The New Ebola: Zika

By: Noopur Ranganathan

Waiting in the doctor's office with her baby son, Jose, Solange Fereira hoped it was nothing more than a case of malnutrition or perhaps a mild case of juvenile growth disorder. But her world came crashing down when the doctor confirmed her worst fears. Her baby boy, Jose Wesley, had microcephaly, a medical condition where babies are born with abnormally small heads and suffer from neurological disorders and short life expectancy.

Solange Ferreira lived in Brazil, the world's fifth largest country. Well known for its cinematic landscapes, kaleidoscopic culture, powerful music, dazzling festivities, and of course football fever, Brazil is no newcomer to feeling the heat under the spotlight. However, since May 2015, it has taken center stage for a completely different reason and little Jose was paying the price. Brazil is at the epicenter of the global pandemic, Zika.

Discovered in the Zika forest of Uganda in 1947, Zika is a mosquito borne virus that causes neurological disorders and neonatal malformations. However there is no evidence that directly links Zika to microcephaly. Infact there are several other factors that cause microcephaly. But experts at the CDC and various medical research laboratories in Brazil believe there is strong evidence for a connection between Zika and microcephaly. Dr. Maria Angela Rocha from the Oswaldo Cruz hospital in Recife, a state capital in northeast Brazil where the Zika virus has proliferated, stated that the staff has seen 300 cases of microcephaly in the past six months as compared to the average of five cases a year. Two neuropediatricians in Recife, Dr.Vanessa Van der Linden Mota and her mother Dr.Ana van der Linden, suspected something was terribly wrong when they began seeing dozens of microcephaly cases in just a short period of time rather than the occasional case every few months.Their concern intensified when they took on a case of twins where one baby was normal and the other had a serious case of microcephaly. The Zika virus was found in the blood of another baby that died due to microcephaly. The amniotic fluid from two pregnant women revealed genetic material of the Zika virus. Post delivery, their babies were diagnosed with microcephaly. These incidents and the spike in cases of congenital microcephaly, provided enough evidence to alert State Health authorities and state the Zika virus as the possible prime suspect for the rise in cases of microcephaly. In short, Zika virus is the prime cause of fetal microcephaly.

A flavivirus, the Zika virus, belongs to the family of Flaviviridae. It causes severe diseases such as Yellow fever, West Nile, Chikungunya, Japanese encephalitis and Dengue. Vincent Racaniello, Professor of microbiology at Columbia University, states that the genome is enclosed in a capsid and surrounded by a membrane, which contains the envelope glycoprotein. This glycoprotein allows the attachment of the virus particle to the host cell receptor to initiate infection.

The exact manner in which the Zika virus attacks the central nervous system of a fetus is not clear. However many theories abound. According to virologist Katherine Spindler from the University of Michigan, human cytomegalovirus (CMV) has a strong link with many birth defects, one among them being microcephaly, just like they saw in Brazil. The exact relationship between CMV and brain abnormalities hasn't been established as of yet but one report suggests that during early brain development, the stem cells (no details about the exact location of the brain) get attacked by the virus, thereby inhibiting the stem cell's' ability to differentiate into proper cells, resulting in the brain tissue getting destroyed. This early loss of fetal brain tissue may be the reason for the abnormal shape of the fetal brain. Another theory published in BMC Med Genomics attributes the occurrence of autosomal recessive primary microcephaly (MCPH) to the mutation of certain genes such as Microcephalin and WDR62. Due to the lack of deep research, these are only hypotheses that have been published. Since we are in a very early stage, there isn't much data, analysis, or conclusions as a result.

Transmitted by the Aedes aegypti mosquito, Zika has spread to 29 countries and is expected to infect 3 to 4 million people across the Americas. General Margaret Chan, World Health Organization Director, has declared it a public health emergency. Brazil has recorded 4000 cases of microcephaly since 2015. Doctors in Brazil struggle to find words of encouragement as they break the tragic news to infected young women. Devastated mothers try to cope with the sudden realization of the future their precious babies will face.

With very little research done on the Zika virus, we do not know its exact modus operandi. Due to this lack of knowledge, there are no vaccines to prevent it nor any effective treatment options to treat the infection. Herein lies the whole challenge of tackling the Zika virus. Due to the lack of knowledge and research in this area, there have been no data, analyses, or conclusive information that furthers the study of the Zika virus. As a result, we are relying on published hypotheses and suppositions that give the scientific community some direction to performing further in-depth research.

Rather unsophisticated, prevention of the mosquito bite remains our only defense at the moment. CDC has urged people to take precautions while travelling to the infected countries. Use of long sleeved shirts, long pants, socks, boots, insect repellents and mosquito net are some of the precautionary measures recommended. People, especially young women and pregnant women, have been advised against travelling to those countries. Brazil has undertaken measures to eradicate mosquitos through fumigation and supplying insect repellents to pregnant women free of charge.

We are just beginning to get a grasp of the behavior of the Zika virus. And the more we unravel, the more mysterious it becomes. Why only some women infected with the Zika virus have babies with birth defects while some others have normal babies? How does it affect only one baby among a set of twins? Does the virus affect other animals? Does it get transmitted by other species? What is the duration of the virus strain in the body? What are the chances of getting reinfected if one had contracted it before? Besides wrecking the fetal nervous system, does it cause any other damage?

Zika has fast become the most important public health challenge of this decade. There is an urgent need to find a potential cure in the form of a vaccine or a treatment. Tim Tellinghuisen, from Scripps Florida, is working on finding a chemical compound that inhibits the virus. Another group is analyzing the suspected link between Zika and microcephaly. And Seek, a London based biotechnology firm, is working on a very novel and creative solution by targeting the mosquito saliva. The human blood contains a coagulant that prevents us from bleeding to death. On the other hand, the saliva of the mosquito, contains an anti-coagulant that ensures the human blood it sucks, is maintained in its original liquid form for the mosquito to easily digest. Gregory Stoloff and his team of scientists from Seek are working on creating a vaccine against the mosquito saliva. The immune cells of those vaccinated will react with the mosquito's saliva and clump the blood it sucks, thus blocking the transmission of disease to humans and also killing the mosquito in the bargain.

These are just some of the ways in which scientists are trying to combat this menace. Currently, there is no conclusive data-- therein lies the whole challenge of Zika because we are still very early in the stage of research. Through a multi pronged approach, work has begun in earnest to understand, restrain and eventually eradicate this virus. One day, we hope to create that elixir that will set us free. However until then, thousands of babies, just like little Jose Wesley, will continue to suffer from severe mental and physical disabilities before reaching adulthood.

References:

1. Dana, Felipe, Mauricio Savarese, and Peter Prengaman. "Photographer reflects on

‘bucket baby,' Brazil child born with Zika virus-linked

microcephaly." Globalnews.ca. February 4, 2016.

2. Faheem, Muhammad et al. "Molecular Genetics of Human Primary Microcephaly: An Overview."

Ncbi.nlm.nih.gov. January 15, 2015.

3. Johnson, Reed, and Rogerio Jelmayer. "The Brazilian Doctors Who Sounded the

Alarm on Zika and Microcephaly." Wsj.com.January 29, 2016.

4. Lopez, Andres David. "Scripps Florida has Zika team aiming to fight virus."

Palmbeachdailynews.com. February 27, 2016.

5. McNeil Jr., Donald G., Catherine Saint Louis, and Nicholas St. Fleur. "Short

Answers to Hard Questions About Zika Virus." Nytimes.com. February 24, 2016.