Comparison of boiling and chlorination on the quality of stored drinking water and childhood diarrhoea in Indonesian households.

We compared the impact of a commercial chlorination product (brand name Air RahMat) in stored drinking water to traditional boiling practices in Indonesia. We conducted a baseline survey of all households with children 1000 MPN/100 ml (RR 1·86, 95% CI 1·09-3·19) in stored water than in households without detectable E. coli. Although results suggested that Air RahMat water treatment was associated with lower E. coli contamination and diarrhoeal rates among children <5 years than water treatment by boiling, Air RahMat use remained low.

Evaluation of Solanum sisymbriifolium as a Potential Inoculum Source of Verticillium dahliae and Colletotrichum coccodes.

Solanum sisymbriifolium, the litchi tomato, is a perennial herbaceous plant from South America that is used as a trap crop to reduce soilborne populations of the pale cyst nematode Globodera pallida, an important potato pathogen. Possible interactions of soilborne potato pathogens Verticillium dahliae and Colletotrichum coccodes with litchi tomato are unknown, yet important for potato production if litchi tomato is to be planted as a trap crop. The goal of this research was to quantitatively assess if litchi tomato is a potential inoculum source for C. coccodes and V. dahliae by comparing colony forming units (CFU) observed in litchi tomato to susceptible and resistant potato cultivars. The potato cvs. Alturas (P = 0.0003), Ranger Russet (P = 0.0193), and Russet Norkotah (P = 0.0022) produced more CFUs of the potato pathotype of V. dahliae than litchi tomato the first of two years of greenhouse trials. Significantly more CFUs of the potato pathotype of V. dahliae were quantified from stems and roots of only cv. Russet Norkotah compared with litchi tomato (P = 0.0001) in the second year. The CFUs for C. coccodes varied between litchi tomato and the potato cvs., perhaps due to varying levels of resistance since litchi tomato is from a selected intermated seed source. Based on these data, the effect of litchi tomato in rotation with potato is likely to have limited effect on the proliferation of V. dahliae or C. coccodes populations in the soil when compared with a susceptible potato cultivar.

The challenge of improving boiling: lessons learned from a randomized controlled trial of water pasteurization and safe storage in Peru.

Boiling is the most common method of household water treatment in developing countries; however, it is not always effectively practised. We conducted a randomized controlled trial among 210 households to assess the effectiveness of water pasteurization and safe-storage interventions in reducing Escherichia coli contamination of household drinking water in a water-boiling population in rural Peru. Households were randomized to receive either a safe-storage container or a safe-storage container plus water pasteurization indicator or to a control group. During a 13-week follow-up period, households that received a safe-storage container and water pasteurization indicator did not have a significantly different prevalence of stored drinking-water contamination relative to the control group [prevalence ratio (PR) 1·18, 95% confidence interval (CI) 0·92-1·52]. Similarly, receipt of a safe-storage container alone had no effect on prevalence of contamination (PR 1·02, 95% CI 0·79-1·31). Although use of water pasteurization indicators and locally available storage containers did not increase the safety of household drinking water in this study, future research could illuminate factors that facilitate the effective use of these interventions to improve water quality and reduce the risk of waterborne disease in populations that boil drinking water.

Evaluation of the impact of a simple hand-washing and water-treatment intervention in rural health facilities on hygiene knowledge and reported behaviours of health workers and their clients, Nyanza Province, Kenya, 2008.

Many clinics in rural western Kenya lack access to safe water and hand-washing facilities. To address this problem, in 2005 a programme was initiated to install water stations for hand washing and drinking water in 109 health facilities, train health workers on water treatment and hygiene, and motivate clients to adopt these practices. In 2008, we evaluated this intervention's impact by conducting observations at facilities, and interviewing staff and clients about water treatment and hygiene. Of 30 randomly selected facilities, 97% had water stations in use. Chlorine residuals were detectable in at least one container at 59% of facilities. Of 164 interviewed staff, 79% knew the recommended water-treatment procedure. Of 298 clients, 45% had received training on water treatment at a facility; of these, 68% knew the recommended water-treatment procedure. Use of water stations, water treatment, and client training were sustained in some facilities for up to 3 years.

Recurrent epidemic cholera with high mortality in Cameroon: persistent challenges 40 years into the seventh pandemic.

Cameroon has experienced recurrent cholera epidemics with high mortality rates. In September 2009, epidemic cholera was detected in the Far North region of Cameroon and the reported case-fatality rate was 12%. We conducted village-, healthcare facility- and community-level surveys to investigate reasons for excess cholera mortality. Results of this investigation suggest that cholera patients who died were less likely to seek care, receive rehydration therapy and antibiotics at a healthcare facility, and tended to live further from healthcare facilities. Furthermore, use of oral rehydration salts at home was very low in both decedents and survivors. Despite the many challenges inherent to delivering care in Cameroon, practical measures could be taken to reduce cholera mortality in this region, including the timely provision of treatment supplies, training of healthcare workers, establishment of rehydration centres, and promotion of household water treatment and enhanced handwashing with soap.

Extension of FRI for modeling of electrocardiogram signals.

Recent work has developed a modeling method applicable to certain types of signals having a "finite rate of innovation" (FRI). Such signals contain a sparse collection of time- or frequency-limited pulses having a restricted set of allowable pulse shapes. A limitation of past work on FRI is that all of the pulses must have the same shape. Many real signals, including electrocardiograms, consist of pulses with varying widths and asymmetry, and therefore are not well fit by the past FRI methods. We present an extension of FRI allowing pulses having variable pulse width (VPW) and asymmetry. We show example results for electrocardiograms and discuss the possibility of application to signal compression and diagnostics.

Microbiologic effectiveness of boiling and safe water storage in South Sulawesi, Indonesia.

In Indonesia, where diarrhea remains a major cause of mortality among children <5 years, the government promotes boiling of drinking water. We assessed the impact of boiling on water quality in South Sulawesi. We surveyed randomly selected households with at least one child <5 years old in two rural districts and tested source and stored water samples for Escherichia coli contamination. Among 242 households, 96% of source and 51% of stored water samples yielded E. coli. Unboiled water samples, obtained from 15% of households, were more likely to yield E. coli than boiled samples [prevalence ratios (PR) = 2.0, 95% confidence interval (CI) 1.7-2.5]. Water stored in wide-mouthed (PR = 1.4, 95% CI = 1.1-1.8) or uncovered (PR = 1.8, 95% CI = 1.3-2.4) containers, or observed to be touched by the respondent's hands (PR = 1.6, 95% CI = 1.3-2.1) was more likely to yield E. coli. A multivariable model showed that households that did not boil water were more likely to have contaminated stored water than households that did boil water (PR = 1.9, 95% CI = 1.5-2.3). Although this study demonstrated the effectiveness of boiling in reducing contamination, overall impact on water quality was suboptimal. Future studies are needed to identify factors behind the success of boiling water in Indonesia to inform efforts to scale up other effective water treatment practices.

Aetiology of diarrhoea among persons with HIV and their family members in rural Uganda: a community-based study.

OBJECTIVES: To identify pathogens associated with diarrhoea in HIV-infected persons and their HIV-uninfected family members. DESIGN: Prospective cohort study. SETTING: Rural community in eastern Uganda. SUBJECTS: Eight hundred and seventy nine HIV-infected adults (74% females and median age 35 years (IQR, 29-41) and 2771 HIV-uninfected family members (51% females and median age 11 years (IQR 6-16) were included. MAIN OUTCOME MEASURES: Using microscopy and culture, stools were tested for parasites, bacteria and bacterial-antimicrobial-susceptibility. Logistic regression models, adjusting for age, CD4 cells, season, household clustering and use of safe-water system were used for relationships between pathogens, diarrhoea and HIV. RESULTS: Persons with HIV had similar pathogens in diarrhoeal (69%) and nondiarrhoeal stools (57%). Most diarrhoea was not associated with identifiable aetiology; the population attributable risk of diarrhoea for known diarrhoea pathogens was 32%. Enteric bacteria (19%), enteropathogenic or enterotoxigenic E. coli (8%), Aeromonas species (7%), Strongyloides stercoralis (8%) and Cryptosporidium parvum (5%). HIV-infected, stools had more Cryptosporidium parvum than HIV-uninfected (OR 2.64, 95% CI 1.43-4.87). Most bacteria were resistant to commonly used antimicrobials irrespective of HIV status. CONCLUSIONS: Irrespective of HIV-status, aetiologies of majority of their diarrhoea in Uganda cannot be identified by microscopy and culture. Bacterial pathogens isolated have high resistance to common antimicrobials. Empiric treatment should be tailored to local bacterial-resistance patterns.

Predicting arteriovenous fistula maturation with intraoperative blood flow measurements.

OBJECTIVE: To establish the criteria for intraoperative blood flow measurements taken at the time of autologous arteriovenous fistula (AVF) construction to predict future access maturation and thereby avoid waiting periods for futile fistulas to declare themselves. METHODS: From April 2006 through to March 2007 consecutive patients undergoing native AVF construction at one institution underwent intraoperative measurements of blood flow using transit-time ultrasound technology. No action was taken based upon the flow measurement at the time of surgery. Patients were followed and data collected comprising demographics and AVF maturation. A fistula was considered mature when it was successfully accessed for hemodialysis (HD) at least three times. Statistical analysis was performed including receiver operating characteristics (ROC), ANOVA, and Chi square using the JMP software package. RESULTS: During the 12-month period, 70 autologous AVFs were created including 41 antecubital brachiocephalic, 21 radiocephalic, and 8 basilic vein transpositions in 35 females and 33 males with a mean age of 58+/-1.7 (mean+/-SEM). The group included 37 Hispanic, 17 Native American, 10 Caucasian, 3 African American and 1 Asian patient. The etiology of renal failure comprised 53 diabetics, 13 hypertensives, 1 polycystic kidney disease and 1 congenital abnormality. Complete follow-up was available in 69/70 AVFs in 67 patients. Patients were excluded from analysis if they had not yet started dialysis (n=12), stopped or died (n=4) before their fistula was accessed. Patients whose AVFs were patent, but required a secondary procedure to achieve a functional access were considered non-functional. There was a significant difference between the maximal intraoperative flow rates between functional and non-functional AVFs (573.6+/-103 mL/min vs. 216.8+/-35.8 mL/min; p<0.05). There was no difference between groups in regard to age, gender, race or etiology of renal failure. ROC analysis suggested a threshold value of 140 mL/min for radiocephalic and 308 mL/min for brachiocephalic AVFs to predict maturation to a functional access. CONCLUSION: Intraoperative blood flow measurements obtained at the time of autologous AVF construction can identify fistulas that are unlikely to mature; and therefore, that require immediate revision or abandonment which will ultimately expedite the establishment of a useful access in the HD patient. This is the first study to establish the minimal flow values uniquely needed for both radial artery and brachial artery AVFs to expect primary maturation to a functional access.

Diarrhoea prevention in a high-risk rural Kenyan population through point-of-use chlorination, safe water storage, sanitation, and rainwater harvesting.

Lack of access to safe water and sanitation contributes to diarrhoea moribidity and mortality in developing countries. We evaluated the impact of household water treatment, latrines, shallow wells, and rainwater harvesting on diarrhoea incidence in rural Kenyan children. We compared diarrhoea rates in 960 children aged <5 years in 556 households in 12 randomly selected intervention villages and six randomly selected comparison villages during weekly home visits over an 8-week period. On multivariate analysis, chlorinating stored water [relative risk (RR) 0.44, 95% confidence interval (CI) 0.28-0.69], latrine presence (RR 0.71, 95% CI 0.54-0.92), rainwater use (RR 0.70, 95% CI 0.52-0.95), and living in an intervention village (RR 0.31, 95% CI 0.23-0.41), were independently associated with lower diarrhoea risk. Diarrhoea risk was higher among shallow well users (RR 1.78, 95% CI 1.12-2.83). Chlorinating stored water, latrines, and rainwater use all decreased diarrhoea risk; combined interventions may have increased health impact.

Disinfection by-product formation and mitigation strategies in point-of-use chlorination of turbid and non-turbid waters in western Kenya.

Over 1.1 billion people in the world lack access to improved drinking water. Diarrheal and other waterborne diseases cause an estimated 2.2 million deaths per year. The Safe Water System (SWS) is a proven household water treatment intervention that reduces diarrheal disease incidence in users in developing countries. Because the SWS recommends the addition of sodium hypochlorite to unfiltered water sources, concerns have been raised about the potential long-term health effects of disinfection by-products to SWS users. This study investigated the production of trihalomethanes (THMs) in water treated with sodium hypochlorite from six sources used for drinking water in western Kenya. The turbidity values of these sources ranged from 4.23 NTU to 305 NTU. THM concentrations were analysed at 1, 8, and 24 hours after addition of sodium hypochlorite. No sample exceeded the World Health Organization (WHO) guideline values for any of the four THMs: chloroform, bromodichloromethane, dibromochloromethane, or bromoform. In addition, no sample exceeded the WHO additive total THM guideline value. These results clearly show that point-of-use chlorination of a variety of realistic source waters used for drinking did not lead to THM concentrations that pose a significant health risk to SWS users.

Utilization of a basic care and prevention package by HIV-infected persons in Uganda.

Opportunistic infections are the leading cause of mortality among HIV-infected people. Several simple interventions prevent illness, prolong life, or prevent HIV transmission from HIV-infected people in Africa. These include: cotrimoxazole prophylaxis; insecticide-treated bed nets; supplies for household water treatment and safe storage; materials promoting family voluntary counselling and testing (VCT); and condoms. We provided these interventions to adults and children with HIV who were members of the AIDS Support Organization in Uganda. To evaluate use of this basic care and prevention package, we surveyed a representative sample of 112 clients of TASO in their homes. Among respondents, 95% reported taking cotrimoxazole everyday, 89% said they had slept under a bednet the night before, 65% reported current treatment of household drinking water, 89% of sexually active respondents reported using condoms, and 96% reported family use of VCT. Household observations verified that use of cotrimoxazole, bednets, and water treatment products were consistent with reported use. This evaluation suggests successful distribution and use of basic care and prevention services at an AIDS organization in Uganda.

The impact of a school-based safe water and hygiene programme on knowledge and practices of students and their parents: Nyanza Province, western Kenya, 2006.

Safe drinking water and hygiene are essential to reducing Kenya's diarrhoeal disease burden. A school-based safe water and hygiene intervention in Kenya was evaluated to assess its impact on students' knowledge and parents' adoption of safe water and hygiene practices. We surveyed 390 students from nine schools and their parents at baseline and conducted a final evaluation of 363 students and their parents. From baseline to final evaluation, improvement was seen in students' knowledge of correct water treatment procedure (21-65%, P<0.01) and knowing when to wash their hands. At final evaluation, 14% of parents reported currently treating their water, compared with 6% at baseline (P<0.01). From 2004 to 2005, school absenteeism in the September-November term decreased in nine project schools by 35% and increased in nine neighbouring comparison schools by 5%. This novel programme shows promise for reducing school absenteeism and promoting water and hygiene interventions in the home.

Establishing a corky ringspot disease plot for research purposes.

A method to establish two experimental corky ringspot disease (CRS) plots that had no prior CRS history is described. CRS is a serious disease of potato in the Pacific Northwest caused by tobacco rattle virus (TRV) and transmitted primarily by Paratrichodorus allius. 'Samsun NN' tobacco seedlings were inoculated with viruliferous P. allius in the greenhouse before they were transplanted into the field soil at the rate of 3,000 plus seedlings/ha. Care was taken to keep soil around plants in the greenhouse and transplants in the field moist to avoid vector mortality. The vector population in the soil of one of the fields was monitored by extraction, examination under microscope and bioassay on tobacco seedlings to ascertain that they were virus carriers. Presence of virus in tobacco bioassay plants was determined by visual symptoms on tobacco leaves and by testing leaves and roots using ELISA. Although TRV transmission was rapid, there was loss of infectivity in the first winter which necessitated a re-inoculation. After two years of planting infected tobacco seedlings, 100% of soil samples collected from this field contained viruliferous P. allius. In the second field, all five commercial potato cultivars, known to be susceptible, expressed symptoms of CRS disease indicating that the procedure was successful.

Epidemic cholera in urban Zambia: hand soap and dried fish as protective factors.

Between 28 November 2003 and 23 February 2004, 4343 cases and 154 deaths from cholera (case-fatality rate 3.5%) were reported in Lusaka, Zambia. A case-control study was conducted in February 2004 to assess potential transmission routes and prevention strategies. Consumption of raw vegetables was significantly associated with cholera [adjusted odds ratio (aOR) 4.7, 95% confidence interval (CI) 1.7-13, P=0.003). Consumption of a local sardine-like fish was protective (aOR 0.3, 95% CI 0.1-0.7, P=0.008). Hand soap was present in 90% of control homes and 58% of case homes. Observed hand soap was a strongly protective factor (aOR 0.1, 95% CI 0.04-0.4, P=0.001). No water source or treatment practice was significantly associated with cholera. This study documents the importance of foodborne transmission of cholera, illustrates the protective role of hand washing in an epidemic setting, and identifies a novel possible protective factor, a local fish, which warrants further research.

Sustained high levels of stored drinking water treatment and retention of hand-washing knowledge in rural Kenyan households following a clinic-based intervention.

Nyanza Province, Kenya is characterized by poor water quality and high diarrhoea prevalence. To address these problems, nurses in a maternal and child health clinic in Homa Bay, Kenya were trained in household water chlorination with a locally available, social marketed product, and in six steps of proper hand washing. They were asked to communicate this information to their clients. Interviews immediately following the training by nurses were conducted on 220 clients, of whom 168 (76%) reported being taught both procedures during their clinic visit. After 2 weeks, free chlorine residuals were present in stored drinking water in 67 out of 98 (68%) clients' homes and, 1 year later, in 36 out of 51 (71%) clients' homes. After 2 weeks, all six hand-washing steps were correctly demonstrated by 41 (44%) out of 93 clients, and by 17 out of 51 (34%) 1 year later. This brief, practical intervention shows promise for vulnerable populations.

Changing community behaviour: experience from three African countries.

In the developing world, more than 1 billion people lack access to safe water. To address this problem, the US Centers for Disease Control and Prevention developed the Safe Water System (SWS), a household-based intervention with three elements: water disinfection, safe storage and behaviour change techniques, and tested these in three countries. In Zambia, social marketing (SM) was used to implement the SWS, and 100 randomly selected households also received motivational interviewing (MI). In Madagascar, the SWS was implemented using SM and community mobilisation (CM). In rural Western Kenya, the SWS was also implemented with SM and CM. In Zambia, 3 months after the SM project launch, 14% of households in the SM-only group had adopted the disinfectant compared with 78% of households in the SM plus MI group. Through SM, over 1 million bottles of disinfectant were sold in 3 years in Zambia. In Antananarivo, Madagascar, 6 months after launch of the water disinfectant, 8% of households in an early stage of the CM process were using the disinfectant compared with 20% in households at a late stage of the CM process. In 1 year, over 500,000 bottles of disinfectant were sold in Madagascar. In Kenya, adoption of the water disinfectant exceeded 60% in intervention households and diarrhoea rates decreased by 58% in children < 5 years. Social marketing permits widespread dissemination of interventions, but may have limited penetration into economically disadvantaged communities. Additional, targeted interventions, such as MI and CM, can increase product adoption. A combination of behaviour change interventions can increase project impact.

Enoxaparin treatment in high-risk trauma patients limits the utility of surveillance venous duplex scanning.

OBJECTIVE: The value of surveillance venous duplex scanning for detecting unsuspected deep venous thrombosis (DVT) in trauma patients who are receiving enoxaparin prophylaxis is open to question. This study was undertaken to determine whether enoxaparin reduced the clinical utility of surveillance scanning and whether management of these patients was altered by findings of the scans. METHODS: The medical records of trauma patients who met defined criteria for high DVT risk, admitted during 30 consecutive months, were reviewed. These patients received enoxaparin 30 mg every 12 hours for the duration of their admissions. Per protocol, surveillance lower extremity venous duplex scans were performed within 72 hours of enoxaparin administration and then weekly until patients were discharged from the hospital. The records were reviewed for thromboembolic events (DVT or pulmonary embolism [PE]), patient location and ambulatory status, therapeutic interventions (systemic anticoagulation, vena cava filter), and complications of enoxaparin therapy. RESULTS: A total 241 patients underwent 513 venous duplex examinations (1-13 per patient). Eight patients had DVT on the initial scan; seven of these patients were asymptomatic. Five were treated with anticoagulation and/or vena cava filter placement. Of the 233 patients with initially negative duplex scan results, five patients (2%) developed clinically unsuspected lower extremity DVT while hospitalized. All of these five patients were in an intensive care unit. Three of the five patients had no change in treatment. Two of the five underwent anticoagulation, and one vena cava filter was placed. PE occurred in two hospitalized patients, one of whom was ambulatory, with negative duplex scan results. After hospital discharge, six other patients had symptomatic DVT or PE despite in-hospital scans with negative results. Complications associated with enoxaparin included hemorrhage (2) and thrombocytopenia (8). CONCLUSIONS: After initial negative scan results, repeat surveillance duplex scanning during hospitalization detected a low incidence (2%) of DVT in high-risk patients. Furthermore, the detection of unsuspected DVT altered the clinical management of less than 1% of the patients tested. Thus, after a venous duplex scan with negative results and initiation of enoxaparin prophylaxis, subsequent surveillance duplex examinations are not warranted in asymptomatic trauma patients.

Challenges in implementing a point-of-use water quality intervention in rural Kenya.

To prevent diarrheal diseases in western Kenya, CARE Kenya initiated the Water, Sanitation, and Education for Health (WASEH) Project in 1998. The project targets 72 farming and fishing communities with a total population of 43 000. Although the WASEH Project facilitated construction of shallow wells and pit latrines, the water quality still needed improvement. Consequently, in 2001, CARE implemented the Safe Water System (which consists of point-of-use water treatment with sodium hypochlorite, safe storage, and behavior change techniques) within the already established WASEH infrastructure, using existing community organizations in combination with a social marketing approach that introduced affordable products. The project has resulted in adoption rates of 33.5% for chemical water treatment and 18.5% for clay pots modified for safe water storage.

Impact of the safe water system on water quality in cyclone-affected communities in Madagascar.

Cyclone Hudah struck the northeastern coast of Madagascar in the spring of 2000. Over a 5-month period, 11 700 relief kits consisting of bottles of water disinfectant and foldable jerry cans were distributed to the affected population. Five months after the cyclone, a survey was conducted in 12 villages to determine the impact of these relief kits on water quality. Seventy-six percent of the surveyed households reported using jerry cans, and 65% reported using the disinfectant. Stored water in households using both products had significantly less microbiological contamination than stored water in other households. To improve the prospects for a sustainable intervention, the response plan for future disasters should incorporate a transition to recovery and development, including formative research into local customs, beliefs, and water handling habits, and funding support to initiate social marketing.