Judy Omumbo

#<p>See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0053198#pone-0053198-t001" target="_blank">Table 1</a> for definitions of map codes (1–11);</p>*<p>E: NMS goal is elimination;</p>**<p>PE: NMS aims to achieve pre-elimination;</p>&<p>M&E plan available; Cells shaded in grey indicate that no report is available.</p

Introduction: Rational decision making on malaria control depends on an understanding of the epidemiological risks and control measures. National Malaria Control Programmes across Africa have access to a range of state-of-the-art malaria risk mapping products that might serve their decision-making needs. The use of cartography in planning malaria control has never been methodically reviewed. Materials and Methods: An audit of the risk maps used by NMCPs in 47 malaria endemic countries in Africa was undertaken

Summary The objective of this study was to produce a malaria distribution map that would constitute a useful tool for development and health planners in West Africa. The recently created continental database of malaria survey results (MARA/ARMA 1998) provides the opportunity for producing empirical models and maps of malaria distribution at a regional and eventually at a continental level. This paper reports on the mapping of malaria distribution for sub-Saharan West Africa based on these data. The strategy was to undertake a spatial statistical analysis of malaria parasite prevalence in relation to those potential bio-physical environmental factors involved in the distribution of malaria transmission intensity which are readily available at any map location. The resulting model was then used to predict parasite prevalence for the whole of West Africa. We also produced estimates of the proportion of population of each country in the region exposed to various categories of risk to sh...

Records from tea estates in the Kericho district in Kenya show that malaria reemerged in the 1980s. Renewed epidemic activity coincided with the emergence of chloroquine-resistant Plasmodium falciparum malaria and may have been triggered by the failure of antimalarial drugs. Meteorologic changes, population movements, degradation of health services, and changes in Anopheles vector populations are possible contributing factors. The highland malaria epidemics of the 1940s were stopped largely by sporontocidal drugs, and combination chemotherapy has recently limited transmission. Antimalarial drugs can limit the pool of gametocytes available to infect mosquitoes during the brief transmission season. Epidemic malaria is a term applied to describe Plasmodium falciparum transmission characteristics

<div> <div> <div> <div> <div> <div> <div> <div> <div> <div>The World Meteorological Organization (WMO) Research Board has set up an interdisciplinary and international Task Team to respond to the challenge of providing timely decision support and relevant knowledge on Meteorological and Air Quality (MAQ) factors affecting the SARS-CoV-2/COVID-19 pandemic. The Task Team aims to provide decision makers and the public with a rapid summary of the state of knowledge regarding potential MAQ influences on SARS-CoV-2/COVID-19; to offer general technical guidance for researchers and service providers who wish to consider MAQ data in their analyses, estimates, predictions and projections of COVID-19 risks. The work of the task  motivated both by the global relevance of the subject and by the staggering number of papers and pre-prints currently available, which emphasizes the need for careful review and communication of the state of the science. This first  report presents a summary of key findings of the review to date, as informed by peer reviewed literature.</div> <p> </p> <div>A key finding is that the underlying mechanisms that drive seasonality of respiratory viral infections are not yet well understood. To date, COVID-19 transmission dynamics appear to have been controlled primarily by government interventions rather than meteorological factors. Respiratory viral infections frequently exhibit some form of seasonality, particularly in temperate climates and some evidence from laboratory studies of SARS-CoV-2, suggests that the virus survives longer under cold, dry, and low ultraviolet radiation conditions. There is also evidence that chronic and short-term exposure to air pollution exacerbates symptoms and increases mortality rates for some respiratory diseases and this is consistent with early studies of COVID-19 mortality rates. However, there is no direct, peer reviewed evidence of pollution impacts on the transmission of SARS-CoV-2 at this time. Process-based modeling studies anticipate that COVID-19 transmission may become seasonal over time, suggesting Meteorology and Air Quality (MAQ) factors may support monitoring and forecasting of COVID-19 in the coming months and years.</div> <p> </p> <div>Additional research quantifying links between MAQ factors and COVID-19 is needed.</div> </div> </div> </div> </div> </div> </div> </div> </div> </div>

<div> <div> <div> <div> <div> <div> <div> <div> <div> <div>The World Meteorological Organization (WMO) Research Board has set up an interdisciplinary and international Task Team to respond to the challenge of providing timely decision support and relevant knowledge on Meteorological and Air Quality (MAQ) factors affecting the SARS-CoV-2/COVID-19 pandemic. The Task Team aims to provide decision makers and the public with a rapid summary of the state of knowledge regarding potential MAQ influences on SARS-CoV-2/COVID-19; to offer general technical guidance for researchers and service providers who wish to consider MAQ data in their analyses, estimates, predictions and projections of COVID-19 risks. The work of the task  motivated both by the global relevance of the subject and by the staggering number of papers and pre-prints currently available, which emphasizes the need for careful review and communication of the state of the science. This first  report presents a summary of key findings of the review to date, as informed by peer reviewed literature.</div> <p> </p> <div>A key finding is that the underlying mechanisms that drive seasonality of respiratory viral infections are not yet well understood. To date, COVID-19 transmission dynamics appear to have been controlled primarily by government interventions rather than meteorological factors. Respiratory viral infections frequently exhibit some form of seasonality, particularly in temperate climates and some evidence from laboratory studies of SARS-CoV-2, suggests that the virus survives longer under cold, dry, and low ultraviolet radiation conditions. There is also evidence that chronic and short-term exposure to air pollution exacerbates symptoms and increases mortality rates for some respiratory diseases and this is consistent with early studies of COVID-19 mortality rates. However, there is no direct, peer reviewed evidence of pollution impacts on the transmission of SARS-CoV-2 at this time. Process-based modeling studies anticipate that COVID-19 transmission may become seasonal over time, suggesting Meteorology and Air Quality (MAQ) factors may support monitoring and forecasting of COVID-19 in the coming months and years.</div> <p> </p> <div>Additional research quantifying links between MAQ factors and COVID-19 is needed.</div> </div> </div> </div> </div> </div> </div> </div> </div> </div>

Remotely sensed imagery has been used to update and improve the spatial resolution of malaria transmission intensity maps in Tanzania, Uganda, and Kenya. Discriminant analysis achieved statistically robust agreements between historical maps of the intensity of malaria transmission and predictions based on multitemporal meteorological satellite sensor data processed using temporal Fourier analysis. The study identified land surface temperature as the best predictor of transmission intensity. Rainfall and moisture availability as inferred by cold cloud duration (ccd) and the normalized difference vegetation index (ndvi), respectively, were identified as secondary predictors of transmission intensity. Information on altitude derived from a digital elevation model significantly improved the predictions. "Malaria-free" areas were predicted with an accuracy of 96 percent while areas where transmission occurs only near water, moderate malaria areas, and intense malaria transmissi...

Insecticide-treated bed nets (ITN) provide real hope for the reduction of the malaria burden across Africa. Understanding factors that determine access to ITN is crucial to debates surrounding the optimal delivery systems. The influence of homestead wealth on use of nets purchased from the retail sector is well documented, however, the competing influence of mother's education and physical access to net providers is less well understood. Between December 2004 and January 2005, a random sample of 72 rural communities was selected across four Kenyan districts. Demographic, assets, education and net use data were collected at homestead, mother and child (aged < 5 years) levels. An assets-based wealth index was developed using principal components analysis, travel time to net sources was modelled using geographic information systems, and factors influencing the use of retail sector nets explored using a multivariable logistic regression model. Homestead heads and guardians of 3,7...

The use of insecticide-treated bednets (ITBNs) has been shown to be effective in reducing mortality and morbidity from malaria. However, there is mixed evidence as to whether or not community-wide use of ITBNs engenders a 'mass effect', such that those not sleeping under bednets are offered protection from widespread ITBN use in the area in which they live. We have analysed data collected in Kilifi, Kenya, from a cohort of children followed from birth to investigate how the degree of net usage in the locality of a child affects the risk of developing malaria. This effect was explored using a Cox proportional hazards model. For those not using ITBNs, we found that an increasing level of ITBN usage within the area surrounding each child was associated with a decreasing risk of developing malaria, thus providing evidence in support of a mass community effect. The size and significance of this effect were found to decrease as non-overlapping areas of increasing distance away from a child's home were considered. The effect was significant for areas at distances of up to 1.5 km away from each child.

Plasmodium falciparum morbid and fatal risks are considerably higher in areas supporting parasite prevalence > or =25%, when compared with low transmission areas supporting parasite prevalence below 25%. Recent descriptions of the health impacts of malaria in Africa are based upon categorical descriptions of a climate-driven fuzzy model of suitability (FCS) for stable transmission developed by the Mapping Malaria Risk in Africa collaboration (MARA). An electronic and national search was undertaken to identify community-based parasite prevalence surveys in Kenya. Data from these surveys were matched using ArcView 3.2 to extract spatially congruent estimates of the FCS values generated by the MARA model. Levels of agreement between three classes used during recent continental burden estimations of parasite prevalence (0%, >0-<25% and > or =25%) and three classes of FCS (0, >0-<0.75 and > or =0.75) were tested using the kappa (k) statistic and examined as continuou...

Both malaria and undernutrition are major causes of paediatric mortality and morbidity in sub-Saharan Africa. The introduction of insecticide-treated bed nets (ITBN) during a randomized controlled trial on the Kenyan coast significantly reduced severe, life-threatening malaria and all-cause childhood mortality. This paper describes the effects of the intervention upon the nutritional status of infants aged between 1 and 11 months of age. Seven hundred and eighty seven infants who slept under ITBN and 692 contemporaneous control infants, were seen during one of three cross-sectional surveys conducted during a one year period. Standardized weight-for-age and mid-upper arm circumference measures were significantly higher among infants who used ITBN compared with control infants. Whether these improvements in markers of nutritional status were a direct result of concomitant reductions in clinical malaria episodes remains uncertain. Never-the-less evidence suggests that even moderate increases in weight-for-age scores can significantly reduce the probability of mortality in childhood and ITBN may provide additional gains to child survival beyond their impressive effects upon malaria-specific events.