Mosquito Control and the Elimination of Malaria in the U.S.

A few weeks ago, within a few days of one another, the subject of malaria came up twice. In an email someone said to me (Pardon me if I’m misquoting.) that Kenyans found malaria scarier than terrorism. A few days later, in a comment thread about the possibility of migrants in Europe bringing in diseases someone scoffed at the idea that they might bring in malaria because it is, according to that person, a “tropical” disease.

That last bit pricked up my ears. Now, I didn’t get a chance to ask that commenter if he was from the U.S. or not. One thing that everyone in the U.S. knows, or at least should know, is that the early English settlers in North America famously built their first permanent settlement, Jamestown, in the middle of a swamp. The very basic, school children’s version of events, is that many settlers died of malaria. From Wikipedia:

It soon became apparent why the Virginia Indians did not occupy the site: Jamestown Island is a swampy area, and its isolation from the mainland meant that there was limited hunting available as most game animals required larger foraging areas. The settlers quickly hunted and killed off all the large and smaller game animals that were found on the tiny peninsula. In addition, the low, marshy area was infested with airborne pests, including mosquitoes which carried malaria, and the brackish water of the tidal James River was not a good source of water. Over 135 settlers died from malaria, and drinking the salinated and contaminated water caused many to suffer from saltwater poisoning, fevers and dysentery.

This, I would like to emphasize, is not controversial or revisionist history. It is the mainstream history children learn in school.

For those of you who are not familiar with the regional climates of the U.S., most of the country is in what people usually call “the temperate zone.” The nearest city to Jamestown with which most people outside of the U.S. are probably familiar is Washington D.C. The average yearly temperature is 13.5°. This is between the average annual temperatures of Paris (11.3°) and Rome (15.5°). To pick Rome as our point of comparison, Washington D.C. is wetter with 1035 mm of precipitation and 115 days of rain.

I suspect many people who are not from the East Coast of the United States are a little unaware of the weather we have here. Hot in the summer, cold in the winter and humid, wet and mucky all year long. And we have lots of swamps. In other words, this is mosquito heaven.

“So, why aren’t people in the U.S. terrified of malaria?” Glad you asked!

During the Second World War, many U.S. military training bases were located in the Southeastern United States, the region of the country that also happened to have the highest rates of transmission. Since governments are never so interested in keeping you alive as when they’re about to send you to get killed, the U.S. government decided to do something about the malaria. They created an Office of Malaria Control in War Areas, which also, by the way, combated typhus and other vector-borne diseases.

These efforts were so successful that at the end of the war and at the founding of CDC, one of the initial tasks was to oversee the completion of the elimination of malaria as a major public health problem.

And how did they do that?

The program commenced operations on July 1, 1947. It consisted primarily of DDT application to the interior surfaces of rural homes or entire premises in counties where malaria was reported to have been prevalent in recent years. … It also included drainage, removal of mosquito breeding sites, and spraying (occasionally from aircrafts) of insecticides.

Map of regions in the U.S. where malaria was prevalent in 1882, 1912, 1932 and 193-1935. Source: cdc.gov

Malaria is today considered to have been officially eliminated from the U.S. in the early fifties.

The next logical question is, “But isn’t DDT bad?” Although in recent days I have read some blog posts in which people have argued it is not, I have not been convinced by them and still adhere to the general consensus that DDT is bad. So is malaria. If you have read my blog for any length of time, you may have come to realize that I believe there are no easy answers in the world. It’s always about weighing costs and benefits, which have to be weighed and re-weighed according to the specific circumstances. Both the right and the left have reason to dislike this little bit of history. For the right, it was a highly successful government program which took on a problem for which there was no “market solution.” On the left, well, that solution used a potentially dangerous pesticide.

A few years ago, there was a brief panic when cases of West Nile virus first started to appear in New York City. I can’t find any articles now, so I’m going on memory, but I remember reading something about how the State of New York was going to develop a mosquito control program in response. I wondered if New Jersey was going to develop a similar program and looked it up. What I found out is that New Jersey has had a mosquito control program since the early 1900s. “That makes sense,” I thought at the time. Whenever I hear the Bruce Springsteen line, “And my machine she’s a dud, all stuck in the mud, somewhere in the swamps of Jersey,” I think to myself, “Well, that could be just about anywhere.”

Those conversations about mosquitoes and malaria came up before the current news about zika. I was going to write this anyway because it’s the sort of undramatic history we tend to forget. I don’t want to be misinterpreted as advocating for one response or another to current problems. I’m not a scientist. I do, however, think it’s important to have our facts straight. The idea that malaria is a “tropical” disease confined to certain highly limited regions is not correct. As you can see from the U.S. maps above, even in the nineteenth century malaria didn’t exist in the mountainous regions of North America or in the dry areas of the West Coast. However, it existed in vast swathes of the country, including the Mississippi river basin all the way up through to the Dakotas (average low daily temperature in January: -20°C – ie. not tropical).

Map of New Jersey color coded by land use. For those of you not from the region, the western boundary is the Delaware River, the south is Delaware Bay and the east is the Atlantic Ocean, so they are entirely surrounded by water.

Maybe when the weather gets a little nicer, I’ll persuade my sister to go on a frog, flower and photo expedition to New Jersey. Believe it or not, the least glamorous state in the union is known for rare orchids and rare amphibians.

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1 comment
  1. More people have died more of road accidents and malaria, this year alone than we killed by terrorists the entire last year. I think our resources should be aimed more at Road safety and reducing malaria deaths, than terrorism. My two cents

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