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Monday, February 15, 2016

ZIKA: Balancing Fear with Facts

By: OCR-Mama

You have heard about Zika virus. You have seen the heart-wrenching images of babies born with microcephaly or an abnormally small head. The World Health Organization is talking about it. The Centers for Disease Control and Prevention is talking about it. Your grandma is calling you to talk about it. Zika is spreading rapidly and can have dire health effects. Even as I write this new stories are popping up by the minute, but what are the facts about Zika? What is the real risk for you as a pregnant mom in the US? Before you finish your gestation in a DEET-filled cave, let’s look at what is known and unknown about Zika.

What is Zika virus and how do you get it?


Zika virus disease or ZIKV or Zika fever is caused by a mosquito-borne virus that was first identified in 1947 in a caged rhesus monkey in Africa. In humans the first cases were identified in 1952. In 2013 and 2014 French Polynesia had a ZIKV outbreak with an uptick in central nervous system malformations including microcephaly.

In 2015 a Zika virus outbreak swept through Brazil. 2016 has seen no end to the outbreak and Zika continues to spread through the Americas. So although this disease is not new, the areas of the world that have been impacted by the Zika virus are expanding and the effects on these naive populations are getting attention.

Mosquitos carry the virus and infect the human by acting as a vector for transmission. Mosquitos are excellent vectors because they break through the top layer of skin or epidermis and get into the dermis below. They do this because blood is their meal, but this also allows the virus to make it’s way into the host’s blood. The skin, like a suit of armor, protects against most dangers but a poisonous needle piercing through a chink can cause grave harm.

The cells of the dermis called dendritic cells and fibroblasts have receptors that allow Zika to enter the cell and replicate. The virus has other factors contributing to the rapid spread in areas with many mosquitos. A mosquito can pick up Zika from an infected person and then pass it along to another person. Meaning, a mosquito can become a carrier by biting someone who is sick.

Transmission is no longer thought to be limited to the work of mosquitos either. There is growing evidence that Zika virus disease can be transmitted sexually and remains in semen longer than it has cleared from the blood in an infected person. So if your partner has travelled to a region with Zika it is wise to use condoms or abstain until he has been cleared from the disease whether or not symptoms occur. This route of transmission, however, is much less likely than from a mosquito. So while unlikely to be an issue, better safe than sorry.

Not all mosquitoes carry the Zika virus. In fact, transmission is mainly by Aedes mosquitoes which are most commonly found in tropical environments. For US women concerns about contracting Zika are mainly around travel to area that have cases of Zika and sexual contact with partners that have experienced Zika virus disease. The CDC and WHO are actively tracking the disease and issuing travel guidelines for pregnant women or women who may become pregnant. Currently no locally-acquired cases of this disease have presented in the US, but travel-related cases have. Tracking of the disease and its spread are ongoing and if you have travel plans check with these sources for the latest recommendations.

What are the symptoms of Zika virus disease?

If Zika virus disease occurs symptoms are likely to begin around a couple days after exposure and symptoms are generally mild, lasting 2-7 days. These symptoms include fever, skin rash, discomfort, headache, joint and muscle pain, and eye redness. Most people infected with Zika virus will have no lasting harm from the disease. If a woman is pregnant when the Zika virus is contracted, however, the virus may cause severe brain damage to the unborn and is linked to a condition called microcephaly. The relationship between Zika virus and microcephaly is not fully understood by scientists.

How is Zika virus disease treated?

Symptoms of Zika virus can be eased with rest, drinking plenty of water, and taking pain relievers like ibuprofen. No antiviral medications are recommended at this time for Zika and no vaccination is available. If you are pregnant and suspect you have Zika virus talk to your doctor about what tests are available. Blood, urine, and saliva tests may be used to find viral RNA and the CDC has released an algorithm for testing. Ultrasound may be used to look for calcifications in the fetal skull and microcephaly. Recommended testing is still controversial and not widely available. The reality is that if you haven’t travelled to a region currently affected by Zika or live in that region then you aren’t considered to be at risk for Zika.

What is microcephaly and does Zika cause it?


Microcephaly is a condition that literally means small head. The head grows in a developing fetus because the brain is growing. In microcephaly the brain is not growing normally and this can be linked to a range of serious difficulties. Many causes of microcephaly are known such as infections like rubella, toxoplasmosis, and cytomegalovirus. Malnutrition or toxic exposures in development like alcohol can also cause microcephaly. ZIKV genetic material has been found in the brain tissue samples of a fetus with microcephaly whose mother was exposed to ZIKV during her pregnancy and experienced symptoms of ZIKA fever in her 13th week of pregnancy. ZIKV genetic material has also been found through amniocentesis. It is not proven that Zika causes microcephaly, but researchers think that the virus may target and replicate in the developing brain of a fetus. Zika doesn’t seem to cause lasting harm in other organs or tissues but stays and replicates in the brain stem.

The best prevention for ZIKV is to not get bit by a mosquito. Consider guidelines and consult with your doctor about travel plans. Look at the EPA’s recommendation for mosquito repellants and follow the directions carefully if you are expecting exposure. If you do they are safe to use during pregnancy. Wearing long pants and shirts can help as well. Standing water is prime breeding ground for mosquitos and can become a safety risk so care should be taken to prevent this. So the ZIKV media frenzy may be inducing worries in your pregnant mind, but fear is a beast that thrives on attention. Arm yourself with facts and be well.

References:

Akpan, Nsikan (January 29, 2016  updated February 1, 2016) How does Zika virus shrink a baby’s brain and other FAQs.  PBS NewsHour. Retreived from: http://www.pbs.org/newshour/updates/zika-virus-faqs-ultrasound-detection/

Centers for Disease Control and Prevention. (February 12, 2016).
Facts about Microcephaly (article). Retreived from: http://www.cdc.gov/ncbddd/birthdefects/microcephaly.html

Centers for Disease Control and Prevention. (January 29, 2016).
Possible Association Between Zika Virus Infection and Microcephaly — Brazil, 2015
(Morbidity and Mortality Weekly Report).   Retreived from: http://www.cdc.gov/mmwr/volumes/65/wr/mm6503e2.htm

Mlakar, J M.D., Korva, M Ph.D., Tul, N M.D., Ph.D., Popović, M M.D., Ph.D., Poljšak-Prijatelj,  M Ph.D., Mraz, J  M.Sc.,... Avšič Županc, T Ph.D. (February 10, 2016) Zika Virus Associated with Microcephaly.  The New England Journal of Medicine.  DOI: 10.1056/NEJMoa1600651

McNeiL, D.G. Jr., Saint Louis, C. & St. Fleur, N.  ( February 16, 2016).  Short Answers to Hard Questions about Zika Virus. The New York Times. Retreived at: http://www.nytimes.com/interactive/2016/health/what-is-zika-virus.html?_r=0

World Health Organization.  (February 2016).  Zika Virus (fact sheet). Retreived from: http://www.who.int/mediacentre/factsheets/zika/en/






7 comments:

  1. Zonmbiland

    I enjoyed reading your paper. I especially appreciated the fact that it was regarding a very recent issue that is in the news currently. I did feel, however, that it was targeted at a small audience of pregnant women. While reading it, I felt that it did not apply to me because I am not pregnant. Otherwise, great job! One question I have: Is there anything that might put a male at risk for Zika, other than sexual contact?

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    1. OCR-Mama

      Thanks for your comment. If you get bit by a mosquito carrying the Zika virus (a vector) you can get Zika fever. This applies to all folks and certainly is not limited to pregnant women. The signs and symptoms of Zika fever are relatively mild. The only population of people that seem to get microcephaly related to Zika are those that are gestating. This puts women who are pregnant at a higher risk than others. The link between Zika virus and microcephaly is actively being investigated. There are other viruses similar to Zika that have a link to microcephaly.

      In even more recent news, Guillain-Barre Syndrome may also be linked to Zika virus.
      Check out this news story to learn more: http://time.com/4229778/cdc-zika-virus-guillain-barre-syndrome/

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  2. Very good introduction, definitely got my attention in continuing to read your blog post. The metaphor you used in describing skin and how mosquitosʻ use their poisonous needle to transmit ZIKA was very creative! My only advice would to cite some of facts you have stated in your blog just in case your readers wanted to read more into it, they know which reference and etc. Just out of curiosity, does ZIKA have the same effects on animals as well?

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    1. this comment was from feedmeee3

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    2. OCR-Mama

      Thanks for your comment. That is a great tip for me to use in the future.

      I am not sure if Zika virus affects other animals the same way. The original discovery of Zika was in a macaque so primates can and do get Zika fever, but I have not heard of microcephaly in primates linked to Zika. As far as non primates go, I really don't know if they can get Zika virus and if that would cause Zika fever or other linked pathologies.

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  3. Ragujo
    I really enjoyed reading your blog post as it answered several questions I had about transmission of the virus. It was well organized and the section headers made it easy to follow. My only suggestion would be to include a little information about how microcephaly affects the life of an individual – if Zika virus does cause microcephaly then what might be the lasting effects of contracting the virus in utero? My question is merely for clarification, just in case I ever find myself pregnant during mosquito season in Western Oregon: if someone contracts the Zika virus in another country and then comes to Portland, will our local mosquitos not be able to transmit the virus?

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    1. OCR-Mama

      Thanks for commenting on my post. Are you asking what life with microcephaly would be like? That topic would be one that would have put me well over my word count limit. :-) Not only is there a difference in how the head looks, there is underdevelopment of the brain that leads to a range of neurologic affects. The CDC has nice page that simplifies the basics of microcephaly. http://www.cdc.gov/ncbddd/birthdefects/microcephaly.html

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