Use of insecticide-treated school uniforms for prevention of dengue in schoolchildren: a cost-effectiveness analysis

BACKGROUND

Dengue-related illness is a leading cause of hospitalization and death, particularly among children. Practical, acceptable and affordable measures are urgently needed to protect this age group. Schools where children spend most of their day is proposed as an ideal setting to implement preventive strategies against day-biting Aedes mosquitoes. The use of insecticide-treated school uniforms is a promising strategy currently under investigation.

METHODS

Using a decision-analytic model, we evaluated the cost-effectiveness of the use of insecticide-treated school uniforms for prevention of dengue, compared with a "do-nothing" alternative, in schoolchildren from the societal perspective. We explored how the potential economic value of the intervention varied under various scenarios of intervention effectiveness and cost, as well as dengue infection risk in school-aged children, using data specific to Thailand.

RESULTS

At an average dengue incidence rate of 5.8% per year in school-aged children, the intervention was cost-effective (ICER≤$16,440) in a variety of scenarios when the intervention cost per child was $5.3 or less and the intervention effectiveness was 50% or higher. In fact, the intervention was cost saving (ICER<0) in all scenarios in which the intervention cost per child was $2.9 or less per year and the intervention effectiveness was 50% or higher. The results suggested that this intervention would be of no interest to Thai policy makers when the intervention cost per child was $10.6 or higher per year regardless of intervention effectiveness (ICER>$16,440).

CONCLUSIONS

Our results present the potential economic value of the use of insecticide-treated uniforms for prevention of dengue in schoolchildren in a typical dengue endemic setting and highlight the urgent need for additional research on this intervention.

Acceptability of impregnated school uniforms for dengue control in Thailand: a mixed methods approach

Background

As current dengue control strategies have been shown to be largely ineffective in reducing dengue in school-aged children, novel approaches towards dengue control need to be studied. Insecticide-impregnated school uniforms represent an innovative approach with the theoretical potential to reduce dengue infections in school children.

Objectives

This study took place in the context of a randomised control trial (RCT) to test the effectiveness of permethrin-impregnated school uniforms (ISUs) for dengue prevention in Chachoengsao Province, Thailand. The objective was to assess the acceptability of ISUs among parents, teachers, and principals of school children involved in the trial.

Methodology

Quantitative and qualitative tools were used in a mixed methods approach. Class-clustered randomised samples of school children enrolled in the RCT were selected and their parents completed 321 self-administered questionnaires. Descriptive statistics and logistic regression were used to analyse the quantitative data. Focus group discussions and individual semi-structured interviews were conducted with parents, teachers, and principals. Qualitative data analysis involved content analysis with coding and thematic development.

Results

The knowledge and experience of dengue was substantial. The acceptability of ISUs was high. Parents (87.3%; 95% CI 82.9–90.8) would allow their child to wear an ISU and 59.9% (95% CI 53.7–65.9) of parents would incur additional costs for an ISU over a normal uniform. This was significantly associated with the total monthly income of a household and the educational level of the respondent. Parents (62.5%; 95% CI 56.6–68.1) indicated they would be willing to recommend ISUs to other parents.

Conclusions

Acceptability of the novel tool of ISUs was high as defined by the lack of concern along with the willingness to pay and recommend. Considering issues of effectiveness and scalability, assessing acceptability of ISUs over time is recommended.

Efficacy of Bacillus thuringiensis var. israelensis against malaria mosquitoes in northwestern Burkina Faso

Background

In Sub Saharan Africa malaria remains one of the major health problems and its control represents an important public health measure. Integrated malaria control comprises the use of impregnated mosquito nets and indoor residual spraying. The use of drugs to treat patients can create additional pressure on the equation of malaria transmission. Vector control may target the adult mosquitoes or their aquatic larval stages. Biological larvicides such as Bacillus thuringiensis israelensis (Bti) represent a promising approach to support malaria control programs by creating additional pressure on the equation of malaria transmission.

Methods

In this study we examined the efficacy of a water-dispersible granule formulation (WDG) of the biological larvicide Bti (VectoBac®) against wild Anopheles spp. larvae. Different concentrations of the larvicide were tested in standardized plastic tubs in the field against untreated controls. In weekly intervals tubs were treated with fixed concentrations of larvicide and the percentage reduction of larvae and pupae was calculated.

Results

All used concentrations successfully killed 100 percent of the larvae within 24 hours, while the higher concentrations showed a slightly prolonged residual effect. Natural reconolization of larvae took place after two and three days respectively, late instar larvae were not found before 5 days after treatment. For the higher concentrations, up to three days no new larvae were found, implicating that the residual effect of WDG in tropical conditions is approximately one to two days. The overall pupae reduction in treated tubs was 98.5%.

Conclusions

Biological larviciding with Bti can be a promising, additional tool in the fight against malaria in Africa. Environmental particularities in tropical Africa, first and foremost the rapid development of mosquitoes from oviposition to imago have to be taken into account before implementing such counter measures in national or international vector control programs. Nonetheless biological larviciding seems to be an appropriate measure for selected conditions, offering a significant contribution to the future of malaria control.

Use of traditional medicines to cope with climate-sensitive diseases in a resource poor setting in Bangladesh

BACKGROUND

This study aims to explore the use of traditional medicines to cope with climate sensitive diseases in areas vulnerable to climate change. We assessed the extent to which traditional or alternative medicines were used for the treatment of the climate sensitive diseases by villagers as part of their health-coping strategies.

METHODS

The study deployed a mixed-method research design to know the health-coping strategies of the people in a resource-poor setting.A cross sectional study was conducted from September 2010 to March 2011 among 450 households selected randomly in the districts of Rajshahi and Khulna, Bangladesh. The elder males or females of each household were interviewed. For qualitative methods, twelve focus group discussions (six with females and six with males) and fifteen key informant interviews were conducted by the research team, using interview guidelines on the use of traditional medicine.

RESULTS

Univariate analysis showed that the use of traditional medicines has increased among community members of all socio-economic and demographic backgrounds. Due to the increased incidence of disease and sickness respondents had to increase the use of their cultural means to cope with adverse health situations.

CONCLUSIONS

A systematic collection of knowledge on the use of traditional medicines to cope with climate-sensitive diseases can help the adaptation of communities vulnerable to climate change. In addition it can be instrumental in creating a directory of traditional medicine components used for specific diseases and highlight the effectiveness and relevance of traditional medicines as health-coping strategies. This may be useful for policymakers, researchers, and development partners to adapt existing health care policy in resource-limited contexts. It may also encourage WHO, national and international institutions, such as pharmaceutical companies, to carry out research investigating the effectiveness of these traditional medicines and integrate them with modern medicine. Overall, it could increase the health coping capacity of people in a resource-poor setting and contribute to their adaptation capabilities.

Biomass smoke in Burkina Faso: what is the relationship between particulate matter, carbon monoxide, and kitchen characteristics?

In Burkina Faso where cooking with biomass is very common, little information exists regarding kitchen characteristics and their impact on air pollutant levels. The measurement of air pollutants such as respirable particulate matter (PM10), an important component of biomass smoke that has been linked to adverse health outcomes, can also pose challenges in terms of cost and the type of equipment needed. Carbon monoxide could potentially be a more economical and simpler measure of air pollution. The focus of this study was to first assess the association of kitchen characteristics with measured PM10 and CO levels and second, the relationship of PM10 with CO concentrations, across these different kitchen characteristics in households in Nouna, Burkina Faso. Twenty-four-hour concentrations of PM10 (area) were measured with portable monitors and CO (area and personal) estimated using color dosimeter tubes. Data on kitchen characteristics were collected through surveys. Most households used both wood and charcoal burned in three-stone and charcoal stoves. Mean outdoor kitchen PM10 levels were relatively high (774 μg/m(3), 95 % CI 329-1,218 μg/m(3)), but lower than indoor concentrations (Satterthwaite t value, -6.14; p < 0.0001). In multivariable analyses, outdoor kitchens were negatively associated with PM10 (OR = 0.06, 95 % CI 0.02-0.16, p value <0.0001) and CO (OR = 0.03, 95 % CI 0.01-0.11, p value <0.0001) concentrations. Strong area PM10 and area CO correlations were found with indoor kitchens (Spearman's r = 0.82, p < 0.0001), indoor stove use (Spearman's r = 0.82, p < 0.0001), and the presence of a smoker in the household (Spearman's r = 0.83, p < 0.0001). Weak correlations between area PM10 and personal CO levels were observed with three-stone (Spearman's r = 0.23, p = 0.008) and improved stoves (Spearman's r = 0.34, p = 0.003). This indicates that the extensive use of biomass fuels and multiple stove types for cooking still produce relatively high levels of exposure, even outdoors, suggesting that both fuel subsidies and stove improvement programs are likely necessary to address this problem. These findings also indicate that area CO color dosimeter tubes could be a useful measure of area PM10 concentrations when levels are influenced by strong emission sources or when used in indoors. The weaker correlation observed between area PM10 and personal CO levels suggests that area exposures are not as useful as proxies for personal exposures, which can vary widely from those recorded by stationary monitors.

Insecticide-treated mosquito nets in rural Burkina Faso: assessment of coverage and equity in the wake of a universal distribution campaign

Insecticide-treated mosquito nets (ITNs) are an essential tool of the Roll Back Malaria strategy. An increasing number of African countries have embarked on mass distribution campaigns of long-lasting insecticide-treated nets (LLINs) with the ultimate goal of universal coverage. Such a national campaign with the goal of one ITN for every two people has been conducted in Burkina Faso in 2010. Our aim was to assess the coverage and equity effect of the universal distribution campaign of LLINs in Burkina Faso and to identify determinants of ITN ownership across households after the campaign. We evaluated its effects through comparison of data from two household surveys conducted in early 2010 (before the campaign) and early 2011 (after the campaign) on a representative rural district in north-western Burkina Faso. Data were collected on household characteristics (including socio-economic status) and ITN ownership. We used concentration curves and indices to compare ITN coverage indicators before and after the campaign and multilevel multivariate logistic regression to estimate factors associated with achievement of the universal coverage target in 2011. The survey included 1106 households in 2010 and 1094 in 2011. We found that the proportion of households with at least one ITN increased from 59% before the campaign to 99% afterwards, whereas the concentration index dropped from 0.087 (standard error (SE): 0.014) to 0.002 (SE: 0.002). Fifty-two per cent of households reached the target of one ITN for every two people per household, with the relevant concentration index at -0.031 (SE: 0.016). Eighty-six per cent of households owned at least one ITN for every three people. The main characteristics significantly associated with the targeted intra-household coverage were family size and distance to the health centre but not socio-economic status. In conclusion, despite not having fully met its target, the national LLIN campaign achieved a high level of coverage and fostered equity.

Health coping strategies of the people vulnerable to climate change in a resource-poor rural setting in Bangladesh

BACKGROUND

Among the many challenges faced by the people of Bangladesh, the effects of climate change are discernibly threatening, impacting on human settlement, agricultural production, economic development, and human health. Bangladesh is a low-income country with limited resources; its vulnerability to climate change has influenced individuals to seek out health coping strategies. The objectives of the study were to explore the different strategies/measures people employ to cope with climate sensitive diseases and sickness.

METHODS

A cross-sectional study was conducted among 450 households from Rajshahi and Khulna districts of Bangladesh selected through multi-stage sampling techniques, using a semi-structured questionnaire supplemented by 12 focus group discussions and 15 key informant interviews.

RESULTS

Respondents applied 22 types of primary health coping strategies to prevent climate related diseases and sickness. To cope with health problems, 80.8% used personal treatment experiences and 99.3% sought any treatments available at village level. The percentage of respondents that visited unqualified health providers to cope with climate induced health problems was quite high, namely 92.7% visited village doctors, 75.9% drug stores, and 67.3% self-medicated. Ninety per cent of the respondents took treatment from unqualified providers as their first choice. Public health facilities were the first choice of treatment for only 11.0% of respondents. On average, every household spent Bangladesh Currency Taka 9,323 per year for the treatment of climate sensitive diseases and sickness. Only 46% of health expenditure was managed from their savings. The rest, 54% expenditure, was supported by using 24 different sources, such as social capital and the selling of family assets. The rate of out-of-pocket payment was almost 100%.

CONCLUSION

People are concerned about climate induced diseases and sickness and sought preventive as well as curative measures to cope with health problems. The most common and widely used climate health coping strategies among the respondents included self-medicating and seeking the health service of unqualified private health care providers. Per family spending to cope with such health problems is expensive and completely based on out of pocket payment. There is no fund pooling, community funding or health insurance program in rural areas to support the health coping of the people. Policies are needed to reduce out-of-pocket payment, to improve the quality of the unqualified providers and to extend public health services at rural areas and support climate related health coping. Collection of such knowledge on climate related health coping strategies can allow researchers to study any specific issue on health coping, and policy makers to initiate effective climate related health coping strategies for climate vulnerable people.

The impact of insecticide-treated school uniforms on dengue infections in school-aged children: study protocol for a randomised controlled trial in Thailand

Background

There is an urgent need to protect children against dengue since this age group is particularly sensitive to the disease. Since dengue vectors are active mainly during the day, a potential target for control should be schools where children spend a considerable amount of their day. School uniforms are the cultural norm in most developing countries, worn throughout the day. We hypothesise that insecticide-treated school uniforms will reduce the incidence of dengue infection in school-aged children. Our objective is to determine the impact of impregnated school uniforms on dengue incidence.

Methods

A randomised controlled trial will be conducted in eastern Thailand in a group of schools with approximately 2,000 students aged 7–18 years. Pre-fabricated school uniforms will be commercially treated to ensure consistent, high-quality insecticide impregnation with permethrin. A double-blind, randomised, crossover trial at the school level will cover two dengue transmission seasons.

Discussion

Practical issues and plans concerning intervention implementation, evaluation, analysing and interpreting the data, and possible policy implications arising from the trial are discussed.

Trial registration

clinicaltrial.gov. Registration number: NCT01563640

Long-term effects of malaria prevention with insecticide-treated mosquito nets on morbidity and mortality in African children: randomised controlled trial

OBJECTIVE

The objective is to investigate the effect of malaria control with insecticide-treated mosquito nets (ITNs) regarding possible higher mortality in children protected during early infancy, due to interference with immunity development, and to assess long-term effects on malaria prevalence and morbidity.

METHODS

Between 2000 and 2002, a birth cohort was enrolled in 41 villages of a malaria holoendemic area in north-western Burkina Faso. All neonates (n = 3387) were individually randomised to ITN protection from birth (group A) vs. ITN protection from age 6 months (group B). Primary outcome was all-cause mortality. In 2009, a survey took place in six sentinel villages, and in 2010, a census was conducted in all study villages.

RESULTS

After a median follow-up time of 8.3 years, 443/3387 (13.1%) children had migrated out of the area and 484/2944 (16.4%) had died, mostly at home. Long-term compliance with ITN protection was good. There were no differences in mortality between study groups (248 deaths in group A, 236 deaths in group B; rate ratio 1.05, 95% CI: 0.889-1.237, P = 0.574). The survey conducted briefly after the rainy season in 2009 showed that more than 80% of study children carried asexual malaria parasites and up to 20% had clinical malaria.

CONCLUSION

Insecticide-treated mosquito net protection in early infancy is not a risk factor for mortality. Individual ITN protection does not sufficiently reduce malaria prevalence in high-transmission areas. Achieving universal ITN coverage remains a major challenge for malaria prevention in Africa.

Malnutrition in young children of rural Burkina Faso: comparison of survey data from 1999 with 2009

OBJECTIVE

For measurement of progress towards the Millennium Development Goal (MDG) 1, reliable data on nutrition indicators of specific countries are essential. Malnutrition is also the main determinant for childhood mortality, which is addressed in MDG 4.

METHODS

In the health and demographic surveillance area of Kossi Province in north-western Burkina Faso, nutritional parameters were compared in two cohorts of young children of the same age range from eight villages. Surveys took place in June and December of the year 1999 and 2009. A multivariate model was used to control for confounding variables.

RESULTS

For the 1999 study, data were analysed for 179 and 197 children who took part in the June and December survey respectively. In 2009, corresponding data were analysed for 460 and 409 children. Prevalence of underweight was highest in December 1999 (42.6%) and lowest in December 2009 (34.1%). After adjustment for age, sex and village, there was a slight but not always significant improvement in the z-scores of weight-for-age, weight-for-length, length-for-age, and mid-arm circumference over time.

CONCLUSIONS

The findings from this study confirm the still unacceptable high prevalence of malnutrition in young children of rural sub-Saharan Africa (SSA). Progress in the reduction of malnutrition remains slow on this continent making it rather unlikely that the corresponding MDGs will be achieved. Large-scale multi-sectoral community-based interventions are urgently needed for a sustainable improvement of child health in SSA.

DengueTools: innovative tools and strategies for the surveillance and control of dengue

Dengue fever is a mosquito-borne viral disease estimated to cause about 230 million infections worldwide every year, of which 25,000 are fatal. Global incidence has risen rapidly in recent decades with some 3.6 billion people, over half of the world's population, now at risk, mainly in urban centres of the tropics and subtropics. Demographic and societal changes, in particular urbanization, globalization, and increased international travel, are major contributors to the rise in incidence and geographic expansion of dengue infections. Major research gaps continue to hamper the control of dengue. The European Commission launched a call under the 7th Framework Programme with the title of 'Comprehensive control of Dengue fever under changing climatic conditions'. Fourteen partners from several countries in Europe, Asia, and South America formed a consortium named 'DengueTools' to respond to the call to achieve better diagnosis, surveillance, prevention, and predictive models and improve our understanding of the spread of dengue to previously uninfected regions (including Europe) in the context of globalization and climate change.The consortium comprises 12 work packages to address a set of research questions in three areas:Research area 1: Develop a comprehensive early warning and surveillance system that has predictive capability for epidemic dengue and benefits from novel tools for laboratory diagnosis and vector monitoring.Research area 2: Develop novel strategies to prevent dengue in children.Research area 3: Understand and predict the risk of global spread of dengue, in particular the risk of introduction and establishment in Europe, within the context of parameters of vectorial capacity, global mobility, and climate change.In this paper, we report on the rationale and specific study objectives of 'DengueTools'. DengueTools is funded under the Health theme of the Seventh Framework Programme of the European Community, Grant Agreement Number: 282589 Dengue Tools.

Falciparum malaria in young children of rural Burkina Faso: comparison of survey data in 1999 with 2009

Background

Roll Back Malaria (RBM) interventions such as insecticide-treated mosquito nets (ITN) and artemisinin-based combination therapy (ACT) have become implemented with different velocities in the endemic countries of sub-Saharan Africa (SSA) in recent years. There is conflicting evidence on how much can be achieved under real life conditions with the current interventions in the highly endemic savannah areas of SSA.

Methods

The study took place in a rural area of north-western Burkina Faso, which was defined as holoendemic in 1999. Clinical and parasitological data were compared in two cohorts of young children of the same age range from eight villages. Surveys took place in June and December of the year 1999 and 2009 respectively.

Results

Prevalence of mosquito net use increased from 22% in 1999 to 73% in 2009, with the majority of nets being ITNs in 2009. In 2009, P. falciparum prevalence was significantly lower compared to 1999 (overall reduction of 22.8%).

Conclusions

The reduction in malaria prevalence in young children observed between 1999 and 2009 in a rural and formerly malaria holoendemic area of Burkina Faso is likely attributable to the increase in ITN availability and utilization over time.

Determinants of utilisation of maternal care services after the reduction of user fees: a case study from rural Burkina Faso

OBJECTIVE

To identify determinants of utilisation for antenatal care (ANC) and skilled attendance at birth after a substantial reduction in user fees.

METHODS

The study was conducted in the Nouna Health District in north-western Burkina Faso in early 2009. Data was collected by means of a representative survey on a sample of 435 women who reported a pregnancy in the prior 12 months. Two independent logit models were used to assess the determinants of (a) ANC utilisation (defined as having attended at least 3 visits) and (b) skilled assistance at birth (defined as having delivered in a health facility).

RESULTS

76% of women had attended at least 3 ANC visits and 72% had delivered in a facility. Living within 5 km from a facility was positively associated, while animist religion, some ethnicities, and household wealth were negatively associated with ANC utilisation. Some ethnicities, living within 5 km from a health facility, and having attended at least 3 ANC visits were positively associated with delivering in a facility.

CONCLUSIONS

User fee alleviation secured equitable access to care across socio-economic groups, but alone did not ensure that all women benefited from ANC and from skilled attendance at birth. Investments in policies to address barriers beyond financial ones are urgently needed.

The Health and Demographic Surveillance System (HDSS) in Nouna, Burkina Faso, 1993-2007

The Nouna Health and Demographic Surveillance System (HDSS) is located in rural Burkina Faso and has existed since 1992. Currently, it has about 78,000 inhabitants. It is a member of the International Network for the Demographic Evaluation of Populations and Their Health in Developing Countries (INDEPTH), a global network of members who conducts longitudinal health and demographic evaluation of populations in low- and middle-income countries. The health facilities consist of one hospital and 13 basic health centres (locally known as CSPS). The Nouna HDSS has been used as a sampling frame for numerous studies in the fields of clinical research, epidemiology, health economics, and health systems research. In this paper we review some of the main findings, and we describe the effects that almost 20 years of health research activities have shown in the population in general and in terms of the perception, economic implications, and other indicators. Longitudinal data analyses show that childhood, as well as overall mortality, has significantly decreased over the observation period 1993–2007. The under-five mortality rate dropped from about 40 per 1,000 person-years in the mid-1990s to below 30 per 1,000 in 2007. Further efforts are needed to meet goal four of the Millennium Development Goals, which is to reduce the under-five mortality rate by two-thirds between 1990 and 2015.

The effects of zooprophylaxis and other mosquito control measures against malaria in Nouna, Burkina Faso

Background

In the absence of large scale, organized vector control programmes, individual protective measures against mosquitoes are essential for reducing the transmission of diseases like malaria. Knowledge of the types and effectiveness of mosquito control methods used by households can aid in the development and promotion of preventive measures.

Methods

A matched, population-based case control study was carried out in the semi-urban region of Nouna, Burkina Faso. Surveys and mosquito captures were conducted for each participating household. Data were analysed using conditional logistic regression and Pearson's product-moment correlations.

Results

In Nouna, Burkina Faso, the main types of reported mosquito control measures used included sleeping under bed nets (insecticide-treated and untreated) and burning mosquito coils. Most of the study households kept animals within the compound or house at night. Insecticide house sprays, donkeys, rabbits and pigs were significantly associated with a reduced risk of malaria only in univariate analyses.

Conclusion

Given the conflicting results of the effects of zooprophylaxis from previous studies, other community-based preventive measures, such as bed nets, coils and insecticide house-spraying, may be of more benefit.

Transmission dynamics of pulmonary tuberculosis between autochthonous and immigrant sub-populations

Background

The overall incidence of tuberculosis (TB) in Western Europe has been declining since the 19^th Century. However, immigrant sub-groups from high-prevalence countries are slowing down this trend. The aim of this study was to describe how immigration influences TB transmission in Germany. For that we prospectively investigated the dynamics of TB transmission between TB high-prevalence immigrant and TB low-prevalence local populations with molecular epidemiological methods and conventional contact investigations. Besides, we assessed transmission in relation to social mixing using an innovative tool that measures the integration of immigrants into the local social environment.

Methods

A prospective study of confirmed culture positive cases of pulmonary TB and their contacts was carried out in a German federal state from 2003 to 2005. Data for the study included: 1) case data routinely collected by the local public health staff and transmitted to the state health office and the national surveillance centre, 2) a study questionnaire designed to capture social interactions of relevance for TB transmission and 3) molecular genotyping data (IS6110 DNA fingerprint and spoligotyping). The proportion of German cases caused by foreign-born cases, and vice versa, was estimated and an integration index was computed using a selected set of questions from the study questionnaire.

Results

A total of 749 cases of culture-positive pulmonary tuberculosis voluntarily enrolled in the study, representing 57.8% of all registered cases diagnosed over the study period. Data that included study questionnaire and DNA fingerprinting were available for 41% (n = 308) of the study participants. Forty-seven clusters, defined as a least two cases infected by the same TB strains, were identified by molecular methods and included 132 (17%) of the study participants. Epidemiological links were identified for 28% of the clusters by conventional epidemiological data. In mixed clusters, defined as clusters including German and foreign-born individuals, the probability of cases to be caused by foreign-born cases was estimated at 18.3%. We observed a trend to mixed clusters with increasing time spent by immigrants in the host country. This group also presented comparatively higher integration indexes than immigrants in immigrant-only clusters.

Conclusion

Our results confirm the findings of other studies that there is no significant TB transmission from TB high-prevalence immigrant to TB low-prevalence autochthonous population. This may be explained by the good performance of tuberculosis screening programmes for certain groups arriving in Germany from high- prevalence countries, by a low degree of mixing of immigrants with the local population or by a combination of both.

Access to malaria treatment in young children of rural Burkina Faso

Background

Effective and timely treatment is an essential aspect of malaria control, but remains a challenge in many parts of sub-Saharan Africa. The objective of this study was to describe young children's access to malaria treatment in Nouna Health District, Burkina Faso.

Methods

In February/March 2006, a survey was conducted in a representative sample of 1,052 households.

Results

Overall 149/1052 (14%) households reported the current possession of anti-malarial medicine, which was significantly associated with urban area, literacy of household head, having young children, and high socio-economic status. Out of a total of 802 children under five years, at least one malaria episode was reported for 239 (30%) within the last month. Overall 95% of children received treatment, either modern (72%), traditional (18%) or mixed (5%). Most of the medicines were provided as home treatment by the caregiver and half of children received some type of modern treatment within 24 hours of the occurrence of first symptoms. Despite a recent policy change to artemisinin-based combination therapy, modern anti-malarials consisted mainly of chloroquine (93%). Modern drugs were obtained more often from a health facility in localities with a health facility compared to those without (60% vs. 25.6%, p < 0.001). In contrast, beside informal providers, volunteer community health workers (CHW) were the main source of modern medicine in localities without a health centre (28% vs. 3%, p < 0.001).

Conclusion

Access to modern health services providing quality controlled effective combination therapies against malaria needs to be strengthened in rural Africa, which should include a re-investigation of the role of CHW 30 years after Alma Ata.

Local scale prediction of Plasmodium falciparum malaria transmission in an endemic region using temperature and rainfall

Background

To support malaria control strategies, prior knowledge of disease risk is necessary. Developing a model to explain the transmission of malaria, in endemic and epidemic regions, is of high priority in developing health system interventions. We develop, fit and validate a non-spatial dynamic model driven by meteorological conditions that can capture seasonal malaria transmission dynamics at the village level in a malaria holoendemic area of north-western Burkina Faso.

Methods

A total of 676 children aged 6–59 months took part in this study. Trained interviewers visited children at home weekly from December 2003 to November 2004 for Plasmodium falciparum malaria infection detection. Anopheles daily biting rate, mortality rate and growth rate were evaluated. Digital meteorological stations measured ambient temperature, humidity and rainfall in each site.

Results

The overall P. falciparum malaria infection incidence was 1.1 episodes per person year. There was strong seasonal variation in P. falciparum malaria infection incidence with a peak observed in August and September, corresponding to the rainy season and a high number of mosquitoes. The model estimates of monthly mosquito abundance and the incidence of malaria infection correlated well with observed values. The fit was sensitive to daily mosquito survival and daily human parasite clearance.

Conclusion

The model has demonstrated potential for local scale seasonal prediction of P. falciparum malaria infection. It could therefore be used to understand malaria transmission dynamics using meteorological parameters as the driving force and to help district health managers in identifying high-risk periods for more focused interventions.

Effect of meteorological factors on clinical malaria risk among children: an assessment using village-based meteorological stations and community-based parasitological survey

Background

Temperature, rainfall and humidity have been widely associated with the dynamics of malaria vector population and, therefore, with spread of the disease. However, at the local scale, there is a lack of a systematic quantification of the effect of these factors on malaria transmission. Further, most attempts to quantify this effect are based on proxy meteorological data acquired from satellites or interpolated from a different scale. This has led to controversies about the contribution of climate change to malaria transmission risk among others. Our study addresses the original question of relating meteorological factors measured at the local scale with malaria infection, using data collected at the same time and scale.

Methods

676 children (6–59 months) were selected randomly from three ecologically different sites (urban and rural). During weekly home visits between December 1, 2003, and November 30, 2004, fieldworkers tested children with fever for clinical malaria. They also collected data on possible confounders monthly. Digital meteorological stations measured ambient temperature, humidity, and rainfall in each site. Logistic regression was used to estimate the risk of clinical malaria given the previous month's meteorological conditions.

Results

The overall incidence of clinical malaria over the study period was 1.07 episodes per child. Meteorological factors were associated with clinical malaria with mean temperature having the largest effect.

Conclusion

Temperature was the best predictor for clinical malaria among children under five. A systematic measurement of local temperature through ground stations and integration of such data in the routine health information system could support assessment of malaria transmission risk at the district level for well-targeted control efforts.

Micro-epidemiology of Plasmodium falciparum malaria: Is there any difference in transmission risk between neighbouring villages?

BACKGROUND

Malaria control strategies are designed as a solution for either the whole region or the whole country and are assumed to suit every setting. There is a need to shift from this assumption because transmission may be different from one local setting to another. The aim of this study was to assess the risk of clinical malaria given the village of residence among under-five children in rural north-western Burkina Faso.

METHODS

867 children (6-59 months) were randomly selected from four sites. Interviewers visited the children weekly at home over a one-year period and tested them for fever. Children with fever were tested for malaria parasites. An episode of clinical malaria was defined as fever (axillary temperature > or = 37.5 degrees C) + parasites density > or = 5,000 parasites/microl. Logistic regression was used to assess the risk of clinical malaria among children at a given site of residence.

RESULTS

Children accumulated 758 person years (PYs). Overall, 597 episodes of clinical malaria were observed, giving an incidence rate of 0.79 per PY. The risk of clinical malaria varied amongst the four sites. Taking one village as reference the odds ratio for the other three sites ranged from 0.66; 95% CI: 0.44-0.98 to 1.49; 95% CI: 1.10-2.01.

CONCLUSION

Malaria control strategies should be designed to fit the local context. The heterogeneity of transmission should be assessed at the district level to allow cost-effective resource allocation that gives priority to locations with high risk. Functional routine health information systems could provide the necessary data for context specific risk assessment.

Biomass solid fuel and acute respiratory infections: The ventilation factor

Biomass solid fuel smoke is linked to acute respiratory infections (ARI). In future, its use will likely increase among poor households, and better ventilation is one important measure that can reduce this health impact. The authors aimed to study the extent to which improvement in ventilation-related factors reduces the fraction of ARI attributable to exposure to biomass smoke in children under 5 years old. An explorative study was carried out in 2004 by applying a questionnaire on 51 households randomly selected from a health district in Burkina Faso. The prevalence of exposure in the population was estimated using ventilation coefficients, and proportions of households with different stove types and locations. An attributable fraction of 0.56 (95% CI: 0.47-0.62) was estimated using the traditional formula for attributable fraction, and 0.26 (95% CI: 0.19-0.31) after weighting exposure by ventilation coefficients, stove type and location. Two scenarios were created: (1) Assuming that most households cooked inside, the fraction becomes 0.54 (95% CI: 0.45-0.61). (2) Assuming that indoor ventilation and cooking device are improved by 20%, the fractions decreased slightly. Improving cooking devices and indoor ventilation reduces the fraction of ARI in children under 5 years attributable to exposure to biomass smoke, but a higher reduction is achieved by cooking outdoors.

Temperature-driven Campylobacter seasonality in England and Wales

Campylobacter incidence in England and Wales between 1990 and 1999 was examined in conjunction with weather conditions. Over the 10-year interval, the average annual rate was determined to be 78.4 +/- 15.0 cases per 100,000, with an upward trend. Rates were higher in males than in females, regardless of age, and highest in children less than 5 years old. Major regional differences were detected, with the highest rates in Wales and the southwest and the lowest in the southeast. The disease displayed a seasonal pattern, and increased campylobacter rates were found to be correlated with temperature. The most marked seasonal effect was observed for children under the age of 5. The seasonal pattern of campylobacter infections indicated a linkage with environmental factors rather than food sources. Therefore, public health interventions should not be restricted to food-borne approaches, and the epidemiology of the seasonal peak in human campylobacter infections may best be understood through studies in young children.