it before, and residents of the place where either local or imported cases have been notified. Due to the  fact that Aedes mosquito has been found in the entire region except for Canada and Chile, there are chances of possible outbreaks in other countries where no cases have been reported yet.

What is the difference between Zika, dengue, and chikungunya?

Zika, dengue and chikungunya come with similar symptoms that indicate towards one of the three diseases.

Chikungunya shows symptoms of intense joint pain, particularly in the back, knees, feet and hands along with high fever. It is also known to make people disabled bending them so much that they are unable to walk or perform simple tasks like opening a water bottle.

Dengue comes with symptoms like severe muscle pain and really high fever. Complications may occur when the fever subsides. Special attention should be given to signs like bleeding.

Zika infection does not present clear symptoms but, mostly patients have been reported to have conjunctivitis and skin rashes.

Is there a relationship between Guillain-Barré syndrome and Zika virus? 

Guillain Barre syndrome has been noticed to be on the rise in places where cases of Zika virus outbreaks have been reported. For example, in places like Brazil and French Polynesia.

A link between Guillain Barre Syndrome and Zika virus infection has not yet been established. Genetic factors or previous infections of dengue can trigger cases of GBS. Many studies are being carried out to see if there is any relationship between GBS and Zika.

GBS is known to occur if the immune system of a person invades itself by specifically having an adverse effect on the cells of the nervous system. This process begins when the body is infected by different bacteria or viruses. The dominant symptoms consist of tingling in legs and arms, muscular weakness along with critical complications in case the respiratory muscles are affected too. Serious patients are required to be admitted in intensive care units.

Circulation Of Zika Virus

Which countries have reported cases of Zika in the Americas? 

Chile had reported the case of Zika virus being transmitted on Eastern Island to WHO.  There it continued to prevail till June 2014.

On May 2015, Brazil notified its public health authorities about the presence of Zika virus in the northeastern part of the country. Other parts of America and other countries, particularly Caribbean and Latin America started reporting its presences since October 2015.

What causes rapid transmission in an area?

The rapid transmission is due to 2 reasons:

  1. Due to the favorable temperature, humidity and climatic conditions of tropical countries, Aedes mosquito is present in large number.
  2. As this is a new virus in the United States, people are not yet aware of how to defend themselves from this virus. Due to this reason, the whole population remains vulnerable to Zika virus.

Is it advisable to travel to countries where Zika virus is circulating? 

WHO highly recommends NOT travelling at all. There are even international trade restrictions t the moment because of the widespread epidemic of Zika virus and the alarming speed at which it is spreading. And still if you really have to travel, all travellers should take the necessary precautions in order to avoid mosquito bites.

How many Zika cases have been reported in the Region of the Americas? 

Countries have reported this virus as soon as they notice its spreading in their region. The difficult part is to maintain a case count as people who are affected by it don’t necessarily go see health services and the symptoms seem to be mild. The detection of this virus’s circulation should be taken into account so that health services can give quicker responses along with taking care of serious complications and cases. Suspected cases are reported to state or local health departments by the health providers in order to diagnose and minimize the open risk of local transmission.

Aedes species of mosquitoes do exist in the U.S mainland. They can be infected by Zika virus and act as vectors to spread the virus. People who are travelling to U.S where Zika is already prevalent can become infected simply by a bite of a mosquito. The number of travellers either visiting or returning to the United States is predicted to increase because of the recent epidemic. Such cases might further cause the spread of this virus. This epidemic requires strong monitoring in order to stop it from spreading any further.

Zika Virus Prevention

What measures should be taken to prevent Zika virus infection? 

Preventative measure basically center around decreasing the population of mosquito and keeping away from mosquito bites particularly in day time. Controlling and killing Aedes aegypti mosquito breeding places decreases chances of transmission of dengue, chikungunya and Zika. What is needed is a unified response covering different aspects such as environment, education and health.

The following things should be taken care of in order to control and eliminate mosquitoes:

  • Unblock drains to prevent water from standing.
  • Do not collect a lot of garbage. Put them in closed containers and closed plastic bags.
  • Keep the domestic water tanks covered so that mosquitoes cannot enter them.
  • Do not leave water filled up in outdoor containers like bottles, flower pots, buckets or any other container. This is to prevent making them the breeding sites of mosquitoes.
  • Make use of mosquito nets and screens in doors and windows to minimize any kind of interaction between people and mosquitoes.

There are some preventative measures for people residing in areas where cases of this virus have been reported. Travellers and particularly pregnant women should take these measures.

  • Sleep inside mosquito nets.
  • Use mosquito repellents that are recommended by health authorities. Use them as instructed on the label.
  • Wear clothes that cover your entire body. Cover your skin with trousers, long sleeved shirts and hats.

If people notice any kind of signs and symptoms associated with dengue, Zika or chikungunya should immediately consult a doctor.

WHO(world health organization) together with countries of America is working to formulate strategies in order to detect and confirm Zika virus cases along with treating the affected people effectively. WHO has provided much support by doing the following:

  • Putting a check on the vector by eradicating the population of mosquitoes
  • Advising people about what ways they should respond upon the arrival of new virus.
  • Enabling laboratories to detect Zika virus on time.
  • Providing support to health ministry in the steps that they have taken with the intention of facilitating the learning of this virus’s characterisitcs, possible consequences of infection and its impact on health.
  • Keeping the virus geographically monitored and countries confirming the presence of the virus via International Health Regulations channel along with monitoring of serious cases with complications.
  • By collaborating with expert from different countries and professional associations, recommendations are prepared for clinical care and infected persons to be monitored.

How is Zika Virus diagnosed?

In most cases, the patient is diagnosed on the basis of clinical symptoms as well as epidemiological circumstances like trips to areas where this virus is spreading or Zika epidemic in the area where the patient lives. Check with your health care provider as soon as you notice any symptoms after visiting areas where Zika exists. In case you travelled, do let your healthcare provider know where you have been.

Blood tests also aid in confirming the infection. Virological PCR test help in the 3 to 5 days after the symptoms are noticed. On the other hand serological test help after 5 days. They help to detect the presence of antibodies. Blood tests help to find out if it is Zika or other similar viruses like chikungunya or dengue.

As soon as it is known that the virus is present in a certain region, it is not necessary to confirm all cases. Lab testing can be switched to the virological surveillance of the infection.

Zika Virus Treatment

Treatment involves relieving the symptoms like fever, pain and others.Here is what treatment consists of:

  • No particular drug or vaccine is available for treating Zika infections.
  • Treat the symptoms by:
    • Taking medicines like acetaminophen to alleviate pain and fever.
    • Drink lots of water and other fluids to prevent dehydration.
    • Take ample rest.
    • Do NOT take medicines like aspirin or any other non-steroidal anti-inflammatory drugs (NSAIDs) such as naproxen and ibuprofen. To prevent the risk of bleeding (hemorrhage), aspirin and NSAIDs should not at all be taken. If you are taking medicine due to other reasons, do consult with your doctor about it.
  • If you are already infected by Zika virus, keep yourself from being bitten by mosquitoes during the first week of your illness. It is in the first week that Zika virus is present in your blood and can be transmitted to another person if a mosquito bites you and carries the virus to some other person by biting him.

Sources

http://www.nytimes.com/interactive/2016/health/what-is-zika-virus.html?_r=0
http://www.medicalnewstoday.com/articles/305163.php
http://www.wpro.who.int/mediacentre/factsheets/fs_05182015_zika/en/
http://www.medicinenet.com/zika_virus/article.htm

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