Effects of Different Solid Loading Rates of Faecal Sludge on the Dewatering Performance of Unplanted Filter Bed.

The aim of this study was to investigate which Solid Loading Rate (SLR) of faecal sludge will best improve the dewatering performance of selected sand with particle sizes range of (? 0.1 ? 0.5) mm raised on bench scale filter beds. Public toilet sludge  and septage collected from suction trucks discharging at Dompoase stabilisation  ponds in Kumasi , Ghana, mixed in the ratio of 1:1, 1:2 and 1:3 by volume representing SLR1, SLR2 and SLR3 respectively, were used for the dewatering. Percolate volume was measured every 24 hour. The faecal sludge of SLR1, SLR2 and SLR3 dewatered at average dewatering times of 7, 5 and 4 days respectively. Removal efficiencies of the different solid loading rates though very high for TS, SS, TVS, COD, DCOD, NH3-N, did not show any significant difference. Organic matter build up in the top 10cm of the filter bed was least in SLR3. Again SLR3 showed the highest potential for annual generation of biosolids at 438, 421 and 379 (kg/m2 year) for SL3, SLR2 and SLR1 respectively. Therefore SLR3 of faecal sludge is recommended for dewatering on the selected filter bed. Key words: Faecal sludge, solid loading rate, dewatering time, filter bed, percolate

Long-term effect of Mali phosphate rock on the grain yield of interspecifics and saltiva rice cultivars on acid soil in a humid forest zone of Côte d’Ivoire

To generate knowledge of upland rice intensification in West Africa, the grain yields of four interspecific cultivars (V2 = WAB450-1 B-P-38-HB; V3 = WAB450-11-1-P-40-HB; V4 = WAB450-11-1-P-40-1-H; and V5 = WAB450-24-3-2-P-18-HB) were compared with that of a soil acidity tolerant sativa (WAB 56-104 = V1) on acid soil at Man in the humid forest zone in Côte d’Ivoire during five cropping seasons (1998, 1999, 2000, 2001 and 2002). Nitrogen and potassium were annually applied at 100 and 50 kg ha-1 respectively. Mali phosphate rock from Tilemsi was applied once in 1998 at 0, 150, 300 and 450 kg P ha-1 in a randomized complete block design with three replications. The results revealed a grain yield ranging from 0.5 t ha-1 to 2.6 t ha-1 with highest productivity of interspecific cultivars V3 and V4 even at 0 kg P ha-1 compared to acid tolerant saltiva (V1). Annual optimum rates of P application were determined at 31.5 and 45 kg P ha-1 respectively for V3 and V4. Applying Mali PR at 31.5 and 45 kg P ha-1 respectively for V3 and V4 was recommended for upland rice intensification in the humid forest zone of Côte d’Ivoire.Keywords: Mali phosphate rock, rice, Côte d’Ivoire, interspecific, acid soil

Environmental determinants of access to shared sanitation in informal settlements: a cross-sectional study in Abidjan and Nairobi

BACKGROUND: Universal access to basic sanitation remains a global challenge, particularly in low- and middle-income countries. Efforts are underway to improve access to sanitation in informal settlements, often through shared facilities. However, access to these facilities and their potential health gains-notably, the prevention of diarrheal diseases-may be hampered by contextual aspects related to the physical environment. This study explored associations between the built environment and perceived safety to access toilets, and associations between the latter and diarrheal infections. METHODS: A cross-sectional study was carried out between July 2021 and February 2022, including 1714 households in two informal settlements in Abidjan (Cote d'Ivoire) and two in Nairobi (Kenya). We employed adjusted odds ratios (aORs) obtained from multiple logistic regressions (MLRs) to test whether the location of the most frequently used toilet was associated with a perceived lack of safety to use the facility at any time, and whether this perceived insecurity was associated with a higher risk of diarrhea. The MLRs included several exposure and control variables, being stratified by city and age groups. We employed bivariate logistic regressions to test whether the perceived insecurity was associated with settlement morphology indicators derived from the built environment. RESULTS: Using a toilet outside the premises was associated with a perceived insecurity both in Abidjan [aOR = 3.14, 95% confidence interval (CI): 1.13-8.70] and in Nairobi (aOR = 57.97, 95% CI: 35.93-93.53). Perceived insecurity to access toilets was associated with diarrheal infections in the general population (aOR = 1.90, 95% CI: 1.29-2.79 in Abidjan, aOR = 1.69, 95% CI: 1.22-2.34 in Nairobi), but not in children below the age of 5 years. Several settlement morphology features were associated with perceived insecurity, namely, buildings' compactness, the proportion of occupied land, and angular deviation between neighboring structures. CONCLUSIONS: Toilet location was a critical determinant of perceived security, and hence, must be adequately addressed when building new facilities. The sole availability of facilities may be insufficient to prevent diarrheal infections. People must also be safe to use them. Further attention should be directed toward how the built environment affects safety

Efficiency of common washing treatments in reducing microbial levels on lettuce in Mali

Lettuce is one of the most cultivated vegetables (eaten raw) in Mali with a percentage of 69.4 amongst leafy vegetables and 30.4 of all vegetables. Vegetables consumed raw, particularly lettuce, are sources of foodborne pathogens. This study was conducted to assess bacterial contamination of unwashed lettuce and the efficiency of disinfecting it with tap water and varying concentrations of some chemical disinfectants: bleach (0.00285, 0.00570 and 0.00855 ppm), potassium permanganate (170, 340 and 510 ppm), vinegar (0.00285, 0.00570 and 0.00855 ppm) and common salt (500, 1000 and 1500 ppm) based on the three consecutive washing protocol recommended for vegetables in Mali. Lettuce samples were randomly selected from farms irrigated with untreated river water within communities five and six in Bamako. Lettuce leaves were exposed to low concentration of the chemical disinfectants at 15 min, intermediate at 10 min and high at 5 min. A bleach (0.00285 ppm)/vinegar (0.00285 ppm) combination disinfection was also tested at 15 min. Tap water, bleach, potassium permanganate, vinegar and common salt reduced faecal coliform populations by 1.3–2.9, 1.5–3.0 and 1.9–3.5 log CFU/100 g, at 5, 10 and 15 min, respectively. Disinfection treatment using bleach (0.00285 ppm) was found to be more effective than other disinfectants at all contact times. All the disinfectants reduced Escherichia coli populations by 2.0–2.8 log CFU/100 g on lettuce and completely eliminated Salmonella spp. at all treatment contact times. Disinfection treatment using bleach/vinegar combination at 15 min also reduced faecal coliform populations on lettuce by 2.8 log CFU/100 g and completely eliminated E. coli and Salmonella spp. All chemical disinfectants including tap water at 15 min reduced faecal coliform populations below the undesirable ICMSF (2011) level (1000 CFU/100 g wet weight). These could contribute to reduce the health risk associated with the consumption of lettuce in Mali

Prevalence of Schistosoma mono- and co-infections with multiple common parasites and associated risk factors and morbidity profile among adults in the Taabo health and demographic surveillance system, South-Central Côte d'Ivoire

BACKGROUND: Schistosomiasis remains an important public health problem, also among adults, and infected individuals not treated serve as a reservoir for continued transmission. Despite this fact, evidence on the epidemiology of schistosomiasis in adults in Cote d'Ivoire is scanty. This study aimed to determine the prevalence and risk factors of Schistosoma infection and co-infection with other helminth species and Plasmodium among adults in the Taabo region in the south-central part of Cote d'Ivoire. METHODS: A cross-sectional survey was carried out in April and May 2017 in the frame of the "Cote d'Ivoire Dual Burden of Disease Study" (CoDuBu). A total of 901 randomly selected individuals, aged 18-90 years, provided blood, stool and urine samples for the diagnosis of malaria and helminth infections. Stool samples were subjected to the Kato-Katz technique for detection of Schistosoma mansoni and soil-transmitted helminth eggs, while urine samples were examined for eggs of Schistosoma haematobium and circulating cathodic antigen of S. mansoni. Risk factors and morbidity profiles were assessed using health examination and questionnaires. Multinomial logistic regressions were employed to identify risk factors and morbidity patterns associated with S. mansoni mono- and co-infections. RESULTS: The prevalence of S. mansoni and S. haematobium was 23.2% and 1.0%, respectively. Most S. mansoni were mono-infections (81.3%). Independent determinants of S. mansoni infection were young age, low socioeconomic status (mono- and co-infection) and poor hygiene practices (co-infection) (P < 0.05). S. mansoni infection was independently associated with higher pain and symptom scores (mono-infection), poor self-rated health and low healthcare use (co-infection) (P < 0.05). CONCLUSIONS: This study showed that adults represent a substantial reservoir of S. mansoni. To sustain schistosomiasis control and improve people's wellbeing, it is important to expand preventive chemotherapy from school-aged children to adults, coupled with hygiene and health education

Sensitivity study of the regional climate model RegCM4 to different convective schemes over West Africa

Abstract. The latest version of RegCM4 with CLM4.5 as a land surface scheme was used to assess the performance and sensitivity of the simulated West African climate system to different convection schemes. The sensitivity studies were performed over the West African domain from November 2002 to December 2004 at a spatial resolution of 50 km × 50 km and involved five convective schemes: (i) Emanuel; (ii) Grell; (iii) Emanuel over land and Grell over ocean (Mix1); (iv) Grell over land and Emanuel over ocean (Mix2); and (v) Tiedtke. All simulations were forced with ERA-Interim data. Validation of surface temperature at 2 m and precipitation were conducted using data from the Climate Research Unit (CRU), Global Precipitation Climatology Project (GPCP) and the Tropical Rainfall Measurement Mission (TRMM) during June to September (rainy season), while the simulated atmospheric dynamic was compared to ERA-Interim data. It is worth noting that the few previous similar sensitivity studies conducted in the region were performed using BATS as a land surface scheme and involved less convective schemes. Compared with the previous version of RegCM, RegCM4-CLM also shows a general cold bias over West Africa whatever the convective scheme used. This cold bias is more reduced when using the Emanuel convective scheme. In terms of precipitation, the dominant feature in model simulations is a dry bias that is better reduced when using the Emanuel convective scheme. Considering the good performance with respect to a quantitative evaluation of the temperature and precipitation simulations over the entire West African domain and its subregions, the Emanuel convective scheme is recommended for the study of the West African climate system

Evaluating Short-Term Patient Outcomes after HIV Care Interventions in a Low Resource Setting: Preparing for an HIV Vaccine Trial Site in Bamako, Mali

Poster Presentation From AIDS Vaccine 2012 Boston, MA, USA. 9-12 September 201