Tag Archives: Chile

Nosocomial diarrhea outbreak, Chile

Coria P, Urízar C, Alba A, Noemí I, Pino A, Cerva JL. [The water supply of a pediatric hospital as a possible source of an outbreak of diarrhea due to Microsporidium spp. in immunocompromised patients] Rev Chilena Infectol. 2016 Aug;33(4):373-379. [Article in Spanish]

INTRODUCTION: The hospital water supply is a reservoir of a variety of potentially pathogenic microorganisms that can particularly affect children and immunocompromised patients. Potentially pathogenic Microsporidium spp. have been identified in water. Microsporidiosis is an emerging parasitic and opportunistic infection in immunocompromised patients.

OBJECTIVE AND METHOD: to describe an outbreak of nosocomial diarrhea due to Microsporidium, species Encephalitozoon intestinalis.

RESULTS: Seven cases of E. intestinalis associated diarrhea were reported between november 2012 and february 2013, in a unit of immunocompromised patients in L. Calvo Mackenna Children’s Hospital. Microsporidium spp. was found in the hospital water supply and water reservoir tank. Secondary cases were transmitted by contact. Control measures included contact precautions, not to use faucet water for hand washing, bottled water for drinking and water reservoir tank sanitation.

CONCLUSIONS: This research is about a nosocomial outbreak associated with water supply. Water quality in Chilean hospitals is an unresolved issue, especially in immunocompromised patient areas. Compliance of cleaning and disinfection of water supply systems in hospitals must be ensured.

Risk of Lung Disease Associated with Early-Life Arsenic Exposure, Chile

Steinmaus C, Ferreccio C, Acevedo J, Balmes JR, Liaw J, Troncoso P, Dauphiné DC, Nardone A, Smith AH. High risks of lung disease associated with early-life and moderate lifetime arsenic exposure in northern Chile. Toxicol Appl Pharmacol. 2016 Oct 8;313:10-15. doi: 10.1016/j.taap.2016.10.006

BACKGROUND: Arsenic in drinking water has been associated with increases in lung disease, but information on the long-term impacts of early-life exposure or moderate exposure levels are limited.

METHODS: We investigated pulmonary disease and lung function in 795 subjects from three socio-demographically similar areas in northern Chile: Antofagasta, which had a well-described period of high arsenic water concentrations (860μg/L) from 1958 to 1970; Iquique, which had long-term arsenic water concentrations near 60μg/L; and Arica, with long-term water concentrations ≤10μg/L.

RESULTS: Compared to adults never exposed >10μg/L, adults born in Antofagasta during the high exposure period had elevated odds ratios (OR) of respiratory symptoms (e.g., OR for shortness of breath=5.56, 90% confidence interval (CI): 2.68-11.5), and decreases in pulmonary function (e.g., 224mL decrease in forced vital capacity in nonsmokers, 90% CI: 97-351mL). Subjects with long-term exposure to arsenic water concentrations near 60μg/L also had increases in some pulmonary symptoms and reduced lung function.

CONCLUSIONS: Overall, these findings provide new evidence that in utero or childhood arsenic exposure is associated with non-malignant pulmonary disease in adults. They also provide preliminary new evidence that long-term exposures to moderate levels of arsenic may be associated with lung toxicity, although the magnitude of these latter findings were greater than expected and should be confirmed.

Arsenic Effective in Reducing Breast Cancer Mortality?

This is rather an unexpected finding. Typically arsenic is only thought of as causing harm. This study suggests that inorganic arsenic may be beneficial under certain circumstances.

Smith AH, Marshall G, Yuan Y, Steinmaus C, Liaw J, Smith MT, Wood L, Heirich M, Fritzemeier RM, Pegram MD, Ferreccio C. Rapid reduction in breast cancer mortality with inorganic arsenic in drinking water. EBioMedicine. 2014 Nov 1;1(1):58-63.

BACKGROUND: Arsenic trioxide is effective in treating promyelocytic leukemia, and laboratory studies demonstrate that arsenic trioxide causes apoptosis of human breast cancer cells. Region II in northern Chile experienced very high concentrations of inorganic arsenic in drinking water, especially in the main city Antofagasta from 1958 until an arsenic removal plant was installed in 1970.

METHODS: We investigated breast cancer mortality from 1950 to 2010 among women in Region II compared to Region V, which had low arsenic water concentrations. We conducted studies on human breast cancer cell lines and compared arsenic exposure in Antofagasta with concentrations inducing apoptosis in laboratory studies.

FINDINGS: Before 1958, breast cancer mortality rates were similar, but in 1958-1970 the rates in Region II were half those in Region V (rate ratio RR = 0·51, 95% CI 0·40-0·66; p<0·0001). Women under the age of 60 experienced a 70% reduction in breast cancer mortality during 1965-1970 (RR=0·30, 0·17-0·54; p<0·0001). Breast cancer cell culture studies showed apoptosis at arsenic concentrations close to those estimated to have occurred in people in Region II.

INTERPRETATION: We found biologically plausible major reductions in breast cancer mortality during high exposure to inorganic arsenic in drinking water which could not be attributed to bias or confounding. We recommend clinical trial assessment of inorganic arsenic in the treatment of advanced breast cancer.

High perchlorate levels found in atacama desert (Chile)

I wonder why these perchlorate concentrations were detected so high. Was there a problem with sampling or analysis? Is there an obvious source of perchlorate?

R Calderon, P. Palma, D Parker, M Molina, FA Godoy, M Escudey. Perchlorate levels in soil and waters from the atacama desert. Archives Of Environmental Contamination And Toxicology, 2014 Feb; Vol. 66 (2), 155-61.

Perchlorate is an anion that originates as a contaminant in ground and surface waters. The presence of perchlorate in soil and water samples from northern Chile (Atacama Desert) was investigated by ion chromatography-electrospray mass spectrometry. Results indicated that perchlorate was found in five of seven soils (cultivated and uncultivated) ranging from 290 ± 1 to 2,565 ± 2 μg/kg. The greatest concentration of perchlorate was detected in Humberstone soil (2,565 ± 2 μg/kg) associated with nitrate deposits. Perchlorate levels in Chilean soils are greater than those reported for uncultivated soils in the United States. Perchlorate was also found in superficial running water ranging from 744 ± 0.01 to 1,480 ± 0.02 μg/L. Perchlorate water concentration is 30-60 times greater than levels established by the United States Environmental Protection Agency (24.5 μg/L) for drinking.

Lung and Bladder Cancer in Northern Chile: Arsenic, Tobacco Smoke, Occupation

The primary difficulty with such studies as these is that US exposure levels are nowhere near these arsenic concentrations in Chile. Hence, this study is not relevant to the United States. The multiplicative effect of smoking on the effect of exposure to certain contaminants has been previously demonstrated.

Ferreccio C, Yuan Y, Calle J, Benítez H, Parra RL, Acevedo J, Smith AH, Liaw J, Steinmaus C. Arsenic, Tobacco Smoke, and Occupation: Associations of Multiple Agents with Lung and Bladder Cancer. Epidemiology. 2013 Sep 12.

BACKGROUND: Millions of people worldwide are exposed to arsenic in drinking water, and many are likely coexposed to other agents that could substantially increase their risks of arsenic-related cancer.

METHODS: We performed a case-control study of multiple chemical exposures in 538 lung and bladder cancer cases and 640 controls in northern Chile, an area with formerly high drinking water arsenic concentrations. Detailed information was collected on lifetime arsenic exposure, smoking, secondhand smoke, and other known or suspected carcinogens, including asbestos, silica, and wood dust.

RESULTS: Very high lung and bladder cancer odds ratios (ORs), and evidence of greater than additive effects, were seen in people exposed to arsenic concentrations >335 µg/L and who were tobacco smokers (OR = 16, 95% confidence interval = 6.5-40 for lung cancer; and OR = 23 [8.2-66] for bladder cancer; Rothman Synergy Indices = 4.0 [1.7-9.4] and 2.0 [0.92-4.5], respectively). Evidence of greater than additive effects were also seen in people coexposed to arsenic and secondhand tobacco smoke and several other known or suspected carcinogens, including asbestos, silica, and wood dust.

CONCLUSIONS: These findings suggest that people coexposed to arsenic and other known or suspected carcinogens have very high risks of lung or bladder cancer.

Click here for full paper (fee).

Cortes et al 2011: Boron exposure assessment using drinking water and urine in the North of Chile.

S. Cortes, E. Reynega-Delgado, A.M. Sancha, and C. Ferreccio. Boron exposure assessment using drinking water and urine in the North of Chile. Science of the Total Environment. 2011 Dec 1; 410(411):96-101.

Boron is an essential trace element for plants and humans however it is still an open question what levels of boron are actually safe for humans. This study, conducted between 2006 and 2010, measured exposure levels of boron in drinking water and urine of volunteers in Arica, an area in the North of Chile with high levels of naturally occurring boron. Samples were taken of tap and bottled water (173 and 22, respectively), as well as urine from 22 volunteers, and subsequently analyzed by inductively coupled plasma spectroscopy (ICP-OES). Boron varied in public tap water from 0.22 to 11.3mgL(-1), with a median value of 2.9mgL(-1), while concentrations of boron in bottled water varied from 0.01 to 12.2mgL(-1). Neither tap nor bottled water samples had concentrations of boron within WHO recommended limits. The concentration of boron in urine varied between 0.45 and 17.4mgL(-1), with a median of 4.28mgL(-1) and was found to be correlated with tap water sampled from the homes of the volunteers (r=0.64). Authors highly recommend that in northern Chile – where levels of boron are naturally high – that the tap and bottled water supplies be monitored in order to protect public health and that regulatory standards also be established for boron in drinking water in order to limit exposure.

Click here to obtain the full paper (fee).