Correspondence

Amebiasis from the “Miraculous Water of Tlacote”

N Engl J Med 1995; 332:687-688March 9, 1995

Article

To the Editor:

Infection with Entamoeba histolytica in the United States usually occurs only in recent immigrants, travelers outside the United States, homosexuals, and institutionalized patients. Transmission through fecal contamination of hands or food with environmentally resistant cysts is probably the most common route. Cysts can survive for up to a month in water, however, as demonstrated by the 1409 infections and 98 deaths caused by the infamous epidemic of amebiasis during the 1933 World's Fair in Chicago.1 We report an unusual case of waterborne amebiasis, which stresses the importance of obtaining a careful epidemiologic history from all patients with invasive amebiasis.

A 31-year-old man with muscular dystrophy presented with a four-day history of blood-tinged, watery diarrhea and cramps, but no fever. He had not traveled out of the country in two years. He was homosexual, but denied fecal–oral exposure. A trichrome stain of his stool revealed cysts and trophozoites of E. histolytica, and an amebic culture was positive at 48 hours. Isoenzyme analysis of his isolate revealed pathogenic zymodeme II,2 and amplification with the polymerase chain reaction revealed ACP1, a cysteine proteinase gene unique to invasive strains of E. histolytica. 3 His symptoms resolved after treatment with metronidazole and paromomycin. On closer questioning about potential epidemiologic risk factors, he revealed that he regularly received shipments of Agua de Tlacote, water from a spring in Querétaro, Mexico. He stored the 5-gallon containers at room temperature and drank three cups of the water a day for its curative properties.

Although we lack definitive proof in the form of the isolation of E. histolytica from the spring water, it is the most likely source of the patient's infection. The “curative” properties of the water in Tlacote El Bajo were discovered in 1987 when a dying dog was reportedly healed by the water. Word spread quickly, and the trademark “Tlacote” is now patented. Each day hundreds of people wait in lines up to 4 km long for water. The spring water is stored in stainless-steel tanks but undergoes no purification. Unusually heavy rainfall and flooding in the three months preceding our patient's illness could have caused fecal contamination of the ground water. No outbreaks had been reported, but changes in the relatively high local rate of enteric infections would be difficult to detect.

It is possible that the patient was exposed through homosexual activities, although he denied high-risk behavior. E. histolytica has been detected in the stools of up to 30 percent of sexually active homosexuals, but invasive amebiasis is distinctly unusual4 because these patients are colonized with entamoeba of noninvasive zymodemes.2 Differences in restriction-fragment–length polymorphisms of every cloned entamoeba gene have led to the suggestion that E. histolytica consists of two species: noninvasive E. dispar and potentially invasive E. histolytica.5,6

This case report highlights the need for physicians to consider tropical diseases in the differential diagnosis of all patients presenting with appropriate clinical syndromes. In the era of modern travel, the relative risk factors for “nonendemic” parasitic diseases have to be reassessed.

Sharon L. Reed, M.D.
Charles E. Davis, M.D.
Horacio Jinich, M.D.
University of California, San Diego, Medical Center, San Diego, CA 92106-8416

6 References

1. 1

   Epidemic amebic dysentery: the Chicago outbreak of 1933. National Institutes of Health Bulletin no. 166. Washington, D.C.: Public Health Service, 1936.
   

2. 2

   Sargeaunt PG, Williams JE, Grene JD. The differentiation of invasive and non-invasive Entamoeba histolytica by isoenzyme electrophoresis. Trans R Soc Trop Med Hyg 1978;72:519-521
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   Reed S, Bouvier J, Pollack AS, et al. Cloning of a virulence factor of Entamoeba histolytica: pathogenic strains possess a unique cysteine proteinase gene. J Clin Invest 1993;91:1532-1540
   CrossRef | Web of Science | Medline

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   Reed SL, Wessel DW, Davis CE. Entamoeba histolytica infection and AIDS. Am J Med 1991;90:269-271
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   Clark CG, Diamond LS. Ribosomal RNA genes of `pathogenic' and `nonpathogenic' Entamoeba histolytica are distinct. Mol Biochem Parasitol 1991;49:297-302
   CrossRef | Web of Science | Medline

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   Sargeaunt PG. `Entamoeba histolytica' is a complex of two species. Trans R Soc Trop Med Hyg 1992;86:348-348
   CrossRef | Web of Science | Medline

Citing Articles (2)

Citing Articles

1. 1

   Ellen Li, Samuel L. Stanley. (1996) PROTOZOA. Gastroenterology Clinics of North America 25:3, 471-492
   CrossRef

2. 2

   David Mirelman, Yael Nuchamowitz, Brigitte Böhm-Gloning, Brigitte Walderich. (1996) A homologue of the cysteine proteinase gene (ACP1 or Eh-CPp3) of pathogenic Entamoeba histolytica is present in non-pathogenic E. dispar strains. Molecular and Biochemical Parasitology 78:1-2, 47-54
   CrossRef