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The Cochrane Database of Systematic... Sep 2021Anaemia is a prevalent health problem worldwide. Some types are preventable or controllable with iron supplementation (pills or drops), fortification (sprinkles or... (Review)
Review
BACKGROUND
Anaemia is a prevalent health problem worldwide. Some types are preventable or controllable with iron supplementation (pills or drops), fortification (sprinkles or powders containing iron added to food) or improvements to dietary diversity and quality (e.g. education or counselling).
OBJECTIVES
To summarise the evidence from systematic reviews regarding the benefits or harms of nutrition-specific interventions for preventing and controlling anaemia in anaemic or non-anaemic, apparently healthy populations throughout the life cycle.
METHODS
In August 2020, we searched MEDLINE, Embase and 10 other databases for systematic reviews of randomised controlled trials (RCTs) in anaemic or non-anaemic, apparently healthy populations. We followed standard Cochrane methodology, extracting GRADE ratings where provided. The primary outcomes were haemoglobin (Hb) concentration, anaemia, and iron deficiency anaemia (IDA); secondary outcomes were iron deficiency (ID), severe anaemia and adverse effects (e.g. diarrhoea, vomiting).
MAIN RESULTS
We included 75 systematic reviews, 33 of which provided GRADE assessments; these varied between high and very low. Infants (6 to 23 months; 13 reviews) Iron supplementation increased Hb levels and reduced the risk of anaemia and IDA in two reviews. Iron fortification of milk or cereals, multiple-micronutrient powder (MMNP), home fortification of complementary foods, and supplementary feeding increased Hb levels and reduced the risk of anaemia in six reviews. In one review, lipid-based nutrient supplementation (LNS) reduced the risk of anaemia. In another, caterpillar cereal increased Hb levels and IDA prevalence. Food-based strategies (red meat and fortified cow's milk, beef) showed no evidence of a difference (1 review). Preschool and school-aged children (2 to 10 years; 8 reviews) Daily or intermittent iron supplementation increased Hb levels and reduced the risk of anaemia and ID in two reviews. One review found no evidence of difference in Hb levels, but an increased risk of anaemia and ID for the intermittent regime. All suggested that zinc plus iron supplementation versus zinc alone, multiple-micronutrient (MMN)-fortified beverage versus control, and point-of-use fortification of food with iron-containing micronutrient powder (MNP) versus placebo or no intervention may increase Hb levels and reduce the risk of anaemia and ID. Fortified dairy products and cereal food showed no evidence of a difference on the incidence of anaemia (1 review). Adolescent children (11 to 18 years; 4 reviews) Compared with no supplementation or placebo, five types of iron supplementation may increase Hb levels and reduce the risk of anaemia (3 reviews). One review on prevention found no evidence of a difference in anaemia incidence on iron supplementation with or without folic acid, but Hb levels increased. Another suggested that nutritional supplementation and counselling reduced IDA. One review comparing MMN fortification with no fortification observed no evidence of a difference in Hb levels. Non-pregnant women of reproductive age (19 to 49 years; 5 reviews) Two reviews suggested that iron therapy (oral, intravenous (IV), intramuscular (IM)) increased Hb levels; one showed that iron folic acid supplementation reduced anaemia incidence; and another that daily iron supplementation with or without folic acid or vitamin C increased Hb levels and reduced the risk of anaemia and ID. No review reported interventions related to fortification or dietary diversity and quality. Pregnant women of reproductive age (15 to 49 years; 23 reviews) One review apiece suggested that: daily iron supplementation with or without folic acid increased Hb levels in the third trimester or at delivery and in the postpartum period, and reduced the risk of anaemia, IDA and ID in the third trimester or at delivery; intermittent iron supplementation had no effect on Hb levels and IDA, but increased the risk of anaemia at or near term and ID, and reduced the risk of side effects; vitamin A supplementation alone versus placebo, no intervention or other micronutrient might increase maternal Hb levels and reduce the risk of maternal anaemia; MMN with iron and folic acid versus placebo reduced the risk of anaemia; supplementation with oral bovine lactoferrin versus oral ferrous iron preparations increased Hb levels and reduced gastrointestinal side effects; MNP for point-of-use fortification of food versus iron and folic acid supplementation might decrease Hb levels at 32 weeks' gestation and increase the risk of anaemia; and LNS versus iron or folic acid and MMN increased the risk of anaemia. Mixed population (all ages; 22 reviews) Iron supplementation versus placebo or control increased Hb levels in healthy children, adults, and elderly people (4 reviews). Hb levels appeared to increase and risk of anaemia and ID decrease in two reviews investigating MMN fortification versus placebo or no treatment, iron fortified flour versus control, double fortified salt versus iodine only fortified salt, and rice fortification with iron alone or in combination with other micronutrients versus unfortified rice or no intervention. Each review suggested that fortified versus non-fortified condiments or noodles, fortified (sodium iron ethylenediaminetetraacetate; NaFeEDTA) versus non-fortified soy sauce, and double-fortified salt versus control salt may increase Hb concentration and reduce the risk of anaemia. One review indicated that Hb levels increased for children who were anaemic or had IDA and received iron supplementation, and decreased for those who received dietary interventions. Another assessed the effects of foods prepared in iron pots, and found higher Hb levels in children with low-risk malaria status in two trials, but no difference when comparing food prepared in non-cast iron pots in a high-risk malaria endemicity mixed population. There was no evidence of a difference for adverse effects. Anaemia and malaria prevalence were rarely reported. No review focused on women aged 50 to 65 years plus or men (19 to 65 years plus).
AUTHORS' CONCLUSIONS
Compared to no treatment, daily iron supplementation may increase Hb levels and reduce the risk of anaemia and IDA in infants, preschool and school-aged children and pregnant and non-pregnant women. Iron fortification of foods in infants and use of iron pots with children may have prophylactic benefits for malaria endemicity low-risk populations. In any age group, only a limited number of reviews assessed interventions to improve dietary diversity and quality. Future trials should assess the effects of these types of interventions, and consider the requirements of different populations.
Topics: Adolescent; Adult; Aged; Anemia; Anemia, Iron-Deficiency; Animals; Child; Dietary Supplements; Female; Food, Fortified; Humans; Iron; Life Cycle Stages; Male; Micronutrients; Middle Aged; Pregnancy; Systematic Reviews as Topic; Young Adult
PubMed: 34564844
DOI: 10.1002/14651858.CD013092.pub2 -
BMC Gastroenterology Jul 2021The chronic and progressive evolution of Inflammatory Bowel Diseases (IBD), with its prototypical fluctuating trend, creates a condition of psycho-social discomfort,... (Review)
Review
BACKGROUND
The chronic and progressive evolution of Inflammatory Bowel Diseases (IBD), with its prototypical fluctuating trend, creates a condition of psycho-social discomfort, impacting the quality of life in terms of personal, working, and interpersonal.
AIMS
In this article, we want to identify the nature and extent of the research evidence on the life experiences, the perceived engagement, the psychological, social care and welfare needs of people affected by IBD across the lifecycle.
METHODS
Following the approach set out by Arksey and O'Malley and the PRISMA extension for scoping reviews, we conducted a scoping review in March 2019 and closed the review with an update in October 2019. It was performed using electronic databases covering Health and Life Sciences, Social Sciences and Medical Sciences, such as PubMed, Medline, Embase, Scopus, Cochrane, Web of Science, PsycInfo.
RESULTS
We identified 95 peer-reviewed articles published from 2009 to 2019, that allowed to detection the main needs in children (psychological, need to be accepted, physical activity, feeding, parent style, support, social needs), adolescents (to understand, physical and psychological needs, protection, relational, gratitude, respect, and engagement) and adults (information, medical, psychological, social, work-related, practical, future-related, engagement). Although the literature confirms that the majority of the IBD units have planned provision for the different types of transitions, the quality and appropriateness of these services have not been assessed or audited for all the kinds of challenges across the life cycle.
CONCLUSIONS
The literature shows the relevance of organizing a flexible, personalized health care process across all the critical phases of the life cycle, providing adequate benchmarks for comparison in a multidisciplinary perspective and ensuring continuity between hospital and territory.
Topics: Adolescent; Adult; Animals; Child; Humans; Inflammatory Bowel Diseases; Life Cycle Stages; Parents; Quality of Life; Social Support
PubMed: 34261434
DOI: 10.1186/s12876-021-01850-1 -
NPJ Science of Food Aug 2023The consumption of insects as food and feed has been recently suggested as a possible alternative to the rising global food need, thus it is crucial to monitor any... (Review)
Review
The consumption of insects as food and feed has been recently suggested as a possible alternative to the rising global food need, thus it is crucial to monitor any potential food safety hazards in the insect supply chain. The aims of this systematic review were to collect, select, and evaluate studies investigating the persistence of Salmonella in insects. We searched PUBMED, EMBASE, WEB of Science Core Collection, and Food Science and Technology Abstracts. In total, 36 papers investigating the persistence of Salmonella in insects (both holometabolous and heterometabolous) were included after screening. Regarding complete metamorphosis insects, the longest Salmonella persistence was reported in Phormia regina, in which the pathogen persisted for 29 days at 5 °C. Similarly, Salmonella persisted in the feces of Alphitobius diaperinus for 28 days. The incomplete metamorphosis insect showing the longest Salmonella persistence (>10 months) was Blatella germanica. Periplaneta americana excreted Salmonella via feces for 44 days until all the insects were dead. The retrieved data on the persistence of Salmonella can be useful for further analysis by risk assessors and decision-makers involved in the safety of insect-based food, contributing to defining the sanitary requirements and risk mitigation measures along the supply chain. The review protocol is registered in PROSPERO database (CRD42022329213).
PubMed: 37640696
DOI: 10.1038/s41538-023-00223-0 -
The Cochrane Database of Systematic... Aug 2019Larviciding refers to the regular application of chemical or microbial insecticides to water bodies or water containers to kill the aquatic immature forms of the...
BACKGROUND
Larviciding refers to the regular application of chemical or microbial insecticides to water bodies or water containers to kill the aquatic immature forms of the mosquito (the larvae and pupae).
OBJECTIVES
To summarize research evidence evaluating whether larviciding with chemical or microbial insecticides prevents 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; Embase; CAB Abstracts; LILACS; the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP); ClinicalTrials.gov; and the ISRCTN registry up to 6 June 2019.
SELECTION CRITERIA
We included cluster-randomized controlled trials (cRCTs), interrupted time series (ITS), randomized cross-over studies, non-randomized cross-over studies, and controlled before-and-after studies (CBAs) that compared larviciding with no larviciding.
DATA COLLECTION AND ANALYSIS
We independently assessed trials for eligibility and risk of bias, and extracted data. We assessed the certainty of evidence using the GRADE approach.
MAIN RESULTS
Four studies (one cRCT, two CBAs, and one non-randomized cross-over design) met the inclusion criteria. All used ground application of larvicides (people hand-delivering larvicides); one evaluated chemical and three evaluated microbial agents. Studies were carried out in The Gambia, Tanzania, Kenya, and Sri Lanka. Three studies were conducted in areas where mosquito aquatic habitats were less extensive (< 1 km²), and one where habitats were more extensive (> 1 km²; a cross-over study from The Gambia).For aquatic habitats of less than 1 km², one cRCT randomized eight villages in Sri Lanka to evaluate chemical larviciding using insect growth regulator; and two CBA studies undertaken in Kenya and Tanzania evaluated microbial larvicides. In the cRCT, larviciding across all villages was associated with lower malaria incidence (rate ratio 0.24, 4649 participants, low-certainty evidence) and parasite prevalence (risk ratio (RR) 0.26, 5897 participants, low-certainty evidence) compared to no larviciding. The two CBA studies reported lower malaria prevalence during the intervention period (parasite prevalence RR 0.79, 95% confidence interval (CI) 0.71 to 0.89; 70,902 participants; low-certainty evidence). The Kenyan study also reported a reduction in the incidence of new malaria cases (RR 0.62, 95% CI 0.38 to 1.01; 720 participants; very low-certainty evidence).For aquatic habitats of more than 1 km², the non-randomized cross-over trial using microbial larvicides did not detect an effect for malaria incidence (RR 1.58, 95% CI 0.94 to 2.65; 4226 participants), or parasite prevalence (RR 1.15, 95% CI 0.41 to 3.20; 3547 participants); both were very low-certainty evidence. The Gambia trial also reported the mean haemoglobin level, and there was no difference across the four comparisons (mean difference -0.13, 95% CI -0.40 to 0.13; 3586 participants).We were unable to summarize or pool entomological outcomes due to unreported and missing data.
AUTHORS' CONCLUSIONS
Most controlled studies on larviciding have been performed with microbial agents. Ground larviciding for non-extensive larval habitats may have an effect on malaria transmission, and we do not know if there is an effect in large-scale aquatic habitats. We found no studies using larviciding application techniques that could cover large aquatic habitats, such as aerial spraying using aircraft.
Topics: Animals; Culicidae; Disease Reservoirs; Ecosystem; Humans; Insecticides; Interrupted Time Series Analysis; Larva; Malaria; Mosquito Control; Randomized Controlled Trials as Topic
PubMed: 31425624
DOI: 10.1002/14651858.CD012736.pub2 -
PLoS Neglected Tropical Diseases Oct 2019Myiasis due to Old World screw-worm fly, Chrysomya bezziana, is an important obligate zoonotic disease in the OIE-list of diseases and is found throughout much of...
BACKGROUND
Myiasis due to Old World screw-worm fly, Chrysomya bezziana, is an important obligate zoonotic disease in the OIE-list of diseases and is found throughout much of Africa, the Indian subcontinent, southeast and east Asia. C. bezziana myiasis causes not only morbidity and death to animals and humans, but also economic losses in the livestock industries. Because of the aggressive and destructive nature of this disease in hosts, we initiated this study to provide a comprehensive understanding of human myiasis caused by C. bezziana.
METHODS
We searched the databases in English (PubMed, Embase and African Index Medicus) and Chinese (CNKI, Wanfang, and Duxiu), and international government online reports to 6th February, 2019, to identify studies concerning C. bezziana. Another ten human cases in China and Papua New Guinea that our team had recorded were also included.
RESULTS
We retrieved 1,048 reports from which 202 studies were ultimately eligible for inclusion in the present descriptive analyses. Since the first human case due to C. bezziana was reported in 1909, we have summarized 291 cases and found that these cases often occurred in patients with poor hygiene, low socio-economic conditions, old age, and underlying diseases including infections, age-related diseases, and noninfectious chronic diseases. But C. bezziana myiasis appears largely neglected as a serious medical or veterinary condition, with human and animal cases only reported in 16 and 24 countries respectively, despite this fly species being recorded in 44 countries worldwide.
CONCLUSION
Our findings indicate that cryptic myiasis cases due to the obligate parasite, C. bezziana, are under-recognized. Through this study on C. bezziana etiology, clinical features, diagnosis, treatment, epidemiology, prevention and control, we call for more vigilance and awareness of the disease from governments, health authorities, clinicians, veterinary workers, nursing homes, and also the general public.
Topics: Animals; Databases, Factual; Diptera; Humans; Hygiene; Life Cycle Stages; Screw Worm Infection; Socioeconomic Factors; Treatment Outcome; Zoonoses
PubMed: 31618203
DOI: 10.1371/journal.pntd.0007391 -
PloS One 2019Bees and the pollination services they deliver are beneficial to both food crop production, and for reproduction of many wild plant species. Bee decline has stimulated...
Bees and the pollination services they deliver are beneficial to both food crop production, and for reproduction of many wild plant species. Bee decline has stimulated widespread interest in assessing hazards and risks to bees from the environment in which they live. While there is increasing knowledge on how the use of broad-spectrum insecticides in agricultural systems may impact bees, little is known about effects of other pesticides (or plant protection products; PPPs) such as herbicides and fungicides, which are used more widely than insecticides at a global scale. We adopted a systematic approach to review existing research on the potential impacts of fungicides and herbicides on bees, with the aim of identifying research approaches and determining knowledge gaps. While acknowledging that herbicide use can affect forage availability for bees, this review focussed on the potential impacts these compounds could have directly on bees themselves. We found that most studies have been carried out in Europe and the USA, and investigated effects on honeybees. Furthermore, certain effects, such as those on mortality, are well represented in the literature in comparison to others, such as sub-lethal effects. More studies have been carried out in the lab than in the field, and the impacts of oral exposure to herbicides and fungicides have been investigated more frequently than contact exposure. We suggest a number of areas for further research to improve the knowledge base on potential effects. This will allow better assessment of risks to bees from herbicides and fungicides, which is important to inform future management decisions around the sustainable use of PPPs.
Topics: Animals; Bees; Fungicides, Industrial; Herbicides; Life Cycle Stages; Research; Species Specificity
PubMed: 31821341
DOI: 10.1371/journal.pone.0225743 -
Journal of Medical Entomology Jan 2024Mosquito-borne diseases (MBDs) are emerging in response to climate and land use changes. As mosquito (Diptera: Culicidae) habitat selection is often contingent on water... (Meta-Analysis)
Meta-Analysis
Mosquito-borne diseases (MBDs) are emerging in response to climate and land use changes. As mosquito (Diptera: Culicidae) habitat selection is often contingent on water availability for egg and larval development, studies have recognized water quality also influences larval habitats. However, underlying species-, genera-, and mosquito level preferences for water quality conditions are varied. This systematic review and meta-analysis aimed to identify, characterize, appraise, and synthesize available global data on the relationships between water quality and mosquito presence and abundance (MPA); with the goal to further our understanding of the geographic expansion of MBD risks. A systematic review was conducted to identify studies investigating the relationships between water quality properties and MPA. Where appropriate, random-effects meta-analyses were conducted to provide pooled estimates for the association between the most reported water quality properties and MPA. The most reported water quality parameters were pH (87%), nitrogen concentrations (56%), turbidity (56%), electrical conductivity (54%), dissolved oxygen (43%), phosphorus concentrations (30%), and alkalinity (10%). Overall, pH (P = 0.05), turbidity (P < 0.0001), electrical conductivity (P = 0.005), dissolved oxygen (P < 0.0001), nitrogen (P < 0.0001), and phosphorus (P < 0.0001) showed significantly positive pooled correlations with MPA, while alkalinity showed a nonsignificant null pooled correlation (P = 0.85). We observed high heterogeneity in most meta-analyses, and climate zonation was shown to influence the pooled estimates. Linkages between MPA and water quality properties will enhance our capacity to predict MBD risks under changing environmental and land use changes.
Topics: Animals; Culicidae; Water Quality; Ecosystem; Oxygen; Nitrogen; Phosphorus; Larva
PubMed: 37832159
DOI: 10.1093/jme/tjad139 -
The Lancet. Microbe Oct 2022Various studies have evaluated the infection of Ixodes ticks and humans with the relapsing fever spirochaete Borrelia miyamotoi. However, to our knowledge, the... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Various studies have evaluated the infection of Ixodes ticks and humans with the relapsing fever spirochaete Borrelia miyamotoi. However, to our knowledge, the prevalence of infection and disease has not been assessed systematically. We aimed to examine the prevalence of B miyamotoi in Ixodes ticks and humans, and the disease it can cause, in the northern hemisphere.
METHODS
For this systematic review and meta-analysis, we searched PubMed and Web of Science up to March 1, 2021. Studies assessing Ixodes tick infection published since Jan 1, 2011 were eligible, whereas no time limitation was placed on reports of human infection and disease. We extracted B miyamotoi test positivity ratios and used a random-effects model to calculate estimated proportions of infected ticks, infected humans, and human disease with 95% CI. This study was registered with PROSPERO, CRD42021268996.
FINDINGS
We identified 730 studies through database searches and 316 additional studies that referenced two seminal articles on B miyamotoi. Of these 1046 studies, 157 were included in the review, reporting on 165 637 questing ticks, 45 608 unique individuals, and 504 well described cases of B miyamotoi disease in humans. In ticks, the highest prevalence of B miyamotoi was observed in Ixodes persulcatus (2·8%, 95% CI 2·4-3·1) and the lowest in Ixodes pacificus (0·7%, 0·6-0·8). The overall seroprevalence in humans was 4·4% (2·8-6·3), with significantly (p<0·0001) higher seroprevalences in the high-risk group (4·6%, 2·6-7·1), participants with confirmed or suspected Lyme borreliosis (4·8%, 1·8-8·8), and individuals suspected of having a different tick-borne disease (11·9%, 5·6-19·9) than in healthy controls (1·3%, 0·4-2·8). Participants suspected of having a different tick-borne disease tested positive for B miyamotoi by PCR significantly more often than did the high-risk group (p=0·025), with individuals in Asia more likely to test positive than those in the USA (odds ratio 14·63 [95% CI 2·80-76·41]).
INTERPRETATION
B miyamotoi disease should be considered an emerging infectious disease, especially in North America and Asia. Prospective studies and increased awareness are required to obtain further insights into the burden of disease.
FUNDING
ZonMW and the European Regional Development Fund (Interreg).
Topics: Animals; Borrelia; Humans; Ixodes; Nymph; Prevalence; Prospective Studies; Seroepidemiologic Studies; Tick-Borne Diseases
PubMed: 36113496
DOI: 10.1016/S2666-5247(22)00157-4 -
PLoS Neglected Tropical Diseases Oct 2022Schistosomiasis is a parasitic disease that is endemic in 78 countries and affects almost 240 million people worldwide. It has been acknowledged that an integrated...
BACKGROUND
Schistosomiasis is a parasitic disease that is endemic in 78 countries and affects almost 240 million people worldwide. It has been acknowledged that an integrated approach that goes beyond drug treatment is needed to achieve control and eventual elimination of the disease. Improving hygiene has been encouraged by World Health Organisation, and one aspect of good hygiene is using soap during water-contact activities, such as bathing and doing laundry. This hygiene practice might directly reduce the skin exposure to cercariae at transmission sites. A systematic review was carried out to investigate the efficacy of soap against schistosome cercariae and to identify the knowledge gaps surrounding this topic.
METHODOLOGY
Six online databases were searched between 5th and 8th July of 2021. Records returned from these databases were screened to remove duplicates, and the remaining records were classified by reading titles, abstracts, and full texts to identify the included studies. The results were categorised into two groups based on two different protective mechanisms of soap (namely, damage to cercariae and protection of skin).
CONCLUSIONS
Limited research has been conducted on the efficacy of soap against schistosome cercariae and only 11 studies met the criteria to be included in this review. The review demonstrates that soap has the potential of protecting people against schistosome cercariae and there are two protective aspects: (1) soap affects cercariae adversely; (2) soap on the skin prevents cercariae from penetrating the skin, developing into adult worms and producing eggs. Both aspects of protection were influenced by many factors, but the differences in the reported experimental conditions, such as the cercarial endpoint measurement used and the cercaria numbers used per water sample, lead to low comparability between the previous studies. This review indicates that more evidence is needed to inform hygiene advice for people living in schistosomiasis endemic areas.
Topics: Animals; Cercaria; Schistosoma; Schistosomiasis; Soaps; Water
PubMed: 36191022
DOI: 10.1371/journal.pntd.0010820 -
The Cochrane Database of Systematic... Nov 2022Larval source management (LSM) may help reduce Plasmodium parasite transmission in malaria-endemic areas. LSM approaches include habitat modification (permanently or... (Review)
Review
BACKGROUND
Larval source management (LSM) may help reduce Plasmodium parasite transmission in malaria-endemic areas. LSM approaches include habitat modification (permanently or temporarily reducing mosquito breeding aquatic habitats); habitat manipulation (temporary or recurrent change to environment); or use of chemical (e.g. larviciding) or biological agents (e.g. natural predators) to breeding sites. We examined the effectiveness of habitat modification or manipulation (or both), with and without larviciding. This is an update of a review published in 2013.
OBJECTIVES
1. To describe and summarize the interventions on mosquito aquatic habitat modification or mosquito aquatic habitat manipulation, or both, on malaria control. 2. To evaluate the beneficial and harmful effects of mosquito aquatic habitat modification or mosquito aquatic habitat manipulation, or both, on malaria control.
SEARCH METHODS
We used standard, extensive Cochrane search methods. The latest search was from January 2012 to 30 November 2021.
SELECTION CRITERIA
Randomized controlled trials (RCT) and non-randomized intervention studies comparing mosquito aquatic habitat modification or manipulation (or both) to no treatment or another active intervention. We also included uncontrolled before-after (BA) studies, but only described and summarized the interventions from studies with these designs. Primary outcomes were clinical malaria incidence, malaria parasite prevalence, and malaria parasitaemia incidence.
DATA COLLECTION AND ANALYSIS
We used standard Cochrane methods. We assessed risk of bias using the Cochrane RoB 2 tool for RCTs and the ROBINS-I tool for non-randomized intervention studies. We used a narrative synthesis approach to systematically describe and summarize all the interventions included within the review, categorized by the type of intervention (habitat modification, habitat manipulation, combination of habitat modification and manipulation). Our primary outcomes were 1. clinical malaria incidence; 2. malaria parasite prevalence; and 3. malaria parasitaemia incidence. Our secondary outcomes were 1. incidence of severe malaria; 2. anaemia prevalence; 3. mean haemoglobin levels; 4. mortality rate due to malaria; 5. hospital admissions for malaria; 6. density of immature mosquitoes; 7. density of adult mosquitoes; 8. sporozoite rate; 9. entomological inoculation rate; and 10.
HARMS
We used the GRADE approach to assess the certainty of the evidence for each type of intervention.
MAIN RESULTS
Sixteen studies met the inclusion criteria. Six used an RCT design, six used a controlled before-after (CBA) study design, three used a non-randomized controlled design, and one used an uncontrolled BA study design. Eleven studies were conducted in Africa and five in Asia. Five studies reported epidemiological outcomes and 15 studies reported entomological outcomes. None of the included studies reported on the environmental impacts associated with the intervention. For risk of bias, all trials had some concerns and other designs ranging from moderate to critical. Ten studies assessed habitat manipulation (temporary change to the environment). This included water management (spillways across streams; floodgates; intermittent flooding; different drawdown rates of water; different flooding and draining regimens), shading management (shading of drainage channels with different plants), other/combined management approaches (minimal tillage; disturbance of aquatic habitats with grass clearing and water replenishment), which showed mixed results for entomological outcomes. Spillways across streams, faster drawdown rates of water, shading drainage canals with Napier grass, and using minimal tillage may reduce the density of immature mosquitoes (range of effects from 95% reduction to 1.7 times increase; low-certainty evidence), and spillways across streams may reduce densities of adult mosquitoes compared to no intervention (low-certainty evidence). However, the effect of habitat manipulation on malaria parasite prevalence and clinical malaria incidence is uncertain (very low-certainty evidence). Two studies assessed habitat manipulation with larviciding. This included reducing or removal of habitat sites; and drain cleaning, grass cutting, and minor repairs. It is uncertain whether drain cleaning, grass cutting, and minor repairs reduces malaria parasite prevalence compared to no intervention (odds ratio 0.59, 95% confidence interval (CI) 0.42 to 0.83; very low-certainty evidence). Two studies assessed combination of habitat manipulation and permanent change (habitat modification). This included drainage canals, filling, and planting of papyrus and other reeds for shading near dams; and drainage of canals, removal of debris, land levelling, and filling ditches. Studies did not report on epidemiological outcomes, but entomological outcomes suggest that such activities may reduce the density of adult mosquitoes compared to no intervention (relative risk reduction 0.49, 95% CI 0.47 to 0.50; low-certainty evidence), and preventing water stagnating using drainage of canals, removal of debris, land levelling, and filling ditches may reduce the density of immature mosquitoes compared to no intervention (ranged from 10% to 55% reductions; low-certainty evidence). Three studies assessed combining manipulation and modification with larviciding. This included filling or drainage of water bodies; filling, draining, or elimination of rain pools and puddles at water supply points and stream bed pools; and shoreline work, improvement and maintenance to drainage, clearing vegetation and undergrowth, and filling pools. There were mixed effect sizes for the reduction of entomological outcomes (moderate-certainty evidence). However, filling or draining water bodies probably makes little or no difference to malaria parasite prevalence, haemoglobin levels, or entomological inoculation rate when delivered with larviciding compared to no intervention (moderate-certainty evidence).
AUTHORS' CONCLUSIONS
Habitat modification and manipulation interventions for preventing malaria has some indication of benefit in both epidemiological and entomological outcomes. While the data are quite mixed and further studies could help improve the knowledge base, these varied approaches may be useful in some circumstances.
Topics: Adult; Animals; Humans; Culicidae; Ecosystem; Hemoglobins; Larva; Malaria; Mosquito Control; Water
PubMed: 36367444
DOI: 10.1002/14651858.CD008923.pub3