Contextual factors associated with diarrhea among under-five children in the Gambia: a multi-level analysis of population-based data.

BACKGROUND: Diarrhea poses a significant threat to the lives of children in The Gambia, accounting for approximately 9% of all deaths among children under the age of five. Addressing and reducing child mortality from diarrhea diseases is crucial for achieving the Sustainable Development Goal (SDG) 3, specifically target 3.2, which aims to eliminate preventable deaths in newborns and children under the age of five by 2030. Thus, this research aims to assess the prevalence and contextual factors associated with diarrhea among under-five children in The Gambia. METHODS: This research employed secondary data from the 2019/20 Gambia Demographic Health Survey (GDHS). The study initially involved 8,362 women aged between 15 and 49 years. Of these, 6,929 women with children under five were included in this analysis. Data were analyzed using STATA with cross-tabulation and model fitting. Multilevel logistic regression was applied to accommodate the hierarchical structure of the demographic health survey data. The model comparison parameters were BIC, AIC, deviance, and LLR. Variables with a p-value less than 0.05 were selected for multivariable analysis. The statistical significance of the factors was determined using an adjusted odds ratio with a 95% confidence interval (CI) and a p-value of less than 0.05. RESULTS: The prevalence of diarrhea in under-five children was 53.2% in males and 46.8% in females. In the final model, Kerewan (aOR = 0.58; 95% CI = 0.33-0.98) and Basse (aOR = 0.59; 95% CI = 0.35-0.98) have significantly lower odds of childhood diarrhea compared to Banjul, female children show slightly lower, yet significant, odds of diarrhea compared to males (aOR = 0.96; 95% CI = 0.86-0.98), deliveries at government health centers are associated with higher odds of childhood diarrhea compared to home births (aOR = 1.24; 95% CI = 1.01-1.52). Mothers with post-secondary education had significantly lower odds of having children with diarrhea than those without any education (aOR = 0.50; 95% CI = 0.26-0.99) after controlling for confounders. CONCLUSION: The study findings indicate that several factors significantly impact the risk of childhood diarrhea in The Gambia. These factors include region of residence, sex of the child, place of delivery, and education level of the mother. The study suggests that existing interventions aimed at improving child health outcomes in the country should take into consideration these influential factors. Addressing these modifiable factors can enhance the effectiveness of interventions and promote better health outcomes for children in Gambia.

Childhood vaccination uptake and associated factors among children 12-23 months in rural settings of the Gambia: a community-based cross-sectional study.

BACKGROUND: Globally, immunization prevents 2-3 million deaths annually from vaccine-preventable diseases such as diphtheria, tetanus, pertussis, influenza, and measles. In developing countries, several immunization programs have made progress, but the coverage remains a standstill in some areas. In order to inform policies and practices, the present study aimed at assessing vaccination uptake and contextual-associated factors among children aged 12-23 months in rural Gambia. METHODS: A community-based triangulated cross-sectional design was conducted in January 2020, with 200 caregivers with children aged 12-23 months in selected households in rural communities across Upper River Region of the Gambia using multistage sampling technique were recruited. A structured interview questionnaire was developed and Infant Welfare Cards were assessed to elicit information regarding contextual household characteristics towards childhood immunization uptake. Percentages, chi-square/fisher exact test for variables with p-value ≤0.15 were considered for inclusion into logistic regression model. The significance level was set at p < 0.05. The adjusted Odds Ratio (aOR) with 95% Confidence Interval (CI) were reported to declare significance. RESULTS: The proportion of children who received all the required vaccines was 66%. At the level of antigen-specific coverage, about 88.5% received BCG, 71% received OPV 3, 82.5% received Penta 3, while 72 and 71% received Measles-Rubella and yellow fever, respectively. Caregivers who had primary education level 88.8% (aOR = 0.112; 95% CI = 0.029-0.434), secondary & above 87.2% (aOR = 0.128; 95% CI = 0.029, 0. 561) and arabic/madrassa 95.7% (aOR = 0.043; 95% CI = 0.008-1.227) were less likely to be fully vaccinated when compared to those who have never been to school. Farmers are less likely by 88.9% (aOR = 0.111; 95% CI 0.020, 0.635) while children from family size of more than 20 members had reduced odds (aOR = 0.420; 95% CI = 0.197, 0.894) for their children to complete their vaccination schedule as compared to those with at most 20 household members. CONCLUSION: There is moderately a burden of incomplete vaccination in rural Gambia. Vaccination programs should be constantly monitored and evaluated by the Ministry of Health, especially in rural areas. To increase societal awareness and vaccine acceptance, a robust community-based health education efforts are desperately needed as part of initiatives to increase vaccine service utilization for these high-risk classes.

Knowledge, Attitude, and Practice of Provincial Dwellers on Prevention and Control of Schistosomiasis: Evidence from a Community-Based Cross-Sectional Study in the Gambia.

BACKGROUND: Socioeconomically disadvantaged and neglected communities were found to be the most affected groups for schistosomiasis as a result of inadequate safe water and sanitation facilities. In order to inform policies and practices, the present study examined the influence of sociodemographic factors and attitudes on the knowledge and practice in the prevention and control of schistosomiasis in eighteen endemic rural communities in the Gambia. METHODS: In January 2019, a community-based cross-sectional study was conducted in which 383 household heads in rural communities across Kuntaur and Janjanbureh Local Government Areas (LGAs) in Central River Region were recruited. A structured interview questionnaire was developed to elicit information regarding residents' knowledge, attitude, and practice on schistosomiasis prevention and control measures. Percentages, chi-square test, and binary and multiple logistic regression models were used to identify sociodemographic factors associated with the KAP variables. The significance level was set at p < 0.05. RESULTS: Among the 383 participants, only 14.9% had good knowledge, while 54.3% had poor knowledge, 96.9% had positive attitude, and 57.7% had good practice towards prevention and control of schistosomiasis. Older age (≥40 years), compared with residents aged 30-39 years (AOR = 0.331; 95% CI: 0.133, 0.825); ever heard of bilharziasis (AOR = 11.911; 95% CI: 3.452, 41.099); and risks of contact with the polluted river (AOR = 0.101; 95% CI: 0.042, 0.242) were more likely to have good knowledge on schistosomiasis prevention and control in the rural Gambia. Conversely, young people (≤30 years), compared with residents aged ≥40 years (AOR = 2.503; 95% CI = 1.539, 4.071); residents aged 30-39 years (AOR = 2.880; 95% CI = 1.559, 5.320); and male residents (AOR = 2.631; 95% CI = 1.703, 4.067) were more likely to have good practice towards schistosomiasis prevention and control in the rural Gambia. CONCLUSION: Despite the low knowledge, rural dwellers' attitudes were found to be positive with slightly good practice towards schistosomiasis prevention and control measures. Thus, while maintaining health system improvement strategies, disease control efforts should focus on these factors as they may influence the knowledge and practices of rural dwellers in a given setting. The findings could prompt appropriate policy responses towards improving the knowledge and practices on schistosomiasis prevention and control in the Gambia.

Emergence of tan spot disease caused by toxigenic Pyrenophora tritici-repentis in Australia is not associated with increased deployment of toxin-sensitive cultivars.

The wheat disease tan (or yellow leaf) spot, caused by Pyrenophora tritici-repentis, was first described in the period 1934 to 1941 in Canada, India, and the United States. It was first noted in Australia in 1953 and only became a serious disease in the 1970s. The emergence of this disease has recently been linked to the acquisition by P. tritici-repentis of the ToxA gene from the wheat leaf and glume blotch pathogen, Stagonospora nodorum. ToxA encodes a host-specific toxin that interacts with the product of the wheat gene Tsn1. Interaction of ToxA with the dominant allele of Tsn1 causes host necrosis. P. tritici-repentis races lacking ToxA give minor indistinct lesions on wheat lines, whereas wheat lines expressing the recessive tsn1 are significantly less susceptible to the disease. Although the emergence and spread of tan spot had been attributed to the adoption of minimum tillage practices, we wished to test the alternative idea that the planting of Tsn1 wheat lines may have contributed to the establishment of the pathogen in Australia. To do this, wheat cultivars released in Australia from 1911 to 1986 were tested for their sensitivity to ToxA. Prior to 1941, 16% of wheat cultivars were ToxA-insensitive and hence, all other factors being equal, would be more resistant to the disease. Surprisingly, only one of the cultivars released since 1940 was ToxA insensitive, and the area planted to ToxA-insensitive cultivars varied from 0 to a maximum of only 14% in New South Wales. Thus, the majority of the cultivars were ToxA-sensitive both before and during the period of emergence and spread of the disease. We therefore conclude that the spread of P. tritici-repentis in Australia cannot be causally linked to the deployment of ToxA-sensitive cultivars.

The nitrogen content of the tomato leaf apoplast increases during infection by Cladosporium fulvum.

To address the problem of the nutritional requirements of phyto-pathogenic fungi growing in planta, the environment for the intercellular biotrophic pathogen, Cladosporium fulvum Cooke, of tomato (Lycopersicon esculentum Mill.) was analysed. Using a novel technique for infiltrating the intercellular space, we measured the concentrations of 21 amino acids, nitrate and ammonia in the apoplast of the tomato leaf during infection. The concentrations of most amino acids, and total nitrogen content, increased during infection. The levels of nearly all amino acids remained relatively unchanged during an incompatible interaction. All protein amino acids were detected during infection, except cysteine and tryptophan. Most amino acids were present at a concentration between 0.1-0.7 mM. The non-protein amino acid gamma-aminobutyric acid was detected at the highest concentration (up to 2.5 mM) during the compatible interaction. Preliminary investigations on the source of the amino acids revealed that protease activity within the apoplast increased during infection and that infection induced the expression of the pathogenicity-related extracellular serine protease P69B. The nitrogen status of the infecting fungus and sources for the additional amino acids are discussed.

Molybdate-dependent expression of dimethylsulfoxide reductase in Rhodobacter capsulatus.

Expression of the dimethylsulfoxide respiratory (dor) operon of Rhodobacter is regulated by oxygen, light intensity and availability of substrate. Since dimethylsulfoxide reductase contains a pterin molybdenum cofactor, the role of molybdate in the regulation of dor operon expression was investigated. In this report we show that the molybdate-responsive transcriptional regulator, MopB, and molybdate are essential for maximal dimethylsulfoxide reductase activity and expression of a dorA::lacZ transcriptional fusion in Rhodobacter capsulatus. In contrast, mop genes are not required for the expression of the periplasmic nitrate reductase or xanthine dehydrogenase in R. capsulatus under conditions of molybdenum sufficiency. This is the first report demonstrating a clear functional difference between the ModE homologues MopB and MopA in this bacterium. The results suggest that MopA is primarily involved in the regulation of nitrogen fixation gene expression in response to molybdate while MopB has a role in nitrogen fixation and dimethylsulfoxide respiration.

Methionine synthase, a gene required for methionine synthesis, is expressed in planta by Cladosporium fulvum.

Abstract The nutritional requirements of phytopathogenic fungi growing in planta has to date been largely ignored. We have begun to address this problem by investigating the methionine requirement for the biotrophic pathogen of tomato Cladosporium fulvum during infection. The Met6 gene from Cladosporium fulvum encoding a cobalamin-independent 5-methyltetrahydropteroyltriglutamate-homocysteinemethyltransferase, was cloned by functional yeast complementation. The open reading frame was found to be 2304 bp, containing no introns and encoding a protein of 87 kDa. In vitro Northern analysis demonstrated high levels of Met6 expression in the absence of externally supplied methionine. However in the presence of methionine or in the absence of carbon, expression of Met6 decreased significantly. Analysis of Met6 expression in planta revealed a strong increase during infection suggesting the requirement for methionine synthesis in planta by Cladosporium fulvum. This study demonstrates that Cladosporium fulvum is starving for methionine during infection and thus implies the essentiality of primary biosynthetic pathways to the infecting fungus.

Xanthine dehydrogenase from the phototrophic purple bacterium Rhodobacter capsulatus is more similar to its eukaryotic counterparts than to prokaryotic molybdenum enzymes.

Fourteen Rhodobacter capsulatus mutants unable to grow with xanthine as sole nitrogen source were isolated by random Tn5 mutagenesis. Five of these Tn5 insertions were mapped within two adjacent chromosomal EcoRI fragments hybridizing to oligonucleotides synthesized according to conserved amino acid sequences of eukaryotic xanthine dehydrogenases. DNA sequence analysis of this region revealed two open reading frames, designated xdhA and xdhB, encoding xanthine dehydrogenase. The deduced amino acid sequence of XDHA contains binding sites for two [2Fe-2S] clusters and FAD, whereas XDHB is predicted to contain the molybdopterin cofactor. In contrast to R. capsulatus, these three cofactor binding sites reside within a single polypeptide chain in eukaryotic xanthine dehydrogenases. The amino acid sequence of xanthine dehydrogenase from R. capsulatus showed a higher degree of similarity to eukaryotic xanthine dehydrogenases than to the xanthine dehydrogenase-related aldehyde oxidoreductase from Desulphovibrio gigas. The expression of an xdhA-lacZ fusion was induced when hypoxanthine or xanthine was added as sole nitrogen source. Mutations in nifR1 (ntrC) and nifR4 (rpoN, encoding sigma54) had no influence on xdh gene expression. A putative activator sensing the availability of substrate seems to respond to xanthine but not to hypoxanthine. The transcriptional start site of xdhA was mapped by primer extension analysis. Comparison with known promoter elements revealed no significant homology. Xanthine dehydrogenase from R. capsulatus was purified to homogeneity. The enzyme consists of two subunits with molecular masses of 85 kDa and 50 kDa respectively. N-terminal amino acid sequencing of both subunits confirmed the predicted start codons. The molecular mass of the native enzyme was determined to be 275 kDa, indicating an alpha2beta2-subunit structure. Analysis of the molybdenum cofactor of xanthine dehydrogenase from R. capsulatus revealed that it contains the molybdopterin cofactor and not a molybdopterin dinucleotide derivative.

Characterisation of the pterin molybdenum cofactor in dimethylsulfoxide reductase of Rhodobacter capsulatus.

Analysis of dimethylsulfoxide reductase from Rhodobacter capsulatus showed that it contained 1 mol Mo and 2 mol GMP. This indicates that the molybdenum cofactor in dimethylsulfoxide reductase is bis(molybdopterin guanine dinucleotide) molybdenum. The absorption spectrum of the molybdopterin guanine dinucleotide released from dimethylsulfoxide reductase after denaturation of the holoenzyme was compared with those of pterin standards of known redox state. The spectra were most similar to pterin standards in the dihydro state and oxidised state. The reduction of 2,6-dichloroindophenol by molybdopterin guanine dinucleotide released from dimethylsulfoxide reductase and by pterin standards was also measured and approximately 2 mol electrons/2 mol molybdopterin guanine dinucleotide were found to reduce 2,6-dichloroindophenol. These results are consistent with the presence of one molybdopterin guanine dinucleotide moiety with a pyrazine ring at the oxidation level of a dihydropteridine and one molybdopterin guanine dinucleotide moiety with a pyrazine ring at the oxidation level of a fully aromatic pteridine. It is suggested that the pyrazine ring of Q-molybdopterin guanine dinucleotide is fully aromatic and contains a 5,6 double bond.

Dimethylsulfide:acceptor oxidoreductase from Rhodobacter sulfidophilus. The purified enzyme contains b-type haem and a pterin molybdenum cofactor.

Dimethylsulfide:receptor oxidoreductase was purified from the purple non-sulfur phototrophic bacterium Rhodobacter sulfidophilus. The native form of the enzyme had a molecular mass of 152 kDa and was composed of three distinct subunits of 94, 38 and 32 kDa. Dimethylsulfide:acceptor oxidoreductase did not oxidise other thioethers which were tested. The enzyme was able to reduce a variety of N-oxides using reduced methylviologen as electron donor but it reduced dimethylsulfoxide at a very low rate. The resting form of dimethylsulfide:acceptor oxidoreductase exhibited a spectrum which was characteristic of a reduced cytochrome with absorbance maxima at 562 nm, 533 nm and 428 nm. Pyridine haemochrome analysis established that the cytochrome contained a b-type haem and a content of 0.65 mol protohaem/mol enzyme was determined. After oxidation of the haem with ferricyanide, the absorbance spectrum of the reduced cytochrome was restored by reduction with dimethylsulfide. Metal analysis revealed that dimethylsulfide:acceptor oxidoreductase contained 0.5 mol Mo and 3.5 mol Fe/mol enzyme. Heat treatment of the enzyme released material with fluorescence excitation and emission spectra which were characteristic of form B of the pterin component of the pterin molybdenum cofactor. From this analysis it is concluded that dimethylsulfide:acceptor oxidoreductase is a molybdenum oxotransferase which may also contain a iron-sulfur cluster. It is suggested that the haem and pterin molybdenum cofactor are associated with the 94-kDa subunit.