Response to malaria epidemics in Africa.

Malaria epidemics affect nonimmune populations in many highland and semi-arid areas of Africa. Effective prevention of these epidemics is challenging, particularly in the highlands where predictive accuracy of indicators is not sufficiently high to allow decisions involving expensive measures such as indoor residual spraying of insecticides. Advances in geographic information systems have proved useful in stratification of areas to guide selective targeting of interventions, including barrier application of insecticides in transmission foci to prevent spread of infection. Because rainfall is associated with epidemics in semi-arid areas, early warning methods based on seasonal climate predictions have been proposed. For most areas, response measures should focus on early recognition of anomalies and rapid mass drug administration. Vector control measures are useful if abnormal transmission is highly likely and if they can be selectively implemented at the early stages of an outbreak

Early warning systems for malaria in Africa: from blueprint to practice.

Although the development of early warning systems for malaria has been advocated by international agencies and academic researchers for many years, practical progress in this area has been relatively modest. In two recent articles, Thomson et al. provide new evidence that models of malaria incidence that incorporate monitored or predicted climate can provide early warnings of epidemics one to five months in advance in semi-arid areas. Although the potential benefits of these models in terms of improved management of epidemics are clear, several technical and practical hurdles still need to be overcome before the models can be widely integrated into routine malaria-control strategies

NEW VALIDATED STABILITY-INDICATING RP-HPLC METHOD FOR THE SIMULTANEOUS DETERMINATION OF METFORMIN HYDROCHLORIDE, LINAGLIPTIN AND EMPAGLIFLOZIN IN BULK AND PHARMACEUTICAL DOSAGE FORMS

Objective: The purpose of the present study is to develop simple, fast, accurate, precise, and robust stability-indicating reverse phase high-performance liquid chromatographic (RP-HPLC) method for the simultaneous determination of metformin HCl, empagliflozin, and linagliptin in their combinations. Methods: Separation was performed on Agilent Eclipse XDB-C18 (250 mm x 4.6 mm, 5 µm) column with a mobile phase consisting of 0.1 % triethylamine (pH =3) buffer and acetonitrile in the ratio 40: 60 (v/v) at a flow rate of 1 ml/min. Detection of the analytes was carried out at a wavelength of 240 nm with a photodiode array detector. The developed method was validated as per the International Conference on Harmonization (ICH) guidelines. Results: The retention time values under the optimized condition were 2.660 min, 3.586 min, and 5.412 min for metformin HCl, linagliptin, and empagliflozin, respectively. The method was linear over a concentration range of 100 µg/ml-1500 µg/ml, 0.5 µg/ml-7.5 µg/ml, and 2.5 µg/ml-37.5 µg/ml for metformin HCl,linagliptin and empagliflozin respectively. The limit of detection (LOD) of the method was found to be 4.00 µg/ml, 0.02 µg/ml, and 1.00 µg/ml for metformin HCl, linagliptin, and empagliflozin, respectively. The degradation peaks were clearly resolved from the parent drug peaks in the chromatograms of forced degradation studies. Conclusion: The validated method was successfully applied for the determination of metformin HCl, linagliptin, and empagliflozin in their combined tablet dosage forms and hence can be used for the routine quality control of the drugs in pharmaceutical bulk, and dosage forms

The linkages between agriculture and malaria: Issues for policy, research, and capacity strengthening

"Malaria afflicts many people in the developing world, and due to its direct and indirect costs it has widespread impacts on growth and development. The global impact of malaria on human health, productivity, and general well-being is profound. Human activity, including agriculture, has been recognized as one of the reasons for the increased intensity of malaria around the world, because it supports the breeding of mosquitoes that carry the malaria parasite. Malaria can cause illness (morbidity), disability, or death; and all three effects have direct and indirect costs that can affect productivity. Since agriculture is the main activity of rural people in many endemic areas, it has been suggested that effective malaria control measures can be devised if attention was paid to the two-way effects of agriculture and malaria. There is the need to compute the direct costs of malaria treatment and control and the impacts of those costs on the ability of farm households to adopt new agricultural technology and improved practices, and keep farm and household assets. It is equally important to know the indirect costs of seeking health care and taking care of children and others who are afflicted by malaria and the relationship of the indirect costs to the farm labor supply and productivity. On the other hand, many agricultural activities like irrigation projects, water-harvesting and storage, land and soil management techniques, and farm work sequencing can lead to increase in mosquito populations and therefore increase the incidence of malaria in agricultural regions. This paper has raised issues on the two-way effects of agriculture and malaria and recommended areas that require policy actions and further research. The research findings can then be used in devising effective policies for controlling malaria in endemic areas of the world and assist in preparing a tool kit for capacity development on agriculture and malaria." from authors' abstractMalaria, Agriculture, Development, technology, Impact, Research, Policy, Capacity strengthening, Innovation, Institutional change, Science and technology,

Effect of environmental variables and kdr resistance genotype on survival probability and infection rates in Anopheles gambiae (s.s.).

BACKGROUND: Environmental factors, especially ambient temperature and relative humidity affect both mosquitoes and malaria parasites. The early part of sporogony is most sensitive and is affected by high temperatures and temperature fluctuation immediately following ingestion of an infectious blood meal. The aim of this study was to explore whether environmental variables such as temperature, together with the presence of the kdr insecticide resistance mutations, have an impact on survival probability and infection rates in wild Anopheles gambiae (s.s.) exposed and unexposed to a pyrethroid insecticide. METHODS: Anopheles gambiae (s.s.) were collected as larvae, reared to adults, and fed on blood samples from 42 Plasmodium falciparum-infected local patients at a health facility in mid-western Uganda, then exposed either to nets treated with sub-lethal doses of deltamethrin or to untreated nets. After seven days, surviving mosquitoes were dissected and their midguts examined for oocysts. Prevalence (proportion infected) and intensity of infection (number of oocysts per infected mosquito) were recorded for each group. Mosquito mortality was recorded daily. Temperature and humidity were recorded every 30 minutes throughout the experiments. RESULTS: Our findings indicate that apart from the effect of deltamethrin exposure, mean daily temperature during the incubation period, temperature range during the first 24 hours and on day 4 post-infectious feed had a highly significant effect on the risk of infection. Deltamethrin exposure still significantly impaired survival of kdr homozygous mosquitoes, while mean daily temperature and relative humidity during the incubation period independently affected mosquito mortality. Significant differences in survival of resistant genotypes were detected, with the lowest survival recorded in mosquitoes with heterozygote L1014S/L1014F genotype. CONCLUSIONS: This study confirmed that the early part of sporogony is most affected by temperature fluctuations, while environmental factors affect mosquito survival. The impact of insecticide resistance on malaria infection and vector survival needs to be assessed separately for mosquitoes with different resistance mechanisms to fully understand its implications for currently available vector control tools and malaria transmission

Invited review: Genomic selection for small ruminants in developed countries: how applicable for the rest of the world?

Improved management and use of estimated breeding values in breeding programmes, have resulted in rapid genetic progress for small ruminants (SR) in Europe and other developed countries. The development of single nucleotide polymorphisms chips opened opportunities for genomic selection (GS) in SR in these countries. Initially focused on production traits (growth and milk), GS has been extended to functional traits (reproductive performance, disease resistance and meat quality). The GS systems have been characterized by smaller reference populations compared with those of dairy cattle and consisting mostly of cross- or multi-breed populations. Molecular information has resulted in gains in accuracy of between 0.05 and 0.27 and proved useful in parentage verification and the identification of QTLs for economically important traits. Except for a few established breeds with some degree of infrastructure, the basic building blocks to support conventional breeding programmes in small holder systems are lacking in most developing countries. In these systems, molecular data could offer quick wins in undertaking parentage verification and genetic evaluations using G matrix, and determination of breed composition. The development of next-generation molecular tools has prompted investigations on genome-wide signatures of selection for mainly adaptive and reproduction traits in SR in developing countries. Here, the relevance of the developments and application of GS and other molecular tools in developed countries to developing countries context is examined. Worth noting is that in the latter, the application of GS in SR will not be a ‘one-size fits all’ scenario. For breeds with some degree of conventional genetic improvement, classical GS may be feasible. In small holder systems, where production is key, community-based breeding programmes can provide the framework to implement GS. However, in fragile growth systems, for example those found in marginal environments, innovative GS to maximize adaptive diversity will be required. A cost-benefit analysis should accompany any strategy of implementing GS in these systems

Forecasting malaria incidence from historical morbidity patterns in epidemic-prone areas of Ethiopia: a simple seasonal adjustment method performs best.

The aim of this study was to assess the accuracy of different methods of forecasting malaria incidence from historical morbidity patterns in areas with unstable transmission. We tested five methods using incidence data reported from health facilities in 20 areas in central and north-western Ethiopia. The accuracy of each method was determined by calculating errors resulting from the difference between observed incidence and corresponding forecasts obtained for prediction intervals of up to 12 months. Simple seasonal adjustment methods outperformed a statistically more advanced autoregressive integrated moving average method. In particular, a seasonal adjustment method that uses mean deviation of the last three observations from expected seasonal values consistently produced the best forecasts. Using 3 years' observation to generate forecasts with this method gave lower errors than shorter or longer periods. Incidence during the rainy months of June-August was the most predictable with this method. Forecasts for the normally dry months, particularly December-February, were less accurate. The study shows the limitations of forecasting incidence from historical morbidity patterns alone, and indicates the need for improved epidemic early warning by incorporating external predictors such as meteorological factors

Exposure to deltamethrin affects development of Plasmodium falciparum inside wild pyrethroid resistant Anopheles gambiae s.s. mosquitoes in Uganda.

BACKGROUND: Pyrethroid resistance in African vector mosquitoes is a threat to malaria control. Resistant mosquitoes can survive insecticide doses that would normally be lethal. We studied effects of such doses on Plasmodium falciparum development inside kdr-resistant Anopheles gambiae s.s. in Uganda. METHODS: We collected An. gambiae s.s. homozygous for kdr-L1014S mutation, fed them on blood samples from 42 P. falciparum-infected local patients, then exposed them either to nets treated with sub-lethal doses of deltamethrin or to untreated nets. After seven days, we dissected 692 mosquitoes and examined their midguts for oocysts. Prevalence (proportion infected) and intensity of infection (number of oocysts per infected mosquito) were recorded for each group. RESULTS: Both prevalence and intensity of infection were significantly reduced in deltamethrin-exposed mosquitoes, compared to those exposed to untreated nets. With low doses (2.5-5.0 mg/m(2)), prevalence was reduced by 59% (95% CI = 22%-78%) and intensity by 41% (95% CI = 25%-54%). With high doses (10-16.7 mg/m(2)), prevalence was reduced by 80% (95% CI = 67%-88 %) and intensity by 34 % (95 % CI = 20%-46%). CONCLUSIONS: We showed that, with locally-sampled parasites and mosquitoes, doses of pyrethroids that are sub-lethal for resistant mosquitoes can interfere with parasite development inside mosquitoes. This mechanism could enable pyrethroid-treated nets to prevent malaria transmission despite increasing vector resistance