Chemoprophylaxis and intermittent treatment for preventing malaria in children

Intermittent preventive treatment for malaria in infants

BACKGROUND

Intermittent preventive treatment could help prevent malaria in infants (IPTi) living in areas of moderate to high malaria transmission in sub-Saharan Africa. The World Health Organization (WHO) policy recommended IPTi in 2010, but its adoption in countries has been limited.

OBJECTIVES

To evaluate the effects of intermittent preventive treatment (IPT) with antimalarial drugs to prevent malaria in infants living in malaria-endemic areas.

SEARCH METHODS

We searched the following sources up to 3 December 2018: the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (the Cochrane Library), MEDLINE (PubMed), Embase (OVID), LILACS (Bireme), and reference lists of articles. We also searched the metaRegister of Controlled Trials (mRCT) and the WHO International Clinical Trials Registry Platform (ICTRP) portal for ongoing trials up to 3 December 2018.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared IPT to placebo or no intervention in infants (defined as young children aged between 1 to 12 months) in malaria-endemic areas.

DATA COLLECTION AND ANALYSIS

The primary outcome was clinical malaria (fever plus asexual parasitaemia). Two review authors independently assessed trials for inclusion, evaluated the risk of bias, and extracted data. We summarized dichotomous outcomes and count data using risk ratios (RR) and rate ratios respectively, and presented all measures with 95% confidence intervals (CIs). We extracted protective efficacy values and their 95% CIs; when an included trial did not report this data, we calculated these values from the RR or rate ratio with its 95% CI. Where appropriate, we combined data in meta-analyses and assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 12 trials that enrolled 19,098 infants; all were conducted in sub-Saharan Africa. Three trials were cluster-RCTs. IPTi with sulfadoxine-pyrimethamine (SP) was evaluated in 10 trials from 1999 to 2013 (n = 15,256). Trials evaluating ACTs included dihydroartemisinin-piperaquine (1 trial, 147 participants; year 2013), amodiaquine-artesunate (1 study, 684 participants; year 2008), and SP-artesunate (1 trial, 676 participants; year 2008). The earlier studies evaluated IPTi with SP, and were conducted in Tanzania (in 1999 and 2006), Mozambique (2004), Ghana (2004 to 2005), Gabon (2005), Kenya (2008), and Mali (2009). One trial evaluated IPTi with amodiaquine in Tanzania (2000). Later studies included three conducted in Kenya (2008), Tanzania (2008), and Uganda (2013), evaluating IPTi in multiple trial arms that included artemisinin-based combination therapy (ACT). Although the effect size varied over time and between drugs, overall IPTi impacts on the incidence of clinical malaria overall, with a 30% reduction (rate ratio 0.70, 0.62 to 0.80; 10 studies, 10,602 participants). The effect of SP appeared to attenuate over time, with trials conducted after 2009 showing little or no effect of the intervention. IPTi with SP probably resulted in fewer episodes of clinical malaria (rate ratio 0.78, 0.69 to 0.88; 8 trials, 8774 participants, moderate-certainty evidence), anaemia (rate ratio 0.82, 0.68 to 0.98; 6 trials, 7438 participants, moderate-certainty evidence), parasitaemia (rate ratio 0.66, 0.56 to 0.79; 1 trial, 1200 participants, moderate-certainty evidence), and fewer hospital admissions (rate ratio 0.85, 0.78 to 0.93; 7 trials, 7486 participants, moderate-certainty evidence). IPTi with SP probably made little or no difference to all-cause mortality (risk ratio 0.93, 0.74 to 1.15; 9 trials, 14,588 participants, moderate-certainty evidence). Since 2009, IPTi trials have evaluated ACTs and indicate impact on clinical malaria and parasitaemia. A small trial of DHAP in 2013 shows substantive effects on clinical malaria (RR 0.42, 0.33 to 0.54; 1 trial, 147 participants, moderate-certainty evidence) and parasitaemia (moderate-certainty evidence).

AUTHORS' CONCLUSIONS

In areas of sub-Saharan Africa, giving antimalarial drugs known to be effective against the malaria parasite at the time to infants as IPT probably reduces the risk of clinical malaria, anaemia, and hospital admission. Evidence from SP studies over a 19-year period shows declining efficacy, which may be due to increasing drug resistance. Combinations with ACTs appear promising as suitable alternatives for IPTi.

Intermittent preventive treatment for malaria in infants

BACKGROUND

Intermittent preventive treatment could help prevent malaria in infants (IPTi) living in areas of moderate to high malaria transmission in sub-Saharan Africa. The World Health Organization (WHO) policy recommended IPTi in 2010, but its adoption in countries has been limited.

OBJECTIVES

To evaluate the effects of intermittent preventive treatment (IPT) with antimalarial drugs to prevent malaria in infants living in malaria-endemic areas.

SEARCH METHODS

We searched the following sources up to 3 December 2018: the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (the Cochrane Library), MEDLINE (PubMed), Embase (OVID), LILACS (Bireme), and reference lists of articles. We also searched the metaRegister of Controlled Trials (mRCT) and the WHO International Clinical Trials Registry Platform (ICTRP) portal for ongoing trials up to 3 December 2018.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared IPT to placebo or no intervention in infants (defined as young children aged between 1 to 12 months) in malaria-endemic areas.

DATA COLLECTION AND ANALYSIS

The primary outcome was clinical malaria (fever plus asexual parasitaemia). Two review authors independently assessed trials for inclusion, evaluated the risk of bias, and extracted data. We summarized dichotomous outcomes and count data using risk ratios (RR) and rate ratios respectively, and presented all measures with 95% confidence intervals (CIs). We extracted protective efficacy values and their 95% CIs; when an included trial did not report this data, we calculated these values from the RR or rate ratio with its 95% CI. Where appropriate, we combined data in meta-analyses and assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 12 trials that enrolled 19,098 infants; all were conducted in sub-Saharan Africa. Three trials were cluster-RCTs. IPTi with sulfadoxine-pyrimethamine (SP) was evaluated in 10 trials from 1999 to 2013 (n = 15,256). Trials evaluating ACTs included dihydroartemisinin-piperaquine (1 trial, 147 participants; year 2013), amodiaquine-artesunate (1 study, 684 participants; year 2008), and SP-artesunate (1 trial, 676 participants; year 2008). The earlier studies evaluated IPTi with SP, and were conducted in Tanzania (in 1999 and 2006), Mozambique (2004), Ghana (2004 to 2005), Gabon (2005), Kenya (2008), and Mali (2009). One trial evaluated IPTi with amodiaquine in Tanzania (2000). Later studies included three conducted in Kenya (2008), Tanzania (2008), and Uganda (2013), evaluating IPTi in multiple trial arms that included artemisinin-based combination therapy (ACT). Although the effect size varied over time and between drugs, overall IPTi impacts on the incidence of clinical malaria overall, with a 27% reduction (rate ratio 0.73, 0.65 to 0.82; 10 studies, 10,602 participants). The effect of SP appeared to attenuate over time, with trials conducted after 2009 showing little or no effect of the intervention. IPTi with SP probably resulted in fewer episodes of clinical malaria (rate ratio 0.79, 0.74 to 0.85; 8 trials, 8774 participants, moderate-certainty evidence), anaemia (rate ratio 0.82, 0.68 to 0.98; 6 trials, 7438 participants, moderate-certainty evidence), parasitaemia (rate ratio 0.66, 0.56 to 0.79; 1 trial, 1200 participants, moderate-certainty evidence), and fewer hospital admissions (rate ratio 0.85, 0.78 to 0.93; 7 trials, 7486 participants, moderate-certainty evidence). IPTi with SP probably made little or no difference to all-cause mortality (risk ratio 0.93, 0.74 to 1.15; 9 trials, 14,588 participants, moderate-certainty evidence). Since 2009, IPTi trials have evaluated ACTs and indicate impact on clinical malaria and parasitaemia. A small trial of DHAP in 2013 shows substantive effects on clinical malaria (RR 0.42, 0.33 to 0.54; 1 trial, 147 participants, moderate-certainty evidence) and parasitaemia (moderate-certainty evidence).

AUTHORS' CONCLUSIONS

In areas of sub-Saharan Africa, giving antimalarial drugs known to be effective against the malaria parasite at the time to infants as IPT probably reduces the risk of clinical malaria, anaemia, and hospital admission. Evidence from SP studies over a 19-year period shows declining efficacy, which may be due to increasing drug resistance. Combinations with ACTs appear promising as suitable alternatives for IPTi. 2 December 2019 Up to date All studies incorporated from most recent search All eligible published studies found in the last search (3 Dec, 2018) were included.

Comparative effectiveness of malaria prevention measures: a systematic review and network meta-analysis

Background

Malaria causes significant morbidity and mortality worldwide. There are several preventive measures that are currently employed, including insecticide-treated nets (ITNs, including long-lasting insecticidal nets and insecticidal-treated bed nets), indoor residual spraying (IRS), prophylactic drugs (PD), and untreated nets (UN). However, it is unclear which measure is the most effective for malaria prevention. We therefore undertook a network meta-analysis to compare the efficacy of different preventive measures on incidence of malaria infection.

Methods

A systematic literature review was undertaken across four medical and life sciences databases (PubMed, Cochrane Central, Embase, and Web of Science) from their inception to July 2016 to compare the effectiveness of different preventive measures on malaria incidence. Data from the included studies were analysed for the effectiveness of several measures against no intervention (NI). This was carried out using an automated generalized pairwise modeling (GPM) framework for network meta-analysis to generate mixed treatment effects against a common comparator of no intervention (NI).

Results

There were 30 studies that met the inclusion criteria from 1998–2016. The GPM framework led to a final ranking of effectiveness of measures in the following order from best to worst: PD, ITN, IRS and UN, in comparison with NI. However, only ITN (RR: 0.49, 95% CI: 0.32–0.74) showed precision while other methods [PD (RR: 0.24, 95% CI: 0.004–15.43), IRS (RR: 0.55, 95% CI: 0.20–1.56) and UN (RR: 0.73, 95% CI: 0.28–1.90)] demonstrating considerable uncertainty associated with their point estimates.

Conclusion

Current evidence is strong for the protective effect of ITN interventions in malaria prevention. Even though ITNs were found to be the only preventive measure with statistical support for their effectiveness, the role of other malaria control measures may be important adjuncts in the global drive to eliminate malaria.

Electronic supplementary material

The online version of this article (10.1186/s13071-018-2783-y) contains supplementary material, which is available to authorized users.

Mefloquine for preventing malaria during travel to endemic areas

BACKGROUND

Mefloquine is one of four antimalarial agents commonly recommended for preventing malaria in travellers to malaria-endemic areas. Despite its high efficacy, there is controversy about its psychological side effects.

OBJECTIVES

To summarize the efficacy and safety of mefloquine used as prophylaxis for malaria in travellers.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL), published on the Cochrane Library; MEDLINE; Embase (OVID); TOXLINE (https://toxnet.nlm.nih.gov/newtoxnet/toxline.htm); and LILACS. We also searched the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP; http://www.who.int/ictrp/en/) and ClinicalTrials.gov (https://clinicaltrials.gov/ct2/home) for trials in progress, using 'mefloquine', 'Lariam', and 'malaria' as search terms. The search date was 22 June 2017.

SELECTION CRITERIA

We included randomized controlled trials (for efficacy and safety) and non-randomized cohort studies (for safety). We compared prophylactic mefloquine with placebo, no treatment, or an alternative recommended antimalarial agent. Our study populations included all adults and children, including pregnant women.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility and risk of bias of trials, extracted and analysed data. We compared dichotomous outcomes using risk ratios (RR) with 95% confidence intervals (CI). Prespecified adverse outcomes are included in 'Summary of findings' tables, with the best available estimate of the absolute frequency of each outcome in short-term international travellers. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 20 RCTs (11,470 participants); 35 cohort studies (198,493 participants); and four large retrospective analyses of health records (800,652 participants). Nine RCTs explicitly excluded participants with a psychiatric history, and 25 cohort studies stated that the choice of antimalarial agent was based on medical history and personal preference. Most RCTs and cohort studies collected data on self-reported or clinician-assessed symptoms, rather than formal medical diagnoses. Mefloquine efficacyOf 12 trials comparing mefloquine and placebo, none were performed in short-term international travellers, and most populations had a degree of immunity to malaria. The percentage of people developing a malaria episode in the control arm varied from 1% to 82% (median 22%) and 0% to 13% in the mefloquine group (median 1%).In four RCTs that directly compared mefloquine, atovaquone-proguanil and doxycycline in non-immune, short-term international travellers, only one clinical case of malaria occurred (4 trials, 1822 participants). Mefloquine safety versus atovaquone-proguanil Participants receiving mefloquine were more likely to discontinue their medication due to adverse effects than atovaquone-proguanil users (RR 2.86, 95% CI 1.53 to 5.31; 3 RCTs, 1438 participants; high-certainty evidence). There were few serious adverse effects reported with mefloquine (15/2651 travellers) and none with atovaquone-proguanil (940 travellers).One RCT and six cohort studies reported on our prespecified adverse effects. In the RCT with short-term travellers, mefloquine users were more likely to report abnormal dreams (RR 2.04, 95% CI 1.37 to 3.04, moderate-certainty evidence), insomnia (RR 4.42, 95% CI 2.56 to 7.64, moderate-certainty evidence), anxiety (RR 6.12, 95% CI 1.82 to 20.66, moderate-certainty evidence), and depressed mood during travel (RR 5.78, 95% CI 1.71 to 19.61, moderate-certainty evidence). The cohort studies in longer-term travellers were consistent with this finding but most had larger effect sizes. Mefloquine users were also more likely to report nausea (high-certainty evidence) and dizziness (high-certainty evidence).Based on the available evidence, our best estimates of absolute effect sizes for mefloquine versus atovaquone-proguanil are 6% versus 2% for discontinuation of the drug, 13% versus 3% for insomnia, 14% versus 7% for abnormal dreams, 6% versus 1% for anxiety, and 6% versus 1% for depressed mood. Mefloquine safety versus doxycyclineNo difference was found in numbers of serious adverse effects with mefloquine and doxycycline (low-certainty evidence) or numbers of discontinuations due to adverse effects (RR 1.08, 95% CI 0.41 to 2.87; 4 RCTs, 763 participants; low-certainty evidence).Six cohort studies in longer-term occupational travellers reported our prespecified adverse effects; one RCT in military personnel and one cohort study in short-term travellers reported adverse events. Mefloquine users were more likely to report abnormal dreams (RR 10.49, 95% CI 3.79 to 29.10; 4 cohort studies, 2588 participants, very low-certainty evidence), insomnia (RR 4.14, 95% CI 1.19 to 14.44; 4 cohort studies, 3212 participants, very low-certainty evidence), anxiety (RR 18.04, 95% CI 9.32 to 34.93; 3 cohort studies, 2559 participants, very low-certainty evidence), and depressed mood (RR 11.43, 95% CI 5.21 to 25.07; 2 cohort studies, 2445 participants, very low-certainty evidence). The findings of the single cohort study reporting adverse events in short-term international travellers were consistent with this finding but the single RCT in military personnel did not demonstrate a difference between groups in frequencies of abnormal dreams or insomnia.Mefloquine users were less likely to report dyspepsia (RR 0.26, 95% CI 0.09 to 0.74; 5 cohort studies, 5104 participants, low certainty-evidence), photosensitivity (RR 0.08, 95% CI 0.05 to 0.11; 2 cohort studies, 1875 participants, very low-certainty evidence), vomiting (RR 0.18, 95% CI 0.12 to 0.27; 4 cohort studies, 5071 participants, very low-certainty evidence), and vaginal thrush (RR 0.10, 95% CI 0.06 to 0.16; 1 cohort study, 1761 participants, very low-certainty evidence).Based on the available evidence, our best estimates of absolute effect for mefloquine versus doxycyline were: 2% versus 2% for discontinuation, 12% versus 3% for insomnia, 31% versus 3% for abnormal dreams, 18% versus 1% for anxiety, 11% versus 1% for depressed mood, 4% versus 14% for dyspepsia, 2% versus 19% for photosensitivity, 1% versus 5% for vomiting, and 2% versus 16% for vaginal thrush.Additional analyses, including comparisons of mefloquine with chloroquine, added no new information. Subgroup analysis by study design, duration of travel, and military versus non-military participants, provided no conclusive findings.

AUTHORS' CONCLUSIONS

The absolute risk of malaria during short-term travel appears low with all three established antimalarial agents (mefloquine, doxycycline, and atovaquone-proguanil).The choice of antimalarial agent depends on how individual travellers assess the importance of specific adverse effects, pill burden, and cost. Some travellers will prefer mefloquine for its once-weekly regimen, but this should be balanced against the increased frequency of abnormal dreams, anxiety, insomnia, and depressed mood.

Mass Azithromycin and Malaria Parasitemia in Niger: Results from a Community-Randomized Trial

Studies designed to determine the effects of mass administration of azithromycin on trachoma have suggested that mass azithromycin distributions may also reduce the prevalence of malaria. These studies have typically examined the impact of a small number of treatments over short durations. In this prespecified substudy of a cluster-randomized trial for trachoma, we compared malaria parasitemia prevalence in 24 communities in Niger randomized to receive either annual or biannual mass azithromycin distributions over 3 years. The 12 communities randomized to annual azithromycin received three treatments during the high-transmission season, and the 12 communities randomized to biannual azithromycin received a total of six treatments: three during the high-transmission season and three during the low-transmission season. Blood samples were taken to assess malariometric indices among children in all study communities at a single time point during the high-transmission season after 3 years of the intervention. No significant differences were identified in malaria parasitemia, parasite density, or hemoglobin concentration between the annual and biannual treatment arms. When compared with annual mass azithromycin alone, additional mass azithromycin distributions given during the low-transmission season did not significantly reduce the subsequent prevalence of malaria parasitemia or parasite density after 3 years, as measured during the high-transmission season.

Safety and benefits of interventions to increase folate status in malaria-endemic areas

For decades, folic acid has routinely been given to prevent or treat anaemia in children, pregnant women and people with sickle cell disease. However, there is no conclusive evidence that folate deficiency anaemia constitutes a public health problem in any of these groups. Industrial flour fortification is recommended and implemented in many countries to combat neural tube defects. Dietary folates or folic acid can antagonise the action of antifolate drugs that play a critical role in the prevention and treatment of malaria. Randomised trials have shown that folic acid supplementation increases the rate of treatment failures with sulfadoxine-pyrimethamine. The efficacy of antifolate drugs against Plasmodium is maximized in the absence of exogenous folic acid, suggesting that there is no safe minimum dose of ingested folic acid. We here review the safety and benefits of interventions to increase folate status in malaria-endemic countries. We conclude that formal cost-benefit analyses are required.

Asymptomatic only at first sight: malaria infection among schoolchildren in highland Rwanda

Background

Plasmodium infection and malaria in school children are increasingly recognized as a relevant public health problem, but data on actual prevalence and health consequences are insufficient. The present study from highland southern Rwanda aimed at estimating infection prevalence among children attending school, at identifying associated factors and at assessing the clinical consequences of these infections.

Methods

In a survey including 12 schools in the Huye district of Rwanda, 1089 children aged 6–10 years were clinically and anthropometrically examined, malaria parasites were diagnosed by microscopy and PCR, haemoglobin concentrations were measured, and socio-economic and behavioural parameters as well as medical histories were obtained.

Results

Upon examination, the vast majority of children was asymptomatic (fever 2.7%). Plasmodium infection was detected in 22.4% (Plasmodium falciparum, 18.8%); 41% of these were submicroscopic. Independent predictors of infection included low altitude, higher age, preceding antimalarial treatment, and absence of electricity or a bicycle in the household. Plasmodium infection was associated with anaemia (mean haemoglobin difference of −1.2 g/dL; 95% CI, −0.8 to −1.5 g/dL), fever, underweight, clinically assessed malnutrition and histories of fever, tiredness, weakness, poor appetite, abdominal pain, and vomiting. With the exception of underweight, these conditions were also increased at submicroscopic infection.

Conclusion

Malaria infection is frequent among children attending school in southern highland Rwanda. Although seemingly asymptomatic in the vast majority of cases, infection is associated with a number of non-specific symptoms in the children´s histories, in addition to the impact on anaemia. This argues for improved malaria surveillance and control activities among school children.

Oral iron supplements for children in malaria-endemic areas

BACKGROUND

Iron-deficiency anaemia is common during childhood. Iron administration has been claimed to increase the risk of malaria.

OBJECTIVES

To evaluate the effects and safety of iron supplementation, with or without folic acid, in children living in areas with hyperendemic or holoendemic malaria transmission.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL), published in the Cochrane Library, MEDLINE (up to August 2015) and LILACS (up to February 2015). We also checked the metaRegister of Controlled Trials (mRCT) and World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) up to February 2015. We contacted the primary investigators of all included trials, ongoing trials, and those awaiting assessment to ask for unpublished data and further trials. We scanned references of included trials, pertinent reviews, and previous meta-analyses for additional references.

SELECTION CRITERIA

We included individually randomized controlled trials (RCTs) and cluster RCTs conducted in hyperendemic and holoendemic malaria regions or that reported on any malaria-related outcomes that included children younger than 18 years of age. We included trials that compared orally administered iron, iron with folic acid, and iron with antimalarial treatment versus placebo or no treatment. We included trials of iron supplementation or fortification interventions if they provided at least 80% of the Recommended Dietary Allowance (RDA) for prevention of anaemia by age. Antihelminthics could be administered to either group, and micronutrients had to be administered equally to both groups.

DATA COLLECTION AND ANALYSIS

The primary outcomes were clinical malaria, severe malaria, and death from any cause. We assessed the risk of bias in included trials with domain-based evaluation and assessed the quality of the evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. We performed a fixed-effect meta-analysis for all outcomes and random-effects meta-analysis for hematological outcomes, and adjusted analyses for cluster RCTs. We based the subgroup analyses for anaemia at baseline, age, and malaria prevention or management services on trial-level data.

MAIN RESULTS

Thirty-five trials (31,955 children) met the inclusion criteria. Overall, iron does not cause an excess of clinical malaria (risk ratio (RR) 0.93, 95% confidence intervals (CI) 0.87 to 1.00; 14 trials, 7168 children, high quality evidence). Iron probably does not cause an excess of clinical malaria in both populations where anaemia is common and those in which anaemia is uncommon. In areas where there are prevention and management services for malaria, iron (with or without folic acid) may reduce clinical malaria (RR 0.91, 95% CI 0.84 to 0.97; seven trials, 5586 participants, low quality evidence), while in areas where such services are unavailable, iron (with or without folic acid) may increase the incidence of malaria, although the lower CIs indicate no difference (RR 1.16, 95% CI 1.02 to 1.31; nine trials, 19,086 participants, low quality evidence). Iron supplementation does not cause an excess of severe malaria (RR 0.90, 95% CI 0.81 to 0.98; 6 trials, 3421 children, high quality evidence). We did not observe any differences for deaths (control event rate 1%, low quality evidence). Iron and antimalarial treatment reduced clinical malaria (RR 0.54, 95% CI 0.43 to 0.67; three trials, 728 children, high quality evidence). Overall, iron resulted in fewer anaemic children at follow up, and the end average change in haemoglobin from base line was higher with iron.

AUTHORS' CONCLUSIONS

Iron treatment does not increase the risk of clinical malaria when regular malaria prevention or management services are provided. Where resources are limited, iron can be administered without screening for anaemia or for iron deficiency, as long as malaria prevention or management services are provided efficiently.

The Effect of Mass Azithromycin Distribution on Childhood Mortality: Beliefs and Estimates of Efficacy

A cluster-randomized trial demonstrated that mass oral azithromycin distribution reduced childhood mortality 49.6% (Trachoma Amelioration in Northern Amhara [TANA]). The relative risk of childhood mortality was then estimated using two approaches: an expert survey and a Bayesian analysis. The survey asked public health experts to estimate the true effect of mass azithromycin distribution on childhood mortality. The Bayesian estimation used the TANA study's results and prior estimates of the efficacy of other effective population-level interventions. The experts believed mass azithromycin reduces childhood mortality (relative risk = 0.83, 95% credible intervals [CrI] = 0.70-1.00). The Bayesian analysis estimated a relative risk of 0.71 (95% CrI = 0.39-0.93). Both estimates suggest that azithromycin may have a true mortality benefit, though of a smaller magnitude than found in the single available trial. Prior information about nonantibiotic, population-level interventions may have informed the expert's opinions. Additional trials are needed to confirm a mortality benefit from mass azithromycin.

Malaria in school-age children in Africa: an increasingly important challenge

School-age children have attracted relatively little attention as a group in need of special measures to protect them against malaria. However, increasing success in lowering the level of malaria transmission in many previously highly endemic areas will result in children acquiring immunity to malaria later in life than has been the case in the past. Thus, it can be anticipated that in the coming years there will be an increase in the incidence of both uncomplicated and severe malaria in school-age children in many previously highly endemic areas. In this review, which focuses primarily on Africa, recent data on the prevalence of malaria parasitaemia and on the incidence of clinical malaria in African school-age children are presented and evidence that malaria adversely effects school performance is reviewed. Long-lasting insecticide treated bednets (LLIN) are an effective method of malaria control but several studies have shown that school-age children use LLINs less frequently than other population groups. Antimalarial drugs are being used in different ways to control malaria in school-age children including screening and treatment and intermittent preventive treatment. Some studies of chemoprevention in school-age children have shown reductions in anaemia and improved school performance but this has not been the case in all trials and more research is needed to identify the situations in which chemoprevention is likely to be most effective and, in these situations, which type of intervention should be used. In the longer term, malaria vaccines may have an important role in protecting this important section of the community from malaria. Regardless of the control approach selected, it is important this is incorporated into the overall programme of measures being undertaken to enhance the health of African school-age children.

Concordance of effects of medical interventions on hospital admission and readmission rates with effects on mortality

BACKGROUND

Many clinical trials examine a composite outcome of admission to hospital and death, or infer a relationship between hospital admission and survival benefit. This assumes concordance of the outcomes "hospital admission" and "death." However, whether the effects of a treatment on hospital admissions and readmissions correlate to its effect on serious outcomes such as death is unknown. We aimed to assess the correlation and concordance of effects of medical interventions on admission rates and mortality.

METHODS

We searched the Cochrane Database of Systematic Reviews from its inception to January 2012 (issue 1, 2012) for systematic reviews of treatment comparisons that included meta-analyses for both admission and mortality outcomes. For each meta-analysis, we synthesized treatment effects on admissions and death, from respective randomized trials reporting those outcomes, using random-effects models. We then measured the concordance of directions of effect sizes and the correlation of summary estimates for the 2 outcomes.

RESULTS

We identified 61 meta-analyses including 398 trials reporting mortality and 182 trials reporting admission rates; 125 trials reported both outcomes. In 27.9% of comparisons, the point estimates of treatment effects for the 2 outcomes were in opposite directions; in 8.2% of trials, the 95% confidence intervals did not overlap. We found no significant correlation between effect sizes for admission and death (Pearson r = 0.07, p = 0.6). Our results were similar when we limited our analysis to trials reporting both outcomes.

INTERPRETATION

In this metaepidemiological study, admission and mortality outcomes did not correlate, and discordances occurred in about one-third of the treatment comparisons included in our analyses. Both outcomes convey useful information and should be reported separately, but extrapolating the benefits of admission to survival is unreliable and should be avoided.

Home- or community-based programmes for treating malaria

BACKGROUND

Malaria is an important cause of morbidity and mortality, in particular among children and pregnant women in sub-Saharan Africa. Prompt access to diagnosis and treatment with effective antimalarial drugs is a central component of the World Health Organization's (WHO) strategy for malaria control. Home- or community-based programmes for managing malaria are one strategy that has been proposed to overcome the geographical barrier to malaria treatment. 

OBJECTIVES

To evaluate home- and community-based management strategies for treating malaria.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials published in The Cochrane Library; MEDLINE; EMBASE; Science Citation Index; PsycINFO/LIT; CINAHL; WHO clinical trial registry platform; and the metaRegister of Controlled Trials up to September 2012.

SELECTION CRITERIA

Randomized controlled trials (RCTs) and non-RCTs that evaluated the effects of a home- or community-based programme for treating malaria in a malaria endemic setting.

DATA COLLECTION AND ANALYSIS

Two authors independently screened and selected studies, extracted data, and assessed the risk of bias. Where possible the effects of interventions are compared using risk ratios (RR), and presented with 95% confidence intervals (CI). The quality of the evidence was assessed using the GRADE approach.

MAIN RESULTS

We identified 10 trials that met the inclusion criteria. The interventions involved brief training of basic-level health workers or mothers, and most provided the antimalarial for free or at a highly subsidized cost. In eight of the studies, fevers were treated presumptively without parasitological confirmation with microscopy or a rapid diagnostic test (RDT). Two studies trained community health workers to use RDTs as a component of community management of fever.Home- or community-based strategies probably increase the number of people with fever who receive an appropriate antimalarial within 24 hours (RR 2.27, 95% CI 1.79 to 2.88 in one trial; RR 9.79, 95% CI 6.87 to 13.95 in a second trial; 3099 participants, moderate quality evidence). They may also reduce all-cause mortality, but to date this has only been demonstrated in rural Ethiopia (RR 0.58, 95% CI 0.44 to 0.77, one trial, 13,677 participants, moderate quality evidence).Hospital admissions in children were reported in one small trial from urban Uganda, with no effect detected (437 participants, very low quality evidence). No studies reported on severe malaria. For parasitaemia prevalence, the study from urban Uganda demonstrated a reduction in community parasite prevalence (RR 0.22, 95% CI 0.08 to 0.64, 365 participants), but a second study in rural Burkina Faso did not (1006 participants). Home- or community-based programmes may have little or no effect on the prevalence of anaemia (three trials, 3612 participants, low quality evidence). None of the included studies reported on adverse effects of using home- or community-based programmes for treating malaria.In two studies which trained community health workers to only prescribe antimalarials after a positive RDT, prescriptions of antimalarials were reduced compared to the control group where community health workers used clinical diagnosis (RR 0.39, 95% CI 0.18 to 0.84, two trials, 5944 participants, moderate quality evidence). In these two studies, mortality and hospitalizations remained very low in both groups despite the lower use of antimalarials (two trials, 5977 participants, low quality evidence).

AUTHORS' CONCLUSIONS

Home- or community-based interventions which provide antimalarial drugs free of charge probably improve prompt access to antimalarials, and there is moderate quality evidence from rural Ethiopia that they may impact on childhood mortality when implemented in appropriate settings.Programmes which treat all fevers presumptively with antimalarials lead to overuse antimalarials, and potentially undertreat other causes of fever such as pneumonia. Incorporating RDT diagnosis into home- or community-based programmes for malaria may help to reduce this overuse of antimalarials, and has been shown to be safe under trial conditions.

The effectiveness of public health interventions to reduce the health impact of climate change: a systematic review of systematic reviews

BACKGROUND

Climate change is likely to be one of the most important threats to public health in the coming years. Yet despite the large number of papers considering the health impact of climate change, few have considered what public health interventions may be of most value in reducing the disease burden. We aimed to evaluate the effectiveness of public health interventions to reduce the disease burden of high priority climate sensitive diseases.

METHODS AND FINDINGS

For each disease, we performed a systematic search with no restriction on date or language of publication on Medline, Web of Knowledge, Cochrane CENTRAL and SCOPUS up to December 2010 to identify systematic reviews of public health interventions. We retrieved some 3176 records of which 85 full papers were assessed and 33 included in the review. The included papers investigated the effect of public health interventions on various outcome measures. All interventions were GRADE assessed to determine the strength of evidence. In addition we developed a systematic review quality score. The interventions included environmental interventions to control vectors, chemoprophylaxis, immunization, household and community water treatment, greening cities and community advice. For most reviews, GRADE showed low quality of evidence because of poor study design and high heterogeneity. Also for some key areas such as floods, droughts and other weather extremes, there are no adequate systematic reviews of potential public health interventions.

CONCLUSION

In conclusion, we found the evidence base to be mostly weak for environmental interventions that could have the most value in a warmer world. Nevertheless, such interventions should not be dismissed. Future research on public health interventions for climate change adaptation needs to be concerned about quality in study design and should address the gap for floods, droughts and other extreme weather events that pose a risk to health.

Intermittent preventive treatment for malaria in Papua New Guinean infants exposed to Plasmodium falciparum and P. vivax: a randomized controlled trial

BACKGROUND

Intermittent preventive treatment in infants (IPTi) has been shown in randomized trials to reduce malaria-related morbidity in African infants living in areas of high Plasmodium falciparum (Pf) transmission. It remains unclear whether IPTi is an appropriate prevention strategy in non-African settings or those co-endemic for P. vivax (Pv).

METHODS AND FINDINGS

In this study, 1,121 Papua New Guinean infants were enrolled into a three-arm placebo-controlled randomized trial and assigned to sulfadoxine-pyrimethamine (SP) (25 mg/kg and 1.25 mg/kg) plus amodiaquine (AQ) (10 mg/kg, 3 d, n = 374), SP plus artesunate (AS) (4 mg/kg, 3 d, n = 374), or placebo (n = 373), given at 3, 6, 9 and 12 mo. Both participants and study teams were blinded to treatment allocation. The primary end point was protective efficacy (PE) against all episodes of clinical malaria from 3 to 15 mo of age. Analysis was by modified intention to treat. The PE (compared to placebo) against clinical malaria episodes (caused by all species) was 29% (95% CI, 10-43, p ≤ 0.001) in children receiving SP-AQ and 12% (95% CI, -11 to 30, p = 0.12) in those receiving SP-AS. Efficacy was higher against Pf than Pv. In the SP-AQ group, Pf incidence was 35% (95% CI, 9-54, p = 0.012) and Pv incidence was 23% (95% CI, 0-41, p = 0.048) lower than in the placebo group. IPTi with SP-AS protected only against Pf episodes (PE = 31%, 95% CI, 4-51, p = 0.027), not against Pv episodes (PE = 6%, 95% CI, -24 to 26, p = 0.759). Number of observed adverse events/serious adverse events did not differ between treatment arms (p > 0.55). None of the serious adverse events were thought to be treatment-related, and the vomiting rate was low in both treatment groups (1.4%-2.0%). No rebound in malaria morbidity was observed for 6 mo following the intervention.

CONCLUSIONS

IPTi using a long half-life drug combination is efficacious for the prevention of malaria and anemia in infants living in a region highly endemic for both Pf and Pv.

Intermittent preventive treatment for malaria in children living in areas with seasonal transmission

BACKGROUND

In malaria endemic areas, pre-school children are at high risk of severe and repeated malaria illness. One possible public health strategy, known as Intermittent Preventive Treatment in children (IPTc), is to treat all children for malaria at regular intervals during the transmission season, regardless of whether they are infected or not.

OBJECTIVES

To evaluate the effects of IPTc to prevent malaria in preschool children living in endemic areas with seasonal malaria transmission.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register (July 2011), CENTRAL (The Cochrane Library 2011, Issue 6), MEDLINE (1966 to July 2011), EMBASE (1974 to July 2011), LILACS (1982 to July 2011), mRCT (July 2011), and reference lists of identified trials. We also contacted researchers working in the field for unpublished and ongoing trials.

SELECTION CRITERIA

Individually randomized and cluster-randomized controlled trials of full therapeutic dose of antimalarial or antimalarial drug combinations given at regular intervals compared with placebo or no preventive treatment in children aged six years or less living in an area with seasonal malaria transmission.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed eligibility, extracted data and assessed the risk of bias in the trials. Data were meta-analysed and measures of effects (ie rate ratio, risk ratio and mean difference) are presented with 95% confidence intervals (CIs). The quality of evidence was assessed using the GRADE methods.

MAIN RESULTS

Seven trials (12,589 participants), including one cluster-randomized trial, met the inclusion criteria. All were conducted in West Africa, and six of seven trials were restricted to children aged less than 5 years.IPTc prevents approximately three quarters of all clinical malaria episodes (rate ratio 0.26; 95% CI 0.17 to 0.38; 9321 participants, six trials, high quality evidence), and a similar proportion of severe malaria episodes (rate ratio 0.27, 95% CI 0.10 to 0.76; 5964 participants, two trials, high quality evidence). These effects remain present even where insecticide treated net (ITN) usage is high (two trials, 5964 participants, high quality evidence).IPTc probably produces a small reduction in all-cause mortality consistent with the effect on severe malaria, but the trials were underpowered to reach statistical significance (risk ratio 0.66, 95% CI 0.31 to 1.39, moderate quality evidence).The effect on anaemia varied between studies, but the risk of moderately severe anaemia is probably lower with IPTc (risk ratio 0.71, 95% CI 0.52 to 0.98; 8805 participants, five trials, moderate quality evidence).Serious drug-related adverse events, if they occur, are probably rare, with none reported in the six trials (9533 participants, six trials, moderate quality evidence). Amodiaquine plus sulphadoxine-pyrimethamine is the most studied drug combination for seasonal chemoprevention. Although effective, it causes increased vomiting in this age-group (risk ratio 2.78, 95% CI 2.31 to 3.35; two trials, 3544 participants, high quality evidence).When antimalarial IPTc was stopped, no rebound increase in malaria was observed in the three trials which continued follow-up for one season after IPTc.

AUTHORS' CONCLUSIONS

In areas with seasonal malaria transmission, giving antimalarial drugs to preschool children (age < 6 years) as IPTc during the malaria transmission season markedly reduces episodes of clinical malaria, including severe malaria. This benefit occurs even in areas where insecticide treated net usage is high.

Anaemia in low-income and middle-income countries

Anaemia affects a quarter of the global population, including 293 million (47%) children younger than 5 years and 468 million (30%) non-pregnant women. In addition to anaemia's adverse health consequences, the economic effect of anaemia on human capital results in the loss of billions of dollars annually. In this paper, we review the epidemiology, clinical assessment, pathophysiology, and consequences of anaemia in low-income and middle-income countries. Our analysis shows that anaemia is disproportionately concentrated in low socioeconomic groups, and that maternal anaemia is strongly associated with child anaemia. Anaemia has multifactorial causes involving complex interaction between nutrition, infectious diseases, and other factors, and this complexity presents a challenge to effectively address the population determinants of anaemia. Reduction of knowledge gaps in research and policy and improvement of the implementation of effective population-level strategies will help to alleviate the anaemia burden in low-resource settings.

Oral iron supplements for children in malaria-endemic areas

BACKGROUND

Iron-deficiency anaemia is common during childhood. Iron supplementation has been claimed to increase the risk of malaria.

OBJECTIVES

To assess the effect of iron on malaria and deaths.

SEARCH STRATEGY

We searched The Cochrane Library, PUBMED, MEDLINE, LILACS; and trial registry databases, all up to June 2011. We scanned references of included trials.

SELECTION CRITERIA

Individually and cluster randomized controlled trials conducted in hypoendemic to holoendemic malaria regions and including children below 18 years of age. We included trials comparing orally administered iron, iron with antimalarial treatment, or iron with folic acid versus placebo or no treatment. Iron fortification was excluded. Antihelminthics could be administered to either group. Additional micronutrients had to be administered equally to both groups.

DATA COLLECTION AND ANALYSIS

The primary outcomes were clinical (symptomatic) malaria, severe malaria, and death. Two authors independently selected the studies and extracted the data. We assessed heterogeneity and conducted subgroup analyses by the presence of anaemia at baseline, age, and malaria endemicity. We assessed risk of bias using domain-based evaluation. We performed a fixed-effect meta-analysis for all outcomes and random-effects meta-analysis for hematological outcomes. We adjusted analyses for cluster randomized trials.

MAIN RESULTS

Seventy-one trials (45,353 children) were included. For clinical malaria, no significant difference between iron alone and placebo was detected, (risk ratio (RR) 0.99, 95% confidence intervals (CI) 0.90 to 1.09, 13 trials). The results were similar in the subgroups of non-anaemic children and children below 2 years of age. There was no significant difference in deaths in hyper- and holoendemic areas, risk difference +1.93 per 1000 children (95% CI -1.78 to 5.64, 13 trials, 17,898 children). Iron administered for treatment of anaemia resulted in a larger increase in haemoglobin than iron given for prevention, and the benefit was similar in hyper- or holoendemic and lower endemicity settings. Iron and folic acid supplementation resulted in mixed results for severe malaria. Overall, the risk for clinical malaria was higher with iron or with iron plus folic acid in trials where services did not provide for malaria surveillance and treatment. Iron with antimalarial treatment significantly reduced malaria. Iron supplementation during an acute attack of malaria did not increase the risk for parasitological failure, (RR 0.96, 95% CI 0.74 to 1.24, three trials) or deaths.

AUTHORS' CONCLUSIONS

Iron alone or with antimalaria treatment does not increase the risk of clinical malaria or death when regular malaria surveillance and treatment services are provided. There is no need to screen for anaemia prior to iron supplementation.

Determinants of the cost-effectiveness of intermittent preventive treatment for malaria in infants and children

BACKGROUND

Trials of intermittent preventive treatment in infants (IPTi) and children (IPTc) have shown promising results in reducing malaria episodes but with varying efficacy and cost-effectiveness. The effects of different intervention and setting characteristics are not well known. We simulate the effects of the different target age groups and delivery channels, seasonal or year-round delivery, transmission intensity, seasonality, proportions of malaria fevers treated and drug characteristics.

METHODS

We use a dynamic, individual-based simulation model of Plasmodium falciparum malaria epidemiology, antimalarial drug action and case management to simulate DALYs averted and the cost per DALY averted by IPTi and IPTc. IPT cost components were estimated from economic studies alongside trials.

RESULTS

IPTi and IPTc were predicted to be cost-effective in most of the scenarios modelled. The cost-effectiveness is driven by the impact on DALYs, particularly for IPTc, and the low costs, particularly for IPTi which uses the existing delivery strategy, EPI. Cost-effectiveness was predicted to decrease with low transmission, badly timed seasonal delivery in a seasonal setting, short-acting and more expensive drugs, high frequencies of drug resistance and high levels of treatment of malaria fevers. Seasonal delivery was more cost-effective in seasonal settings, and year-round in constant transmission settings. The difference was more pronounced for IPTc than IPTi due to the different proportions of fixed costs and also different assumed drug spacing during the transmission season. The number of DALYs averted was predicted to decrease as a target five-year age-band for IPTc was shifted from children under 5 years into older ages, except at low transmission intensities.

CONCLUSIONS

Modelling can extend the information available by predicting impact and cost-effectiveness for scenarios, for outcomes and for multiple strategies where, for practical reasons, trials cannot be carried out. Both IPTi and IPTc are generally cost-effective but could be rendered cost-ineffective by characteristics of the setting, drug or implementation.

A systematic review and meta-analysis of the efficacy and safety of intermittent preventive treatment of malaria in children (IPTc)

BACKGROUND

Intermittent preventive treatment of malaria in children less than five years of age (IPTc) has been investigated as a measure to control the burden of malaria in the Sahel and sub-Sahelian areas of Africa where malaria transmission is markedly seasonal.

METHODS AND FINDINGS

IPTc studies were identified using a systematic literature search. Meta-analysis was used to assess the protective efficacy of IPTc against clinical episodes of falciparum malaria. The impact of IPTc on all-cause mortality, hospital admissions, severe malaria and the prevalence of parasitaemia and anaemia was investigated. Three aspects of safety were also assessed: adverse reactions to study drugs, development of drug resistance and loss of immunity to malaria. Twelve IPTc studies were identified: seven controlled and five non-controlled trials. Controlled studies demonstrated protective efficacies against clinical malaria of between 31% and 93% and meta-analysis gave an overall protective efficacy of monthly administered IPTc of 82% (95%CI 75%-87%) during the malaria transmission season. Pooling results from twelve studies demonstrated a protective effect of IPTc against all-cause mortality of 57% (95%CI 24%-76%) during the malaria transmission season. No serious adverse events attributable to the drugs used for IPTc were observed in any of the studies. Data from three studies that followed children during the malaria transmission season in the year following IPTc administration showed evidence of a slight increase in the incidence of clinical malaria compared to children who had not received IPTc.

CONCLUSIONS

IPTc is a safe method of malaria control that has the potential to avert a significant proportion of clinical malaria episodes in areas with markedly seasonal malaria transmission and also appears to have a substantial protective effect against all-cause mortality. These findings indicate that IPTc is a potentially valuable tool that can contribute to the control of malaria in areas with markedly seasonal transmission.

Population hemoglobin mean and anemia prevalence in Papua New Guinea: new metrics for defining malaria endemicity?

Background

The hypothesis is that hemoglobin-based metrics are useful tools for estimating malaria endemicity and for monitoring malaria control strategies. The aim of this study is to compare population hemoglobin mean and anemia prevalence to established indicators of malaria endemicity, including parasite rates, rates of enlarged spleens in children, and records of (presumptive) malaria diagnosis among populations living with different levels of malaria transmission.

Methodology/Principal Findings

Convenience sample, multisite cross-sectional household surveys conducted in Papua New Guinea. Correlations (r²) between population Hb mean and anemia prevalence and altitude, parasite rate, and spleen rate were investigated in children ages 2 to 10 years, and in the general population; 21,664 individuals from 156 different communities were surveyed. Altitude ranged from 5 to 2120 meters. In young children, correlations between altitude and parasite rate, population Hb mean, anemia prevalence, and spleen rate were high (r²: −0.77, 0.73, −0.81, and −0.68; p<0.001). In the general population, correlations between altitude and population Hb mean and anemia prevalence were 0.83 and 0.85, respectively. Among young children, parasite rate correlated highly with anemia prevalence, population Hb mean, and spleen rate (r²: 0.81, −0.81, and 0.86; p<0.001). Population Hb mean (corrected for direct altitude effects) increased with altitude, from 10.5 g/dl at <500 m to 12.8 g/dl at >1500 m (p<0.001).

Conclusions/Significance

In PNG, where Plasmodium vivax accounts for an important part of all malaria infections, population hemoglobin mean and anemia prevalence correlate well with altitude, parasite, and spleen rates. Hb measurement is simple and affordable, and may be a useful new tool, alone or in association with other metrics, for estimating malaria endemicity and monitoring effectiveness of malaria control programs. Further prospective studies in areas with different malaria epidemiology and different factors contributing to the burden of anemia are warranted to investigate the usefulness of Hb metrics in monitoring malaria transmission intensity.

Epidemiologic features impacting the presentation of malaria in children in Houston

BACKGROUND

Malaria is diagnosed in children in the United States despite availability of effective chemoprophylaxis. The features impacting the presentation of malaria diagnosed in a nonendemic setting are not well characterized in children.

METHODS

A retrospective chart review was conducted of children with peripheral smear-confirmed malaria diagnosed from 1994 to 2007 at 4 tertiary referral hospitals in Houston, TX.

RESULTS

Among 104 children with malaria, 43 were recent immigrants and 61 were travelers leaving the United States. Severe malaria accounted for 21 (20%) of episodes. Children residing in the United States accounted for 86% of those with severe malaria. Factors relating to malaria severity included vacation-related travel (P = 0.005), female gender (P = 0.02), birth in the United States (P = 0.043), short travel duration (P = 0.024), and short duration from return to presentation (P = 0.023). Children with severe malaria more often had a history of vomiting (P = 0.048) and presented with hepatomegaly (P = 0.008), heart murmur (P = 0.041), and higher parasitemia (P < 0.001) than those with uncomplicated malaria. Vacation-related travel (aOR 7.6; 95% CI 1.4–61.5), admission hemoglobin (aOR 0.6; 95% CI 0.4–0.8), and admission platelet count (aOR 1.0; 95% CI 1.0-1.0) remained significant risk factors for severity by multivariate analysis. Prophylaxis appropriate to region of travel was documented in only 8 of 47 children leaving the United States.

CONCLUSIONS

Children diagnosed in Houston with severe malaria usually had traveled from the United States to malaria-endemic regions without benefit of appropriate prophylaxis. Malaria-related morbidity in nonendemic countries could potentially be reduced by optimizing adherence to prophylactic regimens.

SUPPORT Tools for evidence-informed health Policymaking (STP) 8: Deciding how much confidence to place in a systematic review

This article is part of a series written for people responsible for making decisions about health policies and programmes and for those who support these decision makers. The reliability of systematic reviews of the effects of health interventions is variable. Consequently, policymakers and others need to assess how much confidence can be placed in such evidence. The use of systematic and transparent processes to determine such decisions can help to prevent the introduction of errors and bias in these judgements. In this article, we suggest five questions that can be considered when deciding how much confidence to place in the findings of a systematic review of the effects of an intervention. These are: 1. Did the review explicitly address an appropriate policy or management question? 2. Were appropriate criteria used when considering studies for the review? 3. Was the search for relevant studies detailed and reasonably comprehensive? 4. Were assessments of the studies' relevance to the review topic and of their risk of bias reproducible? 5. Were the results similar from study to study?

Drugs for preventing malaria in travellers

BACKGROUND

Malaria infects 10,000 to 30,000 international travellers each year. It can be prevented through anti-mosquito measures and drug prophylaxis. However, antimalaria drugs have adverse effects which are sometimes serious.

OBJECTIVES

To compare the effects of currently used antimalaria drugs when given as prophylaxis to non-immune adult and child travellers who are travelling to regions with Plasmodium falciparum resistance to chloroquine. Specifically, to assess the efficacy, safety, and tolerability of atovaquone-proguanil, doxycycline, and mefloquine compared to each other, and also when compared to chloroquine-proguanil and to primaquine.

SEARCH STRATEGY

In August 2009 we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2008, Issue 4), MEDLINE, EMBASE, LILACS, BIOSIS, mRCT, and reference lists. We handsearched conference proceedings and one specialist journal, and contacted researchers and drug companies. We searched PubMed for drug-related deaths.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials of any antimalaria drug regimen currently used by non-immune international travellers.

DATA COLLECTION AND ANALYSIS

We independently extracted data and assessed eligibility and risk of bias using a standardized data collection form. We resolved any disagreement through discussion. We combined dichotomous outcomes using risk ratio (RR) and continuous data using mean difference (MD), presenting both with 95% confidence intervals (CI).

MAIN RESULTS

Eight trials (4240 participants) met the inclusion criteria. Evidence on comparative efficacy from head-to-head comparisons was limited. Atovaquone-proguanil compared to doxycycline had similar adverse events reported. Compared to mefloquine, atovaquone-proguanil users had fewer reports of any adverse effect (RR 0.72, 95% CI 0.6 to 0.85), gastrointestinal adverse effects (RR 0.54, 95% CI 0.42 to 0.7), neuropsychiatric adverse events (RR 0.86, 95% CI 0.75 to 0.99), and neuropsychiatric adverse effects (RR 0.49, 95% CI 0.38 to 0.63), besides a better total mood disturbance score (MD -7.20, 95% CI -10.79 to -3.61). Similarly, doxycycline users had fewer reported neuropsychiatric events than mefloquine users (RR 0.84, 95% CI 0.73 to 0.96). We also examined these three regimens against chloroquine-proguanil; this latter regimen had more reports of any adverse effect (RR 0.84, 95% CI 0.73 to 0.96) and of gastrointestinal adverse effects (RR 0.71, 95% CI 0.6 to 0.85).

AUTHORS' CONCLUSIONS

Atovaquone-proguanil and doxycycline are the best tolerated regimens, and mefloquine is associated with adverse neuropsychiatric outcomes.

Oral iron supplementation for preventing or treating anaemia among children in malaria-endemic areas

BACKGROUND

Iron-deficiency anaemia is common during childhood. Iron supplementation has been claimed to increase the risk of malaria.

OBJECTIVES

To assess the effect of iron on malaria and deaths.

SEARCH STRATEGY

We searched The Cochrane Library (2009, issue 1); MEDLINE; EMBASE; LILACS and metaRegister of Controlled Trials, all up to March 2009. We scanned references of included trials.

SELECTION CRITERIA

Individually and cluster-randomized controlled trials conducted in hypoendemic to holoendemic malaria regions and including children < 18 years. We included trials comparing orally administered iron with or without folic acid vs. placebo or no treatment. Iron fortification was excluded. Antimalarials and/or antiparasitics could be administered to either group. Additional micronutrients could only be administered equally to both groups.

DATA COLLECTION AND ANALYSIS

The primary outcomes were malaria-related events and deaths. Secondary outcomes included haemoglobin, anaemia, other infections, growth, hospitalizations, and clinic visits. We assessed risk of bias using domain-based evaluation. Two authors independently selected studies and extracted data. We contacted authors for missing data. We assessed heterogeneity. We performed fixed-effect meta-analysis and presented random-effects results when heterogeneity was present. We present pooled risk ratios (RR) with 95% confidence intervals (CIs). We used adjusted analyses for cluster-randomized trials.

MAIN RESULTS

Sixty-eight trials (42,981 children) fulfilled the inclusion criteria. Iron supplementation did not increase the risk of clinical malaria (RR 1.00, 95% CI 0.88 to 1.13; 22,724 children, 14 trials, random-effects model). The risk was similar among children who were non-anaemic at baseline (RR 0.96, 95% CI 0.85 to 1.09). An increased risk of malaria with iron was observed in trials that did not provide malaria surveillance and treatment. The risk of malaria parasitaemia was higher with iron (RR 1.13, 95% CI 1.01 to 1.26), but there was no difference in adequately concealed trials. Iron + antimalarial was protective for malaria (four trials). Iron did not increase the risk of parasitological failure when given during malaria (three trials). There was no increased risk of death across all trials comparing iron versus placebo (RR 1.11, 95% CI 0.91 to 1.36; 21,272 children, 12 trials). Iron supplementation increased haemoglobin, with significant heterogeneity, and malaria endemicity did not affect this effect. Growth and other infections were mostly not affected by iron supplementation.

AUTHORS' CONCLUSIONS

Iron does not increase the risk of clinical malaria or death, when regular malaria surveillance and treatment services are provided. There is no need to screen for anaemia prior to iron supplementation.

The impact of primary health care on malaria morbidity--defining access by disease burden

OBJECTIVES

Primary care facilities are increasingly becoming the focal point for distribution of malaria intervention strategies, but physical access to these facilities may limit the extent to which communities can be reached. To investigate the impact of travel time to primary care on the incidence of hospitalized malaria episodes in a rural district in Kenya.

METHODS

The incidence of hospitalized malaria in a population under continuous demographic surveillance was recorded over 3 years. The time to travel to the nearest primary health care facility was calculated for every child between birth and 5 years of age and trends in incidence of hospitalized malaria as a function of travel time were evaluated.

RESULTS

The incidence of hospitalized malaria more than doubled as travel time to the nearest primary care facility increased from 10 min to 2 h. Good access to primary health facilities may reduce the burden of disease by as much as 66%.

CONCLUSIONS

Our results highlight both the potential of the primary health care system in reaching those most at risk and reducing the disease burden. Insufficient access is an important risk factor, one that may be inequitably distributed to the poorest households.

Intermittent preventive antimalarial treatment to children (IPTc): firebreak or fire trap?

Intermittent preventive treatment is the prescheduled administration of antimalarial drugs to at-risk patients in endemic areas. This approach, which is recommended for pregnant women, is being evaluated in children. Sulfadoxine-pyrimethamine plus amodiaquine recently proved to be more protective than artemisinin-containing regimens. Therefore, the use of artemisinin derivatives could potentially be restricted to symptomatic patients. Determinants of three pending issues: safety, efficacy throughout childhood, and effectiveness--the latter depending on the implementation of sustainable delivery mechanisms--are analyzed in this comment.