Monthly Archives: March 2016

Zika Virus, Part 3: Update on the Science, Some History, a Little Politics, and an Appearance by Pope Francis

Much has happened since our lasting posting on the Brazilian Zika outbreak (1). In particular, the major topic of our last posting was the uncertainty regarding whether Zika virus causes congenital birth defects. Recent findings may be settling the issue.

One reason for the earlier uncertainty was that although Zika virus has spread to more than a dozen countries since its discovery in Uganda more than 50 years ago, Brazil remained the world’s only country in which the virus was associated with microcephaly. However, in February 2016, Brazil’s neighbor, Colombia, now the world’s second-most Zika-affected country, reported its first cases of birth defects linked to Zika.

More direct and compelling evidence for Zika as an agent of microcephaly was reported early this March in the New England Journal of Medicine (2). Ultrasound examination of Zika-infected pregnant woman revealed that 29 percent of them carried fetuses suffering “grave outcomes, including fetal death, placental insufficiency, fetal growth restriction, and CNS injury.” Zika infection of the mothers was confirmed by reverse-transcriptase–polymerase-chain-reaction assays of blood and urine specimens. “To date, 8 of the 42 women in whom fetal ultrasonography was performed have delivered their babies, and the ultrasonographic findings have been confirmed.”

Although the above study examined only 88 women, all at one clinic in Rio de Janeiro, an article in the New York Times (March 5, 2016) quotes Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases as saying, “Now there’s almost no doubt that Zika is the cause.”

Another notable report described a case of a pregnant woman who, while living in Brazil, came down with a Zika-like feverish illness at the end of the first trimester of her pregnancy (3). The mother opted to abort her 29-week-old fetus after it showed signs (by ultrasonography) of microcephaly—subsequently confirmed by autopsy of the fetus. Importantly, a flavivirus was visualized in the fetal brain by electron microscopy, and the entire Zika genome (unambiguously identified by reverse-transcriptase–polymerase-chain-reaction assay) was recovered from it.

Next, we consider a new finding that Zika can be present in breast milk. Whereas Zika is an arthropod-borne virus that is transmitted primarily by its mosquito vector, our first posting on the Brazilian Zika outbreak noted at least one instance in which Zika was transmitted via a blood transfusion (4). In addition, there were reports of Zika being sexually transmitted (5). Now there is a report of Zika virus in the breast milk of a mother in New Caledonia (6).

The woman was feverish in July 2015 when she arrived at the hospital to give birth. Nevertheless, she breast fed her apparently healthy baby immediately after delivering it. Samples of the mother’s serum and breast milk then tested positive for Zika virus by reverse-transcriptase–polymerase-chain-reaction assay, while a test of a serum sample from the 3-day–old baby was ambiguous. The mother’s fever, now accompanied by a characteristic Zika rash, persisted for the next several days. Nonetheless, she and her baby were each healthy when they left the hospital.

This report would appear to raise considerable concern that a Zika-infected mother might transmit the virus to her baby via her breast milk.  All the same, the US Centers for Disease Control and Prevention (CDC) maintains that the benefits of breastfeeding outweigh the theoretical risks of Zika virus infection via breast milk, and recommends that infected women should breastfeed.

Next, we consider some recent history. On February 1, 2016 the WHO declared that Brazil’s Zika outbreak is as an international public-health emergency. But, uncharacteristically, the WHO put forth this pronouncement despite the fact that the scientific community was still not sure of the threat that Zika poses to humans. In point of fact, this was the first instance in which the WHO proclaimed its highest level of alarm for an agent of uncertain danger. [The CDC likewise elevated its Zika virus surveillance program to its highest priority level.]

Why did the WHO make its frightening declaration when the threat posed by Zika was still not clear? Obviously, a failure to take immediate action might allow the Zika outbreak to get well out of hand, with possibly devastating consequences.

In contrast to the hurried response by the WHO to the Zika outbreak, that agency responded more leisurely to the 2013/2014 West African Ebola outbreak, which did get out of control, and which persists even to this day. So, perhaps the more urgent response of the WHO to the Zika outbreak reflects a lesson learned from the Ebola affair.

But, why did the WHO wait longer before responding to the West African Ebola outbreak? One reason is because it was strongly criticized for “overreacting” to the risk posed by the 2009 H1N1 influenza epidemic—which turned out to be far less threatening than originally feared.

While the WHO may have learned a lesson from its somewhat unhurried response to the Ebola outbreak, its more urgent February 1, 2016 Zika declaration did not go far enough for some observers, since it stopped short of advising pregnant women not to travel to Zika-affected regions. For that reason, the WHO has been accused of taking political considerations into account, to the detriment of good public health policy. Any travel ban—even one aimed only at pregnant women—would be embarrassing and costly to Brazil, which has been moving ahead with its plans to host the Olympic Games this summer. Still, hundreds of thousands of people from around the world, including female spectators and participants, some of whom may be pregnant, are expected to attend.

Lastly, we note that the Zika outbreak has been stirring up a fierce religious debate in Latin America; a debate that is actually challenging the very authority of the Catholic Church in the hemisphere. But first, an earlier posting on the blog recounted how in 2002 Colin Powell, at the time Secretary of State in the George W. Bush administration, advocated that sexually active young people should use condoms to protect themselves against HIV/AIDS (7). Powell’s advocacy of condom usage was contrary to the Bush administration’s strongly held abstinence-only approach for preventing sexual transmission of HIV. Moreover, then as now, Powell’s stance was contrary to the official position of the Catholic Church on artificial contraceptives. Nevertheless, Powell asserted, “I certainly respect the position of the Holy Father and the Catholic Church. In my own judgment, condoms are a way to prevent infection. Therefore, I not only support their use, I encourage their use among people who are sexually active and need to protect themselves.”

Now, presumably in response to reports that Zika virus might be transmitted sexually, Pope Francis declared on February 18, 2016—during a mid-air news conference on his flight from Mexico back to Rome—that contraceptives could be used to block the spread of Zika virus. That same day, the WHO advised the sexual partners of pregnant women to use condoms, or to abstain from sex, if they live in a Zika-affected area, or if they are returning from one of those areas. Also, several Latin American governments asked their female citizens to delay getting pregnant.

Pope Francis after deplaning in Ciudad Juarez, Mexico, on February 17, 2016
Pope Francis after deplaning in Ciudad Juarez, Mexico, on February 17, 2016

Those suggestions, whether from Latin American governments, or from the WHO, offended many Latin American women, in part because of the strict anti-abortion laws, and laws that restrict access to contraceptives in some of those countries. Moreover, the situation is compounded in some regions of the hemisphere by rampant sexual violence against women. In any event, the Pope’s pronouncement intensified an angry debate over contraception, and abortion as well, that was already underway in Latin America.

Pope Francis did not condone abortion, which he referred to as an “absolute evil.” But, he did make a point of justifying his statement condoning contraception by citing as a precedent a 1960 judgment by Pope Paul VI, which permitted nuns in the Belgian Congo, who were in danger of being raped, to use contraceptives.

Pope Francis’ remarks, such as “avoiding pregnancy is not an absolute evil,” has encouraged Latin American opponents of the church’s longstanding ban on the use of artificial contraceptives to campaign harder against those policies. In any case, the Pope’s pronouncement, and the heated response it is provoking, shows that the Zika outbreak is now impacting religious institutions. And, as noted by Ana Ayala, the director of the Global Health Law Program at Georgetown University, “The pope’s positioning on this subject can significantly shift how governments see access to contraception.” See Aside 1.

[Aside 1: Ayala’s comment can be found in a February 18, 2016 article in the New York Times, entitled “Francis Says Contraception Can Be Used to Slow Zika”, by Simon Romero and Jim Yardley. This piece offers an extensive account of the response in Latin America, and elsewhere, to the Pope’s comments. “While international researchers are still trying to prove definitely a link between Zika and microcephaly, the pope’s comments on contraception seemed to catch up to the reality in parts of the hemisphere where many Catholics pay little heed to the church’s teachings on birth control.”]

References:

  1. Zika Virus, Part 2: The Link to Birth Defects, Is It Real?, Posted on the blog February 23, 2016.
  2. Brasil, P., Pereira, J.P., Gabaglia, C.J., et al., Zika Virus Infection in Pregnant Women in Rio de Janeiro — Preliminary Report, N. Engl. J. Med., March 4, 2016DOI: 10.1056/NEJMoa1602412
  3.  Mlakar, J., Korva, M., Tul, M., et al., Zika Virus Associated with Microcephaly, N. Engl. J. Med. 2016; 374:951-958 March 10, 2016 DOI:10.1056/NEJMoa1600651
  4. Zika Virus: Background, Politics, and Prospects, Posted on the blog February 4, 2016.
  5. Foy, B.D., K. C. Kobylinski, J.L. Foy, et al., 2011. Probable Non–Vector-borne Transmission of Zika Virus, Colorado, USA, Emerg Infect Dis. 17: 880–882.6.
  6. Myrielle Dupont-Rouzeyrol, M., Biron, A., O’Connor, O., Huguon, E., and Descloux, E., Infectious Zika viral particles in breastmilk, The Lancet 387:1056, March 2016. doi:10.1016/S0140-6736(16)00624-3
  7. Colin Powell on HIV and Condoms, Posted on the blog July 30, 2014.

 

 

 

 

 

 

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Gravity Waves: Human Curiosity Knows no Bounds

Gravitational waves were detected for the first time this past February by the Laser Interferometer Gravitational-Wave Observatory (LIGO), which consists of two widely separated installations within the United States — one in Livingston, Louisiana and one in Hanford, Washington. Before LIGO, there was no technology able to detect these vanishingly weak waves. Consequently, LIGO’s accomplishment has generated considerable excitement in the physics and astronomy communities. First, it confirmed the existence of gravity waves; a key prediction of Einstein’s 1915 theory of general relativity. Second, and remarkably, LIGO detected gravitational waves that were emitted during the final fraction of a second of the merger of two black holes, which were over a billion light-years away (one light-year is about 5.88 trillion miles)! What’s more, LIGO’s findings in fact proved the existence of black holes. Prior to LIGO’s achievement, the existence of black holes was widely accepted, but based only on indirect evidence.

LIGO 1

Physicists and astronomers are also excited by the potential of gravitational-wave detectors to shed light on other basic concerns, such as determining whether gravitational waves travel at the speed of light—an important issue since it would answer whether gravity is transmitted by particles having no mass. These detectors may also enable astronomers to measure the rate at which the universe is expanding, and perhaps observe the effect of dark energy on space.

Most exciting perhaps, gravitational wave detectors may enable astronomers to see almost all the way back to the big bang. Until now, astronomers could only see as far back as 380,000 years after the big bang, when the universe became transparent to light and other electromagnetic radiation. However, gravitational waves would have traveled unhindered through the newborn universe. By scrutinizing gravitational waves from the infant universe, cosmologists hope to learn more about its beginning and, perhaps, even uncover evidence for the existence of other universes. Moreover, gravitational wave detectors might even lead to a “theory of everything (1).”

Scientists from other disciplines, as well as lay people, might very well marvel at the sheer ingenuity and persistence of the physicists and engineers who designed LIGO; a result of decades of instrument research and development. But first, here is a very brief account of gravity waves.

Einstein’s theory of general relativity predicts that matter emits gravity waves. These waves disturb the fabric of space, in fact causing the distances between objects to ebb and flow in an oscillatory manner. However, these oscillations are far too small to have been detected prior to LIGO.

Here is Lawrence M. Krauss’ account in the New York Times of the LIGO technical achievement (2). “To see these waves, the experimenters built two mammoth detectors, one in Washington State, the other in Louisiana, each consisting of two tunnels about 2.5 miles in length at right angles to each other. By shooting a laser beam down the length of each tunnel and timing how long it took for each to be reflected off a mirror at the far end, the experimenters could precisely measure the tunnels’ length. If a gravitational wave from a distant galaxy traverses the detectors at both locations roughly simultaneously, then at each location, the length of one arm would get smaller, while the length of the other arm would get longer, alternating back and forth …To detect the signal they observed they had to be able to measure a periodic difference in the length between the two tunnels by a distance of less than one ten-thousandth the size of a single proton. It is equivalent to measuring the distance between the earth and the nearest star with an accuracy of the width of a human hair….If the fact that this is possible doesn’t astonish, then read these statements again. This difference is so small that even the minuscule motion in the position of each mirror at the end of each tunnel because of quantum mechanical vibrations of the atoms in the mirror could have overwhelmed the signal. But scientists were able to resort to the most modern techniques in quantum optics to overcome this.” See Asides 1 and 2.

[Aside 1: Lawrence M. Krauss is a theoretical physicist and director of the Origins Project at Arizona State University. He is the author of “A Universe from Nothing: Why There is Something Rather than Nothing.”]

[Aside 2: Interestingly, the LIGO detectors had just been turned on for their first observing run when they discovered a clear signal emanating from the colliding black holes. Also, recall that these black holes were over a billion light-years away.]

Krauss later says, “Too often people ask, what’s the use of science like this, if it doesn’t produce faster cars or better toasters. But people rarely ask the same question about a Picasso painting or a Mozart symphony. Such pinnacles of human creativity change our perspective of our place in the universe. Science, like art, music and literature, has the capacity to amaze and excite, dazzle and bewilder. I would argue that it is that aspect of science — its cultural contribution, its humanity — that is perhaps its most important feature (2).”

Also, consider the following from an editorial in the New York Times. “The curiosity of our species knows no bounds; more remarkably, neither does our capacity for satisfying it. And that is truly wonderful in itself, even if it doesn’t lead to a better toaster (3).”  See Aside 3.

[Aside 3: The development of LIGO was made possible by support from the National Science Foundation. “By coincidence, at about the same time that the LIGO discovery was announced, the U.S. House of Representatives passed a bill requiring that National Science Foundation grants be justified ‘in the national interest.’ It is doubtful that LIGO would have survived such political meddling (3).”]

References:

  1. “The Theory of Everything,” Posted on the blog September 15, 2015.
  2.  Lawrence M. Krauss, Finding Beauty in the Darkness, Opinion in Sunday Review, New York Times, February 14, 2016.
  3. The Editorial Board, New York Times, February 17, 2016