***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background In many parts of continental Africa house construction does not appear to impede entry of malaria vectors and , given their generally late biting cycle , the great majority of transmission takes place indoors . In contrast , many houses in São Tomé , 140 km off the coast of Gabon , are raised on stilts and built of wooden planks . Building on stilts is a time-honoured , but largely untested , way of avoiding mosquito bites . Exposure may also be affected by mosquito activity times and age composition of host-seeking females . A study was therefore undertaken on the isl and of São Tomé to determine if exposure to Anopheles gambiae , the only vector on the isl and , varied with house construction or time of the night . Methods A series of all-night l and ing collection s were undertaken out of doors at ground level , inside houses at ground level , on the ver and as of , and inside houses built on stilts . The gonotrophic age of an unselected sample of insects from the first three hours of l and ing collection ( 18:00–21:00 ) was determined by dissection . In addition , 1,149 miniature light-trap collection s were obtained from 125 houses in the study area . Numbers collected were related to house construction . Results Biting of An . gambiae took place primarily outside at ground level . Less than one third of biting occurred inside houses . Houses built on stilts had half the number of An . gambiae in them compared to those built at ground level . Conversely houses with an eaves gap had more An . gambiae in them than houses without such a gap . Gonotrophic age did not affect house entry rates in An . gambiae . House construction affected Culex quinquefasciatus less than An . gambiae . Mean density per house , derived from a series of 1,490 r and omly assigned light-trap collection s , was over-dispersed with 18 % of houses having 70 % of the vectors . Conclusion House construction plays an important role in determining exposure to malaria vectors in São Tomé . Neighbours can have very different exposure levels . Recommendations for improvement in control are given Background One of the best ways to control the transmission of malaria is by breaking the vector-human link , either by reducing the effective population size of mosquitoes or avoiding infective bites . Reducing house entry rates in endophagic vectors by obstructing openings is one simple way of achieving this . Mosquito netting has previously been shown to have this effect . More recently different material s that could also be used have come onto the market . Therefore , a pilot study was conducted to investigate the protective effect of three types of material against Anopheles funestus and Anopheles gambiae s.l entry into village houses in Mozambique when applied over the large opening at the gables and both gables and eaves . Methods A two-step intervention was implemented in which the gable ends of houses ( the largest opening ) were covered with one of three material s ( four year old mosquito bed nets ; locally purchased untreated shade cloth or deltamethrin-impregnated shade cloth ) followed by covering both gable ends and eaves with material . Four experimental rounds ( each of three weeks duration ) , from four houses r and omly assigned to be a control or to receive one of the three intervention material s , were undertaken from March to August 2010 in the village of Furvela in southern Mozambique .  Mosquito entry rates were assessed by light-trap collection and the efficacy of the different material s was determined in terms of incidence rate ratio ( IRR ) , obtained through a Generalized Estimating Equations ( GEE ) , of mosquito entry in a treated house compared to the untreated ( control ) house . Results Altogether 9,692 An . funestus and 1,670 An . gambiae s.l . were collected . Houses treated with mosquito netting or the untreated shade cloth had 61.3 % [ IRR = 0.39 ( 0.32 - 0.46 ) ; P < 0.0001 ] and 70 % [ IRR = 0.30 ( 0.25 – 0.37 ) ; P < 0.001 ] fewer An . funestus in relation to untreated houses , but there was no difference in An . funestus in houses treated with the deltamethrin-impregnated shade cloth [ IRR = 0.92 ( 0.76 –1.12 ) ; P = 0.4 ] compared to untreated houses . Houses treated with mosquito netting reduced entry rates of An . gambiae s.l , by 84 % [ IRR = 0.16 ( 0.10 – 0.25 ) ; P < 0.001 ] , whilst untreated shade cloth reduced entry rates by 69 % [ IRR = 0.31 ( 0.19 –0.53 ) ; P < 0.001 ] and entry rates were reduced by 76 % [ IRR = 0.24 ( 0.15 0.38 ) ; P < 0.001 ] in houses fitted with deltamethrin-impregnated shade cloth OBJECTIVE To identify risk factors for  uncomplicated malaria in highl and areas of East Africa at higher risk of malaria epidemics , in order to design appropriate interventions . METHODS Prospect i ve , population -based , case-control study in the N and i Hills , a highl and area of western Kenya , to identify environmental , sociodemographic and behavioural factors associated with clinical malaria . Data were collected using field observation , a structured question naire , and a global positioning system device . RESULTS We interviewed 488 cases of slide-confirmed malaria and 980 age-matched controls . Multivariate analyses associated higher malaria risk with living < 250 m of a forest [ OR = 3.3 ( 95 % CI 1.5 , 7.1 ) ] , < 250 m of a swamp [ 2.8 ( 1.3 , 5.9 ) ] , < 200 m of maize fields [ 2.0 ( 1.2 , 3.4 ) ] , in the absence of trees < 200 m [ 1.6 ( 1.2 , 2.2 ) ] , on flat l and [ 1.6 ( 1.2 , 2.2 ) ] , in houses without ceilings [ 1.5 ( 1.1 , 2.2 ) ] , in houses with a separate kitchen building [ 1.8 ( 1.4 , 2.3 ) ] and in households where the female household head had no education [ 1.9 ( 1.1 , 3.1 ) ] . Travelling out of the study site [ 2.2 ( 1.2 , 4.1 ) ] was also associated with increased risk . CONCLUSIONS ; In this East African highl and area , risk of developing uncomplicated malaria was multifactorial with a risk factor profile similar to that in endemic regions . Households within close proximity to forest and swamp borders are at higher risk of malaria and should be included in indoor residual spraying campaigns Background Several studies conducted in Northeast Tanzania have documented declines in malaria transmission even before interventions were scaled up . One explanation for these reductions may be the changes in socio-environmental conditions associated with economic development , and in particular improvements in housing construction . Objective This analysis seeks to identify ( 1 ) risk factors for malaria incidence among young children and ( 2 ) household and environmental factors associated with mosquito vector numbers collected in the child ’s sleeping area . Both analyses focus on housing construction quality as a key determinant . Methodology For 435 children enrolled in a larger trial of intermittent preventive treatment for malaria in infants in the Korogwe District in Tanga , Northeastern Tanzania , detailed information on their dwelling characteristics were collected in the last year of the trial . Principal components analysis was used to construct an index of housing structure quality and converted to quintile units for regression analysis . Univariate and multivariate r and om effects negative binomial regressions were used to predict risk factors for child malaria incidence and the mean total number of indoor female Anopheles gambiae and funestus mosquitoes collected per household across three occasions . Findings Building material s have substantially improved in Korogwe over time . Multivariate regressions showed that residing in rural areas ( versus urban ) increased malaria incidence rates by over three-fold and mean indoor female A. gambiae and funestus numbers by nearly two-fold . Compared to those residing in the lowest quality houses , children residing in the highest quality houses had one-third lower malaria incidence rates , even when wealth and rural residence were controlled for . Living in the highest quality houses reduced vector numbers while having cattle near the house significantly increased them . Conclusions Results corroborate findings from other studies that show associations between malaria incidence and housing quality ; associations were concentrated amongst the highest quality houses Background Underst and ing the role of local environmental risk factors for malaria in holo-endemic , poverty-stricken setting s will be critical to more effectively implement- interventions aim ed at eventual elimination . Household-level environmental drivers of malaria risk during the dry season were investigated in rural southern Malawi among children < five years old in two neighbouring rural Traditional Authority ( TA ) regions dominated by small-scale agriculture . Methods Ten villages were r and omly selected from TA Sitola ( n = 6 ) and Nsamala ( n = 4 ) . Within each village , during June to August 2011 , a census was conducted of all households with children under-five and recorded their locations with a geographic position system ( GPS ) device . At each participating house , a nurse administered a malaria rapid diagnostic test ( RDT ) to  children under five years of age , and a question naire to parents . Environmental data were collected for each house , including l and cover within 50-m radius . Variables found to be significantly associated with P. falciparum infection status in bivariate analysis were included in generalized linear models , including multivariate logistic regression ( MLR ) and multi-level multivariate logistic regression ( MLLR ) . Spatial clustering of RDT status , environmental factors , and Pearson residuals from MLR and MLLR were analysed using the Getis-Ord Gi * statistic . Results Of 390 children enrolled from six villages in Sitola ( n = 162 ) and four villages in Nsamala ( n = 228 ) , 45.6 % tested positive ( n = 178 ) for Plasmodium infection by RDT . The MLLR modelled the statistical relationship of Plasmodium positives and household proximity to agriculture ( < 25-m radius ) , controlling for the child sex and age ( in months ) , bed net ownership , elevation , and r and om effects intercepts for village and TA-level unmeasured factors . After controlling for area affects in MLLR , proximity to active agriculture remained a significant predictor of positive RDT result ( OR 2.80 , 95 % CI 1.41 - 5.55 ) . Mapping of Pearson residuals from MLR showed significant clustering ( Gi * z > 2.58 , p < 0.01 ) predominantly within TA Sitola , while residuals from MLLR showed no such clustering . Conclusion This study provides evidence for significant , dry-season heterogeneity of malaria prevalence strongly linked to peridomestic l and use , and particularly of elevated risk associated with nearby crop production Background Identification and better underst and ing of potential risk factors for malaria are important for targeted and cost-effective health interventions . Housing conditions have been suggested as one of the potential risk factors . This study aims to further investigate this risk factor , and is focused on the effect of the type of roof on Plasmodium falciparum infection among children below five years in the North West of Burkina Faso . Methods In a cross-sectional study design , 661 children aged six to 60 months were r and omly selected from three rural and one semi-urban site at the end of the rainy season ( November 2003 ) . The children were screened for fever and tested for Plasmodium falciparum infection . In addition , data on bed net use and house characteristics was collected from the household were each child lived . Using adjusted odds ratios , children living in house roofed with iron-sheet were compared with those in house with mud or grass roof . Results Overall P. falciparum infection prevalence was 22.8 % with a significant variation between ( Chi-square , p < 0.0001 ) . The prevalence in Cissé ( 33.3 % ) and Goni ( 30.6 % ) were twice times more than in Nouna ( 15.2 % ) and Kodougou ( 13.2 % ) . After adjusting for age , sex , use of bed net and housing conditions , children living in houses with mud roofs had significantly higher risk of getting P. falciparum infection compared to those living in iron-sheet roofed houses ( Odds Ratio 2.6 ; 95 % Confidence Interval , 1.4–4.7 ) . Conclusion These results suggest that house characteristics should be taken into consideration when design ing health intervention against P. falciparum infection and particular attention should be paid to children living in houses with mud roofs Background In the pre-intervention year of a r and omized controlled trial investigating the protective effects of house screening against malaria-transmitting vectors , a multi-factorial risk factor analysis study was used to identify factors that influence mosquito house entry . Methods Mosquitoes were sample d using  CDC light traps  in 976 houses , each on one night , in Farafenni town and surrounding villages during the malaria-transmission season in The Gambia . Catches from individual houses were both ( a ) left unadjusted and ( b ) adjusted relative to the number of mosquitoes caught in four sentinel houses that were operated nightly throughout the period , to allow for night-to-night variation . Houses were characterized by location , architecture , human occupancy and their mosquito control activities , and the number and type of domestic animals within the compound . Results 106,536 mosquitoes were caught , of which 55 % were Anopheles gambiae sensu lato , the major malaria vectors in the region . There were seven fold higher numbers of An . gambiae s.l . in the 
    Output:
    
Conclusions Despite low quality evidence , the direction and consistency of effects indicate that housing is an important risk factor for malaria .