***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: Objectives Repellents do not kill mosquitoes - they simply reduce human-vector contact . Thus it is possible that individuals who do not use repellents but dwell close to repellent users experience more bites than otherwise . The objective of this study was to measure if diversion occurs from households that use repellents to those that do not use repellents . Methods The study was performed in three Tanzanian villages using 15%-DEET and placebo lotions . All households were given LLINs . Three coverage scenarios were investigated : complete coverage ( all households were given 15%-DEET ) , incomplete coverage ( 80 % of households were given 15%-DEET and 20 % placebo ) and no coverage ( all households were given placebo ) . A crossover study design was used and coverage scenarios were rotated weekly over a period of ten weeks . The placebo lotion was r and omly allocated to households in the incomplete coverage scenario . The level of compliance was reported to be close to 100 % . Mosquito densities were measured through aspiration of resting mosquitoes . Data were analysed using negative binomial regression models . Findings Repellent-users had consistently fewer mosquitoes in their dwellings . In villages where everybody had been given 15%-DEET , resting mosquito densities were fewer than half that of households in the no coverage scenario ( Incidence Rate Ratio [IRR]=0.39 ( 95 % confidence interval [ CI ] : 0.25 - 0.60 ) ; p<0.001 ) . Placebo-users living in a village where 80 % of the households used 15%-DEET were likely to have over four-times more mosquitoes ( IRR=4.17 ; 95 % CI : 3.08 - 5.65 ; p<0.001 ) resting in their dwellings in comparison to households in a village where nobody uses repellent . Conclusions There is evidence that high coverage of repellent use could significantly reduce man-vector contact but with incomplete coverage evidence suggests that mosquitoes are diverted from households that use repellent to those that do not . Therefore , if repellents are to be considered for vector control , strategies to maximise coverage are required INTRODUCTION American cutaneous leishmaniasis is endemic in Colombia , where approximately 6.000 new cases are reported every year . Current prevention and control measures are restricted to the diagnosis and treatment of cases . OBJECTIVE To evaluate the efficacy of a multifaceted intervention to prevent the transmission of Leishmania in the endemic focus of Tumaco , on the Pacific Coast of Colombia . MATERIAL S AND METHODS A group-r and omized trial was conducted . Twenty villages were matched according to prevalence of Leishmania infection , number of inhabitants and level of community participation , and then r and omly assigned to intervention or control . The intervention included deltamethrin-impregnated bednets , repellent ( 20 % diethyltoluamide and 0.5 % permethrin ) , modification of s and fly resting sites , and health education . Villages were under surveillance for one year and the use of the intervention measures monitored . The incidence of American cutaneous leishmaniasis and Leishmania infection in the two groups were compared , adherence to the intervention and adverse events were monitored , and the results were adjusted for village intraclass correlation . RESULTS Ten cases of American cutaneous leishmaniasis were confirmed in the intervention and 23 in the control group , OR = 0.42 , 95 % CI 0.14 - 1.26 . The intervention had a greater effect in children < 10 years old , in people living on the periphery of the village and in villages with a prevalence of infection in small children > 1 % . Adverse events associated with the use of the bednets and the repellent were reported in 2 % of the participants and were always mild . CONCLUSION Incident cases of American cutaneous leishmaniasis were reduced by 58 % in the intervention group . However , the small number of cases renders the effect estimate imprecise and precludes us to cl aim a protective effect for the intervention . Specific population s could be the targets of simpler and more cost-effective interventions in the future Background Mosquito vectors of malaria in Southeast Asia readily feed outdoors making malaria control through indoor insecticides such as long-lasting insecticidal nets ( LLINs ) and indoor residual spraying more difficult . Topical insect repellents may be able to protect users from outdoor biting , thereby providing additional protection above the current best practice of LLINs . Methods and Findings A double blind , household r and omised , placebo-controlled trial of insect repellent to reduce malaria was carried out in southern Lao PDR to determine whether the use of repellent and long-lasting insecticidal nets ( LLINs ) could reduce malaria more than LLINs alone . A total of 1,597 households , including 7,979 participants , were recruited in June 2009 and April 2010 . Equal group allocation , stratified by village , was used to r and omise 795 households to a 15 % DEET lotion and the remainder were given a placebo lotion . Participants , field staff and data analysts were blinded to the group assignment until data analysis had been completed . All households received new LLINs . Participants were asked to apply their lotion to exposed skin every evening and sleep under the LLINs each night . Plasmodium falciparum and P. vivax cases were actively identified by monthly rapid diagnostic tests . Intention to treat analysis found no effect from the use of repellent on malaria incidence ( hazard ratio : 1.00 , 95 % CI : 0.99–1.01 , p = 0.868 ) . A higher socio-economic score was found to significantly decrease malaria risk ( hazard ratio : 0.72 , 95 % CI : 0.58–0.90 , p = 0.004 ) . Women were also found to have a reduced risk of infection ( hazard ratio : 0.59 , 95 % CI : 0.37–0.92 , p = 0.020 ) . According to protocol analysis which excluded participants using the lotions less than 90 % of the time found similar results with no effect from the use of repellent . Conclusions This r and omised controlled trial suggests that topical repellents are not a suitable intervention in addition to LLINs against malaria amongst agricultural population s in southern Lao PDR . These results are also likely to be applicable to much of the Greater Mekong Sub-region . Trial Registration This trial is registered with number Objective To determine the effectiveness in reducing malaria of combining an insect repellent with insecticide treated bed nets compared with the nets alone in an area where vector mosquitoes feed in the early evening . Design A double blind , placebo controlled cluster-r and omised clinical study . Setting Rural villages and peri-urban districts in the Bolivian Amazon . Participants 4008 individuals in 860 households . Interventions All individuals slept under treated nets ; one group also used a plant based insect repellent each evening , a second group used placebo . Main outcome measure Episodes of Plasmodium falciparum or P vivax malaria confirmed by rapid diagnostic test or blood slide , respectively . Results We analysed 15 174 person months at risk and found a highly significant 80 % reduction in episodes of P vivax in the group that used treated nets and repellent ( incidence rate ratio 0.20 , 95 % confidence interval 0.11 to 0.38 , P<0.001 ) . Numbers of P falciparum cases during the study were small and , after adjustment for age , an 82 % protective effect was observed , although this was not significant ( 0.18 , 0.02 to 1.40 , P=0.10 ) . Reported episodes of fever with any cause were reduced by 58 % in the group that used repellent ( 0.42 , 0.31 to 0.56 , P<0.001 ) . Conclusions Insect repellents can provide protection against malaria . In areas where vectors feed in the early evening , effectiveness of treated nets can be significantly increased by using repellent between dusk and bedtime . This has important implication s in malaria vector control programmes outside Africa and shows that the combined use of treated nets and insect repellents , as advocated for most tourists travelling to high risk areas , is fully justified . Registration NCT 00144716 Background A mosquito repellent has the potential to prevent malaria infection , but there has been few studies demonstrating the effectiveness of combining this strategy with the highly effective long-lasting insecticidal nets ( LLINs ) . This study aim ed to determine the effect of combining community-based mosquito repellent with LLINs in the reduction of malaria . Methods A community-based clustered-r and omised trial was conducted in 16 rural villages with 1,235 households in southern Ethiopia between September and December of 2008 . The villages were r and omly assigned to intervention ( mosquito repellent and LLINs , eight villages ) and control ( LLINs alone , eight villages ) groups . Households in the intervention villages received mosquito repellent ( i.e. , Buzz-Off ® petroleum jelly , essential oil blend ) applied every evening . The baseline survey was followed by two follow-up surveys , at one month interval . The primary outcome was detection of Plasmodium falciparum , Plasmodium vivax , or both parasites , through microscopic examination of blood slides . Analysis was by intention to treat . Baseline imbalances and clustering at individual , household and village levels were adjusted using a generalized linear mixed model . Results 3,078 individuals in intervention and 3,004 in control group were enrolled into the study . Compared with the control arm , the combined use of mosquito repellent and LLINs  significantly reduced malaria infection of all types over time [ adjusted Odds Ratio ( aOR ) = 0.66 ; 95 % CI = 0.45 - 0.97 ] . Similarly , a substantial reduction in P. falciparum malaria infection during the follow-up surveys was observed in the intervention group ( aOR = 0.53 , 95 % CI = 0.31 - 0.89 ) . The protective efficacy of using mosquito repellent and LLINs against malaria infection of both P. falciparum/P. vivax and P. falciparum was 34 % and 47 % , respectively . Conclusions Daily application of mosquito repellent during the evening followed by the use of LLINs during bedtime at community level has significantly reduced malaria infection . The finding has strong implication particularly in areas where malaria vectors feed mainly in the evening before bedtime . Trial registration Clinical Trials.gov identifier : NCT01160809 Background Long-lasting insecticidal nets ( LLINs ) have limited effect on malaria transmitted outside of sleeping hours . Topical repellents have demonstrated reduction in the incidence of malaria transmitted in the early evening . This study assessed whether 15 % DEET topical repellent used in combination with LLINs can prevent greater malaria transmission than placebo and LLINs , in rural Tanzania . Methods A cluster-r and omized , placebo-controlled trial was conducted between July 2009 and August 2010 in a rural Tanzanian village . Sample size calculation determined that 10 clusters of 47 households with five people/household were needed to observe a 24 % treatment effect at the two-tailed 5 % significance level , with 90 % power , assuming a baseline malaria incidence of one case/person/year . Ten clusters each were r and omly assigned to repellent and control groups by lottery . A total of 4,426 individuals older than six months were enrolled . All households in the village were provided with an LLIN per sleeping space . Repellent and placebo lotion was replaced monthly . The main outcome was rapid diagnostic test (RDT)-confirmed malaria measured by passive case detection ( PCD ) . Incidence rate ratios were estimated from a Poisson model , with adjustment for potential confounders , determined a priori . According-to- protocol approach was used for all primary analyses . Results The  placebo group comprised 1972.3 person-years with 68.29 ( 95 % C.I 37.05 - 99.53 ) malaria cases/1,000 person-years . The repellent group comprised 1,952.8 person-years with 60.45 ( 95 % C.I 48.30 - 72.60 ) cases/1,000 person-years , demonstrating a non-significant 11.44 % reduction in malaria incidence rate in this group , ( Wilcoxon rank sum z = 0.529 , p = 0.596 ) . Principal components analysis ( PCA ) of the socio-economic status ( SES ) of the two groups demonstrated that the control group had a higher SES ( Pearson ’s chi square = 13.38 , p = 0.004 ) . Conclusions Lack of an intervention effect was likely a result of lack of statistical power , poor capture of malaria events or bias caused by imbalance in the SES of the two groups . Low malaria transmission during the study period could have masked the intervention effect and a larger study size was needed to increase discriminatory power . Alternatively , topical repellents may have no impact on malaria transmission in this scenario . Design and implementation of repellent intervention studies is discussed . Trial registration The trial was registered IS RCT N92202008 - http://www.controlled-trials.com/IS RCT In Vietnam , a large proportion of all malaria cases and deaths occurs in the central mountainous and forested part of the country . Indeed , forest malaria , despite intensive control activities , is still a major problem which raises several questions about its dynamics . A large-scale malaria morbidity survey to measure malaria endemicity and identify important risk factors was carried out in 43 villages situated in a forested area of Ninh Thuan 
    Output:
    
Conclusions Although topical repellents can provide individual protection against mosquitoes , the results of this meta- analysis indicate that topical repellents are unlikely to provide effective protection against malaria .