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Malaria on the Wallkill


On May 17, 1880 the New York Times reported, “New-Hampton was once one of the most important places in this county (Orange County, New York), being the center of several large manufacturing interests. But, by the authority of the State, the industrial interests of the village were destroyed in order to increase the acreage of the farmers along the upper waters of the Wallkill.

. . . Since then (1871) no water has flowed in the old channel, and its stagnant pools, and decaying vegetation have made the vicinity a most unhealthy one. Malarial fever has never been absent from some households in this place or Denton for nearly 10 years. There have been as many as 100 cases in the two places at one time, and it is no uncommon thing for every member of a family to be prostrated at the same time. Property has greatly decreased in value, and the once busy and prosperous factories are tumbling into ruin.”(Anon. 1880:2)


What was going on? What was done to the Wallkill River and why was the tropical disease malaria seen 75 miles from New York City?

The Wallkill River, named for the Wall River in the Netherlands, arises in northern New Jersey and flows northeast and joins Rondout Creek, then joins the Hudson River just below Kingston. The Rondout is the largest tributary to the Hudson south of the Mohawk River. The natural course of the Wallkill was obstructed by a series of short but abrupt ridges that greatly impeded the water’s flow. A larger natural dam of glacially deposited boulders stretching across the Wallkill Valley at Denton, New York formed an impregnable dam. Consequently, the water pooled behind the ridges, particularly during high-flow events forming what were called locally the “drowned lands.” The drowned lands involved some 50,000 acres in Sussex County, New Jersey and Orange County in New York. Elevated lands in the region are still called islands because of the extensive flooding that routinely occurred. The 1797 American Gazetteer reported that the standing water over a considerable part of the year “exposes the inhabitants to intermittent fevers.” The region’s soil was enriched by the sediment that would drop out under still conditions. This deep, fine-grained, organic muck is perfect for growing onions, lettuce, and turf.

Landowners William Wickham and Henry Wisner started draining the pooled water by digging through the obstruction in 1772. The following year saw New York’s colonial General Assembly providing inspectors to raise funds from landowners in Goshen and to reimburse Wickham and Wisner for their efforts. By 1807 appointed commissioners raised funds and oversaw drainage. Commissioners Ditches are still so called in the Wallkill Valley. The projects initiated in 1807 were only partially successful, and by 1826 more money and authority was put into constructing a canal altering the Wallkill’s course and cutting through the obstruction.

This work benefited farmers owning acreage in the drowned lands. Woolen, fulling, dying, and grain mills taking advantage of water power from the drop of 26 feet below the obstruction were threatened with ruin. By 1829 the legal objections by the mill owners were overcome, but the populace was split into canal and anti-canal factions. The 1826 Act provided for a dam that would partially compensate the mill interests but it was the frequent target of vandalism by the farmers. Irish laborers completed the canal in 1835 at a cost of nearly $60,000, far above the initial appropriation of $26,000. The effect was immediate. Higher water velocities eroded the banks. What was intended to be a canal 8 feet in width and 8 feet in depth eventually became, in places, 1,500 feet wide and 17 feet deep. Property washed away and bridge abutments collapsed.

For decades owners of water rights constructed dams that were torn down by farmers in what was known as the war between the “beavers”, mill owners wanting a dam to restore the older hydrology, and the “muskrats”, agriculturalists who attacked and tore down dams erected by the beavers. The last serious beaver, George Wheeler, was finally ruined by an October 1869 storm that tore apart his latest effort at building a dam and by a definitive court ruling in 1871 denying his right to build a dam.(Borland-Wilcox 1925;Snell 1881)

Ditching is still a routine in the former drowned lands, now called the “black dirt”. Big Island rises up in the background. Nineteenth and 20th Century hydrologic modifications have transformed a depositional area into an erosional one.

Malaria afflicts hundreds of millions of people more often in sub-Saharan Africa than Orange County, New York. Malaria is caused by protozoans, single celled parasites (neither bacteria nor viruses), of the genus Plasmodium transmitted to humans by insect vectors, mosquitoes, of the genus Anopheles. Johann Wilhem Meigen first described the genus Anopheles in 1818, long before the relationships between mosquitoes and disease were known. The name comes from the Greek where “an” means “not” and “opheles” means “profitable” thus Anopheles was named “worthless”. Another mosquito genus described by Meigen was Aedes meaning “odious”. Apparently there are limits to the love of mosquitoes, even by the “father of dipterology.” Roughly 80 species of Anopheles can transmit malaria plasmodia to humans. In the United States two predominate; A. quadrimaculatus (Thomas Say, 1824) and A. maculipennis (Meigen). Modern theory holds that both A. quadrimaculatus and A. maculipennis embrace several morphologically indistinguishable sibling species.(Kaiser 1988, 71:311-323;Rutledge et al. 2009)

Malaria, in humans, is a complex of four different diseases caused by Plasmodium falciparum, P. vivax, P. malariae and P. ovale. P. ovale occurs only in West Africa and P. malariae is rare in the Western Hemisphere. P. falciparum was restricted to the southern United States, playing only transient parts in New York. P. vivax, responsible for all the endemic malaria in the northern United States, had a low mortality rate, perhaps no more than 5% in contrast with 20-40% for P. falciparum in untreated and non-immune people. However, P. vivax can be extremely debilitating. Plasmodium reproduces sexually in the gut of the mosquito host. Other mosquitoes and other Plasmodia infect birds, rats, reptiles, and other primates.(Humphreys 2001) The New York City Department of Health discovered malaria (P. falciparum and, to a lesser extent, P. malariae) outbreaks occurring in 1934 and 1936 when heroin addicts shared contaminated needles.(Imperato, Shookhoff, and Harvey 1973, 73:2495-2502)

By the early 1880s endemic malaria occurred in central California and throughout the remainder of the United States east of the Rockies save for the Appalachian highlands, central and northern New York, and the northern New England states but it’s gone now.(Reiter 2001, 109:141-161) So, the question is how and when did malaria disappear from the Wallkill, and indeed, from the United States? The answer comes in two parts. The first is that a great deal of the “malaria” diagnosed in the 19th and early 20th Centuries was not really malaria. The second part is less clear.

The Italian word “malaria” first appeared in the English language in 1740. Translated as “bad air” the word referred to intermittent and reoccurring fevers and chills engendered by breathing poisons released from decaying vegetation or newly turned soil. While the miasmic theory predominated, alternatives were proposed in the first half of the 19th Century due to observations of marshes without malaria and malaria without marshes. The animaculist theory held that the disease was caused by invisible “insects” or, perhaps, fungi.(Ackerknecht 1945) Following changes in the occurrence of malaria is complicated by the vagueness of the diagnosis previous to Alphonse Laveran’s 1880 discovery of the protozoan parasites. The earlier diagnosis “ague” (appearing first in 1377) applied to acute fevers in general and embraced illnesses now described as influenza and typhoid fever as well as malaria. In 1862 Army surgeon Major J. J. Woodward created the new disease name “typhomalaria” for coincident typhoid and malarial infections. However, most physicians used the name for severe malaria. The New York City Department of Health listed “typhomalarial fever” until 1889.(Imperato, Shookhoff, and Harvey 1973, 73:2372-2381) It is likely that the vast majority of the cases diagnosed as typhomalaria were actually typhoid. There was also confusion of whether “malaria” (literally “bad air”) meant the cause of disease or the disease itself.

Even after an understanding of the cause and transmission of malaria, which was worked out in 1897 by Ronald Ross, clinical diagnoses of malaria were very often overturned by laboratory examinations of blood. At the beginning of the Spanish American War only 12 out of about 20,000 cases diagnosed as typhomalaria were found, on closer examination, to truly be malaria. In the 1930's and 1940's two thirds of the cases in Mississippi clinically identified as malaria were not confirmed by laboratory investigation. False positives included patients afflicted with pneumonia, cirrhosis, tuberculosis, syphilis, and typhoid.(Humphreys 1996, 87:17) A better definition was ague susceptible to treatment, or at least palliation, with the alkaloid quinine derived from Peruvian cinchona bark. In 1820 an extract of the bark, quinine, became available, but at a very high price.

Malaria disappeared from the northern United States, and much of Europe, without the benefit of a conscious public health or medical effort and long before the advent of the pesticide DDT.(Barber 1929, 44:2575-2587;Trask 1916, 31:3445-3452) The reasons why malaria disappeared have been of great interest not only to historians but also to the current question of whether there are lessons applicable to areas where the disease is still prevalent. Others ask if climate change will reverse the disappearance.

The medical historian and anthropologist Erwin Ackerknecht condensed disappearance theories down to a dozen complementary ones:

1) Population movement.

Steep increases in the population of the Midwestern states were accompanied by increases in malaria and a later decreasing rate of population growth saw a decline in malaria. Possible mechanisms linking population growth and malaria are: more susceptible people, more disease carriers, and higher population densities. Prevalence of malaria in New York has been affected by people coming from regions of endemic disease. Troops returning from the Civil War, the Spanish American War, both World Wars, and Vietnam carried malaria, fostering endemicity or at least prevalence.(Imperato, Shookhoff, and Harvey 1973, 73:2495-2502) The presence of the US Public Health Service Hospital on Staten Island caused Richmond County to show high rates of malaria. Immigrants from southern and eastern Europe brought malaria to New York, at least in the late 19th Century. Malaria peaked in New England and New York in the early 1880s(Imperato, Shookhoff, and Harvey 1973, 73:2372-2381) However, the pre-World War I waves of emigrants from Eastern Europe were not blamed for spreading malaria to the United States. Occasionally malaria is brought back by tourists and students.

2) Railroad, steamship and stream regulation.

The introduction of railroads, and later, of automobiles, reduced the time people spent traveling on mosquito infested rivers. Stream regulation, through constructions of dams and levees, reduced flooding and subsequent mosquito-friendly habitat.

3) Clearing, cultivation and drainage.

Land clearing and greater drainage could potentially remove mosquito habitat. The opening of the drowned lands to farming may have shifted the area of mosquito infestation to the Denton and New-Hampton area where the old channel was reduced to pools of stagnant water. Construction often created mosquito breeding areas in wheel ruts, hoof prints, and careless ditching.

4) Prosperity.

Many observers have commented that malaria is a social disease most effectively dealt with by an increased standard of living that provides(Humphreys 2001):

a. Housing.

Better housing is less porous to insects. Well-lit, airy, and dry dwellings are less hospitable to mosquitoes.

b. Screening.

Woven metal screens, first marketed in the late 1860s, became common by the beginning of the 20th Century. Screens on well-built houses greatly reduced mosquito infestation in the evenings and at night. The World Health Organization currently focuses on insecticide (synthetic pyrethrum - pyrethroids) treated bed nets.(World Health Organization 2007)

c. Education.

More education is correlated with a diminution of malaria, and other diseases. Ackerknecht writes that education “could change the attitude toward disease and break the indolence so fatal to all endemic areas.” Education also gives people an understanding, if not the tools, to reduce their exposure to the disease. Nineteenth Century residents in New-Hampton already knew that living near decaying vegetation was unhealthy even if their understanding of the mechanism of disease transmission was faulty.

d. Food.

Can a more nutritious diet reduce disease?

e. Cattle breeding.

Just as better housing reduces mosquito bites on people, better animal housing may provide mosquitoes with other sources of mammalian blood. If mosquitoes could have shelter, particularly with cobwebs (James 1929, 23:71-87), or the odor of dung (Hackett and Missiroli 1931, 13:57-78) they might prefer to dine on non-human blood. This is particularly true for A. maculipennis, the dominant northern vector.(Humphreys 2001)

f. Mosquitoes

Mosquito control has been central to many malaria control projects since the success in Cuba and Panama at the beginning of the 20th Century. Diligent elimination of standing water and oiling to kill larvae were undertaken in New York City. Vast programs of mosquito destruction have had mixed success. In some places, such as post World War II Netherlands, control has been achieved, in others control was temporary, and in still other places, control was never achieved.(Bruce-Chwatt 1954, 1:169-174;Gladwell 2002, 23:479-497;Macdonald 1965, 80:870-879;Paul 1984, 74:63-75) Total elimination of mosquito vectors will eliminate malaria but correlations between Anopheles abundance and malaria are weak. Malaria can occur with few vectors and high vector populations are not necessarily sources of disease. Mosquito control programs played no role in eliminating malaria in the Wallkill.

5) Quinine

Nineteenth Century physicians treated malaria with blood-letting, purgatives like calomel (mercury chloride) and quinine. Quinine was isolated from Peruvian cinchona bark in 1820, but previously ground up bark was administered. Quinine reduces the numbers of parasites and permits a higher level of activity by infected people. Higher levels of activity contribute to prosperity and the advantages that it brings. Lower levels of parasites in blood reduce the rate of disease transmission. The actual effect of quinine on elimination of malaria has been controversial. Numerous 19th Century patent medicines contained quinine, but often at sub-therapeutic concentrations. Therapeutic concentrations are extremely bitter, produce nausea and dizziness, and, particularly in earlier years, were costly. In 1880 the price of quinine was between $2.20 and $3.20/oz but by 1890 the cost had dropped to between $0.32-$0.42/oz.(Ackerknecht 1945)

6) Weather and climate


Climate and weather influence the distribution and life span of mosquitoes and the development of plasmodia. Climate apparently restricted the distribution of P. falciparum, a more virulent form of malaria, to the south. The disappearance of malaria from New York cannot be correlated with a change in climate. Global warming has the potential for increasing precipitation in the northeast. It could make the northeast more hospitable to vectors and to P. falciparum.(Reiter 2001, 109:141-161)

Two centuries of hydrologic modification on the upper Wallkill River have transformed a wetland where sediments deposit to an erosional environment. Valuable farmland has been created but the improvements ruined some 19th Century industrial operations, and brought, or moved, malaria to a new area. Malaria, now associated with poverty-ridden areas in Africa and Asia, was well established in parts of New York in the 1880s. By 1920 endemic malaria was gone from New York State without benefit of a conscious effort from public health authorities. The factors making malaria so hard to control in Africa, such as an efficient vector (Anopheles gambiae), a climate favorable for the vector and the parasite, a high prevalence of the virulent P. falciparum, weak infrastructure, and lack of resources, differ significantly from late 19th Century New York. There appear to be few applicable lessons other than the need for widespread prosperity. Climate change has the potential for expanding the range of P. falciparum but re-establishment of endemic malaria in New York would also require a catastrophic collapse in the economic and social structure of the region.


Prepared August 11, 2011 by Simon Litten, NYS DEC (retired). For questions or comments please contact Simon at  This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Literature Cited

Ackerknecht EH. 1945. Malaria in the Upper Mississippi Valley, 1760-1900. Baltimore: The Johns Hopkins Press.

Anon., 1880. Malaria on the Wallkill. The Orange County Drowned Lands. The Muskrat and Beaver War about a canal dam - New-Hampton's Plight - A people discouraged at the legislature's failure to remove a fatal bed of malaria. New York Times.

Barber MA. 1929. The History of Malaria in the United States. Public Health Reports 44 (43): 2575-2587.

Borland-Wilcox FE. 1925. The Cheechunk and Drowned Lands.

Bruce-Chwatt LJ. 1954. Problems Of Malaria Control In Tropical Africa. British Medical Journal 1 (4855): 169-174.

Gladwell M. 2002. Fred Soper and the Global Malaria Eradication Programm. Journal of Public Health Policy 23 (4): 479-497.

Hackett LW, and Missiroli A. 1931. The Natural Disappearance of Malaria from Certain Regions of Europe. American Journal of Epidemiolog 13 (1): 57-78.

Humphreys M. 1996. Kicking a Dying Dog: DDT and the Demise of Malaria in the American South, 1942-1950. Isis 87 (1): 17.

-----. 2001. Malaria: Poverty, Race, and Public Health in the United States. Baltimore: The Johns Hopkins Press.

Imperato PJ, Shookhoff HB, and Harvey RP. 1973. Malaria in New York City I History of the disease from 1796 to 1903. New York State Journal of Medicine 73 (Oct. 1): 2372-2381.

-----. 1973. Malaria in New York City II. End to the period of endemicity - 1904 to 1939. New York State Journal of Medicine 73 (Oct 15): 2495-2502.

James SP. 1929. The Disappearance of Malaria from England. Proc. Royal Soc. Med 23 (1): 71-87.

Kaiser PA. 1988. Cytotaxonomy as a Tool for Identification of Siblings of the Anopheles quadrimaculatus Complex. The Florida Entomologist 71 (3): 311-323.

Macdonald G. 1965. Eradication of Malaria. Public Health Reports (1896-1970) 80 (10): 870-879.

Paul BK. 1984. Malaria in Bangladesh. Geographical Review 74 (1): 63-75.

Reiter P. 2001. Climate Change and Mosquito-Borne Disease. Environmental Health Perspectives 109 (Supplement 1: Reviews in Environmental Health): 141-161.

Rutledge R, Butler RH, Morris CD, and Nayer JK. 2009. "Human Malaria." 2011. Available from http://edis.ifas.ufl.edu/mg103.

Snell JP. 1881. "Drowned Lands of the Wallkill Including the "Beaver and Muskrat War" As recorded in History of Sussex and Warren Co., NJ." 2011. Available from http://www.albertwisnerlibrary.org/Factsandhistory/History/DrownedLandsoftheWallkill.htm.

Trask JW. 1916. Malaria: A Public Health and Economic Problem in the United States. Public Health Reports 31 (51): 3445-3452.

World Health Organization. 2007. "WHO recommended insecticides for indoor residual spraying against malaria vectors." 2011. Available from http://www.who.int/whopes/Insecticides_IRS_Malaria_ok.pdf.

© Simon Litten 8/4/2011