Around the World as ‘Fast as Money’
Starting in 2015, infection by the Zika virus exploded across Brazil, Latin America, and the Caribbean. Zika is spread usually by the bite of the Aedes aegypti mosquito, which lives in subtropical climates (although recent studies have shown that Zika can also be transmitted sexually). Thanks to climate change, the mosquito’s range has expanded north into the United States, especially southern Florida and south Texas. By the summer of 2016, A. aegypti may spread as far north as New York state (“On the Seasonal Occurrence and Abundance of the Zika Virus Vector Mosquito Aedes aegypti in the Contiguous United States,” Andrew J. Monaghan, et al., PLOS Currents Outbreaks , March 16, 2016; dx.doi.org/10.1371/currents.outbreaks.50dfc7f46798675fc63e7d7da563da76).
For most patients, the Zika virus is merely a nuisance, causing a week of rash and fever. But if a pregnant woman is infected by the virus, it can cause her child to be born with microcephaly, that is, a small, malformed head and brain (“Zika Virus and Birth Defects: Reviewing the Evidence for Causality,” Sonja A. Rasmussen, et al., New England Jour nal of Medicine , April 13, 2016; nejm.org/doi/full/10.1056/ NEJMsr1604338). Since the outbreak began in Brazil, about 5,000 babies have been born with microcephaly; abortion is illegal there, and contraception is difficult to get.
At the same time, in the United States, particularly in the South where A. aegypti have settled in, states have passed laws restricting women’s rights to pregnancy termination services. Florida and Texas have recently enacted legislation that has not only shut down most reproductive health clinics and imposed regulations for those seeking to end a pregnancy, the states have also banned abortions past 20 weeks’ gestation (24 weeks in Florida’s case). Zika cannot usually be detected until the third trimester of pregnancy, which means that women in these states whose fetuses become stricken with microcephaly will be forced to complete their pregnancies.
In addition, these southern states lack the tax base that would give them the funds to help eradicate A. aegypti . In February 2016, President Barack Obama asked Congress to authorize more than $1.8 billion in emergency funding to fight the Zika virus. So far, Congress has not responded (“On Zika, Congress Is Failing to Do Its Job,” The New York Times , April 14, 2016; nytimes.com/2016/04/15/opinion/on-zika-congress-is-failing-to-do-its-job.html).
To be fair, Zika will probably not spread in the United States the way it did in Brazil. For one thing, we in the U.S. usually have screens to keep mosquitos out of our houses and air conditioning to keep us indoors. According to the World Health Organization (WHO), the dissemination of Zika in the continental United States will mimic that of dengue, which is spread by the same mosquito. The difference lies in the consequence of even a single case to a family. “Zika’s effect on unborn children is devastating,” says Dr. Scott Lillibridge, an epidemiologist at the Texas A&M Health Science Center School of Public Health (Goats and Soda: “How Contagious Is Zika?” Michaeleen Doucleff, NPR, April 16, 2016; npr.org/sections/goatsandsoda/2016/04/15/473976155/how-contagious-is-zika).
Zika has officially been declared a pandemic, that is, a “public health emergency of international concern,” or PHEIC (“WHO Director-General Summarizes the Outcome of the Emergency Committee regarding Clusters of Microcephaly and Guillain-Barré Syndrome,” Margaret Chan, Media Centre, WHO, Feb. 1, 2016; who.int/mediacentre/news/statements/2016/emergency-committee-zika-microcephaly/en). This is only the fourth time that the organization has declared a PHEIC since establishing its International Health Regulations (IHR) in 2005 to manage the peril of health risks spreading across borders (who.int/ihr/about/en). The other PHEICs have been the H1N1 influenza in 2009 and polio and Ebola in 2014.
IHR is only the latest move in the historical struggle to control the international dissemination of health risks. “As early as the 14th Century, people used quarantine to keep diseases like the plague from spreading across borders,” according to the Centers for Disease Control and Prevention (CDC) (Global Health: “10 Years of International Health Regulations: Why They Matter,” Feb. 9, 2016; cdc.gov/globalhealth/stories/ten_years_ihr.htm).
Rita R. Colwell of the Center for Bioinformatics and Computa tional Biology at the University of Maryland believes that the dispersion patterns of cholera (Vibrio cholera), which has plagued humans for 2,500 years, provides a model for the international spread of disease. “Until the early nineteenth century, this disease was primarily confined to the Indian subcontinent, but it then spread to Europe and the Americas,” she writes in her article “Infectious Disease and Environment: Cholera as a Paradigm for Waterborne Disease” (Internation al Microbiology , Vol. 7, No. 4, Dec. 2004, pp. 285–9; www.im.microbios.org/0704/0704285.pdf). Colwell continues, “Since 1817, western medical history has described seven global cholera pandemics, each spreading illness and death around the world.” As she notes, in 1832, cholera reached New York City. Within 2 weeks, it hit Philadelphia. From there, it traveled along the East Coast all the way to the Gulf of Mexico. The epidemic lasted 19 more years.
It was London physician John Snow who made the link between sewage, drinking water, and cholera. At the time, it was assumed that bad smells, or “miasma,” spread the disease. In 1854, Snow made a map of that summer’s cholera cases which showed that all of them clustered around a particular water pump on Broad Street (now Broadwick Street in Soho). The well had been contaminated by a woman who emptied a dirty diaper in a nearby cesspool. Her baby was ill with cholera from another source. Within 3 days, 127 people who drank the water from that pump died of cholera. Within months, 616 died. (Workers at a nearby brewery were untouched, as they consumed the house product all day and never touched well water.) Snow’s findings, published in 1855 (“On the Mode of the Communication of Cholera”; www.med.mcgill.ca/epidemiology/hanley/c609/material/SnowCholera/On_the_mode_of_communication_of_cholera.pdf), helped to displace the miasma theory of contagion and to support germ theory, which Louis Pasteur would propose in 1861. Soon after, Sir Joseph Bazalgette designed London’s sewer network, built between 1859 and 1875, which put an end to the cholera threat in the city.
Cholera continues to menace parts of the world that lack sewage systems and access to clean water. These include places in which cholera is endemic and also where it can break out in emergency settings such as refugee camps. In January 2010, when the island of Haiti suffered a tremendous earthquake, United Nations peacekeepers rushed to help. In October, one of these soldiers, a man from Nepal, arrived on the island infected with cholera. The Nepalese base (and cesspool) was near the Artibonite River, a major source of Haitian drinking water (“Nepalese Origin of Cholera Epidemic in Haiti,” R.R. Frerichs, et al., Clinical Microbiology and Infection , Vol. 18, No. 6, June 2012, pp. E158–E163; clinicalmicrobiologyandinfection.com/article/S1198-743X(14)64134-3/pdf). This contamination, which is still active today, caused the largest outbreak of cholera in the modern world. Since 2010, more than 770,000 Haitians have been stricken (almost 8% of the population) and more than 9,200 have died (Goats and Soda: “Why the U.N. Is Being Sued Over Haiti’s Cholera Epidemic,” Rich ard Knox, NPR, March 21, 2016; npr.org/sections/goatsandsoda/2016/03/21/471256913/why-the-u-n-is-being-sued-over-haitis-cholera-epidemic).