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Tropical Medicine and Infectious Disease Aug 2021Oropouche virus (OROV), a member of the genus, is an arthropod-borne virus (arbovirus) and is the etiologic agent of human and animal disease. The primary vector of... (Review)
Review
Observational Characterization of the Ecological and Environmental Features Associated with the Presence of Oropouche Virus and the Primary Vector : Data Synthesis and Systematic Review.
Oropouche virus (OROV), a member of the genus, is an arthropod-borne virus (arbovirus) and is the etiologic agent of human and animal disease. The primary vector of OROV is presumed to be the biting midge, though , , and mosquitoes are considered secondary vectors. The objective of this systematic review is to characterize locations where OROV and/or its primary vector have been detected. Synthesis of known data through review of published literature regarding OROV and vectors was carried out through two independent searches: one search targeted to OROV, and another targeted towards the primary vector. A total of 911 records were returned, but only 90 (9.9%) articles satisfied all inclusion criteria. When locations were characterized, some common features were noted more frequently than others, though no one characteristic was significantly associated with presence of OROV using a logistic classification model. In a separate correlation analysis, vector presence was significantly correlated only with the presence of restingas. The lack of significant relationships is likely due to the paucity of data regarding OROV and its eco-epidemiology and highlights the importance of continued focus on characterizing this and other neglected tropical diseases.
PubMed: 34449725
DOI: 10.3390/tropicalmed6030143 -
PLoS Neglected Tropical Diseases Oct 2014Insecticide-treated nets (ITNs) are one of the main interventions used for malaria control. However, these nets may also be effective against other vector borne diseases... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Insecticide-treated nets (ITNs) are one of the main interventions used for malaria control. However, these nets may also be effective against other vector borne diseases (VBDs). We conducted a systematic review and meta-analysis to estimate the efficacy of ITNs, insecticide-treated curtains (ITCs) and insecticide-treated house screening (ITS) against Chagas disease, cutaneous and visceral leishmaniasis, dengue, human African trypanosomiasis, Japanese encephalitis, lymphatic filariasis and onchocerciasis.
METHODS
MEDLINE, EMBASE, LILACS and Tropical Disease Bulletin databases were searched using intervention, vector- and disease-specific search terms. Cluster or individually randomised controlled trials, non-randomised trials with pre- and post-intervention data and rotational design studies were included. Analysis assessed the efficacy of ITNs, ITCs or ITS versus no intervention. Meta-analysis of clinical data was performed and percentage reduction in vector density calculated.
RESULTS
Twenty-one studies were identified which met the inclusion criteria. Meta-analysis of clinical data could only be performed for four cutaneous leishmaniasis studies which together showed a protective efficacy of ITNs of 77% (95%CI: 39%-91%). Studies of ITC and ITS against cutaneous leishmaniasis also reported significant reductions in disease incidence. Single studies reported a high protective efficacy of ITS against dengue and ITNs against Japanese encephalitis. No studies of Chagas disease, human African trypanosomiasis or onchocerciasis were identified.
CONCLUSION
There are likely to be considerable collateral benefits of ITN roll out on cutaneous leishmaniasis where this disease is co-endemic with malaria. Due to the low number of studies identified, issues with reporting of entomological outcomes, and few studies reporting clinical outcomes, it is difficult to make strong conclusions on the effect of ITNs, ITCs or ITS on other VBDs and therefore further studies be conducted. Nonetheless, it is clear that insecticide-treated materials such as ITNs have the potential to reduce pathogen transmission and morbidity from VBDs where vectors enter houses.
Topics: Animals; Arthropod Vectors; Dengue; Elephantiasis, Filarial; Encephalitis, Japanese; Humans; Immunologic Tests; Insecticide-Treated Bednets; Insecticides; Leishmaniasis; Malaria; Mosquito Control
PubMed: 25299481
DOI: 10.1371/journal.pntd.0003228 -
PLoS Neglected Tropical Diseases Dec 2021Improving our understanding of Mayaro virus (MAYV) ecology is critical to guide surveillance and risk assessment. We conducted a PRISMA-adherent systematic review of the... (Meta-Analysis)
Meta-Analysis
Improving our understanding of Mayaro virus (MAYV) ecology is critical to guide surveillance and risk assessment. We conducted a PRISMA-adherent systematic review of the published and grey literature to identify potential arthropod vectors and non-human animal reservoirs of MAYV. We searched PubMed/MEDLINE, Embase, Web of Science, SciELO and grey-literature sources including PAHO databases and dissertation repositories. Studies were included if they assessed MAYV virological/immunological measured occurrence in field-caught, domestic, or sentinel animals or in field-caught arthropods. We conducted an animal seroprevalence meta-analysis using a random effects model. We compiled granular georeferenced maps of non-human MAYV occurrence and graded the quality of the studies using a customized framework. Overall, 57 studies were eligible out of 1523 screened, published between the years 1961 and 2020. Seventeen studies reported MAYV positivity in wild mammals, birds, or reptiles and five studies reported MAYV positivity in domestic animals. MAYV positivity was reported in 12 orders of wild-caught vertebrates, most frequently in the orders Charadriiformes and Primate. Sixteen studies detected MAYV in wild-caught mosquito genera including Haemagogus, Aedes, Culex, Psorophora, Coquillettidia, and Sabethes. Vertebrate animals or arthropods with MAYV were detected in Brazil, Panama, Peru, French Guiana, Colombia, Trinidad, Venezuela, Argentina, and Paraguay. Among non-human vertebrates, the Primate order had the highest pooled seroprevalence at 13.1% (95% CI: 4.3-25.1%). From the three most studied primate genera we found the highest seroprevalence was in Alouatta (32.2%, 95% CI: 0.0-79.2%), followed by Callithrix (17.8%, 95% CI: 8.6-28.5%), and Cebus/Sapajus (3.7%, 95% CI: 0.0-11.1%). We further found that MAYV occurs in a wide range of vectors beyond Haemagogus spp. The quality of evidence behind these findings was variable and prompts calls for standardization of reporting of arbovirus occurrence. These findings support further risk emergence prediction, guide field surveillance efforts, and prompt further in-vivo studies to better define the ecological drivers of MAYV maintenance and potential for emergence.
Topics: Alphavirus; Alphavirus Infections; Animals; Arthropod Vectors; Birds; Disease Reservoirs; Humans; Mammals; Mosquito Vectors; Primates; Reptiles
PubMed: 34898602
DOI: 10.1371/journal.pntd.0010016 -
Journal of Vector Borne Diseases Dec 2012There have been several attempts made to the appreciation of remote sensing and GIS for the study of vectors, biodiversity, vector presence, vector abundance and the... (Review)
Review
There have been several attempts made to the appreciation of remote sensing and GIS for the study of vectors, biodiversity, vector presence, vector abundance and the vector-borne diseases with respect to space and time. This study was made for reviewing and appraising the potential use of remote sensing and GIS applications for spatial prediction of vector-borne diseases transmission. The nature of the presence and the abundance of vectors and vector-borne diseases, disease infection and the disease transmission are not ubiquitous and are confined with geographical, environmental and climatic factors, and are localized. The presence of vectors and vector-borne diseases is most complex in nature, however, it is confined and fueled by the geographical, climatic and environmental factors including man-made factors. The usefulness of the present day availability of the information derived from the satellite data including vegetation indices of canopy cover and its density, soil types, soil moisture, soil texture, soil depth, etc. is integrating the information in the expert GIS engine for the spatial analysis of other geoclimatic and geoenvironmental variables. The present study gives the detailed information on the classical studies of the past and present, and the future role of remote sensing and GIS for the vector-borne diseases control. The ecological modeling directly gives us the relevant information to understand the spatial variation of the vector biodiversity, vector presence, vector abundance and the vector-borne diseases in association with geoclimatic and the environmental variables. The probability map of the geographical distribution and seasonal variations of horizontal and vertical distribution of vector abundance and its association with vector -borne diseases can be obtained with low cost remote sensing and GIS tool with reliable data and speed.
Topics: Animals; Communicable Diseases; Geographic Information Systems; Geographic Mapping; Humans; Insect Vectors; Remote Sensing Technology; Risk Assessment; Seasons
PubMed: 23428518
DOI: No ID Found -
PLoS Neglected Tropical Diseases May 2018Mosquitoes are incriminated as vectors for many crippling diseases, including malaria, West Nile fever, Dengue fever, and other neglected tropical diseases (NTDs).... (Review)
Review
Mosquitoes are incriminated as vectors for many crippling diseases, including malaria, West Nile fever, Dengue fever, and other neglected tropical diseases (NTDs). microRNAs (miRNAs) can interact with multiple target genes to elicit biological functions in the mosquitoes. However, characterization and function of individual miRNAs and their potential targets have not been fully determined to date. We conducted a systematic review of published literature following PRISMA guidelines. We summarize the information about miRNAs in mosquitoes to better understand their metabolism, development, and responses to microorganisms. Depending on the study, we found that miRNAs were dysregulated in a species-, sex-, stage-, and tissue/organ-specific manner. Aberrant miRNA expressions were observed in development, metabolism, host-pathogen interactions, and insecticide resistance. Of note, many miRNAs were down-regulated upon pathogen infection. The experimental studies have expanded the identification of miRNA target from the 3' untranslated regions (UTRs) of mRNAs of mosquitoes to the 5' UTRs of mRNAs of the virus. In addition, we discuss current trends in mosquito miRNA research and offer suggestions for future studies.
Topics: Animals; Culicidae; Insect Vectors; MicroRNAs
PubMed: 29718912
DOI: 10.1371/journal.pntd.0006463 -
The Cochrane Database of Systematic... Aug 2023Insecticide-based interventions, such as long-lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS), remain the backbone of malaria vector control.... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Insecticide-based interventions, such as long-lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS), remain the backbone of malaria vector control. These interventions target mosquitoes that prefer to feed and rest indoors, but have limited capacity to prevent transmission that occurs outdoors or outside regular sleeping hours. In low-endemicity areas, malaria elimination will require that these control gaps are addressed, and complementary tools are found. The use of topical repellents may be particularly useful for populations who may not benefit from programmatic malaria control measures, such as refugees, the military, or forest goers. This Cochrane Review aims to measure the effectiveness of topical repellents to prevent malaria infection among high- and non-high-risk populations living in malaria-endemic regions.
OBJECTIVES
To assess the effect of topical repellents alone or in combination with other background interventions (long-lasting insecticide-treated nets, or indoor residual spraying, or both) for reducing the incidence of malaria in high- and non-high-risk populations living in endemic areas.
SEARCH METHODS
We searched the following databases up to 11 January 2023: the Cochrane Infectious Diseases Group Specialised Register; CENTRAL (in the Cochrane Library); MEDLINE; Embase; CAB Abstracts; and LILACS. We also searched trial registration platforms and conference proceedings; and contacted organizations and companies for ongoing and unpublished trials.
SELECTION CRITERIA
We included randomized controlled trials (RCTs) and cluster-randomized controlled trials (cRCTs) of topical repellents proven to repel mosquitoes. We also included non-randomized studies that complied with pre-specified inclusion criteria: controlled before-after studies (CBA), controlled interrupted time series (ITS), and controlled cross-over trials.
DATA COLLECTION AND ANALYSIS
Four review authors independently assessed trials for inclusion, and extracted the data. Two authors independently assessed the risk of bias (RoB) using the Cochrane RoB 2 tool. A fifth review author resolved any disagreements. We analysed data by conducting a meta-analysis, stratified by whether studies included populations considered to be at high-risk of developing malaria infection (for example, refugees, forest goers, or deployed military troops). We combined results from cRCTs with RCTs by adjusting for clustering and presented results using forest plots. We used the GRADE framework to assess the certainty of the evidence. We only included data on Plasmodium falciparum infections in the meta-analysis.
MAIN RESULTS
Thirteen articles relating to eight trials met the inclusion criteria and were qualitatively described. We included six trials in the meta-analysis (five cRCTs and one RCT). Effect on malaria incidence Topical repellents may slightly reduce P falciparum infection and clinical incidence when both outcomes are considered together (incidence rate ratio (IRR) 0.74, 95% confidence interval (CI) 0.56 to 0.98; 3 cRCTs and 1 RCT, 61,651 participants; low-certainty evidence); but not when these two outcomes were considered independently. Two cRCTs and one RCT (12,813 participants) evaluated the effect of topical repellents on infection incidence (IRR 0.76, 95% CI 0.56 to 1.02; low-certainty evidence). One cRCT (48,838 participants) evaluated their effect on clinical case incidence (IRR 0.66, 95% CI 0.32 to 1.36; low-certainty evidence). Three studies (2 cRCTs and 1 RCT) included participants belonging to groups considered at high-risk of being infected, while only one cRCT did not include participants at high risk. Adverse events Topical repellents are considered safe. The prevalence of adverse events among participants who used topical repellents was very low (0.6%, 283/47,515) and limited to mild skin reactions. Effect on malaria prevalence Topical repellents may slightly reduce P falciparum prevalence (odds ratio (OR) 0.81, 95% CI 0.67 to 0.97; 3 cRCTs and 1 RCT; 55,366 participants; low-certainty evidence). Two of these studies (1 cRCT and 1 RCT) were carried out in refugee camps, and included exclusively high-risk populations that were not receiving any other background vector control intervention.
AUTHORS' CONCLUSIONS
There is insufficient evidence to conclude that topical repellents can prevent malaria in settings where other vector control interventions are in place. We found the certainty of evidence for all outcomes to be low, primarily due to the risk of bias. A protective effect was suggested among high-risk populations, specially refugees, who might not have access to other standard vector control measures. More adequately powered clinical trials carried out in refugee camps could provide further information on the potential benefit of topical repellents in this setting. Individually randomized studies are also likely necessary to understand whether topical repellents have an effect on personal protection, and the degree to which diversion to non-protected participants affects overall transmission dynamics. Despite this, the potential additional benefits of topical repellents are most likely limited in contexts where other interventions are available.
Topics: Animals; Humans; Insecticides; Mosquito Vectors; Malaria, Falciparum; Controlled Before-After Studies; Culicidae
PubMed: 37602418
DOI: 10.1002/14651858.CD015422.pub2 -
BMC Veterinary Research Apr 2017The optimisation of trypanosomosis control programs warrants a good knowledge of the main vector of animal and human trypanosomes in sub-Saharan Africa, the tsetse fly.... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The optimisation of trypanosomosis control programs warrants a good knowledge of the main vector of animal and human trypanosomes in sub-Saharan Africa, the tsetse fly. An important aspect of the tsetse fly population is its trypanosome infection prevalence, as it determines the intensity of the transmission of the parasite by the vector. We therefore conducted a systematic review of published studies documenting trypanosome infection prevalence from field surveys or from laboratory experiments under controlled conditions. Publications were screened in the Web of Science, PubMed and Google Scholar databases. Using the four-stage (identification, screening, eligibility and inclusion) process in the PRISMA statement the initial screened total of 605 studies were reduced to 72 studies. The microscopic examination of dissected flies (dissection method) remains the most used method to detect trypanosomes and thus constituted the main focus of this analysis. Meta-regression was performed to identify factors responsible for high trypanosome prevalence in the vectors and a random effects meta-analysis was used to report the sensitivity of molecular and serological tests using the dissection method as gold standard.
RESULTS
The overall pooled prevalence was 10.3% (95% confidence interval [CI] = 8.1%, 12.4%) and 31.0% (95% CI = 20.0%, 42.0%) for the field survey and laboratory experiment data respectively. The country and the year of publication were found to be significantly factors associated with the prevalence of trypanosome infection in tsetse flies. The alternative diagnostic tools applied to dissection positive samples were characterised by low sensitivity, and no information on the specificity was available at all.
CONCLUSION
Both temporal and spatial variation in trypanosome infection prevalence of field collected tsetse flies exists, but further investigation on real risk factors is needed how this variation can be explained. Improving the sensitivity and determining the specificity of these alternative diagnostic tools should be a priority and will allow to estimate the prevalence of trypanosome infection in tsetse flies in high-throughput.
Topics: Animals; Insect Vectors; Prevalence; Trypanosoma; Tsetse Flies
PubMed: 28403841
DOI: 10.1186/s12917-017-1012-9 -
Frontiers in Public Health 2022The mosquito species, which are the vectors for the transmission of the dengue virus (DENV) to humans, are becoming increasingly susceptible to the formidable effects... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
The mosquito species, which are the vectors for the transmission of the dengue virus (DENV) to humans, are becoming increasingly susceptible to the formidable effects of influential factors, especially temperature. However, there are still very few studies that have systematically reviewed the existing literature. Hence, in the present study, a systematic literature review and meta-analysis was conducted into the effects of temperature on dengue vectors.
METHOD
Several research methodologies were incorporated into the current study, and a review was carried out using PRISMA as a guide. The publications for this study were chosen from two prominent databases, Scopus and Web of Science. All of the studies were assessed, reviewed, and evaluated independently by two reviewers. The meta-analysis tool, Review Manager (RevMan Copenhagen Version 5.4.1), was used to record the extracted data for the meta-analysis. Moran's and a funnel plot were utilized to measure heterogeneity, and publication bias was investigated. A 95% confidence interval (CI) and overall risk difference (RD) were estimated using a random-effects model.
RESULT AND DISCUSSION
As a consequence of the search efforts, a total of 46 articles were selected for inclusion in the systematic review and meta-analysis. This review was divided into five major themes, based on a thematic analysis: (i) hatching rate, (ii) development time, (iii) longevity, (iv) survival rate, and (v) wing morphology. In addition, the development time, survival rate, and wing morphology revealed significantly higher risk differences between the maximum and minimum temperatures (RD: 0.26, 95% CI: 0.16, 0.36; = < 0.00001; RD: 0.10, 95% CI: 0.05, 0.14; < 0.0001; and RD: 0.07, 95% CI: 0.02, 0.12; = 0.006, respectively). This study makes several substantial contributions to the body of knowledge and to practical applications. Finally, a number of recommendations are made at the conclusion of this research for the future reference of researchers.
Topics: Humans; Animals; Aedes; Temperature; Mosquito Vectors; Fever; Longevity
PubMed: 36600940
DOI: 10.3389/fpubh.2022.1074028 -
Travel Medicine and Infectious Disease 2016Increasing numbers of confirmed cases of Zika virus (ZIKV) infection resulting from non-mosquito-borne transmission have been reported. (Review)
Review
BACKGROUND
Increasing numbers of confirmed cases of Zika virus (ZIKV) infection resulting from non-mosquito-borne transmission have been reported.
METHODS
We performed a systematic literature review (PRISMA guidelines) on intrauterine, intrapartum, sexual and animal bite ZIKV transmission. The presence of the virus in breast milk, urine, saliva and blood transfusions was also reviewed.
RESULTS
The search resulted in 285 papers of possible relevance, of which we included 53 in the systematic review. Mother-to-child transmission was most frequently described with adverse infant outcomes including microcephaly, intracranial calcification and fetal death. Zika virus RNA has been detected in amniotic fluid, breast milk, seminal fluid, saliva, urine and blood. Semen and blood products have proved to be infectious. Male-to-female and male-to-male ZIKV transmission is documented. There are contradictory results concerning the infectiousness of breast milk and urine and data on saliva, animal bites, transplantation, needlestick injury and laboratory work are inconclusive.
CONCLUSIONS
Our systematic analysis shows that non-vector-borne ZIKV transmission plays a role in the spread of ZIKV and has great societal impact. It has important public health implications for the prevention and control of ZIKV globally and will be a basis for policy and further research.
Topics: Animals; Female; Humans; Infectious Disease Transmission, Vertical; Male; Microcephaly; Milk, Human; Mosquito Vectors; Saliva; Sexually Transmitted Diseases, Viral; Zika Virus; Zika Virus Infection
PubMed: 27425793
DOI: 10.1016/j.tmaid.2016.07.002 -
Medical and Veterinary Entomology Sep 2008The aim of this review was to compare the effects of different dengue vector control interventions (i.e. biological control, chemical control, environmental management... (Meta-Analysis)
Meta-Analysis Review
The aim of this review was to compare the effects of different dengue vector control interventions (i.e. biological control, chemical control, environmental management and integrated vector management) with respect to the following entomological parameters: Breteau index (BI), container index (CI), and house index (HI). We systematically searched PubMed, ISI Web of Science, Science Direct, the Dengue Bulletin of the World Health Organization and reference lists of retrieved articles on dengue vector control interventions in developing countries. We extracted data on the effectiveness of different dengue vector control interventions (defined as the relative reduction of an entomological measure caused by the intervention compared with the control or pre-intervention phase) and calculated a measure of combined relative effectiveness, with 95% confidence intervals (95% c.i.). We identified 56 publications covering 61 dengue vector control interventions. Integrated vector management was found to be the most effective method to reduce the CI, HI and BI, resulting in random combined relative effectiveness values of 0.12 (95% c.i. 0.02-0.62), 0.17 (95% c.i. 0.02-1.28) and 0.33 (95% c.i. 0.22-0.48), respectively. Environmental management showed a relatively low effectiveness of 0.71 (95% c.i. 0.55-0.90) for the BI, 0.49 (95% c.i. 0.30-0.79) for the CI and 0.43 (95% c.i. 0.31-0.59) for the HI. Biological control (relative effectiveness for the CI: 0.18) usually targeted a small number of people (median population size: 200; range 20-2500), whereas integrated vector management focused on larger populations (median: 12 450; range: 210-9 600 000). In conclusion, dengue vector control is effective in reducing vector populations, particularly when interventions use a community-based, integrated approach, which is tailored to local eco-epidemiological and sociocultural settings and combined with educational programmes to increase knowledge and understanding of best practice. New research should assess the density-dependent effectiveness of each control measure in order to estimate whether reducing vector numbers has an impact on dengue transmission when populations are at a critical threshold.
Topics: Animals; Culicidae; Dengue; Developing Countries; Humans; Insect Vectors; Mosquito Control
PubMed: 18816269
DOI: 10.1111/j.1365-2915.2008.00740.x