The Centers for Disease Control and Prevention have just released their latest estimate of the habitat in the continental United States of the two mosquito species believed to transmit Zika viral illnesses. It greatly expands the area that both the Yellow Fever mosquito, Aedes aegypti, and the Asian tiger mosquito, Aedes albopictus, might be found in during the hottest and most humid parts of the summer. The range for both species includes the New York City area.
Is there a risk of a mosquito borne illness outbreak in New York City? The answer, based upon history, is yes.
There have been many outbreaks of Yellow Fever, carried by Aedes aegypti, in the early history of the city. That mosquito is currently the vector for all four dengue viral serotypes and for chikungunya, as well as Yellow Fever in the Americas. Any or all of those diseases could appear in New York City if conditions permit.
History of Yellow Fever in New York City
The history of Yellow Fever in early New York comes with a few reminders. New York, until the 1820s, was bounded on the north by Wall Street. Greenwich Village, a hip neighborhood in modern New York, was a real village at the time.
The city lacked the services that modern cities take for granted, such as municipal water and sewage. New York was a smelly, dirty seaport of lesser importance than most other East Coast ports.
Baruch College – the Yellow Fever Epidemic – 1795 to 1804:
The first yellow fever epidemic hit Philadelphia in 1793, killing approximately 5,000 people. The pandemic that emerged so close to New York City (NYC) prompted the creation of the first Board of Health Department. To prevent the spread of yellow fever in NYC, action was taken to quarantine boats coming from Philadelphia. Although early efforts helped delay the epidemic, in the summer of 1795 cases of yellow fever began to emerge in Manhattan. The yellow fever epidemic which lasted until 1803, varied in severity. It reached epidemic proportions three times: in 1795, 1799, and 1803 claiming thousands of lives over the course of its presence in NYC.
At this time, it is believed that the Zika virus is being transmitted from person to person through the bites of female Yellow Fever mosquitoes. Its close relative, the Asian Tiger mosquito, may also be carrying the virus.
Both species have been proven to be competent in a lab environment to carry the Zika virus but, as yet, neither have been proven to do so. Proof requires finding the species in the wild infected with the virus. That has not yet happened. Ae. aegypti is presumed to be the vector for Zika.
Aedes aegypti is a container mosquito. Only the females bite, to obtain blood as part of their reproductive process. They are aggressive daylight feeders and live in and around human habitations. They very rarely feed on any animals but humans.
The mosquito needs just a little fresh water to lay its eggs. Just a couple of ounces will do. The eggs are hardy and can remain viable in mud, for example, under some circumstances for months until conditions improve.
This mosquito sips its blood meal, often feeding on several humans before completing its egg laying. It become infected with Zika or one of the other viruses through biting an infected human. In a week or so, sit is infected and the virus fills its salivary glands. As that mosquito feeds, the virus is passed on to the several humans it is sipping blood from.
The Asian tiger mosquito, Aedes albopictus, is a newcomer to the Americas. It first appeared in 1985 and has been spreading ever since. It is believed to be able to transmit all the same viruses that its cousin, the Yellow Fever mosquito, does. It is also a container mosquito but will feed on animals other than humans. It can be found in and around human habitation but will also inhabit forests and other areas free of humans. It, too, is an aggressive daylight feeder.
The Risk to New York City
The vectors for Zika and the other viral illnesses need a warm or hot climate, fresh water and hosts to feed upon. A hot and humid summer in New York, with its trash-filled lots, clogged rain gutters and flat roofs that do not drain well, provide for much of the needs of the Aedes mosquitoes.
There are 8.5 million people in New York City and 20 percent of those people live in poverty. Many of their homes will not have air conditioning or screens and that sends an open invitation for these mosquitoes.
Add to that the number of travelers to the city that arrive already infected with Zika, dengue, chikungunya or yellow fever. One bite from Aedes and …
- Zika Virus – CDC
- Yellow Fever in New York City, 1791-1799
- Yellow Fever in New York City
- Fighting Yellow Fever and Cholera