Studies of Bladder Stone Disease in Thailand

Abstract

An epidemiologic survey for prevalence of bladder stone disease was conducted in 44 villages and 3 towns in Ubol Province, Thailand. Of 20,806 persons sampled, 253 had a history of stone passing or cystolithotomy; another 540 had one or more lesser symptoms compatible with stone disease. For every patient hospitalized for removal of bladder stone three persons passed stones spontaneously and eight had presumptive symptoms. In the sampled village population the frequency of positive stone episodes was 14.2/1,000; rates were significantly lower among residents of towns with populations of 5,000 or more, the lowest being 2.1/1,000 in Ubol municipality (population, 27,000). Prevalence of bladder stone symptoms did not vary between ethnic groups residing in the same area; it was twice the average among relatives living in the same house but not greater than expected among blood relatives living in other houses. There was a distinct seasonal fluctuation in month of onset of stone symptoms, onsets being most common before and after the rainy season. Females comprised 32% of persons complaining of presumptive symptoms, 18% of those with positive episodes, but only 11% of patients in the 1956–1962 Ubol Hospital series. Unexpectedly, bladder stone disease was not most frequent in villages judged to be poorest in economic state. Instead, symptom rates were highest in villages with good records of fresh fish catches and greater than average vegetable production. It is not known whether nutrition, particularly in infants or mothers, correlates with village economic status. Rates were also high in villages suffering seasonal deprivation of water. Age-specific rates of onset of symptoms suggest two periods of primary urinary stone formation; early infancy and early adulthood. Whether these are similar diseases with the same etiologies is unknown. Extension of epidemiological studies to other bladder stone endemic areas is strongly urged.