Human resources for health governance and leadership strategies for improving health outcomes in low- and middle-income countries: a narrative review

BACKGROUND

Many low- and middle-income countries (LMICs) are facing a crisis of human resources for health (HRH) attributed to poor governance and leadership that characterizes the health sector in this setting. It is unclear which specific strategies are effective in ameliorating the crisis.

METHODS

Selected electronic databases were searched up until 30 May 2020. Two authors screened studies independently and extracted data from included studies. Quality assessment was done using the Mixed Methods Appraisal Tool. Thematic analysis of the outcomes was done.

RESULTS

We included 18 studies of variable designs across Africa, Asia, South America and the Pacific islands. Most were case-based studies and were of moderate to high quality. Several governance strategies with a positive impact on the health workforce and health outcomes identified included decentralization, central coordination and facilitation process, posting and transfer policies as well as the setting up of human resource units.

CONCLUSIONS

Governance and leadership strategies targeting the HRH crises in LMIC are variable, interdependent and complex. While some show benefits in improving health workforce outcomes, only a few have an impact on population health outcomes.

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.

Overexpression of Activated AMPK in the Anopheles stephensi Midgut Impacts Mosquito Metabolism, Reproduction and Plasmodium Resistance

Mitochondrial integrity and homeostasis in the midgut are key factors controlling mosquito fitness and anti-pathogen resistance. Targeting genes that regulate mitochondrial dynamics represents a potential strategy for limiting mosquito-borne diseases. AMP-activated protein kinase (AMPK) is a key cellular energy sensor found in nearly all eukaryotic cells. When activated, AMPK inhibits anabolic pathways that consume ATP and activates catabolic processes that synthesize ATP. In this study, we overexpressed a truncated and constitutively active α-subunit of AMPK under the control of the midgut-specific carboxypeptidase promotor in the midgut of female Anopheles stephensi. As expected, AMPK overexpression in homozygous transgenic mosquitoes was associated with changes in nutrient storage and metabolism, decreasing glycogen levels at 24 h post-blood feeding when transgene expression was maximal, and concurrently increasing circulating trehalose at the same time point. When transgenic lines were challenged with Plasmodium falciparum, we observed a significant decrease in the prevalence and intensity of infection relative to wild type controls. Surprisingly, we did not observe a significant difference in the survival of adult mosquitoes fed either sugar only or both sugar and bloodmeals throughout adult life. This may be due to the limited period that the transgene was activated before homeostasis was restored. However, we did observe a significant decrease in egg production, suggesting that manipulation of AMPK activity in the mosquito midgut resulted in the re-allocation of resources away from egg production. In summary, this work identifies midgut AMPK activity as an important regulator of metabolism, reproduction, and innate immunity in An. stephensi, a highly invasive and important malaria vector species.

Hematopoietic stem cell transplantation for people with sickle cell disease

BACKGROUND

Sickle cell disease is a genetic disorder involving a defect in the red blood cells due to its sickled hemoglobin. The main therapeutic interventions include preventive and supportive measures. Hematopoietic stem cell transplantations are carried out with the aim of replacing the defective cells and their progenitors (hematopoietic (i.e. blood forming) stem cells) in order to correct the disorder. This is an update of a previously published review.

OBJECTIVES

To determine whether stem cell transplantation can improve survival and prevent symptoms and complications associated with sickle cell disease. To examine the risks of stem cell transplantation against the potential long-term gain for people with sickle cell disease.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Group's Haemoglobinopathies Trials Register complied from electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (updated each new issue of the Cochrane Library) and quarterly searches of MEDLINE. We also searched trial registries for ongoing trials up to April 2020. Date of the most recent search of the Group's Haemoglobinopathies Trials Register: 09 December 2019.

SELECTION CRITERIA

Randomized controlled and quasi-randomized trials that compared any method of stem cell transplantation with either each other or with any of the preventive or supportive interventions (e.g. periodic blood transfusion, use of hydroxyurea, antibiotics, pain relievers, supplemental oxygen) in people with sickle cell disease irrespective of the type of sickle cell disease, gender and setting.

DATA COLLECTION AND ANALYSIS

No trials were eligible for inclusion in the review.

MAIN RESULTS

We identified 12 potentially-eligible trials by the searches; we excluded 11 of these and the remaining trial is an ongoing trial that may be eligible for inclusion in a future version of the review.

AUTHORS' CONCLUSIONS

Reports on the use of hematopoietic stem cell transplantation improving survival and preventing symptoms and complications associated with sickle cell disease are currently limited to observational and other less robust studies. We did not find any eligible randomized controlled trials assessing the benefit or risk of hematopoietic stem cell transplantations. However, there is an ongoing quasi-randomized trial comparing hematopoietic stem cell transplantation with standard care, Thus, this systematic review identifies the need for a multicentre randomized controlled trial assessing the benefits and possible risks of hematopoietic stem cell transplantations comparing sickle status and severity of disease in people with sickle cell disease.

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.

Interventions for improving coverage of childhood immunisation in low- and middle-income countries

BACKGROUND

Immunisation is a powerful public health strategy for improving child survival, not only by directly combating key diseases that kill children but also by providing a platform for other health services. However, each year millions of children worldwide, mostly from low- and middle-income countries (LMICs), do not receive the full series of vaccines on their national routine immunisation schedule. This is an update of the Cochrane review published in 2011 and focuses on interventions for improving childhood immunisation coverage in LMICs.

OBJECTIVES

To evaluate the effectiveness of intervention strategies to boost and sustain high childhood immunisation coverage in LMICs.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) 2016, Issue 4, part of The Cochrane Library. www.cochranelibrary.com, including the Cochrane Effective Practice and Organisation of Care (EPOC) Group Specialised Register (searched 12 May 2016); MEDLINE In-Process and Other Non-Indexed Citations, MEDLINE Daily and MEDLINE 1946 to Present, OvidSP (searched 12 May 2016); CINAHL 1981 to present, EbscoHost (searched 12 May 2016); Embase 1980 to 2014 Week 34, OvidSP (searched 2 September 2014); LILACS, VHL (searched 2 September 2014); Sociological Abstracts 1952 - current, ProQuest (searched 2 September 2014). We did a citation search for all included studies in Science Citation Index and Social Sciences Citation Index, 1975 to present; Emerging Sources Citation Index 2015 to present, ISI Web of Science (searched 2 July 2016). We also searched the two Trials Registries: ICTRP and ClinicalTrials.gov (searched 5 July 2016) SELECTION CRITERIA: Eligible studies were randomised controlled trials (RCT), non-RCTs, controlled before-after studies, and interrupted time series conducted in LMICs involving children aged from birth to four years, caregivers, and healthcare providers.

DATA COLLECTION AND ANALYSIS

We independently screened the search output, reviewed full texts of potentially eligible articles, assessed risk of bias, and extracted data in duplicate; resolving discrepancies by consensus. We then conducted random-effects meta-analyses and used GRADE to assess the certainty of evidence.

MAIN RESULTS

Fourteen studies (10 cluster RCTs and four individual RCTs) met our inclusion criteria. These were conducted in Georgia (one study), Ghana (one study), Honduras (one study), India (two studies), Mali (one study), Mexico (one study), Nicaragua (one study), Nepal (one study), Pakistan (four studies), and Zimbabwe (one study). One study had an unclear risk of bias, and 13 had high risk of bias. The interventions evaluated in the studies included community-based health education (three studies), facility-based health education (three studies), household incentives (three studies), regular immunisation outreach sessions (one study), home visits (one study), supportive supervision (one study), information campaigns (one study), and integration of immunisation services with intermittent preventive treatment of malaria (one study).We found moderate-certainty evidence that health education at village meetings or at home probably improves coverage with three doses of diphtheria-tetanus-pertussis vaccines (DTP3: risk ratio (RR) 1.68, 95% confidence interval (CI) 1.09 to 2.59). We also found low-certainty evidence that facility-based health education plus redesigned vaccination reminder cards may improve DTP3 coverage (RR 1.50, 95% CI 1.21 to 1.87). Household monetary incentives may have little or no effect on full immunisation coverage (RR 1.05, 95% CI 0.90 to 1.23, low-certainty evidence). Regular immunisation outreach may improve full immunisation coverage (RR 3.09, 95% CI 1.69 to 5.67, low-certainty evidence) which may substantially improve if combined with household incentives (RR 6.66, 95% CI 3.93 to 11.28, low-certainty evidence). Home visits to identify non-vaccinated children and refer them to health clinics may improve uptake of three doses of oral polio vaccine (RR 1.22, 95% CI 1.07 to 1.39, low-certainty evidence). There was low-certainty evidence that integration of immunisation with other services may improve DTP3 coverage (RR 1.92, 95% CI 1.42 to 2.59).

AUTHORS' CONCLUSIONS

Providing parents and other community members with information on immunisation, health education at facilities in combination with redesigned immunisation reminder cards, regular immunisation outreach with and without household incentives, home visits, and integration of immunisation with other services may improve childhood immunisation coverage in LMIC. Most of the evidence was of low certainty, which implies a high likelihood that the true effect of the interventions will be substantially different. There is thus a need for further well-conducted RCTs to assess the effects of interventions for improving childhood immunisation coverage in LMICs.

Hematopoietic stem cell transplantation for people with sickle cell disease

BACKGROUND

Sickle cell disease is a genetic disorder involving a defect in the red blood cells due to its sickled hemoglobin. The main therapeutic interventions include preventive and supportive measures. Hematopoietic stem cell transplantations are carried out with the aim of replacing the defective cells and their progenitors (hematopoietic (i.e. blood forming) stem cells) in order to correct the disorder. This is an update of a previously published review.

OBJECTIVES

To determine whether stem cell transplantation can improve survival and prevent symptoms and complications associated with sickle cell disease. To examine the risks of stem cell transplantation against the potential long-term gain for people with sickle cell disease.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Group's Haemoglobinopathies Trials Register complied from electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (updated each new issue of The Cochrane Library) and quarterly searches of MEDLINE.Unpublished work was identified by searching the abstract books of major conference proceedings and we conducted a search of the website: www.ClinicalTrials.gov.Date of the most recent search of the Group's Haemoglobinopathies Trials Register: 06 October 2015.

SELECTION CRITERIA

Randomized controlled and quasi-randomized studies that compared any method of stem cell transplantation with either each other or with any of the preventive or supportive interventions (e.g. periodic blood transfusion, use of hydroxyurea, antibiotics, pain relievers, supplemental oxygen) in people with sickle cell disease irrespective of the type of sickle cell disease, gender and setting.

DATA COLLECTION AND ANALYSIS

No relevant trials were identified.

MAIN RESULTS

Ten trials were identified by the initial search and none for the update. None of these trials were suitable for inclusion in this review.

AUTHORS' CONCLUSIONS

Reports on the use of hematopoietic stem cell transplantation improving survival and preventing symptoms and complications associated with sickle cell disease are currently limited to observational and other less robust studies. No randomized controlled trial assessing the benefit or risk of hematopoietic stem cell transplantations was found. Thus, this systematic review identifies the need for a multicentre randomized controlled trial assessing the benefits and possible risks of hematopoietic stem cell transplantations comparing sickle status and severity of disease in people with sickle cell disease.

Interventions for preventing unintended pregnancies among adolescents

BACKGROUND

Unintended pregnancy among adolescents represents an important public health challenge in high-income countries, as well as middle- and low-income countries. Numerous prevention strategies such as health education, skills-building and improving accessibility to contraceptives have been employed by countries across the world, in an effort to address this problem. However, there is uncertainty regarding the effects of these interventions, hence the need to review the evidence-base.

OBJECTIVES

To assess the effects of primary prevention interventions (school-based, community/home-based, clinic-based, and faith-based) on unintended pregnancies among adolescents.

SEARCH METHODS

We searched all relevant studies regardless of language or publication status up to November 2015. We searched the Cochrane Fertility Regulation Group Specialised trial register, The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2015 Issue 11), MEDLINE, EMBASE, LILACS, Social Science Citation Index and Science Citation Index, Dissertations Abstracts Online, The Gray Literature Network, HealthStar, PsycINFO, CINAHL and POPLINE and the reference lists of articles.

SELECTION CRITERIA

We included both individual and cluster randomised controlled trials (RCTs) evaluating any interventions that aimed to increase knowledge and attitudes relating to risk of unintended pregnancies, promote delay in the initiation of sexual intercourse and encourage consistent use of birth control methods to reduce unintended pregnancies in adolescents aged 10 years to 19 years.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial eligibility and risk of bias, and extracted data. Where appropriate, binary outcomes were pooled using a random-effects model with a 95% confidence interval (Cl). Where appropriate, we combined data in meta-analyses and assessed the quality of the evidence using the GRADE approach.

MAIN RESULTS

We included 53 RCTs that enrolled 105,368 adolescents. Participants were ethnically diverse. Eighteen studies randomised individuals, 32 randomised clusters (schools (20), classrooms (6), and communities/neighbourhoods (6). Three studies were mixed (individually and cluster randomised). The length of follow up varied from three months to seven years with more than 12 months being the most common duration. Four trials were conducted in low- and middle- income countries, and all others were conducted in high-income countries. Multiple interventionsResults showed that multiple interventions (combination of educational and contraceptive-promoting interventions) lowered the risk of unintended pregnancy among adolescents significantly (RR 0.66, 95% CI 0.50 to 0.87; 4 individual RCTs, 1905 participants, moderate quality evidence. However, this reduction was not statistically significant from cluster RCTs. Evidence on the possible effects of interventions on secondary outcomes (initiation of sexual intercourse, use of birth control methods, abortion, childbirth, sexually transmitted diseases) was not conclusive.Methodological strengths included a relatively large sample size and statistical control for baseline differences, while limitations included lack of biological outcomes, possible self-report bias, analysis neglecting clustered randomisation and the use of different statistical tests in reporting outcomes. Educational interventionsEducational interventions were unlikely to significantly delay the initiation of sexual intercourse among adolescents compared to controls (RR 0.95, 95% CI 0.71 to 1.27; 2 studies, 672 participants, low quality evidence).Educational interventions significantly increased reported condom use at last sex in adolescents compared to controls who did not receive the intervention (RR 1.18, 95% CI 1.06 to 1.32; 2 studies, 1431 participants, moderate quality evidence).However, it is not clear if the educational interventions had any effect on unintended pregnancy as this was not reported by any of the included studies. Contraceptive-promoting interventionsFor adolescents who received contraceptive-promoting interventions, there was little or no difference in the risk of unintended first pregnancy compared to controls (RR 1.01, 95% CI 0.81 to 1.26; 2 studies, 3,440 participants, moderate quality evidence).The use of hormonal contraceptives was significantly higher in adolescents in the intervention group compared to those in the control group (RR 2.22, 95% CI 1.07 to 4.62; 2 studies, 3,091 participants, high quality evidence)

AUTHORS' CONCLUSIONS

A combination of educational and contraceptive-promoting interventions appears to reduce unintended pregnancy among adolescents.  Evidence for programme effects on biological measures is limited. The variability in study populations, interventions and outcomes of included trials, and the paucity of studies directly comparing different interventions preclude a definitive conclusion regarding which type of intervention is most effective.

Mosquito genomics. Highly evolvable malaria vectors: the genomes of 16 Anopheles mosquitoes

Variation in vectorial capacity for human malaria among Anopheles mosquito species is determined by many factors, including behavior, immunity, and life history. To investigate the genomic basis of vectorial capacity and explore new avenues for vector control, we sequenced the genomes of 16 anopheline mosquito species from diverse locations spanning ~100 million years of evolution. Comparative analyses show faster rates of gene gain and loss, elevated gene shuffling on the X chromosome, and more intron losses, relative to Drosophila. Some determinants of vectorial capacity, such as chemosensory genes, do not show elevated turnover but instead diversify through protein-sequence changes. This dynamism of anopheline genes and genomes may contribute to their flexible capacity to take advantage of new ecological niches, including adapting to humans as primary hosts.

Genome analysis of a major urban malaria vector mosquito, Anopheles stephensi

Background

Anopheles stephensi is the key vector of malaria throughout the Indian subcontinent and Middle East and an emerging model for molecular and genetic studies of mosquito-parasite interactions. The type form of the species is responsible for the majority of urban malaria transmission across its range.

Results

Here, we report the genome sequence and annotation of the Indian strain of the type form of An. stephensi. The 221 Mb genome assembly represents more than 92% of the entire genome and was produced using a combination of 454, Illumina, and PacBio sequencing. Physical mapping assigned 62% of the genome onto chromosomes, enabling chromosome-based analysis. Comparisons between An. stephensi and An. gambiae reveal that the rate of gene order reshuffling on the X chromosome was three times higher than that on the autosomes. An. stephensi has more heterochromatin in pericentric regions but less repetitive DNA in chromosome arms than An. gambiae. We also identify a number of Y-chromosome contigs and BACs. Interspersed repeats constitute 7.1% of the assembled genome while LTR retrotransposons alone comprise more than 49% of the Y contigs. RNA-seq analyses provide new insights into mosquito innate immunity, development, and sexual dimorphism.

Conclusions

The genome analysis described in this manuscript provides a resource and platform for fundamental and translational research into a major urban malaria vector. Chromosome-based investigations provide unique perspectives on Anopheles chromosome evolution. RNA-seq analysis and studies of immunity genes offer new insights into mosquito biology and mosquito-parasite interactions.

Electronic supplementary material

The online version of this article (doi:10.1186/s13059-014-0459-2) contains supplementary material, which is available to authorized users.

Hematopoietic stem cell transplantation for people with sickle cell disease

BACKGROUND

Sickle cell disease is a genetic disorder involving a defect in the red blood cells due to its sickled hemoglobin. The main therapeutic interventions include preventive and supportive measures. Hematopoietic stem cell transplantations are carried out with the aim of replacing the defective cells and their progenitors (hematopoietic (i.e. blood forming) stem cells) in order to correct the disorder.

OBJECTIVES

To determine whether stem cell transplantation can improve survival and prevent symptoms and complications associated with sickle cell disease. To examine the risks of stem cell transplantation against the potential long-term gain for people with sickle cell disease.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Group's Haemoglobinopathies Trials Register complied from electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (updated each new issue of The Cochrane Library) and quarterly searches of MEDLINE.Unpublished work was identified by searching the abstract books of major conference proceedings and we conducted a search of the website: www.ClinicalTrials.gov.Date of the most recent search of the Group's Haemoglobinopathies Trials Register: 16 August 2012.

SELECTION CRITERIA

Randomized controlled and quasi-randomized studies that compared any method of stem cell transplantation with either each other or with any of the preventive or supportive interventions (e.g. periodic blood transfusion, use of hydroxyurea, antibiotics, pain relievers, supplemental oxygen) in people with sickle cell disease irrespective of the type of sickle cell disease, gender and setting.

DATA COLLECTION AND ANALYSIS

No relevant trials were identified.

MAIN RESULTS

Ten trials were identified by the initial search and none for the update. None of these trials were suitable for inclusion in this review.

AUTHORS' CONCLUSIONS

Reports on the use of hematopoietic stem cell transplantation improving survival and preventing symptoms and complications associated with sickle cell disease are currently limited to observational and other less robust studies. No randomized controlled trial assessing the benefit or risk of hematopoietic stem cell transplantations was found. Thus, this systematic review identifies the need for a multicentre randomized controlled trial assessing the benefits and possible risks of hematopoietic stem cell transplantations comparing sickle status and severity of disease in people with sickle cell disease.

Open-label trial of three dosage regimens of fixed-dose combination of artemisinin and naphthoquine for treating uncomplicated falciparum malaria in Calabar, Nigeria

BACKGROUND

The use of anti-malarial drug combinations with artemisinin, or with one of its derivatives, is now widely recommended to overcome drug resistance in falciparum malaria. Fixed-dose combination of artemisinin and naphthoquine is a new generation artemisinin combination therapy (ACT) offered as a single dose therapy. The aim of the study was to assess the therapeutic efficacy, safety and tolerability of three dosage schedules of fixed-dose combination of artemisinin (125 mg) and naphthoquine (50 mg) for treating uncomplicated Plasmodium falciparum malaria among adolescents and adults in Calabar, South-east Nigeria.

METHOD

A total of 121 patients aged ≥15 years with uncomplicated P. falciparum malaria were enrolled and randomly assigned to three dosage schedules: (A) 700 mg (four tablets) single dose; (B) 700 mg 12-hourly x two doses; and (C) 1,400 mg (eight tablets) single dose. Patients were observed for 28 days, with clinical, parasitological, and haematological assessments.

RESULTS

A total of 108 patients completed the study. The overall 28-day cure rate was 88.9%. Day 28-cure rates of the three dosage schedules were 85.3%, 93.1% and 88.9% for Group A, B and C respectively. Adverse events were few and mild, the commonest being weakness and headache; there was no serious adverse event.

CONCLUSION

Concerns for emergence of parasite resistance due to the use of artemisinin-naphthoquine as single dose regimen is likely to compromise the usefulness of this potentially important combination treatment. A robust multi-centre trial is recommended to evaluate a three-day regimen with potentials to achieve high cure rates while minimizing the risk of emergence of resistant parasite strains.

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.

Interventions for improving coverage of child immunization in low- and middle-income countries

BACKGROUND

Immunization coverage remains low, particularly in low- and middle-income countries (LMIC), despite its proven effectiveness in reducing the burden of childhood infectious diseases. A Cochrane review has shown that patient reminder recall is effective in improving coverage of immunization but technologies to support this strategy are lacking in LMIC.

OBJECTIVES

To evaluate the effectiveness of intervention strategies to boost and sustain high childhood immunization coverage in LMIC.

SEARCH STRATEGY

We searched the following databases for primary studies: Cochrane Central Register of Controlled Trials (CENTRAL) 2010, Issue 1, part of The Cochrane Library. www.thecochranelibrary.com, including the Cochrane Effective Practice and Organisation of Care (EPOC) Group Specialised Register (searched 8 July 2010); MEDLINE, Ovid (1948 to March Week 3 2011) (searched 30 March 2011); EMBASE, Ovid (1980 to 2010 Week 26) (searched 8 July 2010); CINAHL, EBSCO (1981 to present ) (searched 8 July 2010); LILACS, VHL (1982 to present) (searched 8 July 2010); Sociological Abstracts, CSA Illumnia (1952 to current) (searched 8 July 2010). Reference lists of all papers and relevant reviews were identified and searched for additional studies.

SELECTION CRITERIA

Included studies were randomized controlled trials (RCTs), non-randomized controlled trials (NRCTs), and interrupted-time-series (ITS) studies. Study participants were children aged 0 to 4 years, caregivers, and health providers. Interventions included patient and community-oriented interventions, provider-oriented interventions, health system interventions, multi-faceted (any combination of the above categories of interventions), and any other single or multifaceted intervention intended to improve childhood immunisation coverage The primary outcome was the proportion of the target population fully immunized with recommended vaccines by age.

DATA COLLECTION AND ANALYSIS

Two authors independently screened full articles of selected studies, extracted data, and assessed study quality.

MAIN RESULTS

Six studies were included in the review; four were at high risk of bias. There was low quality evidence that: facility based health education may improve the uptake of combined vaccine against diphtheria, pertussis, and tetanus (DPT3) coverage (risk ratio (RR) 1.18; 95% CI 1.05 to 1.33); and also that a combination of facility based health education and redesigned immunization cards may improve DPT3 coverage (RR 1.36; 95% CI 1.22 to 1.51). There was also moderate quality evidence that: evidence-based discussions probably improve DPT3 coverage (RR 2.17; 95% CI 1.80 to 2.61), and that information campaigns probably increase uptake of at least a dose of a vaccine (RR 1.43; 95% CI 1.01 to 2.02).

AUTHORS' CONCLUSIONS

Home visits and health education may improve immunization coverage but the quality of evidence is low.

Priority setting for systematic review of health care interventions in Nigeria

OBJECTIVES

In an era of evidence based medicine and systematic review, this study seeks to identify priority systematic review topics that address common health problems in Nigeria.

METHODS

Firstly, a primary list of health problems was compiled from the National Health Management Information Systems and information from key informants (health professionals, researchers and NGOs) drawn from the six geo-political zones in Nigeria. Key steps included compilation and ranking of a comprehensive list of health problems into 4 categories: adult communicable, non-communicable, maternal and child health; searching the Cochrane Library and electronic databases for systematic reviews on identified priority problems, analysis of search outputs to identify gaps; listing and ranking of new priority systematic review topics using pre-determined criteria.

RESULTS

Eighteen questions made the final list of priorities systematic reviews and 9 of them were related to malaria. There were 7 additional issues that the panelists identified as crucial cross-cutting issues that need to be addressed in systematic reviews.

CONCLUSION

Identification and prioritization of systematic reviews relevant to health care in Nigeria will improve the opportunity to deliver evidence-based and equitable health care to the people. These topics are likely to be also important for health care decision in other resource-poor settings.

Patterns of cord, placental and post-delivery maternal malaria parasitemia

Malaria transmission is high and perennial in south-east Nigeria and is associated with a high burden of morbidity and mortality in children under 5 years and pregnant women. It is associated with maternal anemia, placental infection, intrauterine growth retardation and low birth weight. To evaluate the status of malaria in pregnancy in Cross River State, Nigeria, we assessed the prevalence rates of maternal, cord and placental malaria parasitemia in the dry and rainy seasons for 626 consecutively recruited pregnant women who delivered at two rural and two urban health facilities. Demographic data were obtained at delivery and maternal, placental and cord blood samples were collected and examined for malaria parasites by light microscopy. Of the mother and infant pairs, 120 (19.2%), 69 (14.7%) and 62 (13.5%), respectively, had positive maternal, placental and cord blood parasitemia. Parasitemia rates in the rainy season were higher than in the dry season (p < 0.05). There were no significant differences in maternal, placental and cord parasitemia between urban and rural areas. The prevalence rates of parasitemia at delivery indicate high malaria transmission and poor control during pregnancy.

Interventions for preventing unintended pregnancies among adolescents

BACKGROUND

Unintended pregnancy among adolescents represent an important public health challenge in developed and developing countries. Numerous prevention strategies such as health education, skills-building and improving accessibility to contraceptives have been employed by countries across the world, in an effort to address this problem. However, there is uncertainty regarding the effects of these intervention, and hence the need to review their evidence-base

OBJECTIVES

To assess the effects of primary prevention interventions (school-based, community/home-based, clinic-based, and faith-based) on unintended pregnancies among adolescents.

SEARCH STRATEGY

We searched electronic databases (CENTRAL, PubMed, EMBASE) ending December 2008. Cross-referencing, hand-searching, and contacting experts yielded additional citations.

SELECTION CRITERIA

We included both individual and cluster randomized controlled trials (RCTs) evaluating any interventions that aimed to increase knowledge and attitudes relating to risk of unintended pregnancies, promote delay in the initiation of sexual intercourse and encourage consistent use of birth control methods to reduce unintended pregnancies in adolescents aged 10-19 years.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial eligibility and risk of bias in studies that met the inclusion criteria. Where appropriate, binary outcomes were pooled using random effects model with a 95% confidence interval (Cl).

MAIN RESULTS

Forty one RCTs that enrolled 95,662 adolescents were included. Participants were ethnically diverse. Eleven studies randomized individuals, twenty seven randomized clusters (schools (19), classrooms (5), and communities/neighbourhoods (3). Three studies were mixed (individually and cluster randomized). The length of follow up varied from 3 months to 4.5 years. Data could only be pooled for a number of studies (15) because of variations in the reporting of outcomes. Results showed that multiple interventions (combination of educational and contraceptive interventions) lowered the rate of unintended pregnancy among adolescents. Evidence on the possible effects of interventions on secondary outcomes (initiation of sexual intercourse, use of birth control methods, abortion, childbirth, sexually transmitted diseases) is not conclusive.Methodological strengths included a relatively large sample size and statistical control for baseline differences, while limitations included lack of biological outcomes, possible self-report bias, analysis neglecting clustered randomization and the use of different statistical test in reporting outcomes.

AUTHORS' CONCLUSIONS

Combination of educational and contraceptive interventions appears to reduce unintended pregnancy among adolescents. Evidence for program effects on biological measures is limited. The variability in study populations, interventions and outcomes of included trials, and the paucity of studies directly comparing different interventions preclude a definitive conclusion regarding which type of intervention is most effective.

Hematopoietic stem cell transplantation for children with sickle cell disease

BACKGROUND

Sickle cell disease is a genetic disorder involving a defect in the red blood cells due to its sickled hemoglobin. The main therapeutic interventions include preventive and supportive measures. Hematopoietic stem cell transplantations are carried out with the aim of replacing the defective cells and their progenitors (hematopoietic (i.e. blood forming) stem cells) in order to correct the disorder.

OBJECTIVES

To determine whether stem cell transplantation can improve survival and prevent symptoms and complications associated with sickle cell disease. To examine the risks of stem cell transplantation against the potential long-term gain for people with sickle cell disease.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Group's Haemoglobinopathies Trials Register complied from electronic searches of the Cochrane Central Register of Controlled Trials (Clinical Trials) (updated each new issue of The Cochrane Library) and quarterly searches of MEDLINE.Unpublished work was identified by searching the abstract books of major conference proceedings and we conducted a search of the website: www.ClinicalTrials.gov.Date of the most recent search of the Group's Haemoglobinopathies Trials Register: September 2008.

SELECTION CRITERIA

Randomized controlled and quasi-randomized studies that compared any method of stem cell transplantation with either each other or with any of the preventive or supportive interventions (e.g. periodic blood transfusion, use of hydroxyurea, antibiotics, pain relievers, supplemental oxygen) in children under 16 years of age irrespective of the type of sickle cell disease, gender and setting.

DATA COLLECTION AND ANALYSIS

No relevant trials have been identified.

MAIN RESULTS

Ten trials were identified by the initial search of which none were suitable for inclusion in this review.

AUTHORS' CONCLUSIONS

Reports on the use of hematopoietic stem cell transplantation improving survival and preventing symptoms and complications associated with sickle cell disease are currently limited to observational and other less robust studies. No randomized controlled trial has assessed the benefit or risk of different types of hematopoietic stem cell transplantations in children. Thus, this systematic review identifies the need for a multicentre randomized controlled trial assessing the benefits and possible risks of different types of hematopoietic stem cell transplantations comparing sickle status and severity of disease in children.