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The Campaign to Battle Zika

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By: Melissa Pegues, Ph.D.

On February 1, 2016 the World Health Organization (WHO) declared the Zika outbreak a public health emergency, meaning that the response requires the coordination of global partners to detect infections, control mosquito populations, and develop vaccines and diagnostic tests to prevent the spread of the disease. With concerns that Zika will move into the US as summer begins, there is an urgent need to contain the epidemic. Congress, however, has been slow to respond and continues to debate how exactly to fund the fight.

Zika infection is rarely fatal and is commonly accompanied by symptoms such as rash, fever, and joint pain, but some do experience more serious symptoms including Guillain-Barre syndrome, a rare form of paralysis. However, Zika gained significant publicity when medical professionals in Brazil and other Latin American countries noticed a frightening association between Zika virus infection in pregnant women and babies born with microcephaly. Microcephaly is a rare birth defect where infants are born with underdeveloped brains and smaller than average head size. Although only considered an association for many months, studies of Zika infection in pregnant mice and monkeys have found evidence supporting the link between Zika infection and microcephaly. In support of the mounting evidence, Tom Frieden, the director of the Centers for Disease Control (CDC), recently stated that “It is now clear that the virus causes microcephaly.

While research moves quickly to demystify the Zika virus, the political system has failed to gain a foothold amongst the confusion. The White House had requested $1.885 billion towards the Zika fight in February, and in a rare bi-partisan effort, Marco Rubio (R-FL) and Bill Nelson (D-FL) topped Obama’s request with a $1.94 billion proposal that included $144 million for vaccine research that would also include funding for research into dengue fever and chikungunya. That proposal ultimately never came to a vote. The Senate has approved $1.1 Billion in emergency funds and the House of Representatives has offered a bill that would reallocate just $622 million from existing programs for the Zika response, but neither measure has been passed by both chambers.

The Capital Hill battle over Zika has revealed a number of underlying political viewpoints that each affect how politicians respond to this crisis. Republicans worry that abortions may increase due to the severe birth defects associated with Zika infections in pregnant women, and with evidence mounting that Zika can be sexually transmitted, Republicans are debating whether the better message is use of contraception or abstinence. Federal public health officials have countered that they do not believe their role is not to tell women if they should become pregnant, but rather focus on preventing spread of the disease. Pope Francis has weighed in and suggested that the use of contraception is acceptable to help prevent the spread of Zika.

On the other hand, Democrats have expressed concern over use of pesticides. In a proposal meant to help control mosquito vector populations, Senator John Cornyn (R-TX) suggested easing regulatory restrictions on pesticides. Democrats have accused Republicans of trying to exploit fears and countered that exceptions for use of pesticides already exist. The White House also commented that the Republican-led House’s proposal removes Clean Water Act protections that are not acceptable during this emergency. Democratic representatives Peter DeFazio (D-OR) and Grace Napolitano (D-CA) stated “Over the years, proponents of exempting pesticide spraying from the Clean Water Act have used the crisis of the day as the reason to support their legislation.”

While Congress debates how to best combat Zika, the CDC reports that the number of cases of pregnant women in the US with the virus has climbed to 279 as of late May, and multiple models are predicting the spread across the US. Furthermore, WHO chief, Margaret Chan, has cited a number of policy failures that allowed for lapses in mosquito control and the spread of Zika. At a recent World Health Assembly meeting, Chan said Zika took the world by surprise and revealed fault lines in the world’s collective preparedness. In addition, the spread of Zika, resurgence of dengue, and the emerging chikungunya threat are prices paid for “a massive policy failure that dropped the ball on mosquito control in the 1970s.”

With the outbreak of Zika spreading, many concerns have arisen over how to respond to Zika and prepare for other emerging threats. In a recent essay, Ronald A. Klain, the White House Ebola response coordinator from 2014 to 2015, urged Congress to put aside their differences and fund preventive measures for new epidemics. He stated that the threat of emerging disease is “not coming to the United States: It is already here.” In support of this, the Senate recently voted 93-2 to move forward with negotiations with the House of Representatives. Public officials have continued to urge politicians to focus on controlling the disease, but Chan stated that for now “all we can offer is advice. Avoid mosquito bites. Avoid pregnancy. Do not travel to areas with ongoing transmission.”

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Written by sciencepolicyforall

June 15, 2016 at 9:00 am

Posted in Essays

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Zika Update: Current Knowledge and New Directions

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By: Keith Jacobs, Ph.D.

Zika is the newest international viral outbreak alarming physicians, researchers and the general public. The virus, which is related to dengue, yellow fever, and West Nile viruses, was first isolated in 1947 from a rhesus monkey in the Zika forest of Uganda. Very limited research was performed on the virus over the next several decades. Of the limited work that was done – including one researcher even injecting himself (under the generic description of a “human volunteer”) and several others documenting their symptoms from accidental exposure – none of it was able to shed any light on the true nature of the virus. Due to its relative obscurity and mild symptoms, there was not any interest in even studying Zika.

Times have certainly changed, however, as Zika has now been declared a “public health emergency of international concern” by the World Health Organization (WHO) in the wake of a 2015 outbreak in Brazil. Zika is transmitted through the Aedes aegypti mosquito which is endemic to South America, however strong evidence suggests that Zika may be sexually transmitted as well. While mosquitos carrying Zika have not been found in the US, over 300 Americans have contracted Zika through either travel or sexual contact with a partner who has traveled to regions where Zika is endemic. The majority of adult patients infected with Zika fail to show any symptoms, with the minority who do only exhibiting mild, general maladies such as aches, fever and rash (with no deaths reported).

While Zika infection is not a concern for adults, Brazilian physicians have noticed a stark increase in cases on microencephaly (small heads/brains) in newborns concurrent with the recent epidemic. Zika virus has also been found in the brains of affected fetuses. These correlations did not provide enough evidence however to definitively state that Zika infection was causing these deformities. A careful assessment of the reported cases cited in Brazil indicates that the recent increased incidence of microencephaly may be at least partially due to awareness bias and a lack of standardized criteria for defining deformations. In other words, physicians may be simply observing what they are already looking for based off the initial reported correlation.

As the Zika story began to spread, an alternative explanation for the explosion of microencephaly surfaced. A group of Argentinian doctors argued that it is not the Zika virus but instead the larvicide pyriproxyfen that is responsible for the increased risk of microencephaly. Ironically, pyriproxyfen is added to water in order to control the spread of the very mosquito that carries Zika and other viruses. This report cited a recommendation by the nonprofit Brazilian public health organization the Brazilian Association for Collective Health (BACH) that criticized the use of pyroxifen and warned against its potential environmental and neurotoxic effects. To add to the controversy, pyriproxyfen is manufactured by a Japanese company that is very loosely connected to the agricultural corporation Monsanto, a popular enemy of environmentalists due to its corporate practices concerning the sale of genetically modified crops. Following these assertions, BACH curiously backed off their initial claims and decried the misinterpretation of their statement. In addition to the increasingly strong data connecting Zika infection with fetal brain abnormalities, there is no evidence to support a link between microencephaly and larvicides, and these claims have been disparaged by numerous authorities including the Brazil Ministry of Health:

“Unlike the relationship between the Zika virus and microcephaly, which has had its confirmation attested in tests that indicated the presence of the virus in samples of blood, tissue and amniotic fluid, the association between the use of pyriproxyfen and microcephaly has no scientific basis.”

A case study reported in late March provided the strongest connection to date between maternal Zika infection and fetal brain abnormalities. A woman was infected with Zika 11 weeks into her pregnancy, after which uterine imaging demonstrated a progressive reduction in fetal head size and eventually abnormal gross morphology of the brain. The pregnancy was eventually terminated, and autopsy confirmed large viral loads in the fetal brain and placenta with lower amounts present in other fetal tissues as well. Zika also remained present in the mother for up to 10 weeks following infection. Finally, on April 13th the Centers for Disease Control (CDC) officially declared that the preponderance of evidence supports a causal link relationship between Zika and birth defects.

Prior to this case, physicians believed that Zika only remained active in the body for a week following infection. Likely due to this study, the Centers for Disease Control now recommends that women wait at least 8 weeks after exhibiting symptoms before trying to conceive, or up to 6 months when a male sexual partner has contracted the disease. The absence of any strong symptoms in adults along with the long duration required for viral clearance may thus contribute to Zika’s danger, as pregnant and soon-to-be-pregnant women may be infected without having any knowledge of their exposure. The true risk of Zika, its potential effect on fetal neural development, can therefore be a hidden danger.

While severe birth defects are the most common and perhaps the most threatening aspect of Zika infection, the dangers of Zika are not restricted to pregnant women. Recently, more severe consequences of Zika exposure have been identified in adults. A study published in late February identified a causal link between Zika infection and diagnosis with Guillain-Barré Syndrome. Guillain-Barré syndrome is an auto-immune neurological disease that affects the peripheral (external from brain/spinal cord) nervous system, resulting in potentially severe muscle weakness. Guillain-Barré is often preceded by infection, especially from viral pathogens such as the related dengue fever virus. Systemic infection with these viruses induces an overactive immune system leading to persistent inflammation, and Zika likely acts through this same mechanism.

By leaving its host alive and utilizing abundant mosquitos as a carrier, Zika is likely more contagious than Ebola (which only spreads through direct contact between bodily fluids). The virus therefore has the potential to spread rapidly over a wide range, and without overt visible symptoms it may be difficult to track its true reach. In contrast with Ebola however, where local African culture and poor infrastructure promoted the spread of the disease, the Americas have much better public health resources and preparation. Additionally, a great deal of research is already underway working towards both improved understanding and treatment of Zika. Published studies have described the cell biology of Zika infection, the Food and Drug Administration in the US is reviewing diagnostic tests, and international efforts have already made progress on a vaccine. While the Zika outbreak is somewhat under control, the virus is not likely to go away any time soon. Hopefully the sum of these efforts will neutralize Zika before it becomes an even more significant international public health issue.

Written by sciencepolicyforall

April 14, 2016 at 1:00 pm

Science Policy Around the Web – March 8, 2016

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By: Swapna Mohan, DVM, Ph.D.

Kris Krüg via Photo Pin cc

Public Health Surveillance

Mystery cancers are cropping up in children in aftermath of Fukushima

After the Fukushima Daiichi Nuclear Power Plant accident in 2011 in Japan, a swift and efficient evacuation and containment plan ensured that human suffering was kept at a minimum. This included beginning a more thorough population surveillance for thyroid problems in Fukushima citizens under the age of 18. However, this thyroid screening for children and teens in the months that followed showed an unexpectedly high rate of thyroid related cancers. Anti-nuclear power activists concluded that it is the result of inhaled and ingested radioactivity from the Fukushima incident. However, scientists unequivocally disagree and stress that a majority of cases of thyroid abnormalities have not resulted from radiation exposure. Others indicate that it might be a result of overdiagnosis on the part of public health officials.  Since there are no baseline data from before the incident, it is impossible to verify whether this high report of cases is a direct result of radiation or are just indicative of a high number of thyroid carcinomas in children. Epidemiologists point out the error in comparing the results of this screening (where they used advanced devices to detect even unnoticeable abnormalities) to more traditional clinical screenings (where participants have already detected lumps or symptoms). In order to get a better idea of the baseline of thyroid abnormalities, scientists screened approximately 5000 children from other areas of Japan in comparable age groups. The data did not reveal a significant difference in the rate of thyroid abnormalities in the unexposed populations. This demonstrates that thyroid abnormalities in children is higher than previously thought and must be kept in mind when considering options such as complete or partial thyroidectomy. (Dennis Normile, Science News)

Global Health

A Zika breakthrough: Scientists detail how virus can attack fetal brain

The mechanism by which the Zika virus causes microcephaly in newborns has been described by scientists at Johns Hopkins University, Florida State University and Emory University. With lab grown stem cells, the researchers were able to demonstrate that the virus invades the brain cortex, killing the rapidly dividing stem cells there. This reduction in stem cell numbers in the cortex causes the brain to be malformed and underdeveloped. The study, published in Cell Stem Cell, is the first piece of evidence that conclusively ties Zika infections to microcephaly and developmental defects in newborns. Zika virus, known to induce only mild symptoms in adults, has been linked to an unprecedented increase in cases of microcephaly in babies born in Brazil last year. However, the link between the two had been so far, inconclusive. There was an alternate theory that the incidence of microcephaly could be caused by pesticide and use. This study showed the propensity that the virus has to neural stem cells over other cell types (such as fetal kidney cells or undifferentiated stem cells). The researchers observed that the virus used the rapidly dividing neural stem cells to replicate their numbers and in the end, this leaves the cells depleted and unable to grow properly. Scientists believe that getting a better insight into the pathogenicity of the virus on neural cells is essential for developing preventative and therapeutic measures to fight the disease. (Lena H. Sun and Brady Dennis, Washington Post)

STEM diversity

NSF makes a new bid to boost diversity

To understand why women and certain minorities are underrepresented in the science filed, the National Science Foundation (NSF) has launched an initiative aimed at increasing diversity in the scientific community. The 5-year, $75 million program named INCLUDES (Inclusion across the Nation of Communities of Learners of Underrepresented Discoverers in Engineering and Science) targets proposals for scaling up involvement of underrepresented groups in science education and STEM fields. The proposals solicited for this initiative are required to outline an effective strategy for broadening participation by working with industry, state governments, schools and nonprofit organizations. While NSF has over the years, funded several similar initiatives aimed at increasing diversity, this one is expected to test out novel ideas and approaches. The initial response to this program has been largely positive, with commentators calling it “a bold new initiative” and having high expectations on its potential to strengthen the participation of underrepresented groups in science. (Jeffrey Mervis, Science)

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Written by sciencepolicyforall

March 8, 2016 at 9:00 am

Science Policy Around the Web – January 29, 2016

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By: Daniël P. Melters, Ph.D.

Infectious Diseases

Zika virus, linked to microcephaly, on the rise

Only a few months after the scare of the epidemic of chikungunya, a new virus has emerged on the American continents: Zika virus. The same mosquito (Aedes aegypti) that transmits yellow fever, dengue, and chikungunya also transmits this virus. In the last few months of 2015, there was a sharp rise in babies born with microcephaly. Some hospitals in north Brazil that would only see five cases a year, now see over 300 in six months. These babies have abnormally small heads and the rare neurological disorder Guillain-Barré syndrome. The rise in cases with microcephaly strongly correlated with an ongoing Zika virus epidemic in the north of Brazil. In addition, the Zika virus RNA was found in the amniotic fluid of two fetuses. It is thought that women who were pregnant became infected with the virus and gave it to the growing fetus. Nevertheless, there is no formal evidence that the Zika virus causes microcephaly. In fact, a recent report argues that a surge in finding birth defects is too blame for the increase in microcephaly cases in Latin America.

This has not stopped local and global authorities from warning people of the potential dangers of the Zika virus. Brazil has suggested its citizens in affected regions not get pregnant. The CDC in the U.S. is warning tourists who go to regions where Zika virus is epidemic to take precautionary measures to prevent being bitten by mosquitos. On Thursday, January 28th, the World Health Organization declared an International Emergency. The last International Emergency was the Ebola outbreak in West Africa. Another complicating factor is the expected increase in number of mosquitos due to El Niño. Although most people who get infected by Zika virus will remain asymptomatic, some people will have a rash and a fever. As of now, no cure exists. Therefore, researchers around the world are rushing to develop a vaccine. Two potential vaccines against West Nile virus, after being repurposed for Zika, might enter clinical trials as early as late 2016, according to Dr. Fauci (NIH/NIAID) [recent talk by Dr. Fauci on emerging viruses]. But caution about a quick cure is warranted, as it might take several years before a Zika vaccine becomes commercially available. (, BBC News website)

Mental Health

One step closer to understanding schizophrenia

Schizophrenia is a debilitating psychiatric disease that affects over two million people in the United States alone. Often, this disease start in the later years of adolescence and early adulthood. Delusional thinking and hallucinations characterize schizophrenia, but the drugs available to date to treat schizophrenia are blunt and frequently patients stop using them because of their side effects. Although this new study will not lead to new treatments on the short term, it does provide researchers with first firm biological handle on the disease.

The developing human brain is the site of neuronal pruning. At first, the brain makes an excessive number of connections between neurons, but as children grow-up, most of these redundant connections are lost. You can see this a competition between the connections where the strongest ones survive. Neuronal pruning in the prefrontal cortex, the part of the brain involved in thinking and planning, happens in adolescence and early adulthood. The latest finding, published in Nature, found that people who carry genes that accelerate or intensify that pruning are at higher risk of developing schizophrenia than those who do not. To date, no specific genetic variant has been found, although the MHC locus seems a likely candidate. Indeed, one specific gene in this locus, C4 gene, is involved in neuronal pruning. The C4 gene produces two products: C4-A and C4-B. Too much of the C4-A variant results in too much pruning in mice, which would explain why schizophrenic patients have a thinner prefrontal cortex. These new findings help to connect the dots better than ever before. Next up will be developing drugs that regulate neuronal pruning and the hope is that this will create a new anti-schizophrenia drug. (Benedict Carey, New York Times)

Technology

Analyzing body chemistry through sweat sensor

A small, wearable sensor has been created that can measure the molecular composition of sweat send those results in real time to your smartphone. The sensor, a flexible plastic patch, can be incorporated into wristbands. Several labs have been working on developing such a patch for a while, but most of them could only detect one molecule at a time. This newly developed flexible printed plastic sensor can detect glucose, lactate, sodium, potassium, and body temperature. When the sensor comes in contact with sweat an electrical signal is amplified and filtered. Subsequently, the signal is calibrated with the skin temperature. This latter step is essential, according to the lead scientist Jarvey. The data is then wirelessly transmitted to your smartphone. Because the sensor is not as accurate as a blood test, rigorous testing for medical use is therefore required.

The potential of this new devise is that it can tell, for instance, a diabetic patient in real-time that his blood sugar levels are too low or too high. It could also tell someone who is physically active that she is getting dehydrated and needs to drink water. One particular project could greatly benefit from this new technology. Last year President Obama announced the Precision Medicine Initiative. The goal of this initiative is to enroll over one million American participants and follow them over time to learn about the biological, environmental, and behavioral influences on health and disease. After all, most disease still do not have a proven means of prevention or effective treatments. Having technology such as this that can monitor and track basic biological data in real time could provide a wealth of information to researchers looking to make connections between a person and a disease.  (Linda Geddes, Nature News)

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Written by sciencepolicyforall

January 29, 2016 at 9:00 am