Could Consumption of Trace Element-Contaminated Rice Be a Risk Factor for Acute Interstitial Nephritis with Uncertain Etiology in the Dry Zone of Sri Lanka?

Ingestion of toxic trace elements in the human body has been considered one of the major reasons for renal dysfunction. Chronic kidney disease with uncertain etiological factors (CKDu) is a recently described clinical entity in which the disease is found in geographically isolated pockets in the dry zone of Sri Lanka. In CKDu regions, an increasing number of cases are reported with acute interstitial nephritis without any known reason (AINu). However, recent exposure to certain risk behaviors or nephrotoxins, or both, is suspected for the AINu. Consumption of foods that are contaminated with trace elements is one of the main pathways of human exposure to environmental toxins. The current study was carried out to assess the possibility of trace element-contaminated rice consumption on the etiopathogenesis of AINu. Samples of rice consumed by 32 clinically diagnosed AINu cases were collected and analyzed for possible nephrotoxic trace elements. Out of 32 patients, 26 were histologically confirmed with tubulointerstitial disease. The results revealed that the mean values of Cd, As, and Pb were 0.18, 0.055, and 0.135 mg/kg, with ranges of 0.020-1.06, 0.012-0.222, and 0.003-0.744 mg/kg (on dry weight basis), respectively. This study indicated that the investigated toxic trace element levels of rice consumed by AINu were reasonably below the recommended levels of the Codex Alimentarius Commission of FAO and WHO. Hence, it is less likely that rice consumption is to be a risk factor for the etiology of AINu.

Isolation and characterization of Leptospira interrogans from two patients with leptospirosis in Western Province, Sri Lanka

Leptospirosis is an endemic infectious disease causing considerable morbidity and mortality in Sri Lanka; however, reports on the isolation of Leptospira from infected patients in Sri Lanka have been largely unavailable since the 1970s. Two isolates were obtained and characterized from 100 blood cultures from leptospirosis-suspected patients. Phylogenic analysis of partial flaB gene sequences identified the isolates as Leptospira interrogans. The patient serum samples from which Leptospira was isolated reacted with the Leptospira serogroups Sejroe and Canicola at a titre of 1 : 200. Exposure to domestic sewage and gutters filled with muddy water was suspected to be the source of infection in these two culture-positive patients. This study reports the successful isolation of pathogenic Leptospira from two patients in Western Province, Sri Lanka.