Seasonal variations in fecal contamination of shallow groundwater in Altamira, Amazon, Brazil

Waterborne disease outbreaks caused by various pathogens have been reported from all over the world. They also play an important role in industrialized countries, despite good sanitation and high standards of hygiene. In Switzerland, waterborne disease outbreaks are uncommon but faecal contamination of springs occurs quite frequently in some areas. As a consequence, microbiological quality of drinking water is not constantly sufficient and there is potential for improvement. Based on the hygiene ordinance, cantonal authorities contribute with control actions to the supply of safe water to consumers. Microbiological quality assessment based on current drinking water guidelines do not discriminate between human and animal sources of contamination. However, methods for discriminating between human and animal faecal contamination are needed to identify sources of contamination and to provide specific scientific data as a basis for risk management measures and for the implementation of remedial interventions. The main goal of this thesis was to establish approaches for the identification of human and animal faecal contamination in surface and drinking water and to develop concepts for future investigations. A number of methods can be used to help identify sources of faecal contamination in water. The general concept is referred to as microbial source tracking (MST). Different methodologies for MST were previously used mainly for analysis of faecal samples and recreational waters such as streams, lakes and beaches. Prior to this study, MST was not applied in Switzerland. In the present thesis, source tracking approaches never before used in MST as well as methods previously described in scientific literature were tested for their potential to indicate human or animal faecal contamination in Switzerland. Two bacterial strains (Bacteroides thetaiotaomicron ARABA 84 and B. fragilis ARABA 19) specific for bacteriophages present in human faecal contamination and three strains (B. caccae RBA 63 and RBA 64 as well as B. fragilis KBA 60) specific for bacteriophages indicating animal faecal contamination were isolated from human wastewater and animal faecal specimens. Thereafter they were used to determine the source of surface and spring water faecal contamination. In addition, the potential of Streptococcus agalactiae was tested as a new human MST indicator. Different methods of detecting these bacteria in domestic and slaughterhouse wastewater were compared. Three DNA extraction methods and five polymerase chain reaction (PCR) assays were tested to identify the most suitable combination. The most sensitive detection method, a LightCycler real-time PCR assay, detected S. agalactiae in human wastewater but not in animal samples and showed that this bacteria is potentially useful as human MST indicator. Rhodococcus coprophilus was previously used in MST to indicate animal faecal contamination in water. For the detection of this organism, a culture-dependent method and a conventional as well as a TaqMan real-time PCR assay were previously published. The evaluation of these existing approaches, however, did not reveal any satisfactory result. A novel LightCycler real-time PCR assay was therefore designed and validated in the course of the present thesis. Compared with previously used assays, this new molecular approach showed advantages such as improved sensitivity and specificity and was much faster than the culture-based method. Sorbitol-fermenting bifidobacteria and phages infecting the Bacteroides host strains GA-17 and GB-124 were previously described to indicate human faecal contamination. Together with the newly developed and validated approaches, these established MST indicators were included in a comparative study and their potential to indicate human or animal faecal contamination in Swiss surface and spring water was tested. Based upon this assessment, sorbitol-fermenting bifidobacteria and phages of the human host strains B. thetaiotaomicron ARABA 84 and B. ovatus GB-124 can be recommended for detecting human faecal contamination in Swiss surface and drinking water. The above-mentioned approaches give evidence of the faecal input sites of contamination. To localize possible faecal input sites, they can be followed by an additional approach described in this thesis. This approach is based on the screening of multiresistant Escherichia coli and on the characterisation of selected isolates by antibiotic resistance profiles and pulsed field gel electrophoresis in order to identify identical strains. Thereby, a well equipped toolbox could be provided not only to discriminate sources of faecal contamination but also to localize possible faecal input sites.

The study analysed the spatial and temporal contamination levels of fresh water resources by saline intrusion in the Douala coastal area. Water samples were collected from 19 stations. 3 stations were selected from the mangrove area and 16 stations were selected from the rest of the area partitioned into four transects (coastal transect, inner transect 1, inner transect 2 and inner transect 3). Sampling was done repeatedly during the wet and dry seasons. They were analyzed for physico-chemical parameters according to the American Public Health Association methods. Geostatistical analysis was used in mapping the water properties. Considerable levels of actual electrical conductivity values (208.91 to 660.63 and 45 to 7540 μS/cm for the wet and dry seasons, respectively); calcium (0.06 to 85 and 4 to 256 mg/L for the wet and dry seasons, respectively); sulphate (0 to 103 and 0 to 99 mg/L for the wet and dry seasons) and total dissolved solids (15.79 to 1467 and 20 to 3750 mg/L for the wet and dry seasons, respectively) were observed for ground water in the study area based on spatio-temporal assessment. From the output grid, it could be deduced that the south eastern region had a hint of salt water intrusion (SWI) contamination of fresh water resources with actual value highs of electrical conductivity (1790 and 820 μS/cm) for the dry and wet seasons, respectively. Calcium highs (140 and 16 mg/L) for the dry and wet seasons were obtained at the central part of the study area. The spatial distribution of calcium highs extends from the central zone of the study area in the dry season and the south eastern zone in the wet season. The southern region is more vulnerable to contamination by calcium ions during this season. An up to date scope for surveillance monitoring and forecasting regarding the deterioration of coastal aquifers is recommended. Modelling of aquifers shifts for the coastal zone should be instituted as a means of ensuring efficient fresh water resources evaluation and utilization. An indepth study of the geochemical characteristics of ground water of the coastal zone could determine factors that most significantly impact on fresh water resource quality.

以艾比湖流域主要入湖河流为研究对象，在5月（丰水期）和8月（枯水期）分别沿博尔塔拉河（博河）和精河进行采样，采用平行因子模型（PARAFAC）和三维荧光区域积分法对水体三维荧光特性进行研究并对其与水质的关系在枯、丰水期下的变化进行探讨.结果表明①河流DOM在枯水期与丰水期都含有C1（240、425 nm） UVC类腐殖质，C2（225、290 nm）紫外区内络氨酸类有机物，C3（230/280、330 nm）蛋白类有机物，C4（265、260 nm）腐殖质类共4种组分.通过对水体三维荧光进行区域积分可以看出DOM荧光成分的占比在不同时期的变化.博河在枯水期时EEM光谱中的区域Ⅲ富里酸含量低于丰水期，枯水期时区域Ⅱ芳香类蛋白质、区域Ⅳ可溶性微生物代谢物以及区域Ⅴ类腐殖质酸高于丰水期；对于精河来说，区域Ⅱ芳香类蛋白质和区域Ⅳ可溶性微生物代谢物在枯水期的含量高于丰水期，区域Ⅲ富里酸和区域Ⅴ类腐殖质酸的含量枯水期低于丰水期，这表明水体腐质化程度较高.②本研究选取了一些常规的荧光指数来描述枯、丰水期水体的荧光指数特性.经研究发现，精河的荧光指数、自生源指数和腐殖化指数在不同时期的变化幅度较小，而博河的变化幅度较大.③将荧光指数与水质参数进行相关性分析并建模，结果表明枯水期自生源指数（BIX）与化学需氧量呈显著正相关，相关系数R=0.688；丰水期时BIX与铵态氮浓度呈显著负相关，相关系数R=-0.493.通过对比分析艾比湖主要入湖河流的三维荧光光谱特性与水质在枯、丰水期时的关系进一步表明水体中DOM的特性以及在枯、丰水期下的差异，为艾比湖流域的治理改善提供一定的理论支持和参考依据.;This study takes the main lakes in Lake Ebinur Watershed as the research object, and samples along the Bortala River and Jing River in May (wet season) and August (dry season). The PARAFAC analysis method and the three-dimensional fluorescence region integration method is used to study the three-dimensional fluorescence characteristics of water and its seasonal variation with water quality. The results show that:1)In both dry and wet seasons, river DOM contains C1 (240, 425 nm) and C4 (265, 260 nm) kind of humus, C2 (225, 290 nm) uranium-like organic matter compounds. It found that fulvic acid is lower, while the aromatic protein, soluble microbial and humic acid were highest in dry season than wet season in Bortala River. The concentration of the aromatic protein and soluble microbial in dry season was higher than in wet season, and the fulvic acid and humic acid in dry season was lower than in the wet season in Jing River, based on fluorescence regional integral (FRI) analysis and the regional standards related to water quality and fluorescence. This indicates that the degree of decomposition in water is relatively high; 2)In this study, some conventional fluorescence indexes were selected to describe the fluorescence index characteristics of water in wet and dry season. It found that the three indexes (FI, BIX, HIX) of the water quality of Jing River and Bortala River in dry and wet seasons showed slight changes, comparing to larger changes in the Bortala River. In general, the change of water quality of Jing River and Bortala River in dry and wet seasons is mainly influenced by microbial activities and human activities; 3) In terms of the correlation coefficients of water quality parameters and fluorescence indexes in different seasons, the results showed that the relationship between BIX and COD concentration was best and a significant positive correlation in dry season(R=0.688, P<0.01). Secondly, there is a significant negative correlation between BIX and ammonium nitrogen concentration in wet season (R=-0.493, P<0.05). The study provides theoretical support and reference basis for the improvement of the governance of Lake Ebinur Watershed, which further proved that exogenous characteristics and the differences in different periods of DOM sources in the water.

Biotic and abiotic properties most closely associated with subtropical forest soil respiration differ in wet and dry seasons: A 10-year in situ study

The southwestern mountains of Hainan Island are the southernmost region with tropical karst landform in China. The frequent alternation of dry and wet seasons leads to the loss of the mineral nutrients of limestone, creating karst fissure habitats. Plants living in karst fissure habitats for long periods of time have developed local adaptation mechanisms correspondingly. In the paper, hydrogen–oxygen stable isotope technology was applied to determine the water-use sources of Impatiens hainanensis in the dry and wet seasons, hoping to expound the adaptation mechanism of I. hainanensis in karst fissure habitats to the moisture dynamics in the wet and dry seasons. In the wet season (May to October, 2018), the air humidity is relatively high in the I. hainanensis habitat; in the dry season (November 2018 to April 2019), there is a degree of evaporation. In the wet season, fine-root biomass increases with soil depths, while coarse-root biomass decreases with soil depths; in the dry season, fine-root biomass is lower and coarse-root biomass is higher compared with the wet season. It was found that the average rainfall reached 1523 mm and the main water-use sources were shallow (0–5 cm) and middle (5–10 cm) soil water, epikarst water, and shallow karst fissure water during the wet season; the average rainfall reached 528 mm, and the deep (10–15 cm) soil water and shallow karst fissure water were the main water-use sources during the dry season. Fog water has a partial complementary effect in the dry season. The differences in the distribution of root biomass and each source of water in the wet and dry seasons of I. hainanensis also reflect the different water-use strategies of I. hainanensis in the wet and dry seasons. In both dry and wet seasons, I. hainanensis formed a water-use pattern dominated by soil water and shallow fissure water (0–15 cm) under the influence of the “fissure-soil-plant” system in the karst region.

Water resource contamination is a major concern in several regions, especially in the Niger Delta, in which the oil exploration activities pose serious risks to human health, water resource and the environment. This present study evaluates the properties of surface water in Nembe Creek. Surface water samples were collected from three (3) control stations and twenty-four (24) sampling stations around the creek during the wet and dry seasons. The samples were subjected to analysis following the standard operating procedures of ASTM and APHA analytical methods. The relationship between the parameters and variations of surface water quality of Nembe creek were determined by using descriptive statistics, Analysis of variance (ANOVA) and Pearson correlation analysis. The results indicated pH had a mean value of 6.67± 0.33 (wet season) and 7.21 ± 0.3 (dry season), Electrical Conductivity ranged 200 – 3950 µS/cm (wet season) and 17900 – 25800 µS/cm (dry season), DO ranged between 4.3 – 5.8 (wet season) and 3.9 – 5.6 (dry season), Nitrate had values of 0.007- 0.068 mg/L (wet season) and 0 – 0.007 mg/L (dry season), Sulphate values range 130.58- 158.76 mg/L (wet season) and 215.12 – 657.35 mg/L (dry season). Iron range 3.23 – 5.6 mg/L (wet season) and 0.26 – 7.87 mg/L (dry season), Zinc ranged 0.02 – 0.47 mg/L (wet season) and 0.13 – 2.22 mg/L (dry season). Across all sampling stations and control areas during the wet season, the values for Total Petroleum Hydrocarbon (TPH), total hydrocarbon Content (THC) and Petroleum Aromatic Hydrocarbon (PAH) were below the detection limit; however, the values varied during the dry season. The Pearson Correlation matrix revealed positive, negative and significant correlations between the pairs of parameters at 95% confidence level. Amongst the sampling and control stations, some parameters had no significant difference (p &gt; 0.05), however some differences were statistically significant (p &lt; 0.05). In conclusion, Nembe Creek is marginally more polluted during the dry season than during the wet season. Most parameters on the Person's Correlation matrix were connected with each other based on the metrics. However, some parameters such as metals, do not significantly correlate with one another, indicating that the sources of contamination may have originated from various places. It is possible that the source may not predominantly originate from oil exploration activities but may involve other natural, geological and anthropogenic activities.

水位的洪枯变化通过江湖连通影响泛滥平原湖泊鱼类的组成和分布，因而江湖过渡带是反映泛滥平原生态系统鱼类交流和多样性变动的关键区域.尽管如此，针对江湖过渡带鱼类群落随水位洪枯变化的研究十分匮乏.本研究以菜子湖江湖过渡带为例，分别在洪水和枯水期选取包括静水和流水生境的样点对鱼类群落进行系统的调查采样，探讨水位洪枯变化对菜子湖江湖过渡带鱼类物种和功能多样性的影响.共采集到鱼类6目12科37属52种，其中，洪水期和枯水期物种数差异显著，分别采集到鱼类50和42种，而静水生境和流水生境物种数差异不明显，分别采集到鱼类47和48种.与洪水期相比，枯水期山溪河流性鱼类的物种数、重量、尾数和优势度百分比分别减少了7.3%、6.3%、14.4%和12.0%；与静水生境相比，流水生境山溪河流性鱼类的物种数、重量、尾数和优势度百分比分别增加了5.3%、14.6%、18.0%和22.3%.SIMPER分析结果显示，麦穗鱼（Pseudorasbora parva）、蛇鮈（Saurogobio dabryi）、（Hemiculter leucisculus）、鲤（Cyprinus carpio）、鲫（Carassius auratus）、短颌鲚（Coilia brachygnathus）、似鳊（Pseudobrama simoni）、翘嘴鲌（Culter ilishaeformis）、达氏鲌（Culter dabryi）、光唇蛇鮈（Saurogobio gymnocheilus）和无须鱊（Acheilognathus gracilis）是引起水位洪枯变化以及不同生境类型鱼类群落结构差异的主要物种.优势度分析结果表明枯水期和静水生境的优势种鱼类相似，重要值较高的优势种鱼类为鲤、鲫、和似鳊；而洪水期和流水生境的优势种鱼类同样相似，重要值较高的优势种鱼类为麦穗鱼、蛇鮈、光唇蛇鮈和短颌鲚.通过双因素方差分析解析了水位洪枯变化和不同生境类型对鱼类物种和功能多样性的影响.发现洪枯水位变化仅对物种多样性指数中的物种数（Richness）产生显著差异，而对功能多样性的3个指数（功能丰富度指数（FRic）、功能离散指数（FDiv）和功能分散指数（FDis））均有显著影响.洪水期鱼类的Richness、FRic、FDiv和FDis指数均显著高于枯水期.同时，静水生境条件下的FRic指数要显著高于流水生境.本研究发现，与传统的物种多样性相比，基于功能性状的功能多样性对水位的洪枯变动更为敏感，河流周期性洪泛是泛滥平原生态系统中鱼类功能补充的重要方式.;Water level fluctuations between wet and dry seasons, assisting by lateral connectivity, play a fundamental role in underpinning the composition and distribution of fish fauna in floodplain lakes. The ecotone floodplains between the floodplain rivers and lakes are generally considered as the key areas where witness the exchange of fish species and the variations of biodiversity. However, the study of changes in taxonomic and functional diversity of fish communities in the ecotone floodplain in response to water level fluctuations is limited. Here we address this issue by measuring temporal (dry and wet seasons) and spatial (lotic and lentic habitat patches) changes in taxonomic and functional diversity of fish communities in the ecotone floodplain between the Yangtze River and Lake Caizi. A total of 52 species belonging to 37 genera, 12 families and 6 orders were collected in our study. Among them, there were significant differences in species number between wet and dry seasons, with 50 species and 42 species collected respectively. On the other hand, there was no significant difference in the number of species between lentic and lotic habitat patches, with 47 species and 48 species collected respectively. In comparison with wet season, the species richness, weight, abundance and importance value percentage of riverine species decreased by 7.3%, 6.3%, 14.4% and 12.0% in dry season. In comparison with lentic habitat patches, the species richness, weight, abundance and importance value percentage of riverine species increased by 5.3%, 14.6%, 18.0% and 22.3%. The fish fauna differences between seasons (dry and wet) and habitat patches (lentic and lotic) were determined by the abundance of Pseudorasbora parva, Saurogobio dabryi, Hemiculter leucisculus, Cyprinus carpio, Carassius auratus, Coilia brachygnathus, Pseudobrama simony, Culter ilishaeformis, Culter dabryi, Saurogobio gymnocheilus and Acheilognathus gracilis. Important value analysis showed that the dominant species of fish in lentic habitat patches and dry season were similar, and the dominant species of fish in lotic habitat patches and wet season were similar as well. The dominant species in wet season and lotic habitat patches were P. parva, S. dabryi, S. gymnocheilus and C. brachygnathus, while the dominant species in dry season and lentic habitat patches were C. carpio, C. auratus, H. leucisculus and P. simoni. Two-way ANOVA analysis indicated that one taxonomic diversity indices (Richness) and three functional diversity indices (FRic, FDiv and FDis) significantly differed between wet and dry seasons. Taxonomic richness, functional richness, functional divergence and functional dispersion were significantly higher in wet season than in dry season. Meanwhile, the functional richness was significantly higher in lentic than in lotic habitat patches. Functional diversity exhibited higher sensitivity than the traditional taxonomic diversity, since three functional diversity indices showed significant variations between wet and dry seasons. Meanwhile, our study highlight important functional recruitments of fish assemblages triggered by seasonal flood pulses.

BackgroundDisentangling the relative importance of environmental variables and interspecific interaction in modulating co-occurrence patterns of sympatric species is essential for understanding the mechanisms of community assembly and biodiversity. For the two sympatric Galliformes, Silver Pheasants (Lophura nycthemera) and White-necklaced Partridges (Arborophila gingica), we know little about the role of habitat use and interspecific interactions in modulating their coexistence.MethodsWe adopted a probabilistic approach incorporating habitat preference and interspecific interaction using occupancy model to account for imperfect detection, and used daily activity pattern analysis to investigate the co-occurrence pattern of these two sympatric Galliformes in wet and dry seasons.ResultsWe found that the detection probability of Silver Pheasant and White-necklaced Partridge were related to habitat variables and interspecific interaction. The presence of Silver Pheasant increases the detection probability of White-necklaced Partridge in both the wet and dry season. However, the presence of White-necklaced Partridges increases the detection probability of Silver Pheasants in the wet season, but decreases the probability in the dry season. Further, Silver Pheasants were detected frequently in the sites of high values of enhanced vegetable index (EVI) in both the wet and dry season, and in sites away from human residential settlement in the wet season. White-necklaced partridges were mainly detected in low EVI sites. The site use probabilities of two Galliformes were best explained by habitat variables, Silver Pheasants and White-necklaced Partridges preferred steeper areas during the wet and dry season. Both species mainly occurred in low EVI areas during the wet season and occupied sites away from the resident settlement during the dry season. Moreover, the site use probabilities of two species had opposite relationships with forest canopy coverage. Silver Pheasants preferred areas with high forest canopy coverage whereas White-necklaced Partridges preferred low forest canopy coverage in the dry season, and vice versa in the wet season. Species interaction factor (SIF) corroborated weak evidence of the dependence of the site use of one species on that of the other in the either dry or wet season. Temporally, high overlapping of daily activity pattern indicated no significantly temporal niche differentiation between sympatric Galliformes in both wet and dry seasons.ConclusionsOur results demonstrated that the presence of two species influenced the detection probability interactively and there was no temporal partitioning in activity time between Silver Pheasants and White-necklaced Partridges in the wet and dry seasons. The site use probability of two Galliformes was best explained by habitat variables, especially the forest canopy coverage. Therefore, environmental variables and interspecific interaction are the leading drivers regulating the detection and site use probability and promoting co-occurrence of Silver Pheasants and White-necklaced Partridges.

The study aimed to determine pathological conditions across two seasons, leading to condemnations of beef edible red offals in Kgatleng District, Botswana. Offals are valued in communities of Botswana. Data from slaughter facilities was evaluated for dry/winter and wet/summer seasons. Financial losses were also determined. 7405 cattle were processed in the two seasons, with 4005 cattle slaughtered in the dry season and 3400 in the wet season. Of the slaughtered cattle, 55.2% (2209) of the dry season and 45% (1531) of the wet seasonhad some forms of pathological conditions that led to condemnations of the offals. Lungs were highly condemned at 26.2% in the wet season and 32.7% during the dry season, followed by livers at 16.2 and 18.4% in the wet and dry seasons, respectively. Emphysema led to a condemnation rate of lungs at 20% and 17% for the dry and wet seasons, respectively. The least condemned offals were the spleen at 2.3% (wet season) and 2.1% (dry season), followed by the kidneys at 0.3% (wet season) and 2% (dry season). Financially, the dry season losses were relatively higher at BWP62 950.55 compared to the wet season at BWP43 863.95. Management strategies should be put in place to avail offals to consumers. Key words: Beef, edible red offals, pathological conditions, wet and dry seasons.

北部湾近岸海域浮游动物群落结构特征及季节变化

Microbiological quality of selected ready-to-eat (RTE) street vended foods (SVF) were determined to evaluate the impact of wet and dry seasons on food safety in 3 locations (Makoba-station 1, Elekahia-station 2 and Rivers State University-station 3). Six food products investigated were roasted plantain (RP), roasted fish (RF), roasted yam (RY), suya (SY), meat pie (MP) and doughnuts (DN). Total Aerobic Count (TAC), Total Coliform Count (TCC), Faecal Coliform Count (FCC), Total Staphylococcus Count (TSC), Total Salmonella Count (TSC2), Total Bacillus Count (TBC), Total Mould Count (TMC) and Total Yeast Count (TYC) were examined. Results revealed that TAC had significantly (p&lt;0.05) highest value of 8.46 log10CFU/g in RF2 with no growth in samples RP2, MP1 and DN2 during the wet season while TAC were isolated in all samples during dry season with a range of 5.18 to 7.44 log10CFU/g. TCC was highest in RF2 (8.04 log10CFU/g) and SY2 (7.33 log10CFU/g) during the wet and dry seasons, respectively. FCC ranged from 6.00 to 8.45 log10CFU/g for samples RF2 and MP1 during wet season while 5.15 to 7.10 log10CFU/g was isolated during dry season. TSC ranged from 6.00 to 8.00 log10CFU/g representing 55.55% growth rate during the wet season while no growth was observed in all the samples during dry season except RP1 (5.62 log10CFU/g) and RF2 (6.76 log10CFU/g). There was Salmonella growth in all the SVF with values ranging from 5.00 to 7.04 log10CFU/g during the dry season with NG in SY1 while TSC2 were only isolated in RF1 and SY2 during wet season with the values of 7.11 log10CFU/g and 7.57 log10CFU/g, respectively. TBC ranged from 6.00 to 8.30 log10CFU/g with NG isolated in samples RP3, RF3, RY2, MP3 and DN1 at wet season while significantly highest value of 6.63 log10CFU/g (SY2) was isolated in SY2 and 61.11% NG during dry season. TMC in all the SVF had higher values during wet season than the dry season. TYC was highest in RY2 (7.81 log10CFU/g) and SY1 (8.76 log10CFU/g) during wet and dry seasons, respectively. The study thus, revealed that seasonal variations and locations of SVF have a great impact on their microbiological quality.

Gastrointestinal nematode (GIN) infestations are a major constraint to sheep production in the West Indies (WI). Intensive and semi-intensive management systems are most commonly employed. These islands display tropical weather patterns with wet and dry seasons. Semi-intensive farming combined with increased rainfall during the wet season has been reported to be most favourable for development and survival of GIN. This study was conducted to determine whether there was a relationship between GIN burdens in sheep with seasonality and management practices of farmers in Trinidad and Tobago (T&T). Farms were visited on a monthly basis from January to December 2017. A maximum of ten sheep, three to nine months of age, were selected from each farm. A total of 3,053 faecal samples were collected and analysed using the Modified McMaster technique. Environmental data on daily precipitation and temperature were collected from the Trinidad and Tobago Meteorological Office during the period of sampling. A mixed effects negative binomial regression model was constructed to analyse the relationship between gastrointestinal nematode faecal egg counts (GINFEC) with season, management system and use of dewormers as fixed effects and farm as a random effect. Average diurnal temperatures of T&T fluctuated between 23.2°C to 32.6°C and 23.9°C to 32.3°C in the dry and wet seasons, respectively. Average daily precipitation ranged between 1.6-1.8mm and 6.1-8.5mm during the dry and wet seasons, respectively. A decreased risk of 0.34 (95% CI 0.25-0.47, p<.0001) for GINFEC was observed in dewormed animals versus not dewormed. Semi-intensive management systems experienced an increased risk of GINFEC by 1.39 (95% CI 1.05-1.84, p=.021) compared with intensive and the risk of GINFEC was reduced by 0.40 (95% CI 0.33-0.49, p<.0001) in the wet season versus the dry. A higher prevalence of GIN was observed during the drier months of the year. Climatic conditions observed in T&T remained favourable for GIN survival, development and distribution year-round. Proper management is therefore required for reducing the occurrence of GIN in sheep of T&T throughout the year. This is the first reported study in the WI on the influence of seasonality and management on GIN infestations in sheep during the dry and wet seasons. Further investigation is needed to elucidate why GIN burdens appear to be higher in the dry season than the wet season. This study can be used as a baseline for public education in T&T as well as other developing countries.

High levels of faecal contamination in drinking groundwater and recreational water due to poor sanitation, in the sub-rural neighbourhoods of Kinshasa, Democratic Republic of the Congo.

Modern man-made environments, including urban, agricultural, and industrial environments, have complex ecological interactions among themselves and with the natural surroundings. Microbial source tracking (MST) offers advanced tools to resolve the host source of fecal contamination beyond indicator monitoring. This study was intended to assess karst spring susceptibilities to different fecal sources using MST quantitative PCR (qPCR) assays targeting human, bovine, and swine markers. It involved a dual-time monitoring frame: (i) monthly throughout the calendar year and (ii) daily during a rainfall event. Data integration was taken from both monthly and daily MST profile monitoring and improved identification of spring susceptibility to host fecal contamination; three springs located in close geographic proximity revealed different MST profiles. The Giach spring showed moderate fluctuations of MST marker quantities amid wet and dry samplings, while the Zuf spring had the highest rise of the GenBac3 marker during the wet event, which was mirrored in other markers as well. The revelation of human fecal contamination during the dry season not connected to incidents of raining leachates suggests a continuous and direct exposure to septic systems. Pigpens were identified in the watersheds of Zuf, Shefa, and Giach springs and on the border of the Gaaton spring watershed. Their impact was correlated with partial detection of the Pig-2-Bac marker in Gaaton spring, which was lower than detection levels in all three of the other springs. Ruminant and swine markers were detected intermittently, and their contamination potential during the wet samplings was exposed. These results emphasized the importance of sampling design to utilize the MST approach to delineate subtleties of fecal contamination in the environment.

The impact of seasonal variation on anemia and nutritional status with associated factors in 6–12 years Ghanaian school age children in peri-urban communities