Water source and diarrhoeal disease risk in children under 5 years old in Cambodia: a prospective diary based study

Background

Despite claims that the Millennium Development Goals (MDG) targets on access to safe drinking water have been met, many 100 s of millions of people still have no access. The challenge remains how to provide these people and especially young children with safe drinking water.

Method

We report a longitudinal study designed to assess the effectiveness of an intervention based on provided treated drinking water in containers on self-reported diarrhoea in children. The intervention was “1001 fontaines pour demain” (1001 F) is a non-governmental not for profit organization (created in 2004 and based in Caluire, France) that helps local entrepreneurs treat package, and sell safe drinking water. Cases and controls were chosen at village and household level by propensity score matching Participants were visited twice a month over six months and asked to complete a diarrhoea health diary.

Results

In total 4275 follow-up visits were completed on 376 participants from 309 homes. Diarrhoea was reported in 20.4% of children on each visit, equating to an incidence rate estimate of 5.32 episodes per child per year (95% confidence interval = 4.97 to 5.69). Compared to those drinking 1001 F water, children drinking surface water were 33% (95% CI -1 to 17%), those drinking protected ground water were 62% (95% CI 19 to 120%) and those drinking other bottled water 57% (95% CI 15 to 114%) more likely to report diarrhoea. Children drinking harvested rainwater had similar rates of diarrhoea to Children drinking 1001 F water.

Conclusion

Our study suggests that 1001 F water provides a safer alternative to groundwater or surface water. Furthermore, our study raises serious concerns about the validity of assuming protected groundwater to be safe water for the purposes of assessing the MDG targets. By contrast our study provides addition evidence of the relative safety of rainwater harvesting.

The role of surface disinfection in infection prevention

Background: The Rudolf Schuelke Foundation addresses topics related to hygiene, infection prevention and public health. In this context a panel of scientists from various European countries discussed “The Role of Surface Disinfection in Infection Prevention”. The most important findings and conclusions of this meeting are summarised in the present consensus paper.

Aim: Although the relevance of surface disinfection is increasingly being accepted, there are still a number of issues which remain controversial. In particular, the following topics were addressed: Transferral of microbes from surface to patients as a cause of infection, requirements for surface disinfectants, biocidal resistance and toxicity, future challenges.

Methods and findings: After discussion and review of current scientific literature the authors agreed that contaminated surfaces contribute to the transmission of pathogens and may thus pose an infection hazard. Targeted surface disinfection based on a risk profile is seen as an indispensable constituent in a multibarrier approach of universal infection control precautions. Resistance and cross-resistance depend on the disinfectant agent as well as on the microbial species. Prudent implementation of surface disinfection regimens tested to be effective can prevent or minimize adverse effects.

Conclusions: Disinfection must be viewed as a holistic process. There is a need for defining standard principles for cleaning and disinfection, for ensuring compliance with these principles by measures such as written standard operating procedures, adequate training and suitable audit systems. Also, test procedures must be set up in order to demonstrate the efficacy of disinfectants including new application methods such as pre-soaked wipes for surface disinfection.

Assessment of transpulmonary absorption of ethanol from alcohol-based hand rub

BACKGROUND

Alcohol-based hand rubs (ABHRs) have been associated with a reduction of nosocomial infections. Despite the worldwide introduction of these products in health care settings, the aim of this study was to assess the transpulmonary absorption of ethanol contains in ABHRs used by health care workers (HCWs) in real conditions of work shift.

METHODS

Twenty-six HCWs of Nancy University Hospital were included. Research consisted in monitoring participants during 4 hours of work shift to assess their exposure to ethanol. The measurement of ethanol vapors in exhaled breath was performed using a class B ethylometer (Alco-Sensor FST). Ethanol concentration in inhaled breath was measured using Gilian pump LFS-113. Concentration of ethanol, acetaldehyde, and acetate in blood and urine samples were determined using gas chromatography with flame ionization detector.

RESULTS

Participants were 12% male and 88% female. The mean age was 40 ± 8 years. None of the employees included in the study presented any traces of ethanol or its metabolites in the blood or urine. Ethanol (0.08 ± 0.07 mg/L) was detected in the breath of 10 HCWs at 1 to 2 minutes postexposure. The mean concentration of ethanol in the inhaled air was 46.2 mg/m.

CONCLUSION

Absorption of ethanol vapor from ABHRs among HCWs during their care activities was not detected. Quantification of ethanol fumes inhaled during 4 hours of work shift was below the regulatory limitations of exposure to ethanol.

Emergence of hand contamination with Aspergillus during demolition work

Hand rubbing with hydro-alcoholic solutions prevent the exogenous nosocomial infection, but the hydro-alcoholic solutions were not sporicidal. A major program of demolition was organized on the area of the University Hospital of Nancy (France) between 2007 and 2010, and this period is often considered as a possible source of suspending Aspergillus spores. This study shows the emergence of Aspergillus on the hands of the medical students during demolition period despite the same quality of hand hygiene.

Screening for surgical nosocomial infections by crossing databases

Surgical site infection (SSI) is a major cause of morbidity and mortality, and they are the third cause of nosocomial infections. It has been shown that surveillance can reduce the rate of these infections because the publication of the results that introduce a interrogation on her surgical pratices. However, surveillance requires considerable medical resources. Our objective is to validate a computer algorithm that uses microbiological results and the results of a C-reactive protein (CRP) assay and granulocyte count to detect SSIs.

MATERIALS AND METHODS

All patients who underwent colorectal surgery between the 1st of January and the 30th of June 2009 were included. Administrative, surgical and microbiological data and the appearance of neutrophilia and CRP after surgery and during hospitalization were collected. The algorithm uses four biological variables: CRP, neutrophils, and the bacterium found on the positive sample. The CRP and neutrophil variables were coded in 0 or 1. CRP was coded as 1 if the sample was below 5mg/l at the time of the operation and increased to more than 60mg/l in the 30 days immediately after post-operation. Neutrophils were coded as 1 if the sample was normal at the time of the operation and increased to more than 12,000cells/mm(3) in the 30 days immediately after post-operation. The "type of sample" and "bacterium" variables were coded in categories. For the type of sample, we coded 3 if the sampling site was related to the surgical site, 2 if the sampling site was potentially linked to the surgical site, 1 if the sampling site was not directly or indirectly related to the surgical site and 0 if there was no sample. Regarding the bacteria, we coded 3 for bacteria found in over 5% of SSIs, 2 for bacteria found in 2-5% of SSIs, 1 for bacteria found in less than 2% of SSIs and 0 if there were no bacteria. The algorithm calculates a score from 1 to 5.

RESULTS

Our study included 195 operations, out of which it was possible to study 168. Following the operations, we found neutrophilia above 12,000cells/mm(3) in 41.5% of cases and CRP above 60mg/l in 64.6% of cases. Thirty-seven operations (22%) were complicated by an SSI. The positive predictive values and the negative predictive values in our algorithm were 74.07% and 87.94%, respectively, and the number of records that remain to be investigated is 27 out of 168.

CONCLUSIONS

Linking databases from bacteriology and biology with those containing the hospital records of surgical procedures is a simple method for identifying surgical nosocomial infections.

Assessment of exposure to ethanol vapors released during use of Alcohol-Based Hand Rubs by healthcare workers

BACKGROUND

Despite the increasing use of Alcohol-Based Hand Rub solutions, few studies have quantified the concentrations of inhaled ethanol.

OBJECTIVE

The aim of this study was to assess ethanol exposure during hygienic and surgical hand disinfection practices.

METHOD

Ethanol concentrations were measured at the nose level of a wooden dummy and human volunteers. Two systems were used in parallel to determine short-term ethanol vapor exposures: activated charcoal tubes followed by gas chromatography analysis and direct reading on a photoionization detector (PID). Exposure was assessed for 4 different sequences (N=10) reproducing hand rubs for simple surgery, nursing care, intensive care and surgical scrub.

RESULTS

The ethanol concentrations measured were of a similar order between the dummy and volunteers. The concentrations obtained by PID were higher than the gas chromatography values for the simple care (45%) and nursing care (27%) sequences and reflected specific exposure peaks of ethanol, whereas ethanol concentrations were continuously high for intensive care (440 mg m(-3)) or surgical scrub (650 mg m(-3)).

CONCLUSION

Ethanol concentrations were similar for these two exposure assessment methods and demonstrated a relationship between handled doses and inhaled doses. However, the ethanol vapors released during hand disinfection were safe for the healthcare workers.

Silver as an antimicrobial: facts and gaps in knowledge

Silver has been used for centuries. Today, silver and silver nanoparticles (AgNPs) are used in a wide range of healthcare, food industry, domiciliary applications, and are commonly found in hard surface materials and textiles. Such an extensive use raises questions about its safety, environmental toxicity and the risks associated with microbial resistance and cross-resistance. If the mechanisms of antimicrobial action of ionic silver (Ag+) have been studied, there is little understanding of AgNPs interactions with microorganisms. There have been excellent reviews on the bacterial resistance mechanisms to silver, but there is a paucity of information on resistance to AgNPs. Silver toxicity and accumulation in the environment has been studied and there is a better understanding of silver concentration and species in different environmental compartments. However, owing to the increased applications of silver and AgNPs, questions remain about the presence and consequences of AgNPs in the environment. This review provides an historical perspective of silver usage, an overview of applications, and combined information of microbial resistance and toxicity. Owing the evidence provided in this review, a call for a better understanding and control of silver usage, and for tighter regulations of silver and AgNPs usage is proposed.

Economic evaluation of health consequences of prenatal methylmercury exposure in France

BACKGROUND

Evidence of a dose-response relationship between prenatal exposure to methylmercury (MeHg) and neurodevelopmental consequences in terms of IQ reduction, makes it possible to evaluate the economic consequences of MeHg exposures.

OBJECTIVE

To perform an economic evaluation of annual national benefits of reduction of the prenatal MeHg exposure in France.

METHODS

We used data on hair-Hg concentrations in French women of childbearing age (18-45 years) from a national sample of 126 women and from two studies conducted in coastal regions (n = 161and n = 503). A linear dose response function with a slope of 0.465 IQ point reduction per μg/g increase in hair-Hg concentration was used, along with a log transformation of the exposure scale, where a doubling of exposure was associated with a loss of 1.5 IQ points. The costs calculations utilized an updated estimate of €2008 17,363 per IQ point decrement, with three hypothetical exposure cut-off points (hair-Hg of 0.58, 1.0, and 2.5 μg/g).

RESULTS

Because of higher exposure levels of women in coastal communities, the annual economic impacts based on these data were greater than those using the national data, i.e., € 1.62 billion (national), and € 3.02 billion and € 2.51 billion (regional), respectively, with the linear model, and € 5.46 billion (national), and € 9.13 billion and € 8.17 billion (regional), with the log model, for exposures above 0.58 μg/g.

CONCLUSIONS

These results emphasize that efforts to reduce MeHg exposures would have high social benefits by preventing the serious and lifelong consequences of neurodevelopmental deficits in children.

Dermal and pulmonary absorption of ethanol from alcohol-based hand rub

BACKGROUND

Ethanol intoxication of healthcare workers (HCWs) using alcohol-based hand rubs (ABHRs) in the workplace is a potentially serious issue. This study quantified the level of ethanol absorption among HCWs after hygienic hand disinfection.

METHODS

Eighty-six HCWs from Nancy University Hospital were tested before and after a 4-h shift. Participants used ABHR containing 70% ethanol. Levels of ethanol, acetaldehyde and acetate in blood and urine were determined using gas chromatography. A breathalyzer was used to measure the level of ethanol in expired air.

RESULTS

Ethanol [mean concentration 0.076 (standard deviation 0.05) mg/L] was detected in the expired air of 28 HCWs 1-2 min post exposure. Ethanol, acetaldehyde and acetate were undetectable in blood after a 4-h shift, and urine tests were negative in all participants.

CONCLUSION

Ethanol exposure from ABHR, particularly inhalation of vapours, resulted in positive breathalyzer readings 1-2 min after exposure. Dermal absorption of ethanol was not detected. Pulmonary absorption was detected but was below toxic levels.

Prospective observational study to assess hand skin condition after application of alcohol-based hand rub solutions

BACKGROUND

The use of alcohol-based hand rub solutions (ABHRSs) in health care settings has been associated with increased hand hygiene compliance and reduced rates of nosocomial infection. Deterioration in hand skin condition leads to impaired barrier function, changes in skin flora, and increased bacterial shedding. Thus, poor skin condition can increase the risk of infection. This study evaluated the hand skin condition and dermal tolerance among health care workers (HCWs) after ABHRS application.

METHODS

The study group comprised 231 HCWs (34% nurses, 22% nurse assistants, and 15% hospital cleaners). The mean participant age was 40 years. Stratum corneum hydration and superficial sebum content and surface pH of the skin were measured on the back and palm of each participant's dominant hand before and after ABHRS use. A self-assessment questionnaire was administered to collect information about the participants, their skin problems, and their perception of the ABHRS.

RESULTS

The study group was 83% females. Skin hydration at the 2 assessment sites was markedly increased after ABHRS use (P < .0001). The mean pH value did not change significantly on the back of the hand, but did change significantly on the palm (P = .012). The superficial sebum content decreased significantly on the palm (P < .0001), but not on the back of the hand. HCWs reported excellent or good skin tolerance of ABHRS in 73% of cases.

CONCLUSION

ABHRSs are well tolerated and do not dry the skin. pH and superficial sebum values decreased slightly, but these decreases did not affect skin barrier function. Values remained within the physiological range.

Consensus report: E. coli O104:H4 (HUSEC041) and the potential threat to European water supplies

Among the 3rd Seminar for PhD students working on Water and Health which was held in Cannes on 27–29 June 2011, experts from a number of universities and research institutes took the opportunity to discuss the emergence of Escherichia coli O104:H4 in Europe. Especially, possible threats for European water suppliers were considered. The consensus is summarized in this report. The main conclusion was that E. coli O104:H4 would not pose a substantial risk to well managed water supplies, especially where regular monitoring of indicator E. coli is negative. However, this may not apply for small and very small water systems which are quite common in Europe. New strategies like the Water Safety Plan approach are needed to protect also small scale drinking water systems and private wells in Europe. Water used in the processing of foods likely to be eaten raw, especially sprouts, should be of drinking water quality.

Health effects of disinfection by-products in chlorinated swimming pools

Increased attendance at swimming pools is correlated with higher input of organic and minerals pollutants introduced by swimmers in the swimming pool water. In most swimming pools, microbiological control is performed by disinfection with the addition of chlorine. Chlorine is now well-known to lead to the formation of many disinfection by-products (DBPs) including trihalomethanes and chloramines. The hypothesis of a link between the presence of eye and skin irritation syndromes in swimmers and contact with swimming pool water treated with chlorine was initially proposed by Mood (1953). During recent decades many epidemiological studies have described the importance of DBPs generated with natural or imported organic matter present in water. Many of these DBPs are suspected to be toxic or even carcinogenic. Trihalomethanes and haloacetic acid families are the most studied but others DBPs, like chloral hydrate, haloacetonitriles, N-nitrosodimethylamine and the bromate ion, are emerging compounds of interest. Epidemiological data about the risk of cancer are still controversial. However, numerous publications highlight a toxic risk especially the risk of allergy and respiratory symptoms for babies and elite swimmers. The few publications dedicated to risk assessment do not suggest increased risk, other than for elite swimmers. These publications are likely to underestimate the risk associated with DBPs because of the lack of data in the literature precludes the calculation of risk associated with certain compounds or certain pathways. Thus for regulations, the need to take into account the risks associated with disinfection by-products is now important without forgetting the need of the control of microbiological hazards in swimming pools.

Emerging pollutants in wastewater: a review of the literature

For 20 years, many articles report the presence of new compounds, called "emerging compounds", in wastewater and aquatic environments. The US EPA (United States - Environmental Protection Agency) defines emerging pollutants as new chemicals without regulatory status and which impact on environment and human health are poorly understood. The objective of this work was to identify data on emerging pollutants concentrations in wastewater, in influent and effluent from wastewater treatment plants (WWTPs) and to determine the performance of sewage disposal. We collected 44 publications in our database. We sought especially for data on phthalates, Bisphenol A and pharmaceuticals (including drugs for human health and disinfectants). We gathered concentration data and chose 50 pharmaceutical molecules, six phthalates and Bisphenol A. The concentrations measured in the influent ranged from 0.007 to 56.63 μg per liter and the removal rates ranges from 0% (contrast media) to 97% (psychostimulant). Caffeine is the molecule whose concentration in influent was highest among the molecules investigated (in means 56.63 μg per liter) with a removal rate around 97%, leading to a concentration in the effluent that did not exceed 1.77 μg per liter. The concentrations of ofloxacin were the lowest and varied between 0.007 and 2.275 μg per liter in the influent treatment plant and 0.007 and 0.816 μg per liter in the effluent. Among phthalates, DEHP is the most widely used, and quantified by the authors in wastewater, and the rate of removal of phthalates is greater than 90% for most of the studied compounds. The removal rate for antibiotics is about 50% and 71% for Bisphenol A. Analgesics, anti inflammatories and beta-blockers are the most resistant to treatment (30-40% of removal rate). Some pharmaceutical molecules for which we have not collected many data and which concentrations seem high as Tetracycline, Codeine and contrast products deserve further research.

Impacts of two perfluorinated compounds (PFOS and PFOA) on human hepatoma cells: cytotoxicity but no genotoxicity?

Perfluorinated compounds (PFCs) and particularly two of them, perfluoroctanoate (PFOA) and perfluorooctanesulfonate (PFOS), have been widely produced and used since 1950. They both persist in the environment and accumulate in wildlife and humans. The toxicity of PFOS and PFOA has been studied extensively in rodents with several adverse effects mainly a hepatocarcinogenic potential. Carcinogenic effects are not highlighted in humans' studies. In this study, we investigated the cytotoxic and genotoxic effects of PFOA and PFOS using human HepG2 cells after 1 or 24h of exposure. The cytotoxic and genotoxic potential was evaluated by MTT assay, single cell gel electrophoresis (SCGE) assay and micronucleus assay respectively. We measured the intracellular generation of reactive oxygen species (ROS) using dichlorofluorescein diacetate to identify a potential mechanism of toxicity. We observed a cytotoxic effect of PFOA and PFOS after 24h of exposure starting from a concentration of 200 μM (MTT: -14.6%) and 300 μM (MTT: -51.2%) respectively. We did not observe an increase of DNA damage with the comet assay or micronucleus with the micronucleus assay after exposure to the two PFCs. After 24h of exposure, both PFOA and PFOS highlight a decrease of ROS generation (-5.9% to -23%). We did not find an effect after an hour of exposure. Our findings show that PFOA and PFOS exert a cytotoxic effect on the human cells line HepG2 but nor PFOA or PFOS could induce an increase of DNA damage (DNA strand breaks and micronucleus) or reactive oxygen species at the range concentration tested. Our results do not support that oxidative stress and DNA damage are relevant for potential adverse effects of PFOA and PFOS. These results tend to support epidemiological studies that do not show evidence of carcinogenicity.