scholarly journals Ten years of monitoring malaria trend and factors associated with malaria test positivity rates in Lower Moshi

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Nancy A. Kassam ◽  
Robert D. Kaaya ◽  
Damian J. Damian ◽  
Christentze Schmiegelow ◽  
Reginald A. Kavishe ◽  
...  
Keyword(s):  
High Altitude ◽  
Malaria Transmission ◽  
Negative Binomial ◽  
Pearson Correlation ◽  
Control Measures ◽  
Eastern Africa ◽  
Bed Nets ◽  
Maximum Temperatures ◽  
Malaria Test ◽  
Low Malaria Transmission

Abstract Background High altitude settings in Eastern Africa have been reported to experience increased malaria burden due to vector habitat expansion. This study explored possible associations between malaria test positivity rates and its predictors including malaria control measures and meteorological factors at a high-altitude, low malaria transmission setting, south of Mount Kilimanjaro. Methods Malaria cases reported at the Tanganyika Plantation Company (TPC) hospital’s malaria registers, meteorological data recorded at TPC sugar factory and data on bed nets distributed in Lower Moshi from 2009 to 2018 were studied. Correlation between bed nets distributed and malaria test positivity rates were explored by using Pearson correlation analysis and the associations between malaria test positivity rates and demographic and meteorological variables were determined by logistic regression and negative binomial regression analyses, respectively. Results Malaria cases reported at TPC hospital ranged between 0.48 and 2.26% per year and increased slightly at the introduction of malaria rapid diagnostic tests. The risk of testing positive for malaria were significantly highest among individuals aged between 6 and 15 years (OR = 1.65; 1.65 CI = 1.28–2.13; p = 0.001) and 16–30 years (OR = 1.49; CI = 1.17–1.89; p = 0.001) and when adjusted for age, the risk were significantly higher among male individuals when compared to female individuals (OR = 1.54; 1.00–1.31; p = 0.044). Malaria test positivity rates were positively associated with average monthly minimum temperatures and negatively associated with average monthly maximum temperatures (incidence rate ratio (IRR) = 1.37, 95% confidence interval (CI) = 1.05–1.78, p = 0.019 and IRR = 0.72, 95% CI = 0.58–0.91, p = 0.005, respectively). When analysed with one month lag for predictor variables, malaria test positivity rates were still significantly associated with average monthly minimum and maximum temperatures (IRR = 1.67, 95% CI = 1.28–2.19, p = 0.001 and IRR = 0.68, 95% CI = 0.54–0.85, p = 0.001, respectively). Average monthly rainfall and relative humidity with or without a one month lag was not associated with malaria test positivity rates in the adjusted models. Explopring possible associations between distribution of long-lasting insecticidal nets, (LLINs) and malaria test positivity rates showed no apparent correlation between numbers of LLINs distributed in a particular year and malaria test positivity rates. Conclusion In Lower Moshi, the risk of being tested positive for malaria was highest for older children and male individuals. Higher minimum and lower maximum temperatures were the strongest climatic predictors for malaria test positivity rates. In areas with extensive irrigation activity as in Lower Moshi, vector abundance and thus malaria transmission may be less dependent on rainfall patterns and humidity. Mass distribution of LLINs did not have an effect in this area with already very low malaria transmission.

scholarly journals Control measures of malaria transmission in Rwanda based on SEIR SEI mathematical model

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Emmanuel Hakizimana ◽  
Jean Marie Ntaganda
Keyword(s):  
Mathematical Model ◽  
Optimal Control ◽  
Malaria Transmission ◽  
Optimal Control Problems ◽  
Control Strategies ◽  
Control Measures ◽  
Bed Nets ◽  
Infected People ◽  
Insecticide Treated Bed Nets ◽  
Malaria Model

This research paper investigated the dynamics of malaria transmission in Rwanda using the nonlinear forces of infections which are included in SEIR-SEI mathematical model for human and mosquito populations. The mathematical modeling of malaria studies the interaction among the human and mosquito populations in controlling malaria transmission and eventually eliminating malaria infection. This work investigates the optimal control strategies for minimizing the rate of malaria transmission by applying three control variables through Caputo fractional derivative. The optimal control problems for malaria model found the control parameters which minimize infection. The numerical simulation showed that the number of exposed and infected people and mosquito population are decreased due to the control strategies. Finally, this work found out that the transmission of malaria in Rwanda can be minimized by using the combination of controls like Insecticide Treated bed Nets (ITNs), Indoor Residual Spray (IRS) and Artemisinin based Combination Therapies (ACTs).

scholarly journals Analysis of Control Interventions against Malaria in communities with Limited Resources

2021 ◽  
Vol 29 (2) ◽  
pp. 71-91
Author(s):  
E.A. Bakare ◽  
B.O. Onasanya ◽  
S. Hoskova-Mayerova ◽  
O. Olubosede
Keyword(s):  
Optimal Control ◽  
Malaria Transmission ◽  
Control Strategies ◽  
Indoor Residual Spraying ◽  
Control Measures ◽  
Limited Resources ◽  
Effective Control ◽  
Bed Nets ◽  
Multiple Control ◽  
Potential Impact

Abstract The aim of this paper is to analyse the potential impact of multiple current interventions in communities with limited resources in order to obtain optimal control strategies and provide a basis for future predictions of the most effective control measures against the spread of malaria. We developed a population-based model of malaria transmission dynamics to investigate the effectiveness of five different interventions. The model captured both the human and the mosquito compartments. The control interventions considered were: educational campaigns to mobilise people for diagnostic test and treatment and to sleep under bed nets; treatment through mass drug administration; indoor residual spraying(IRS) with insecticide to reduce malaria transmission; insecticide treated net (ITN) to reduce morbidity; and regular destruction of mosquito breeding sites to reduce the number of new mosquito and bites/contact at dusks and dawn. Analysis of the potential impact of the multiple control interventions were carried out and the optimal control strategies that minimized the number of infected human and mosquito and the cost of applying the various control interventions were determined.

scholarly journals Genetic diversity of Anopheles coustani in high malaria transmission foci in southern and central Africa

2020 ◽  
Author(s):  
Ilinca I. Ciubotariu ◽  
Christine M. Jones ◽  
Tamaki Kobayashi ◽  
Thierry Bobanga ◽  
Mbanga Muleba ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Malaria Transmission ◽  
Malaria Parasite ◽  
Indoor Residual Spraying ◽  
Control Measures ◽  
Sub Saharan Africa ◽  
Health Concern ◽  
Malaria Vectors ◽  
Bed Nets ◽  
Internal Transcribed Spacer Region

AbstractDespite ongoing malaria control efforts implemented throughout sub-Saharan Africa, malaria remains an enormous public health concern. Current interventions such as indoor residual spraying with insecticides and use of insecticide-treated bed nets are aimed at targeting the key malaria vectors that are primarily endophagic and endophilic. While these control measures have resulted in a substantial decline in malaria cases and continue to impact indoor transmission, the importance of alternative vectors for malaria transmission has been largely neglected. Anopheles coustani, an understudied vector of malaria, is a species previously thought to exhibit mostly zoophilic behavior. However, recent studies from across Africa bring to light the contribution of this and ecologically similar anopheline species to human malaria transmission. Like many of these understudied species, An. coustani has greater anthropophilic tendencies than previously appreciated, is often both endophagic and exophagic, and carries Plasmodium falciparum sporozoites. These recent developments highlight the need for more studies throughout the geographic range of this species and the potential need to control this vector. The aim of this study was to explore the genetic variation of An. coustani mosquitoes and the potential of this Anopheles species to contribute to malaria parasite transmission in high transmission settings in Nchelenge District, Zambia, and the Kashobwe and Kilwa Health Zones in Haut-Katanga Province, the Democratic Republic of the Congo (DRC). Morphologically identified An. coustani specimens that were trapped outdoors in these study sites were analyzed by PCR and sequencing for species identification and blood meal sources, and malaria parasite infection was determined by ELISA and qPCR. Fifty specimens were confirmed to be An. coustani by the analysis of mitochondrial DNA cytochrome c oxidase subunit I (COI) and ribosomal internal transcribed spacer region 2 (ITS2). Further, maximum likelihood phylogenetic analysis of COI and ITS2 sequences revealed two distinct phylogenetic groups within this relatively small regional collection. Our findings indicate that both An. coustani groups have anthropophilic and exophagic habits and come into frequent contact with P. falciparum, suggesting that this potential alternative malaria vector might elude current vector controls in Northern Zambia and Southern DRC. This study sets the groundwork for more thorough investigations of bionomic characteristics and genetic diversity of An. coustani and its contribution to malaria transmission in these regions.

Transcriptome profiling reveals the endogenous sponging role of LINC00659 and UST-AS1 in high altitude induced thrombosis

2021 ◽  
Author(s):  
Prabhash Kumar Jha ◽  
Aatira Vijay ◽  
Amit Prabhakar ◽  
Tathagata Chatterjee ◽  
Velu Nair ◽  
...  
Keyword(s):  
Deep Vein Thrombosis ◽  
High Altitude ◽  
Expression Profile ◽  
Thrombus Formation ◽  
Pearson Correlation ◽  
Coagulation Cascade ◽  
Protein Coding ◽  
Vein Thrombosis ◽  
Protein Coding Genes ◽  
Deep Vein

Background: The pathophysiology of Deep vein thrombosis (DVT) is considered as multifactorial, where thrombus formation is interplay of genetic and acquired risk factors. A little is known about the expression profile and roles of lncRNAs in human subjects developing DVT at high altitude. Methods: Using RNAseq, we compared peripheral blood mRNA and lncRNA expression profile in human High Altitude deep Vein Thrombosis (HA-DVT) patients with high altitude control subjects. We used DESeq to identify differentially expressed (DE) genes. We annotated the long noncoding RNAs using NONCODE 3.0 database. In silico putative lncRNA-miRNA association study unravels the endogenous miRNA sponge associated with our candidate lncRNAs. These findings were validated by siRNA knockdown assay of the candidate lncRNAs conducted in primary endothelial cells. Results: We identified 1524 DE mRNA and 973 DE lncRNAs. Co-expressed protein-coding genes analysis resulted in a list of 722 coexpressed protein-coding genes with a Pearson correlation coefficients >0.7. The functional annotation of co-expressed genes and putative proteins revealed their involvement in the hypoxia, immune response and coagulation cascade. Through its miRNA response elements (MREs) to compete for miR-143 and miR-15, lncRNA-LINC00659 and UXT-AS1 regulates the expression of prothrombotic genes. Furthermore, in vitro RNA interference (siRNA) simultaneously suppressed lncRNAs and target gene mRNA level. Conclusions: This transcriptome profile describes novel potential mechanisms of interaction between lncRNAs, the coding genes, miRNAs and regulatory transcription factors that define the thrombotic signature and may be used in establishing lncRNAs as biomarker in HA-DVT.

Simulation of thermal stress and control measures for rock-filled concrete dam in high-altitude and cold regions

2021 ◽  
Vol 230 ◽  
pp. 111721
Author(s):  
Yuxiang Zhang ◽  
Jianwen Pan ◽  
Xinjian Sun ◽  
Jijun Feng ◽  
Dengqiang Sheng ◽  
...  
Keyword(s):  
Thermal Stress ◽  
High Altitude ◽  
Control Measures ◽  
Concrete Dam ◽  
Cold Regions ◽  
And Control

scholarly journals Modeling fire ignition probability and frequency using Hurdle models: a cross-regional study in Southern Europe

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Marina D’Este ◽  
Antonio Ganga ◽  
Mario Elia ◽  
Raffaella Lovreglio ◽  
Vincenzo Giannico ◽  
...  
Keyword(s):  
Mediterranean Basin ◽  
Negative Binomial ◽  
Pearson Correlation ◽  
Fire Occurrence ◽  
Ignition Probability ◽  
Hurdle Models ◽  
Mediterranean Landscapes ◽  
The Mediterranean ◽  
Fire Ignition ◽  
The Mediterranean Basin

Abstract Background Wildfires play a key role in shaping Mediterranean landscapes and ecosystems and in impacting species dynamics. Numerous studies have investigated the wildfire occurrences and the influence of their drivers in many countries of the Mediterranean Basin. However, in this regard, no studies have attempted to compare different Mediterranean regions, which may appear similar under many aspects. In response to this gap, climatic, topographic, anthropic, and landscape drivers were analyzed and compared to assess the patterns of fire ignition points in terms of fire occurrence and frequency in Catalonia (Spain), Sardinia, and Apulia (Italy). Therefore, the objectives of the study were to (1) assess fire ignition occurrence in terms of probability and frequency, (2) compare the main drivers affecting fire occurrence, and (3) produce fire probability and frequency maps for each region. Results In pursuit of the above, the probability of fire ignition occurrence and frequency was mapped using Negative Binomial Hurdle models, while the models’ performances were evaluated using several metrics (AUC, prediction accuracy, RMSE, and the Pearson correlation coefficient). The results showed an inverse correlation between distance from infrastructures (i.e., urban roads and areas) and the occurrence of fires in all three study regions. This relationship became more significant when the frequency of fire ignition points was assessed. Moreover, a positive correlation was found between fire occurrence and landscape drivers according to region. The land cover classes more significantly affected were forest, agriculture, and grassland for Catalonia, Sardinia, and Apulia, respectively. Conclusions Compared to the climatic, topographic, and landscape drivers, anthropic activity significantly influences fire ignition and frequency in all three regions. When the distance from urban roads and areas decreases, the probability of fire ignition occurrence and frequency increases. Consequently, it is essential to implement long- to medium-term intervention plans to reduce the proximity between potential ignition points and fuels. In this perspective, the present study provides an applicable decision-making tool to improve wildfire prevention strategies at the European level in an area like the Mediterranean Basin where a profuse number of wildfires take place.

scholarly journals Asymptomatic malaria and anaemia among pregnant women during high and low malaria transmission seasons in Burkina Faso: household-based cross-sectional surveys in Burkina Faso, 2013 and 2017

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Toussaint Rouamba ◽  
Sékou Samadoulougou ◽  
Mady Ouédraogo ◽  
Hervé Hien ◽  
Halidou Tinto ◽  
...  
Keyword(s):  
Burkina Faso ◽  
Pregnant Women ◽  
Malaria Transmission ◽  
Asymptomatic Malaria ◽  
Cross Sectional ◽  
Transmission Season ◽  
Low Transmission ◽  
High Transmission ◽  
Asymptomatic Carriage ◽  
Low Malaria Transmission

Abstract Background Malaria in endemic countries is often asymptomatic during pregnancy, but it has substantial consequences for both the mother and her unborn baby. During pregnancy, anaemia is an important consequence of malaria infection. In Burkina Faso, the intensity of malaria varies according to the season, albeit the prevalence of malaria and anaemia as well as their risk factors, during high and low malaria transmission seasons is underexplored at the household level. Methods Data of 1751 pregnant women from October 2013 to March 2014 and 1931 pregnant women from April 2017 to June 2017 were drawn from two cross-sectional household surveys conducted in 24 health districts of Burkina Faso. Pregnant women were tested for malaria in their household after consenting. Asymptomatic carriage was defined as a positive result from malaria rapid diagnostic tests in the absence of clinical symptoms of malaria. Anaemia was defined as haemoglobin level less than 11 g/dL in the first and third trimester and less than 10.5 g/dL in the second trimester of pregnancy. Results Prevalence of asymptomatic malaria in pregnancy was estimated at 23.9% (95% CI 20.2–28.0) during the high transmission season (October–November) in 2013. During the low transmission season, it was 12.7% (95% CI 10.9–14.7) between December and March in 2013–2014 and halved (6.4%; 95% CI 5.3–7.6) between April and June 2017. Anaemia prevalence was estimated at 59.4% (95% CI 54.8–63.8) during the high transmission season in 2013. During the low transmission season, it was 50.6% (95% CI 47.7–53.4) between December and March 2013–2014 and 65.0% (95% CI 62.8–67.2) between April and June, 2017. Conclusion This study revealed that the prevalence of malaria asymptomatic carriage and anaemia among pregnant women at the community level remain high throughout the year. Thus, more efforts are needed to increase prevention measures such as IPTp–SP coverage in order to reduce anaemia and contribute to preventing low birth weight and poor pregnancy outcomes.

Influence of occupational heat stress on labour productivity – a case study from Chennai, India

2016 ◽  
Vol 65 (2) ◽  
pp. 245-255 ◽  
Author(s):  
Jeremiah Chinnadurai ◽  
Vidhya Venugopal ◽  
Kumaravel P ◽  
Paramesh R
Keyword(s):  
Climate Change ◽  
Heart Rate ◽  
Heat Stress ◽  
Pearson Correlation ◽  
Labour Productivity ◽  
Productivity Loss ◽  
Threshold Limit Value ◽  
Control Measures ◽  
Economic Losses ◽  
Content Type

Purpose – Raise in temperatures due to climate change is likely to increase the heat stress in occupations that are physically exerting and performed outdoors which might potentially have adverse health and productivity consequences. The purpose of this paper is to estimate the productivities in construction work under the influence of heat stress using the predicted mean vote (PMV) index. Design/methodology/approach – Field studies were conducted during May 2014 which is summer time in Chennai. Continuous heart rate of workers and wet bulb globe temperature measurements are conducted for workers engaged in different jobs in construction. Metabolic rates and the workload of the workers from heart rate were calculated using the ISO method 8996 and the PMV values are calculated using the tool developed by Malchaire based on the method ISO 7730. Direct observations and personal interviews were conducted to substantiate the productivity estimations. Findings – The results showed that workers working outdoors with moderate and heavy workload exceeded the threshold limit value of 28°C and had adverse productivity impacts (18-35 per cent productivity loss), whereas the workers engaged in light indoor work was not affected by heat stress and consequent productivity losses. The productivity estimations using the PMV index is found to be statistically significant for three types of construction works (Pearson correlation coefficient value of −0.78) and also correlated well with the observations and self-reported productivities of the workers. Originality/value – The method used in this paper provides a scientific and reliable estimation of the productivities which may benefit the industry to set realistic project completion goals in hot weather and also implement interventions and policies to protect workers’ health. Developing adaptive strategies and implementing control measures are the need of the hour to protect worker’s health and economic losses in the face of climate change.

scholarly journals Projecting malaria hazard from climate change in eastern Africa using large ensembles to estimate uncertainty

2016 ◽  
Vol 11 (1s) ◽  
Author(s):  
Joseph Leedale ◽  
Adrian M. Tompkins ◽  
Cyril Caminade ◽  
Anne E. Jones ◽  
Grigory Nikulin ◽  
...  
Keyword(s):  
Climate Change ◽  
Malaria Transmission ◽  
Climate Models ◽  
Climate Model ◽  
Eastern Africa ◽  
Future Climate Change ◽  
Climate Projections ◽  
Model Ensemble ◽  
East African Community ◽  
Recent Climate

The effect of climate change on the spatiotemporal dynamics of malaria transmission is studied using an unprecedented ensemble of climate projections, employing three diverse bias correction and downscaling techniques, in order to partially account for uncertainty in climate- driven malaria projections. These large climate ensembles drive two dynamical and spatially explicit epidemiological malaria models to provide future hazard projections for the focus region of eastern Africa. While the two malaria models produce very distinct transmission patterns for the recent climate, their response to future climate change is similar in terms of sign and spatial distribution, with malaria transmission moving to higher altitudes in the East African Community (EAC) region, while transmission reduces in lowland, marginal transmission zones such as South Sudan. The climate model ensemble generally projects warmer and wetter conditions over EAC. The simulated malaria response appears to be driven by temperature rather than precipitation effects. This reduces the uncertainty due to the climate models, as precipitation trends in tropical regions are very diverse, projecting both drier and wetter conditions with the current state-of-the-art climate model ensemble. The magnitude of the projected changes differed considerably between the two dynamical malaria models, with one much more sensitive to climate change, highlighting that uncertainty in the malaria projections is also associated with the disease modelling approach.

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