Zika

The mosquito-transmitted virus Zika has been getting world-wide attention since the World Health Organization’s (WHO) announcement in February that it is a national health concern. More recently, the Zika case in New Jersey is prompting discussion about this disease in the United States. What effects does Zika have on humans? What does this mean to people around the world? What can we do to stop Zika?

An enlarged model from the American Museum of Natural History(AMNH) of Aedes aegypti,the mosquito which transmits Zika.  

Photo was taken on June 30, 2016 by author at AMNH's SciCafe event.

An average individual with no immuno-compromising disorders contracted Zika, nothing much would happen. Maybe the individual would get a headache, conjunctivitis, joint pain, or a mild fever, irritating, but not bad enough to report or go to the hospital. Most people (80%) with Zika don’t even know they have it, and completely recover after the virus leaves the body a few months later. There may be a slight connection between Guillain-Barré syndrome, which can cause severe paralysis, and Zika, but the connection is unproven and does not render Zika a national concern. Why then are people, WHO included, so worried about Zika?

Zika may go virtually unnoticed in adults, but if a fetus contacts Zika from the mother during gestation, it can develop severe birth defects such as microcephaly, increased calcification in the brain, and other motor and behavioral complications. Zika can cause birth defects no matter what trimester of pregnancy it is contracted in.

If Zika continues to spread, it could severely damage human populations. Dr. W. Ian Lipkin, John Snow Professor and Director of the Center of Infection and Immunity at Columbia University, stated at the American Museum of Natural History’s Zika SciCafe on June 30, 2016 that if there is any way to wreak havoc on a species, it is to prevent it from reproducing properly, and that’s what Zika is doing to us.

AMNH SciCafe.  Panelists at the cafe were:
 Dr. W. Ian Lipkin; Catherine Spong, MD; and Jay K. Varma MD.
Event moderator was Dr. Susan Perkins.
Photo taken at the event by author

Now, this virus with barely any noticeable symptoms sounds quite alarming, but thankfully, Zika has not yet overtaken the whole world. The virus remains restricted to southern climates such as those in South America or Africa. International travel can result in cases far from the south, however, and there have been 233 cases were reported in New York City as of July 1, 2016. Healthcare providers everywhere must be prepared to treat and prevent Zika infections. One concern about Zika being carried back to countries like the United States by travelers is that a northern relative of Aedes aegypti, the mosquito which carries Zika, will bite someone with Zika, and then continue to spread the virus to more and more people, eventually interfering with their ability to reproduce.

Where Did Zika Come From?

 Most people, myself included, only heard of Zika recently, but it has likely been around for a long time, and probably passed unnoticed until due to its generally mild symptoms. The first known case occurred in Zika forest in Uganda in the 1940s and generated little attention. In 2007, there was an outbreak on Yap Island, Micronesia which effected a high percentage of the population putting Zika on the international radar.

How Does Zika Spread?

 The main form of Zika transmission is through mosquito bites. The infection process begins when a mosquito ingests Zika-infested blood. The virus then enters the mosquito’s system, including its saliva, which transfers the virus into the next human it bites. Not all mosquitos are good transmitters of Zika. Aedes aegypti is the species of southern, aggressive, day-biting mosquito that can breed in very small amounts of stagnant water and spreads Zika. (We don’t have that species here in New York City.)

Zika can also be transmitted sexually and through blood contact. Zika remains in an infected woman’s body for about two months, and in an infected man’s semen for even longer. To prevent spreading Zika this way and causing birth defects in unborn children, couples traveling to Zika heavy-zones should be tested for Zika and avoid unprotected sex for six months, when they will both be free of the virus.

The blood contact method of transmission means Zika could be spread through blood transfusions or organ donations.

Testing for Zika

Zika is a virus, meaning it is a small packet of genetic information surrounded by proteins that can only reproduce inside of a cell. Viruses attach themselves to their host cell, penetrate the cell, unleash their genetic material, replicate it to produce new viruses, and kill the host cell.

Informational flyer from the NYC Department of Health about Zika.
Photo taken by author.

There are several ways to test for a viral infection like Zika. The preferred method is to run a polymerase chain reaction (PCR) test to determine if there is genetic evidence of the virus in the individual. The second method is to test for presence of the virus’s antibodies. The genetic test is highly accurate at determining if Zika is present, but the antibody test is much less accurate and can test positive even if another virus, not Zika, is present. The antibody test is only used because a viral infection consists of two stages: one where viral genetic information is present in the individual and one where viral antibodies are present, but not the genetic information. Between these stages is a window of time where neither genetic information nor antibodies are present. This means both viral tests are good at determining if a virus is present, but not as good at determining if it is absent. If the test comes out negative, there is still a chance that the individual could have Zika. Catherine Spong MD, Acting Director of the Eunice Kennedy Shriver National Institute of Child Health and Human Development at the National Institutes of Health and speaker at the American Museum of Natural History’s Zika SciCafe, suggests careful monitoring of pregnant women who have Zika, and those who may have contracted Zika throughout their term for the health of the baby.

Zika SciCafe at AMNH. Photo taken by author at the event.

Prevention

 Vaccines for Zika are still being developed and tested. Even once vaccines are on the market they won’t completely eradicate the disease. There are multiple forms of Zika, and while the vaccine may successfully prevent one form, it may actually amplify the effects of a different strain. Being infected to other viral infections similar to Zika, like Dengue, can also amplify the symptoms of Zika.

Cullman Hall of the Universe at AMNH where the Zika SciCafe was held.
Photo taken by author at the event.

Another way to prevent Zika is avoid getting bitten by mosquitos. On a personal level this means wearing bug spray, long sleeved shirts and pants, putting up bug screens, and removing standing water. On a governmental scale, as Jay K. Varma MD, Deputy Commissioner for Disease Control at the New York City Department of Health and Mental Hygiene, explained at the American Museum of Natural History’s Zika SciCafe, this means activating new mosquito control programs that include putting chemicals in standing water which kill mosquito larva, spraying to kill adults, and informing the public of how to stay safe.

Here are some websites with more information on Zika:

https://www1.nyc.gov/site/doh/health/health-topics/zika-virus.page

http://www.who.int/mediacentre/factsheets/zika/en/

https://www.cdc.gov/zika/

Here is the link to my sources page for this post.

Cures That Didn't Work: The Black Death

Why not live life to it's fullest when it could be over any minute? This was the sentiment of many people living in 14th century Europe during the outbreak of the Black Death. Two million people died from the Black Death, and people who weren't dead knew that they could die any day. In their remaining time on earth they decided to abandon the system and just do whatever they wanted. This wasn't a difficult thing to do because the system had basically fallen apart. During the worst outbreaks of the plague regular society stopped as people became too sick or too dead to do their jobs. Those who were still alive and well suffered from fear of the plague, famine (due to lack of food production), and unsanitary conditions (due to lack of garbage disposal). Anarchy took over the land because the governing class was dead or inactive.

Unknown - Jewish Encyclopedia

What Was the Black Death?

The black death first appeared in Italy in the year 1340 and was spread by sailors throughout Europe all the way up to England and Ireland. By the time it ran its course, the black death killed about two million people. The plague turned many bustling cities into ghost towns.

The sheer magnitude of destruction that the black plague caused is in itself a marker of modern society. Without the complex trade roots and high density of city populations, the black death probably would have started and ended in Italy. Or it might never have sprung up.

Symptoms

People who caught the black death generally died within a week or less. The symptoms started with a flu-like fever followed by vomiting. Then, pus-filled buboes appeared and parts of the skin turned purple from internal bleeding. During the last phase of the plague, the lungs filled with fluid and the patient died.

Ineffective Cures

Fear of the deadly Black Death resulted in many treatments that didn't work. These treatments seem illogical today, but in the midst of all the chaos and terror that surrounded the Black Death people were willing to try anything.

The physicians of the time simply had no idea of how to treat this deadly disease. They argued about how it was spread. Some said it was transmitted by sight, others argued that one could contract the disease just by thinking about it. Most physicians advised to purify the air with fire and good-smelling herbs and to avoid the sick at all costs. Some treated ill patients with blood-letting and pastes made of their own excrement, popular treatments at the time which didn't help anything.

One physician contracted the plague, and shockingly, survived by draining the pus from his own buboes. This cure may have worked, but it didn't stop other crazy cures from springing up.

During the middle ages the Church was a huge part of people's lives and the citizens of Europe wanted the Church to save them from the black death. The Church didn't have the power to do this and most of their priests were actually dead. Since it was the priest's job to deliver the last sacraments to the dying, most priests contracted the plague quickly. Many people lost faith in the Church and turned to other religious cults. One of these was the flagellants, a violent group that marched from town to town beating themselves as a sacrifice to God.  Despite these drastic measures the plague continued it's rampage.

Another awful measure taken to end the plague was a mass assassination of the Jews, who were said to have poisoned the wells causing the plague. Jewish people were tortured until they confessed to helping spread the plague and then they were burned at the stake. After all the Jews were gone, the black death still swept the land, but all the debts the townspeople owed to their Jewish neighbors were gone.

           Burning of Jews during the Black Death epidemic, 1349 Unknown - European chronicle, scanned and cropped from History of the Jewish People by H.H. Ben-Sasson, ed. (Harvard University Press, Cambridge, 1976) p.564-565

Aftermath of the Black Death

Eventually in the late 14th century the plague ran it's course and slowly disappeared, but it certainly didn't leave without a trace. The black death began the end of serfdom because so many died that labor became scarce and the still living peasants could demand higher wages and better conditions. This resulted in the peasants becoming more powerful. Art also changed, it became more macabre and paintings featuring death or illness became the norm.

How Was the Black Death Actually Spread?

The BBC documentary (Medieval Apocalypse) that I watched to learn about the Black Death didn't mention how the disease was actually spread. This sparked my interest so I googled it. According to to The Washington Post and Forbes gerbils, not rats probably brought the disease over from Asia, but there is also some evidence that the Black Death may have been airborne. It's fascinating how we are still questioning how a disease that occurred over hundreds of years ago was spread. I think this just goes to show how complex our world is.

Cholera and How It Changed the World

Where does change come from? When I think about change, I tend to picture social activist groups or something like that, but when I read The Ghost Map by Steven Johnson, I realized that change can be instigated by a much more elusive force: disease.

In London England 1854, a baby girl, just born to the Lewis family, died of cholera in a flat on Broad Street. Soon the entire neighborhood was ravaged by the disease which killed thousands of people by the time it ran its course.

Victorian England was not known for being medically advanced. Medical science at the time was practically the same as it was in the Middle Ages. Most people believed that all sickness was caused by "miasmas," or bad air. To quote Edwin Chadwick, a prominent political figure at the time, "All smell is disease."

John Snow, an anesthesiologist working in London at the time, was not convinced by the whole "all smell is disease" idea. He decided to investigate the cause of cholera himself.

After much strenuous snooping, John Snow was convinced that cholera was a water-borne disease. He, with help from local parishioner Henry Whitehead, traced the epidemic back to the Broad Street water pump. The water from this pump was contaminated by the cesspool the Lewis family had dumped the excrement of their sick baby daughter into. Almost everyone who drank from the Broad Street pump died of cholera.

This cholera epidemic was the beginning of a new age. Medical science advanced as people moved away from the old idea of disease and on to the new idea of disease-causing microbes. John Snow and Henry Whitehead created a disease map to show cholera's path of destruction. This map changed epidemiology, and it got people to start looking at the bigger patterns of a disease. The same type of maps are still used today. Cholera also changed waste management systems. People in London no longer piled up their excrement in house-size heaps that were shoveled right into the Thames. Complex sewer systems were built. Now safe sewer systems are a must for developed areas of the world.

This book was a fun read and the pages just flew by. I recommend it to all science and history nerds out there!