The Zika Virus (#1)

By Lauren A. R. Tompkins

A collection/series of blog posts entitled:

The Zika virus pandemic – insights from a scientist

The past few weeks (March 2016) have provided major advances in our understanding of Zika virus through publication of several key research studies. In the wake of the global response to the Ebola virus outbreaks, measures to expedite research and prevention strategies for Zika virus are now underway. Emerging infectious diseases, which manifest outbreaks without warning and often without the presence of effective control measures, are dramatically affecting how information is shared between scientists and how prevention strategies, such as vaccines, are regulated. In a time of public health crisis, the scientific community has pulled together with the common goal of a rapid response to combat Zika virus.

 First blog post for this series, entitled: The politics of Zika virus

             On Monday (April 11, 2016), Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), and Dr. Anne Schuchat, principal deputy director of the Centers for Disease Control and Prevention (CDC), addressed reporters at a White House briefing. The topic of discussion was Zika virus and an appeal for the necessary funds to prepare for mosquito season, when the virus will likely spread to the southern United States. According to the CDC, at least 346 people from the continental United States have been infected with the virus, mainly through travel-related exposure. However, with the summer months approaching, and mosquito populations expanding with warmer weather, local transmission of Zika virus is likely to occur.

A gridlocked Congress is not an unusual concept to the American people. Still, a “public health crisis of international concern”, as stated by the World Health Organization (WHO) in February of this year, should theoretically hold weight if politicians continually claim to have the best interests of Americans in mind, let alone the public health of all inhabitants of our planet. Unfortunately, Congressional Republicans are tightening their wallets and stubbornly resisting the allocation of necessary funds for combating Zika virus. Rather than listening to knowledgeable scientists and public health officials, pleas for appropriations are falling on deaf ears. Indeed, President Obama has asked Congress, again, for the full $1.9 billion dollars that is required to fuel Zika virus research. On Tuesday (April 12, 2016), Congress approved a bill to provide financial incentives to companies to develop treatments for Zika virus infection, although no funding was provided. Currently, roughly $600 million has been diverted from the Ebola virus funds towards Zika virus research.

Let me pause here to let the following concept sink in: now that Ebola is no longer a potential threat to the United States, it is assumed that the rest of the world can handle the fallout itself…but, that doesn’t seem to be the case. Dr. Margaret Chan, WHO director-general, announced in January that although all known chains of transmission in West Africa had stopped, including the most recent outbreak in Liberia, new flare-ups are likely to occur. This will require a sustained response for prevention of future outbreaks. Indeed, Sylvia Mathews Burwell, U.S. Health and Human Services Secretary, told reporters, “We face two global health challenges, Ebola and Zika, and we don’t have an option to set one aside in the name of the other.” The decision to pull money from the Ebola fund is somewhat analogous to withdrawing military troops from countries where the United States has intervened and then pulled out, for one reason or another, hoping for sustainable change in those regions. Historically, this system doesn’t seem to work, and furthers the global opinion that Americans don’t care about non-Americans.

There is a comical phrase among infectious disease scientists: “ATM diseases” get the money. Essentially, the majority of funding is allocated to AIDS/HIV, tuberculosis, and malaria research, which some say are “sexy diseases” as they engender public attention. We know that these diseases are incredibly important to study and combat, but when funding is limited, research on other diseases stalls. Why don’t we know that much about Zika virus? It didn’t cause outbreaks until recently. This is the problem with emerging pathogens: they burst forth rapidly when we don’t have the tools to control them. The scientific community is now scrambling, working around the clock to learn as much as possible, as quickly as possible. $600 million sounds like a great deal of money, but it is nowhere near enough to fight Zika virus, as Dr. Fauci reiterated on Monday.

Pull-quote: “When the president asked for $1.9 billion, we needed $1.9 billion.” – Dr. Fauci, NIAID

One day several years ago, as a novice virologist, I was star struck when I met Dr. Fauci during one of his routine visits to the laboratories of the NIAID. The first thing I noticed was Dr. Fauci’s notorious New York accent, the second, his calm demeanor, humility, and compassion. His lectures inspired me, giving me great faith in the leaders of our scientific community. Why this faith is lacking in our Congressional leaders is nonsensical to me. If we cannot trust those we have appointed to run programs ethically and passionately, then what is the point of having these leaders?

Pull-quote: “Everything we look at with (Zika) virus seems to be a bit scarier than we initially thought.” – Dr. Schuchat, CDC

The NIAID and CDC, institutions that preserve public health in America, are not the only scientific leaders voicing the urgency of combating infectious disease outbreaks before they become uncontrollable pandemics. The WHO has also emphasized the potential consequences of a Zika virus pandemic. Indeed, although Zika virus is an old virus (it was discovered in 1947), it emerged as a rapidly spreading pathogen causing sizeable outbreaks in recent years. In the span of about one year, 440,000 to 1.3 million Brazilians have been infected with Zika virus, which has spread to at least 33 countries. At this point, the association between Zika virus infection during pregnancy and microcephaly, a condition among infants resulting in a smaller than normal head size, has essentially reached causality. That is, scientists can definitively and causally link the virus to microcephaly. [In subsequent posts, I will present some of the important research rocketing into publication regarding this issue.] In addition to microcephaly, the WHO acknowledges that Zika virus infection likely causes Guillain-Barré syndrome, an autoimmune disorder in which a person’s immune system attacks his/her own nerves.

Science is not devoid of political influence. Granted, financial resources are not endless, but history has shown the rapidity with which infectious diseases can spread and the devastation that follows. We were not prepared for Ebola virus, which claimed the lives of over 11,000 people. Will the necessary funding come for Zika virus research, or are we destined to continually ignore potential public health crises until it’s too late to combat them?

Embed from Getty Images

Hot and Spicy Chemicals

By Dr. Doris Kimbrough

You grab a bag of corn chips and a bowl of salsa out of the refrigerator and settle in to watch TV. The salsa is hotter than you expected and after about five chips, your mouth is on fire. Big gulps of ice water don’t help, so you head back to the kitchen to look for sour cream or a glass of milk. What is going on in your mouth? How can cold salsa from the fridge burn your mouth? Why doesn’t cold water help the way it would for hot soup or hot tea? How does the sour cream or whole milk solve the problem?

To answer these questions we have to look at some special nerve cells (neurons) and the chemicals found in hot peppers. In addition to the nerve cells that help you move (motor) and control body functions (autonomic) you have lots of different kinds of sensory nerve cells. Sensory neurons are responsible vision and hearing and all your other senses. There are many different types of neurons involved in touch. Some can detect pain; others respond to pressure, heat, cold, or itchiness to name a few. The nerve cells that detect heat are the ones we need to focus on for this story.

Heat detecting neurons don’t work at or below normal body temperature; think of them as sleeping until you touch a hot stove when they wake up and tell you “Ouch, pull back! Pull back!” Hot peppers like jalapeños contain a chemical called capsaicin (cap-SAY-shin) that fools these nerve cells. The capsaicin binds to the nerve cells and wakes them up. Your brain gets signals that something is burning you even though nothing that is actually hot (in temperature) is involved. There are other chemicals that can do this: piperine and sabinene are chemicals found in ground pepper and curry spices.

So why doesn’t a nice cold drink of water help with the burning? Capsaicin is a chemical that is hydrophobic—literally: “water fearing”. Capsaicin doesn’t really fear water; it can’t because it is a molecule, which cannot have feelings. However hydrophobic compounds, like capsaicin, do not dissolve in water. Other hydrophobic substances are vegetable oil, wax and gasoline. So when you gulp cold water because spicy salsa is “burning” your mouth, the capsaicin stays bound to your neuron and your brain still gets signals that your mouth is burning. Hydrophobic compounds do dissolve in other hydrophobic substances, like oils or fats. You may have heard the expression, “like dissolves like”. The fat in sour cream and whole milk will dissolve the capsaicin and remove it from the nerve cell. This turns off the signaling to the brain and lets you get on with your life.

About the author: Doris Kimbrough is a chemistry professor at CU Denver. She grew up in Atlanta, GA, and went to college at the College of William and Mary in Virginia and to graduate school at Cornell University in Ithaca, New York. She has loved science and chemistry since she was a little girl when her chemist father let her play (safely!) with stuff in his lab.