“CDC's Emergency Operations Center (EOC) was activated January 22, 2016, and moved to a level 1 activation—the highest level–on February 8, 2016. The EOC is the command center for monitoring and coordinating the emergency response to Zika, bringing together CDC scientists with expertise in arboviruses like Zika, reproductive health, birth defects and developmental disabilities, and travel health.”
—U.S. Centers for Disease Control and Prevention
“How many people have fallen in the city of Philadelphia by the pestilential infection is unknown to the Author–and he believes to the inhabitants of the same place, for the accounts are very different, as some mention four, others five, six, and even more than seven thousand: and the latter has been supposed to be not too large. Some have given the disorder one name, and others another, etc. It has been called a ‘genuine plague’; a ‘putrid malignant fever’, a ‘Yellow fever …’”
—Stearns, Samuel. An Account of the Terrible Effects of the Pestilential Infection in the City of Philadelphia; … [1793?]. From the Harvard U. Open Collections Program.
Tens of thousands of North Americans died of yellow fever during the first few hundred years of European colonization. The virus, spread by mosquitoes, was probably imported by African slavers: the wages of sin, one might say. In 1878, about 10% of the population of Memphis, Tenn., died of the disease, despite half the population having fled the city.
Even in 18th-century Philadelphia, physicians had recognized that the disease was related to shipping and that it only appeared in warm weather. It would be more than a hundred years until the link with mosquitoes was clear.
Aedes aegypti, the mosquito responsible for spreading the disease, also transmits other nasty viral infections such as dengue fever, chikungunya, and Zika virus.
Yellow fever probably made its Western Hemisphere debut in the Caribbean in the 17th century. Zika is a more recent import, appearing in Colombia and Brazil in 2015.
Mosquito-borne diseases are nothing new in the tropics, but in late 2015 an unusual birth defect was showing up in unprecedented numbers in the same areas as the Zika outbreak. Infants born with microcephaly are immediately recognizable, with misshapen heads and often brain damage.
Since the association was noticed, it has become increasingly likely that Zika infection during pregnancy can cause microcephaly. We're also learning more about the virus and its transmission; for example, that men can transmit it to women sexually.
But mosquito bites will likely continue to be the main way people become infected. For most people, the infection is either mild or not noticed at all. But the implications for pregnancy are enormous. And Zika is probably heading our way.
Take a look at the map in the New York Times article linked above. Then take a look at these from FiveThirtyEight. The areas most at risk if Zika hits the U.S. have some of the most restrictive abortion laws in the country. Given that Americans are still fighting for basic access to birth control, things are likely to get messy.
I've already seen dozens of patients with questions about Zika virus and travel (I counsel them per CDC recommendations to avoid pregnancy when traveling to affected areas). What happens when it becomes less academic?
Women who contract Zika while pregnant may wish to have abortions. How many would choose this is of course unknown, but we have some serious work to do, and quickly. We need to focus on mosquito control now, as the season is upon us. We need to make sure that women in areas likely to be affected by Zika have information about the disease and access to birth control, and, if desired, abortion.
We like to think that tropical diseases are gone from the U.S., but as West Nile Virus and other outbreaks have taught us, we are 1 shipment of old tires away from an outbreak. We need to prepare for the public health, medical and societal problems that the latest mosquito-borne disease brings with it.
Peter A. Lipson, ACP Member, is a practicing internist and teaching physician in Southeast Michigan. After graduating from Rush Medical College in Chicago, he completed his internal medicine residency at Northwestern Memorial Hospital. This post first appeared at his blog at Forbes. His blog, which has been around in various forms since 2007, offers "musings on the intersection of science, medicine, and culture." His writing focuses on the difference between science-based medicine and "everything else," but also speaks to the day-to-day practice of medicine, fatherhood, and whatever else migrates from his head to his keyboard.