Delivering insecticide-treated nets (ITNs) through a digitized single-phase door-to-door strategy: lessons from Ondo state, Nigeria.

Background: The use of insecticide-treated nets (ITNs) is a strategy recommended by the World Health Organization (WHO) for malaria prevention. In Nigeria, ITNs have been periodically distributed since 2007 through campaigns. Campaign activities and assets are typically tracked using either a paper-based or digital system.

A practical approach for geographic prioritization and targeting of insecticide-treated net distribution campaigns during public health emergencies and in resource-limited settings.

Background: The use of data in targeting malaria control efforts is essential for optimal use of resources. This work provides a practical mechanism for prioritizing geographic areas for insecticide-treated net (ITN) distribution campaigns in settings with limited resources.

Methods: A GIS-based weighted approach was adopted to categorize and rank administrative units based on data that can be applied in various country contexts where Plasmodium falciparum transmission is reported.

Correction to: Monitoring changes in malaria epidemiology and effectiveness of interventions in Ethiopia and Uganda: Beyond Garki Project baseline survey.

Please be advised that one of the author names is incorrectly spelled in the published article: 'Irene Kyomuhagi' should be 'Irene Kyomuhangi'.

Novel strains in malaria vectors from Sub-Saharan Africa.

, a common insect endosymbiotic bacterium that can influence pathogen transmission and manipulate host reproduction, has historically been considered absent from the  genera, but has recently been found in  s.l. populations in West Africa.

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.

Insecticide resistance patterns in Uganda and the effect of indoor residual spraying with bendiocarb on kdr L1014S frequencies in Anopheles gambiae s.s.

Background: Resistance of malaria vectors to pyrethroid insecticides has been attributed to selection pressure from long-lasting insecticidal nets (LLINs), indoor residual spraying (IRS), and the use of chemicals in agriculture. The use of different classes of insecticides in combination or by rotation has been recommended for resistance management. The aim of this study was to understand the role of IRS with a carbamate insecticide in management of pyrethroid resistance.

Travel and the emergence of high-level drug resistance in Plasmodium falciparum in southwest Uganda: results from a population-based study.

Background: The I164L mutation on the dhfr gene confers high level resistance to sulfadoxine-pyrimethamine (SP) but it is rare in Africa except in a cluster of reports where prevalence >10% in highland areas of southwest Uganda and eastern Rwanda. The occurrence of the dhfr I164L mutation was investigated in community surveys in this area and examined the relationship to migration.

Methods: A cross-sectional prevalence survey was undertaken in among villages within the catchment areas of two health facilities in a highland site (Kabale) and a highland fringe site (Rukungiri) in 2007.

The impact of behaviour change communication on the use of insecticide treated nets: a secondary analysis of ten post-campaign surveys from Nigeria.

Background: Mass distribution campaigns of insecticide-treated nets for malaria prevention are usually accompanied by intensive behaviour change communication (BCC) to encourage hanging and use of nets. However, data on the effectiveness of these communication efforts are scarce. In preparation for the next round of mass campaigns in Nigeria, a secondary analysis of existing data from post-campaign surveys was undertaken to investigate the influence of BCC on net hanging and use.

Application of Serological Tools and Spatial Analysis to Investigate Malaria Transmission Dynamics in Highland Areas of Southwest Uganda.

Serological markers, combined with spatial analysis, offer a comparatively more sensitive means by which to measure and detect foci of malaria transmission in highland areas than traditional malariometric indicators. Plasmodium falciparum parasite prevalence, seroprevalence, and seroconversion rate to P. falciparum merozoite surface protein-119 (MSP-119) were measured in a cross-sectional survey to determine differences in transmission between altitudinal strata.

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.

Monitoring changes in malaria epidemiology and effectiveness of interventions in Ethiopia and Uganda: Beyond Garki Project baseline survey.

Background: Scale-up of malaria interventions seems to have contributed to a decline in the disease but other factors may also have had some role. Understanding changes in transmission and determinant factors will help to adapt control strategies accordingly.

Methods: Four sites in Ethiopia and Uganda were set up to monitor epidemiological changes and effectiveness of interventions over time.

Association between recent internal travel and malaria in Ugandan highland and highland fringe areas.

Objective: To examine the association between travel (recency of travel, transmission intensity at destination compared to origin and duration of travel) and confirmed malaria in Uganda.

Methods: Health facility-based case-control study in highland (~2200 m), and highland fringe (~1500 m) areas with adjustment for other covariates.

Results: In the highland site, patients who had travelled to areas of higher transmission intensity than their home (origin) areas recently were nearly seven times more likely to have confirmed malaria than those who had not (OR 6.

Costs of early detection systems for epidemic malaria in highland areas of Kenya and Uganda.

Background: Malaria epidemics cause substantial morbidity and mortality in highland areas of Africa. The costs of detecting and controlling these epidemics have not been explored adequately in the past. This study presents the costs of establishing and running an early detection system (EDS) for epidemic malaria in four districts in the highlands of Kenya and Uganda.

Variations in entomological indices in relation to weather patterns and malaria incidence in East African highlands: implications for epidemic prevention and control.

Background: Malaria epidemics remain a significant public health issue in the East African highlands. The aim of this study was to monitor temporal variations in vector densities in relation to changes in meteorological factors and malaria incidence at four highland sites in Kenya and Uganda and to evaluate the implications of these relationships for epidemic prediction and control.

Methods: Mosquitoes were collected weekly over a period of 47 months while meteorological variables and morbidity data were monitored concurrently.

Determinants of the accuracy of rapid diagnostic tests in malaria case management: evidence from low and moderate transmission settings in the East African highlands.

Background: The accuracy of malaria diagnosis has received renewed interest in recent years due to changes in treatment policies in favour of relatively high-cost artemisinin-based combination therapies. The use of rapid diagnostic tests (RDTs) based on histidine-rich protein 2 (HRP2) synthesized by Plasmodium falciparum has been widely advocated to save costs and to minimize inappropriate treatment of non-malarial febrile illnesses. HRP2-based RDTs are highly sensitive and stable; however, their specificity is a cause for concern, particularly in areas of intense malaria transmission due to persistence of HRP2 antigens from previous infections.

Emergence of a dhfr mutation conferring high-level drug resistance in Plasmodium falciparum populations from southwest Uganda.

The S108N, C59R, and N51I mutations in the Plasmodium falciparum gene that encodes dihydrofolate reductase, dhfr, confer resistance to pyrimethamine and are common in Africa. However, the I164L mutation, which confers high-level resistance, is rarely seen. We found a 14% prevalence of the I164L mutation among a sample of 51 patients with malaria in Kabale District in southwest Uganda in 2005 and a 4% prevalence among 72 patients with malaria in the neighboring district of Rukungiri during the same year.

District-based malaria epidemic early warning systems in East Africa: perceptions of acceptability and usefulness among key staff at health facility, district and central levels.

Malaria epidemics represent a significant public health problem in the highlands of Africa. Many of these epidemics occur in low resource settings, where the development of an effective system for malaria surveillance has been a key challenge. Between 2001 and 2006, the Highland Malaria Project (HIMAL) established a programme to develop and test a district-based surveillance system for the early detection and control of malaria epidemics in four pilot districts in Kenya and Uganda.

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.

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.

The uncertain burden of Plasmodium falciparum epidemics in Africa.

Although the control of malaria epidemics has been a priority for the World Health Organization and other agencies for many years, surprisingly little is known about the public health burden of these epidemics. Here, we evaluate the available evidence of the morbidity and mortality impacts of individual epidemics in Africa and examine the problems associated with using these data to estimate the average annual burden of epidemics at national and continental scales. We argue that conventional approaches that are used to assess the burden of epidemics are inadequate, and outline the future steps that are required to produce estimates that are more accurate.

Malaria epidemic early warning and detection in African highlands.

Malaria epidemics have long been known to recur in the African highlands. Efforts to develop systems of early warning and detection for epidemics are outlined here with special emphasis on the Highland Malaria Project (HIMAL). This project has been conducting research on the operational implementation of a district-based surveillance and epidemic-monitoring system using a network of sentinel sites in four pilot districts of Kenya and Uganda.

Spatial and temporal variations of malaria epidemic risk in Ethiopia: factors involved and implications.

The aim of this study was to describe spatial and temporal variations in malaria epidemic risk in Ethiopia and to examine factors involved in relation to their implications for early warning and interpretation of geographical risk models. Forty-eight epidemic episodes were identified in various areas between September 1986 and August 1993 and factors that might have led to the events investigated using health facility records and weather data. The study showed that epidemics in specific years were associated with specific geographical areas.

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.