Malaria Epidemics Research Articles

PCR/RFLP-based analysis of genetically distinct Plasmodium vivax population of Pvmsp-3α and Pvmsp-3β genes in Pakistan.

BackgroundPlasmodium vivax is one of the widespread human malarial parasites accounting for 75% of malaria epidemics. However, there is no baseline information about the status and nature of genetic variation of Plasmodium species circulating in various parts of Pakistan. The present study was aimed at observing the molecular epidemiology and genetic variation of Plasmodium vivax by analysing its merozoite surface protein-3α (msp-3α) and merozoite surface protein-3β (msp-3β) genes, by using suballele, species-specific, combined nested PCR/RFLP detection techniques.MethodsA total of 230 blood samples from suspected subjects tested slide positive for vivax malaria were collected from Punjab, Sindh, Khyber Pakhtunkhwa, and Balochistan during the period May 2012 to December 2013. Combined nested PCR/RFLP technique was conducted using Pvmsp-3α and Pvmsp-3β genetic markers to detect extent of genetic variation in clinical isolates of P. vivax in the studied areas of Pakistan.ResultsBy PCR, P. vivax, 202/230 (87.82%), was found to be widely distributed in the studied areas. PCR/RFLP analysis showed a high range of allelic variations for both msp-3α and msp-3β genetic markers of P. vivax, i.e., 21 alleles for msp-3α and 19 for msp-3β. Statistically a significant difference (p ≤ 0.05) was observed in the genetic diversity of the suballelic variants of msp-3α and msp-3β genes of P. vivax.ConclusionIt is concluded that P. vivax populations are highly polymorphic and diverse allelic variants of Pvmsp-3α and Pvmsp-3β are present in Pakistan.

Spatial dependence of malaria epidemics in municipalities of the Amazonian Ecosystem.

In 2010, there were 305 (37.8%) municipalities with malaria epidemics in the Brazilian Amazon. The epidemics spread can be explained by the spatial distribution pattern. To analyze the spatial dependence, autocorrelation, of the malaria epidemics in the municipalities of this region. An automated algorithm was used for the detection of epidemic municipalities in 2003, 2007 and 2010. Spatial dependence was analyzed by applying the global and local Moran index on the epidemic months proportion variable. The epidemic municipalities clusters were identified using the TerraView software. The global Moran index values were 0.4 in 2003; 0.6 in 2007; and 0.5 in 2010 (p = 0.01), confirming the spatial dependence among the epidemic municipalities. Box Map and Moran Map identified inter-municipal, interstate and borders clusters with spatial autocorrelation (p < 0.05). There were 10 epidemic municipalities clusters in 2003; 9 in 2007 and 8 in 2010. The epidemic municipalities clusters may be linked to the health facilities difficulties on acting together. The structural limitations of the health services can be overcome by territorial integration to support planning and control activities, strengthening the interventions. The routine analysis of the epidemic municipalities clusters with spatial and temporal persistence may provide a new indicator of planning and integrated control prioritization, contributing to malaria epidemics reducing in inter-municipal, interstate and borders areas.

Strengthening malaria and climate research in Ethiopia

The project “Ethiopian Malaria Prediction System” implemented from 2007 to 2012 combined new population-based malaria transmission information with climate and land use variability data to develop an early warning tool to predict malaria epidemics in Ethiopia. Scientists from Ethiopia and Norway collaborated to incorporate climate variability and forecast information for malaria epidemics. Our study shows that the association between weather and malaria is complex. Statistical models can predict malaria for large areas. However, as malaria transmission varies and depends on local environmental conditions, we need to have good and local knowledge about each area. However, weather variability is the main driver of malaria in Ethiopia. While the generation of precipitation depends on local ascent and cooling of the air, our research provided new data on the transport of moisture into the country that may improve weather forecasting. We developed a new classification of climate zones, have mapped drought episodes in Ethiopia during the last decades, and have improved seasonal weather forecasting. Our hydrology studies show that potential climate change differs among the Ethiopian river basins, with river flows being sensitive to variations in rainfall, and less to temperature changes. The computer model, Open Malaria Warning, incorporates hydrological, meteorological, mosquito-breeding, land-use data, and cattle densities to find out when and where outbreaks are likely to occur. We validated the model with data for malaria transmission in the highlands and lowlands, characterizing malaria transmission over some years in both highlands and lowlands. This provided us with new knowledge on malaria transmission in Ethiopia, how intense the seasonal transmission is, and how malaria occurs in different populations and areas. Our study showed that indigenous malaria transmission during a non-epidemic year takes place above 2000 m altitude. We also showed the ideal temperature for malaria transmission is about 25°C, underlining that global warming may lead to increased risk of malaria in highland areas, and less in the lowlands with already high average temperatures. However, to validate such models, there is a need for several years of active monitoring of malaria cases and mosquito densities. Unfortunately, such data is rare in Africa, and we need to invest in long-term monitoring of malaria transmission.

EPIDEMIA - An EcoHealth Informatics System for integrated forecasting of malaria epidemics

Advance information about the timing and locations of malaria epidemics can facilitate the targeting of resources for prevention and emergency response. However, predictions must be accurate to ensure that potential outbreaks are not missed and resources are not wasted responding to predicted outbreaks that do not occur. Early warning systems based on environmental monitoring can identify critical risk factors before an epidemic actually starts, but their accuracy is constrained by the influences of non-climatic factors on malaria transmission. In contrast, early detection of malaria epidemics based on epidemiological surveillance can be more reliable because it is conditioned on direct observations, but offers limited lead time and requires timely and accurate surveillance data. Ideally, a malaria forecasting system that combines elements of environmental monitoring and malaria case surveillance would be able to leverage the strengths and minimize the limitations of each approach. However, the potential for integration has been hindered by a dearth of established techniques and available tools for assimilating multiple data streams from malaria surveillance and environmental monitoring. In response to this need, we are developing the Epidemic Prognosis Incorporating Disease and Environmental Monitoring for Integrated Assessment (EPIDEMIA) computer system. EPIDEMIA will incorporate software for integrating and processing environmental and epidemiological data from multiple sources, data assimilation techniques that continually update models and forecasts, and a web-based interface that will make the resulting information useful to public health decision makers. The system will be tested by implementing it in the Amhara Region of Ethiopia in collaboration with local stakeholders in the NGO and Public Health sectors. We have conducted an initial co-design workshop in July 2014, with a requirements analysis that identified the main use cases for the public health community and the data requirements for the modelers. Future work will involve a cycle of implementation, training, usability testing, and continuous system development. This innovative translational bioinformatics approach will allow us to assess the practical effectiveness of the tools and continually upgrade and improve the technologies.

Towards seasonal forecasting of malaria in India.

BackgroundMalaria presents public health challenge despite extensive intervention campaigns. A 30-year hindcast of the climatic suitability for malaria transmission in India is presented, using meteorological variables from a state of the art seasonal forecast model to drive a process-based, dynamic disease model.MethodsThe spatial distribution and seasonal cycles of temperature and precipitation from the forecast model are compared to three observationally-based meteorological datasets. These time series are then used to drive the disease model, producing a simulated forecast of malaria and three synthetic malaria time series that are qualitatively compared to contemporary and pre-intervention malaria estimates. The area under the Relative Operator Characteristic (ROC) curve is calculated as a quantitative metric of forecast skill, comparing the forecast to the meteorologically-driven synthetic malaria time series.Results and discussionThe forecast shows probabilistic skill in predicting the spatial distribution of Plasmodium falciparum incidence when compared to the simulated meteorologically-driven malaria time series, particularly where modelled incidence shows high seasonal and interannual variability such as in Orissa, West Bengal, and Jharkhand (North-east India), and Gujarat, Rajastan, Madhya Pradesh and Maharashtra (North-west India). Focusing on these two regions, the malaria forecast is able to distinguish between years of “high”, “above average” and “low” malaria incidence in the peak malaria transmission seasons, with more than 70% sensitivity and a statistically significant area under the ROC curve. These results are encouraging given that the three month forecast lead time used is well in excess of the target for early warning systems adopted by the World Health Organization. This approach could form the basis of an operational system to identify the probability of regional malaria epidemics, allowing advanced and targeted allocation of resources for combatting malaria in India.

Malaria transmission in Bissau, Guinea-Bissau between 1995 and 2012: malaria resurgence did not negatively affect mortality.

IntroductionAs Plasmodium falciparum prevalence decreases in many parts of Sub-Saharan Africa, so does immunity resulting in larger at risk populations and increased risk of malaria resurgence. In Bissau, malaria prevalence decreased from ∼50% to 3% between 1995 and 2003. The epidemiological characteristics of P. falciparum malaria within Bandim health and demographic surveillance site (population ∼100000) between 1995 and 2012 are described.Methods and FindingsThe population was determined by census. 3603 children aged <15 years that were enrolled in clinical trials at the Bandim health centre (1995–2012) were considered incident cases. The mean annual malaria incidence per thousand children in 1995–1997, 1999–2003, 2007, 2011, 2012 were as follows; age <5 years 22→29→4→9→3, age 5–9 years 15→28→4→33→12, age 10–14 years 9→15→1→45→19. There were 4 campaigns (2003–2010) to increase use of insecticide treated bed nets (ITN) amongst children <5 years. An efficacious high-dose chloroquine treatment regime was routinely used until artemisinin based combination therapy (ACT) was introduced in 2008. Long lasting insecticide treated bed nets (LLIN) were distributed in 2011. By 2012 there was 1 net per 2 people and 97% usage. All-cause mortality decreased from post-war peaks in 1999 until 2012 in all age groups and was not negatively affected by malaria resurgence.ConclusionThe cause of decreasing malaria incidence (1995–2007) was probably multifactorial and coincident with the use of an efficacious high-dose chloroquine treatment regime. Decreasing malaria prevalence created a susceptible group of older children in which malaria resurged, highlighting the need to include all age groups in malaria interventions. ACT did not hinder malaria resurgence. Mass distribution of LLINs probably curtailed malaria epidemics. All-cause mortality was not negatively affected by malaria resurgence.

Scarring and Selection Effects of Epidemic Malaria on Human Capital

This paper investigates the impact of exposure to a serious, unusual, and unforeseen malaria epidemic in North East Brazil in 1938-1940 on subsequent human capital attainment. Arguing the event was exogenous, it exploits cohort- and regional-heterogeneity in exposure to identify effects. Given the high mortality rate associated with the epidemic, a model of selection and scarring is used to frame results. Differential mortality rates are expected according to gender and race, and in line with this there is heterogeneity in whether selection or scarring dominates. Non-white (white) women are selected (scarred) overall, whilst men of all races appear to be selected. Results contribute to evidence suggesting that exposure to negative environmental shocks affects human capital attainment, whilst also suggesting it heterogeneously impacts cohort composition.

A mixed method to evaluate burden of malaria due to flooding and waterlogging in Mengcheng County, China: a case study.

BackgroundMalaria is a highly climate-sensitive vector-borne infectious disease that still represents a significant public health problem in Huaihe River Basin. However, little comprehensive information about the burden of malaria caused by flooding and waterlogging is available from this region. This study aims to quantitatively assess the impact of flooding and waterlogging on the burden of malaria in a county of Anhui Province, China.MethodsA mixed method evaluation was conducted. A case-crossover study was firstly performed to evaluate the relationship between daily number of cases of malaria and flooding and waterlogging from May to October 2007 in Mengcheng County, China. Stratified Cox models were used to examine the lagged time and hazard ratios (HRs) of the risk of flooding and waterlogging on malaria. Years lived with disability (YLDs) of malaria attributable to flooding and waterlogging were then estimated based on the WHO framework of calculating potential impact fraction in the Global Burden of Disease study.ResultsA total of 3683 malaria were notified during the study period. The strongest effect was shown with a 25-day lag for flooding and a 7-day lag for waterlogging. Multivariable analysis showed that an increased risk of malaria was significantly associated with flooding alone [adjusted hazard ratio (AHR) = 1.467, 95% CI = 1.257, 1.713], waterlogging alone (AHR = 1.879, 95% CI = 1.696, 2.121), and flooding and waterlogging together (AHR = 2.926, 95% CI = 2.576, 3.325). YLDs per 1000 of malaria attributable to flooding alone, waterlogging alone and flooding and waterlogging together were 0.009 per day, 0.019 per day and 0.022 per day, respectively.ConclusionFlooding and waterlogging can lead to higher burden of malaria in the study area. Public health action should be taken to avoid and control a potential risk of malaria epidemics after these two weather disasters.

Can Timely Vector Control Interventions Triggered by Atypical Environmental Conditions Prevent Malaria Epidemics? A Case-Study from Wajir County, Kenya

BackgroundAtypical environmental conditions with drought followed by heavy rainfall and flooding in arid areas in sub-Saharan Africa can lead to explosive epidemics of malaria, which might be prevented through timely vector-control interventions.ObjectivesWajir County in Northeast Kenya is classified as having seasonal malaria transmission. The aim of this study was to describe in Wajir town the environmental conditions, the scope and timing of vector-control interventions and the associated resulting burden of malaria at two time periods (1996–1998 and 2005–2007).MethodsThis is a cross-sectional descriptive and ecological study using data collected for routine program monitoring and evaluation.ResultsIn both time periods, there were atypical environmental conditions with drought and malnutrition followed by massive monthly rainfall resulting in flooding and animal/human Rift Valley Fever. In 1998, this was associated with a large and explosive malaria epidemic (weekly incidence rates peaking at 54/1,000 population/week) with vector-control interventions starting over six months after the massive rainfall and when the malaria epidemic was abating. In 2007, vector-control interventions started sooner within about three months after the massive rainfall and no malaria epidemic was recorded with weekly malaria incidence rates never exceeding 0.5 per 1,000 population per week.Discussion and ConclusionDid timely vector-control interventions in Wajir town prevent a malaria epidemic? In 2007, the neighboring county of Garissa experienced similar climatic events as Wajir, but vector-control interventions started six months after the heavy un-seasonal rainfall and large scale flooding resulted in a malaria epidemic with monthly incidence rates peaking at 40/1,000 population. In conclusion, this study suggests that atypical environmental conditions can herald a malaria outbreak in certain settings. In turn, this should alert responsible stakeholders about the need to act rapidly and preemptively with appropriate and wide-scale vector-control interventions to mitigate the risk.

Persistent organochlorine pesticides residues in cow and goat milks collected from different regions of Ethiopia

The present study investigated the bioaccumulation of organochlorines in two milk-producing animals (goats and cows) grazed on the same feed to explore the extent of organochlorines availability in milk and any species effect on the bioaccumulation pattern. Six organochlorine pesticides: aldrin, α-endosulfan, β-endosulfan, p,p′-DDE, o,p′-DDT and p,p′-DDT were determined in samples collected from four regions in Ethiopia. Aldrin (11.6μgkg−1) was detected only in one cow milk sample and α-endosulfan was detected in one goat milk sample at a level of 142.1μgkg−1, and in one cow milk sample (47.8μgkg−1) from the same region. p,p′-DDE was detected in 40% of the milk samples analyzed while o,p′-DDT and p,p′-DDT were found in high amounts in almost all samples. The average total DDT (excluding DDD) in the samples was 328.5μgkg−1. Regions known for their malaria epidemics were the most contaminated with DDT residue. The accumulation pattern in both species was not clear under natural sampling.

Analysis of the causes of spawning of large-scale, severe malarial epidemics and their rapid total extinction in western Provence, historically a highly endemic region of France (1745-1850).

BackgroundThe two main puzzles of this study are the onset and then sudden stopping of severe epidemics in western Provence (a highly malaria-endemic region of Mediterranean France) without any deliberate counter-measures and in the absence of significant population flux.MethodsMalaria epidemics during the period from 1745 to 1850 were analysed against temperature and rainfall records and several other potentially relevant factors.ResultsStatistical analyses indicated that relatively high temperatures in early spring and in September/October, rainfall during the previous winter (principally December) and even from November to September and epidemics during the previous year could have played a decisive role in the emergence of these epidemics. Moreover, the epidemics were most likely not driven by other parameters (e.g., social, cultural, agricultural and geographical). Until 1776, very severe malarial epidemics affected large areas, whereas after this date, they were rarer and generally milder for local people and were due to canal digging activities. In the latter period, decreased rainfall in December, and more extreme and variable temperatures were observed. It is known that rainfall anomalies and temperature fluctuations may be detrimental to vector and parasite development.ConclusionThis study showed the particular characteristics of malaria in historical Provence. Contrary to the situation in most other Mediterranean areas, Plasmodium falciparum was most likely not involved (during the years with epidemics, the mean temperature during the months of July and August, among other factors, did not play a role) and the population had no protective mutation. The main parasite species was Plasmodium vivax, which was responsible for very severe diseases, but contrary to in northern Europe, it is likely that transmission occurred only during the period where outdoor sporogony was possible, and P. vivax sporogony was always feasible, even during colder summers. Possible key elements in the understanding of the course of malaria epidemics include changes in the virulence of P. vivax strains, the refractoriness of anophelines and/or the degree or efficiency of acquired immunity. This study could open new lines of investigation into the comprehension of the conditions of disappearance/emergence of severe malaria epidemics in highly endemic areas.

Mass primaquine treatment to eliminate vivax malaria: lessons from the past.

Recent successes in malaria control have put malaria eradication back on the public health agenda. A significant obstacle to malaria elimination in Asia is the large burden of Plasmodium vivax, which is more difficult to eliminate than Plasmodium falciparum. Persistent P. vivax liver stages can be eliminated only by radical treatment with a ≥ seven-day course of an 8-aminoquinoline, with the attendant risk of acute haemolytic anaemia in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Primaquine is the only generally available 8-aminoquinoline. Testing for G6PD deficiency is not widely available, and so whilst it is widely recommended, primaquine is often not prescribed. In the past, some countries aiming for vivax malaria eradication deployed mass treatments with primaquine on a massive scale, without G6PD testing. In Azerbaijan, Tajikistan (formerly USSR), North Afghanistan and DPR Korea 8,270,185 people received either a 14-day “standard” or a 17-day “interrupted” primaquine treatment to control post-eradication malaria epidemics. These mass primaquine preventive treatment campaigns were conducted by dedicated teams who administered the drugs under supervision and then monitored the population for adverse events. Despite estimated G6PD prevalences up to 38.7%, the reported frequency of severe adverse events related to primaquine was very low. This experience shows that with careful planning and implementation of mass treatment strategies using primaquine and adequate medical support to manage haemolytic toxicity, it is possible to achieve high population coverage, substantially reduce malaria transmission, and manage the risk of severe acute haemolytic anaemia in communities with a relatively high prevalence of G6PD deficiency safely.

Entomological and parasitological impacts of indoor residual spraying with DDT, alphacypermethrin and deltamethrin in the western foothill area of Madagascar

BackgroundIn Madagascar, indoor residual spraying (IRS) with insecticide was part of the national malaria control programme since the middle of the twentieth century. It was mainly employed in the highlands and the foothill areas, which are prone to malaria epidemics. Prior to a policy change foreseeing a shift from DDT to pyrethroids, a study was carried out to assess the entomological and parasitological impacts of IRS in areas with DDT or pyrethroids and in areas without IRS.MethodsThe study was carried out from October 2002 to February 2005 in three communes of the western foothill area of Madagascar. Two communes received IRS with DDT in February 2003, then IRS with pyrethroids (alphacypermethrin or deltamethrin) in February 2004. The third commune remained untreated. Mosquitoes were collected at night using human landing catches and early in the morning in resting places. Blood smears were obtained from schoolchildren and microscopically examined for Plasmodium presence.ResultsIn total, 18,168 human landing mosquitoes and 12,932 resting anophelines were collected. The Anopheles species caught comprised 10 species. The main and most abundant malaria vector was Anopheles funestus (72.3% of human-seeking malaria vectors caught indoors). After IRS had taken place, this species exhibited a lower human biting rate and a lower sporozoite index. Overall, 5,174 blood smears were examined with a mean plasmodic index of 19.9%. A total of four Plasmodium species were detected. Amongst tested school children the highest plasmodial index was 54.6% in the untreated commune, compared to 19.9% in the commune sprayed with DDT and 11.9% in the commune sprayed with pyrethroid. The highest prevalence of clinical malaria attacks in children present at school the day of the survey was 33% in the untreated commune compared to 8% in the areas which received IRS.ConclusionIn terms of public health, the present study shows (1) a high efficacy of IRS with insecticide, (2) a similar efficacy of DDT and pyrethroid and (3) a similar efficacy of alphacypermethrin and deltamethrin. The use of IRS with DDT and pyrethroid greatly decreased the vector-human contact, with an associated decrease of the plasmodial index. However malaria transmission did not reach zero, probably due to the exophilic host-seeking and resting behaviours of the malaria vectors, thus avoiding contact with insecticide-treated surfaces indoors. The study highlights the strengths and weaknesses of the IRS implementation and the need for complementary tools for an optimal vector control in Madagascar.

Surveillance and response to drive the national malaria elimination program.

The national action plan for malaria elimination in China (2010-2020) was issued by the Chinese Ministry of Health along with other 13 ministries and commissions in 2010. The ultimate goal of the national action plan was to eliminate local transmission of malaria by the end of 2020. Surveillance and response are the most important components driving the whole process of the national malaria elimination programme (NMEP), under the technical guidance used in NMEP. This chapter introduces the evolution of the surveillance from the control to the elimination stages and the current structure of national surveillance system in China. When the NMEP launched, both routine surveillance and sentinel surveillance played critical role in monitoring the process of NMEP. In addition, the current response strategy of NMEP was also reviewed, including the generally developed "1-3-7 Strategy". More effective and sensitive risk assessment tools were introduced, which cannot only predict the trends of malaria, but also are important for the design and adjustment of the surveillance and response systems in the malaria elimination stage. Therefore, this review presents the landscape of malaria surveillance and response in China as well as their contribution to the NMEP, with a focus on activities for early detection of malaria cases, timely control of malaria foci and epidemics, and risk prediction. Furthermore, challenges and recommendations for accelerating NMEP through surveillance are put forward.

Optimal (Control of) Intervention Strategies for Malaria Epidemic in Karonga District, Malawi

Malaria is a public health problem for more than 2 billion people globally. About 219 million cases of malaria occur worldwide and 660,000 people die, mostly (91%) in the African Region despite decades of efforts to control the disease. Although the disease is preventable, it is life-threatening and parasitically transmitted by the bite of the femaleAnophelesmosquito. A deterministic mathematical model with intervention strategies is developed in order to investigate the effectiveness and optimal control strategies of indoor residual spraying (IRS), insecticide treated nets (ITNs) and treatment on the transmission dynamics of malaria in Karonga District, Malawi. The effective reproduction number is analytically computed, and the existence and stability conditions of the equilibria are explored. The model does not exhibit backward bifurcation. Pontryagin’s Maximum Principle which uses both the Lagrangian and Hamiltonian principles with respect to a time dependent constant is used to derive the necessary conditions for the optimal control of the disease. Numerical simulations indicate that the prevention strategies lead to the reduction of both the mosquito population and infected human individuals. Effective treatment consolidates the prevention strategies. Thus, malaria can be eradicated in Karonga District by concurrently applying vector control via ITNs and IRS complemented with timely treatment of infected people.

The Influence of Social Factors towards Resurgent Malaria and its Mitigation Using Sri Lanka as a Case-study

Social factors of malaria were examined using the case-study of malaria incidence in Sri Lanka. Sri Lanka has currently achieved eradication of malaria but as it is a small island, developing country, it is vulnerable to climate change threats. Therefore the social influences, host immunity, anti-malarial resistance, prosperity and travel, were investigated with particular reference to potential climate change-induced malaria. Development of immunity depends on the intensity and stability of transmission within the region. Although Sri Lanka recently eradicated malaria, it was previously considered a region of low to moderate transmission, with most individual inoculation resulting in infection and disease at all ages. Self-medication when unrequired is particularly significant in contributing to the global issue of anti-malarial resistance. Despite known drug resistance, distribution continues to be widespread due to low over-the-counter cost and rapid relief of symptoms. Poverty promotes transmission of malaria and in turn malaria impedes economic growth. Malaria imposes economic loss beyond direct medical costs and associated effects to macroenomic costs by impacts on worker productivity, school children performance, etc. However improved economic growth is insufficient to eradicate malaria e.g. Oman. Air travel is a vital factor in malaria transmission due to conveyance of asymptomatic carriers from endemic to non-endemic countries, leading to outbreaks of epidemic malaria. Incidence of imported malaria has been observed mainly due to lapse or absence of prophylaxis. The management of malaria was examined under the categories of public healthcare services and mitigation measures. Mitigation measures were evaluated in relation to social factors, to determine their efficacy in the event of resurgent malaria. Mitigation techniques of prominence were anti-malarial therapy, Indoor Residual Spraying, Insecticide Treated Nets and Long Lasting Insecticide Treated Nets and lastly environmental management. Malaria is borne out of multiple risks; both environmental (i.e. climate change and environmental degradation) and social (i.e. anti-malarial resistance, migration and poverty). As observed in Sri Lanka, strong political commitment in prioritising malaria control with sustained resource allocation is vital to eliminate malaria. A multi-measure approach cross cutting public health care services and malaria interventions has proven effective despite some evident climate change impacts

Climate Variability and Malaria Transmission �C Fogera District, Ethiopia, 2003-2011

Background: Epidemic malaria creates serious public health emergencies in Ethiopia. Malaria transmission rates have been linked to temperature and precipitation; factors that will be affected by increasing climate variability. Method: We analyzed climate and malaria data from January 2003-December 2011 in Fogera district of Ethiopia. We compared monthly rainfall and temperature data with the number of confirmed malaria cases. Results: We identified 104,716 confirmed malaria cases, which were treated in the district from 2003-2011 (monthly cases range from 98 – 5038). The annual prevalence rate was 104 per 1000. Annual average rainfall was 1268 mm, and annually there were between four and six months with rainfall that exceeded 80mm. There was a trend associating months with rainfall above 80mm and higher rates of confirmed malaria cases in seven of the nine years of the study period. Average monthly temperatures throughout the nine years period ranged from 180c to 280c. Conclusions: Malaria still constitutes a serious public health problem in Fogera district. Monthly precipitation greater than 80 mm was associated with increased malaria transmission rates in the district, and temperature probably was not a limiting factor. We recommend the development of climate prediction models to help forecast and control malaria outbreaks in the district.

Protein Microarray Analysis of Antibody Responses to Plasmodium falciparum in Western Kenyan Highland Sites with Differing Transmission Levels

Malaria represents a major public health problem in Africa. In the East African highlands, the high-altitude areas were previously considered too cold to support vector population and parasite transmission, rendering the region particularly prone to epidemic malaria due to the lack of protective immunity of the population. Since the 1980’s, frequent malaria epidemics have been reported and these successive outbreaks may have generated some immunity against Plasmodium falciparum amongst the highland residents. Serological studies reveal indirect evidence of human exposure to the parasite, and can reliably assess prevalence of exposure and transmission intensity in an endemic area. However, the vast majority of serological studies of malaria have been, hereto, limited to a small number of the parasite’s antigens. We surveyed and compared the antibody response profiles of age-stratified sera from residents of two endemic areas in the western Kenyan highlands with differing malaria transmission intensities, during two distinct seasons, against 854 polypeptides of P. falciparum using high-throughput proteomic microarray technology. We identified 107 proteins as serum antibody targets, which were then characterized for their gene ontology biological process and cellular component of the parasite, and showed significant enrichment for categories related to immune evasion, pathogenesis and expression on the host’s cell and parasite’s surface. Additionally, we calculated age-fitted annual seroconversion rates for the immunogenic proteins, and contrasted the age-dependent antibody acquisition for those antigens between the two sampling sites. We observed highly immunogenic antigens that produce stable antibody responses from early age in both sites, as well as less immunogenic proteins that require repeated exposure for stable responses to develop and produce different seroconversion rates between sites. We propose that a combination of highly and less immunogenic proteins could be used in serological surveys to detect differences in malaria transmission levels, distinguishing sites of unstable and stable transmission.

Improving decision-making activities for meningitis and malaria

Public health professionals are increasingly concerned about the potential impact that climate variability and change can have on infectious disease. The International Research Institute for Climate and Society (IRI) is developing new products to increase the public health community’s capacity to understand, use and demand the appropriate climate data and climate information to mitigate the public health impacts of climate on infectious disease, in particular meningitis and malaria. In this paper, we present the new and improved products that have been developed for: (i) estimating dust aerosol for forecasting risks of meningitis and (ii) for monitoring temperature and rainfall and integrating them into a vectorial capacity model for forecasting risks of malaria epidemics. We also present how the products have been integrated into a knowledge system (IRI Data Library Map Room, SERVIR) to support the use of climate and environmental information in climate-sensitive health decision-making.

Arbovirus Diseases, Southeastern United States

Arbovirus Diseases, Southeastern United States