WHO Recommendations (who + recommendation)

Distribution by Scientific Domains

Selected Abstracts

Detection and quantification of microcystins from cyanobacteria strains isolated from reservoirs and ponds in Morocco

B. Oudra
Abstract In Morocco, the occurrence of toxic cyanobacteria blooms is confirmed in some water bodies used for recreational and/or as drinking water reservoirs. According to WHO recommendations, the establishment of a monitoring program for microcystins is a necessity. This paper presents toxicological studies of 19 toxic cyanobacteria strains of Microcystis, Synechocystis, Pseudanabaena, and Oscillatoria. These strains were isolated from various water bodies including natural lakes, reservoirs, and ponds located in central regions of Morocco. The isolation, culture, and biomass production of these strains was made on Z8 or BG13 media under laboratory controlled conditions. The hepatotoxicity of cyanobacterial lyophilized material was confirmed by mouse bioassays. The amount of microcystins produced by each strain was determined by the enzyme-linked immunosorbent assay (ELISA). The detection and identification of microcystin variants was performed by high performance liquid chromatography (HPLC) with photodiode array detection. Almost all strains showed medium to high toxicity, the estimated LD50 i.p mice bioassay ranged between 28 to 350 mg/kg body weight. The concentrations of microcystins varied between 2.16 to 944 ,g/g and 26.8 to 1884 ,g/g dry weight determined by ELISA and HPLC, respectively. The screening of bloom-forming and microcystin producer cyanobacteria strains in these fresh water bodies leads us to propose the need for the establishment of a survey of cyanobacteria and a cyanotoxin-monitoring program. 2002 by Wiley Periodicals, Inc. Environ Toxicol 17: 32,39, 2002 [source]

Assessment of Dental Caries Predictors in a Seven-year Longitudinal Study

Elaine Pereira da Silva Tagliaferro DDS
Abstract Objective: To identify, in a group of 6,8-year-old schoolchildren, risk factors for dental caries increment in permanent dentition. Methods: Two hundred and six children from three different schools in Piracicaba, Brazil, were examined at baseline and after 7 years by the same two calibrated dentists. Data on dental caries (dmfs, DMFS, presence of initial lesions), fluorosis, oral hygiene and presence of sealant were collected at the clinical examination that was performed in an outdoor setting, under natural light, using a dental mirror and probe following the WHO recommendations. Information on socioeconomic level, fluoride usage, dental service utilization, dietary and oral hygiene habits was also obtained at baseline in a semi-structured questionnaire sent to the parents. The dependent variable was the 7-year DMFS increment. A univariate analysis was performed to test the association of independent variables in caries increment. Then a logistic regression model was used to estimate the adjusted Odds Ratio for caries increment. Results: Clinical (dmfs, DMFS) and non-clinical variables (daily toothbrushing, use of preventive topical methods, parents' educational level) were entered in the multiple logistic regression analysis. The prediction model included the clinical and socioeconomic variables, DMFS, dmfs and mother's educational level. The best caries predictor was the dmfs variable. Conclusion: Caries experience and mother's educational level were predictors of caries increment in permanent dentition. [source]

The microbiological quality of drinking water sold on the streets in Kumasi, Ghana

K. Obiri-Danso
Abstract Aim: The aim of this study was to assess the microbiological quality of Ghanaian bottled and plastic-bagged drinking water sold on the streets of Metropolitan Kumasi, Ghana. Methods and Results: Eight bottled, 88 factory-filled plastic sachet and 40 hand-filled hand-tied polythene-bagged drinking waters were examined for the presence of heterotrophic bacteria total viable counts (TVCs), indicators of faecal contamination (total coliforms, faecal coliforms and enterococci) and for lead, manganese and iron. Heterotrophic bacteria were found in all three types of water with TVCs per millilitre ranging from 1 to 460 for bottled water, 2,633 105 for factory-bagged sachet water and 233 103,733 1012 for hand-filled hand-tied bagged water. None of the microbial indicators of faecal contamination were detected in bottled water, whereas 45% of the factory-bagged sachets contained total coliforms and 23% faecal coliforms, and 425% of the hand-filled hand-tied bags contained total coliforms, 225% faecal coliforms and 5% enterococci. Iron was found in all three types of drinking water but at concentrations well within the WHO recommendations. Lead and manganese were not detected. Conclusion: Ghanaian bottled water is of good microbiological quality but some factory-bagged sachet and hand-filled hand-tied polythene-bagged drinking water are of doubtful quality. Significance and Impact of the Study: Factory-bagged sachets and hand-filled hand-tied bags of drinking water sold in Ghana should be monitored for microbiological contamination, with the aim of raising standards in the industry and re-assuring the public. [source]

Predictors of the duration of exclusive breastfeeding among first-time mothers,

Sonia Semenic
Abstract Few women currently meet revised WHO recommendations to breastfeed exclusively for 6 months postpartum. In this prospective study we aimed to determine the influence of socio-demographic, psychosocial, and perinatal factors on the length of exclusive breastfeeding among 189 Canadian primiparous mothers. A majority of the participants did not meet their exclusive breastfeeding goals, and only 5% breastfed exclusively for a full 6 months. Breastfeeding self-efficacy, in-hospital formula supplementation, prenatal class attendance, and type of delivery independently predicted exclusive breastfeeding duration. Findings underscore the complex interplay of factors influencing breastfeeding, highlight the early postpartum weeks as a critical period for the establishment of exclusive breastfeeding, and suggest the need for a continuum of pre- and postnatal strategies for prolonging the exclusive breastfeeding period. 2008 Wiley Periodicals, Inc. Res Nurs Health 31:428,441, 2008 [source]