Geographical distribution of endomyocardial fibrosis in south Kerala.
BACKGROUND
Endomyocardial fibrosis (EMF) is a chronic heart disease confined to a few geographically specific locations within 15 degrees of the equator. Several aetiological hypotheses exist, among them filarial infection, eosinophilia, and toxic effect of the monazite element cerium from the soil. This study attempts to find out whether the pattern of distribution of EMF in south Kerala in India is consistent with the geochemical hypothesis.


METHODS
From hospital records we identified all patients from south Kerala who had a confirmed diagnosis of EMF during the period 1978-1994. Our controls were patients from the southern districts diagnosed to have rheumatic heart disease (RHD) during the same period. We traced their residence address to the administrative subunit of taluk, and plotted the distribution of patients with EMF and RHD for each taluk in south Kerala. The taluks were then grouped into areas of high (> 4/100,000), medium (2.01-4/100,000), and low (< or = 2/100,000) density in each case.


RESULTS
We identified an area of high density of EMF comprising four taluks near the coastline situated within the districts of Alapuzha, Kollam, and Pathanamthitta. Two coastal taluks in Kollam and Alapuzha districts are known areas of deposits of monazite elements in the state. Geographical distribution is not related to prevalence of filariasis and eosinophilia.


CONCLUSIONS
Coexistence of high density of occurrence of EMF and deposits of monazite elements support the geochemical hypothesis.
Kutty
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Achutah Menon Centre for Health Science Studies, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India.
Abraham
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Kartha
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D000293:Adolescent; D000328:Adult; D002563:Cerium / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D004719:Endomyocardial Fibrosis / Q000139:chemically induced / Q000453:epidemiology*; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D005843:Geography; D006801:Humans; D007194:India / Q000453:epidemiology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008674:Metals, Rare Earth / Q000009:adverse effects
D008674:Metals, Rare Earth; C015370:monazite; D002563:Cerium