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The Cochrane Database of Systematic... Aug 2015Leishmaniasis is caused by the Leishmania parasite, and transmitted by infected phlebotomine sandflies. Of the two distinct clinical syndromes, cutaneous leishmaniasis... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Leishmaniasis is caused by the Leishmania parasite, and transmitted by infected phlebotomine sandflies. Of the two distinct clinical syndromes, cutaneous leishmaniasis (CL) affects the skin and mucous membranes, and visceral leishmaniasis (VL) affects internal organs. Approaches to prevent transmission include vector control by reducing human contact with infected sandflies, and reservoir control, by reducing the number of infected animals.
OBJECTIVES
To assess the effects of vector and reservoir control interventions for cutaneous and for visceral leishmaniasis.
SEARCH METHODS
We searched the following databases to 13 January 2015: Cochrane Infectious Diseases Group Specialized Register, CENTRAL, MEDLINE, EMBASE, LILACS and WHOLIS, Web of Science, and RePORTER. We also searched trials registers for ongoing trials.
SELECTION CRITERIA
Randomized controlled trials (RCTs) evaluating the effects of vector and reservoir control interventions in leishmaniasis-endemic regions.
DATA COLLECTION AND ANALYSIS
Two review authors independently searched for trials and extracted data from included RCTs. We resolved any disagreements by discussion with a third review author. We assessed the quality of the evidence using the GRADE approach.
MAIN RESULTS
We included 14 RCTs that evaluated a range of interventions across different settings. The study methods were generally poorly described, and consequently all included trials were judged to be at high or unclear risk of selection and reporting bias. Only seven trials reported clinical outcome data which limits our ability to make broad generalizations to different epidemiological settings and cultures. Cutaneous leishmaniasisOne four-arm RCT from Afghanistan compared indoor residual spraying (IRS), insecticide-treated bednets (ITNs), and insecticide-treated bedsheets, with no intervention. Over 15 months follow-up, all three insecticide-based interventions had a lower incidence of CL than the control area (IRS: risk ratio (RR) 0.61, 95% confidence interval (CI) 0.38 to 0.97, 2892 participants, moderate quality evidence; ITNs: RR 0.32, 95% CI 0.18 to 0.56, 2954 participants, low quality evidence; ITS: RR 0.34, 95% CI 0.20 to 0.57, 2784 participants, low quality evidence). No difference was detected between the three interventions (low quality evidence). One additional trial of ITNs from Iran was underpowered to show a difference.Insecticide treated curtains were compared with no intervention in one RCT from Venezuela, where there were no CL episodes in the intervention areas over 12 months follow-up compared to 142 in control areas (RR 0.00, 95% CI 0.00 to 0.49, one trial, 2938 participants, low quality evidence).Personal protection using insecticide treated clothing was evaluated by two RCTs in soldiers, but the trials were underpowered to reliably detect effects on the incidence of CL (RR 0.40, 95% CI 0.13 to 1.20, two trials, 558 participants, low quality evidence). Visceral leishmaniasisIn a single RCT of ITNs versus no intervention from India and Nepal, the incidence of VL was low in both groups and no difference was detected (RR 0.99, 95% CI 0.46 to 2.15, one trial, 19,810 participants, moderate quality evidence).Two trials from Brazil evaluated the effects of culling infected dogs compared to no intervention or IRS. Although they report a reduction in seroconversion over 18 months follow-up, they did not measure or report effects on clinical disease.
AUTHORS' CONCLUSIONS
Using insecticides to reduce phlebotomine sandfly numbers may be effective at reducing the incidence of CL, but there is insufficient evidence from trials to know whether it is better to spray the internal walls of houses or to treat bednets, curtains, bedsheets or clothing.
Topics: Animal Culling; Animals; Clothing; Disease Reservoirs; Disease Vectors; Dog Diseases; Dogs; Household Articles; Humans; Insecticide-Treated Bednets; Insecticides; Leishmaniasis, Cutaneous; Leishmaniasis, Visceral; Population Density; Randomized Controlled Trials as Topic
PubMed: 26246011
DOI: 10.1002/14651858.CD008736.pub2 -
PLoS Neglected Tropical Diseases Nov 2014Dengue presents a formidable and growing global economic and disease burden, with around half the world's population estimated to be at risk of infection. There is wide... (Review)
Review
Dengue presents a formidable and growing global economic and disease burden, with around half the world's population estimated to be at risk of infection. There is wide variation and substantial uncertainty in current estimates of dengue disease burden and, consequently, on economic burden estimates. Dengue disease varies across time, geography and persons affected. Variations in the transmission of four different viruses and interactions among vector density and host's immune status, age, pre-existing medical conditions, all contribute to the disease's complexity. This systematic review aims to identify and examine estimates of dengue disease burden and costs, discuss major sources of uncertainty, and suggest next steps to improve estimates. Economic analysis of dengue is mainly concerned with costs of illness, particularly in estimating total episodes of symptomatic dengue. However, national dengue disease reporting systems show a great diversity in design and implementation, hindering accurate global estimates of dengue episodes and country comparisons. A combination of immediate, short-, and long-term strategies could substantially improve estimates of disease and, consequently, of economic burden of dengue. Suggestions for immediate implementation include refining analysis of currently available data to adjust reported episodes and expanding data collection in empirical studies, such as documenting the number of ambulatory visits before and after hospitalization and including breakdowns by age. Short-term recommendations include merging multiple data sources, such as cohort and surveillance data to evaluate the accuracy of reporting rates (by health sector, treatment, severity, etc.), and using covariates to extrapolate dengue incidence to locations with no or limited reporting. Long-term efforts aim at strengthening capacity to document dengue transmission using serological methods to systematically analyze and relate to epidemiologic data. As promising tools for diagnosis, vaccination, vector control, and treatment are being developed, these recommended steps should improve objective, systematic measures of dengue burden to strengthen health policy decisions.
Topics: Cost of Illness; Costs and Cost Analysis; Dengue; Global Health; Health Care Costs; Humans
PubMed: 25412506
DOI: 10.1371/journal.pntd.0003306 -
Reviews in Medical Virology Jan 2024Vaccines against coronavirus disease 2019 (COVID-19) have been discovered within a very small duration of time as compared to the traditional way for the development of... (Meta-Analysis)
Meta-Analysis Review
Vaccines against coronavirus disease 2019 (COVID-19) have been discovered within a very small duration of time as compared to the traditional way for the development of vaccines, which raised the question about the safety and efficacy of the approved vaccines. The purpose of this study is to look at the effectiveness and safety of vaccine platforms against the incidence of COVID-19. The literature search was performed on PubMed/Medline, Cochrane, and clinical trials.gov databases for studies published between 1 January 2020 and 19 February 2022. Preferred Reporting Items for Systemic Review and Meta-Analysis Statement guidelines were followed. Among 284 articles received by keywords, a total of 11 studies were eligible according to the inclusion and exclusion criteria (studies in special populations, e.g., pregnant women, paediatric patients, editorials, case reports, review articles, preclinical and in vitro studies) of the study. A total of 247,186 participants were considered for randomisation at baseline, among them, 129,572 (52.42%) were provided with vaccine (Intervention group) and 117,614 (47.58%) with the placebo (Control group). A pooled fold change estimation of 0.19 (95% CI: 0.12-0.31, p < 0.0001) showed significant protection against the incidence of COVID-19 in the vaccines received group versus the placebo group. mRNA based, inactivated vaccines and non-replicating viral vector-based vaccines showed significantly protection against the incidence of COVID-19 compared to placebo with pooled fold change estimation was 0.08 (95% CI: 0.06-0.10), 0.20 (95% CI: 0.14-0.29) and 0.36 (95% CI: 0.28-0.46), respectively. Injection site discomfort and fatigue were the most common side effect observed in mRNA, non-replicating viral vector, inactivated, and protein subunit-based vaccines. All the approved vaccines were found safe and efficacious but mRNA-based vaccines were found to be more efficacious against SARS-CoV-2 than other platforms.
Topics: Humans; COVID-19; COVID-19 Vaccines; Randomized Controlled Trials as Topic; SARS-CoV-2; Vaccines, Inactivated
PubMed: 38282394
DOI: 10.1002/rmv.2507 -
Vector Borne and Zoonotic Diseases... Jul 2016In high-income countries, homeless individuals in urban areas often live in crowded conditions with limited sanitation and personal hygiene. The environment of... (Review)
Review
INTRODUCTION
In high-income countries, homeless individuals in urban areas often live in crowded conditions with limited sanitation and personal hygiene. The environment of homelessness in high-income countries may result in intensified exposure to ectoparasites and urban wildlife, which can transmit infections. To date, there have been no systematic evaluations of the published literature to assess vector-borne and zoonotic disease risk to these populations.
OBJECTIVES
The primary objectives of this study were to identify diversity, prevalence, and risk factors for vector-borne and zoonotic infections among people experiencing homelessness and extreme poverty in urban areas of high-income countries.
METHODS
We conducted a systematic review and narrative synthesis of published epidemiologic studies of zoonotic and vector-borne infections among urban homeless and very poor people in the United States and Europe from 1990 to 2014.
RESULTS
Thirty-one observational studies and 14 case studies were identified (n = 45). Seroprevalence to the human louse-borne pathogen Bartonella quintana (seroprevalence range: 0-37.5%) was identified most frequently, with clinical disease specifically observed among HIV-positive individuals. Seropositivity to Bartonella henselae (range: 0-10.3%) and Rickettsia akari (range: 0-16.2%) was noted in multiple studies. Serological evidence of exposure to Rickettsia typhi, Rickettsia prowazekii, Bartonella elizabethae, West Nile virus, Borellia recurrentis, lymphocytic choriomeningitis virus, Wohlfartiimonas chitiniclastica, Seoul hantavirus (SEOV), and Leptospira species was also identified in published studies, with SEOV associated with chronic renal disease later in life. HIV infection, injection drug use, and heavy drinking were noted across multiple studies as risk factors for infection with vector-borne and zoonotic pathogens.
CONCLUSIONS
B. quintana was the most frequently reported vector-borne infection identified in our article. Delousing efforts and active surveillance among HIV-positive individuals, who are at elevated risk of complication from B. quintana infection, are advised to reduce morbidity. Given documented exposure to rodent-borne zoonoses among urban homeless and marginalized people, reducing human contact with rodents remains an important public health priority.
Topics: Animals; Bacterial Infections; Europe; Ill-Housed Persons; Humans; Social Marginalization; United States; Zoonoses
PubMed: 27159039
DOI: 10.1089/vbz.2015.1863 -
Frontiers in Veterinary Science 2021is a worldwide emerging zoonotic tick-borne pathogen transmitted by ticks and naturally maintained in complex and incompletely assessed enzootic cycles. Several... (Review)
Review
is a worldwide emerging zoonotic tick-borne pathogen transmitted by ticks and naturally maintained in complex and incompletely assessed enzootic cycles. Several studies have demonstrated an extensive genetic variability with variable host tropisms and pathogenicity. However, the relationship between genetic diversity and modified pathogenicity is not yet understood. Because of their proximity to humans, dogs are potential sentinels for the transmission of vector-borne pathogens. Furthermore, the strong molecular similarity between human and canine isolates of in Europe and the USA and the positive association in the distribution of human and canine cases in the USA emphasizes the epidemiological role of dogs. infects and survives within neutrophils by disregulating neutrophil functions and evading specific immune responses. Moreover, the complex interaction between the bacterium and the infected host immune system contribute to induce inflammatory injuries. Canine granulocytic anaplasmosis is an acute febrile illness characterized by lethargy, inappetence, weight loss and musculoskeletal pain. Hematological and biochemistry profile modifications associated with this disease are unspecific and include thrombocytopenia, anemia, morulae within neutrophils and increased liver enzymes activity. Coinfections with other tick-borne pathogens (TBPs) may occur, especially with , complicating the clinical presentation, diagnosis and response to treatment. Although clinical studies have been published in dogs, it remains unclear if several clinical signs and clinicopathological abnormalities can be related to this infection.
PubMed: 34250067
DOI: 10.3389/fvets.2021.686644 -
Tropical Medicine & International... Sep 2023To analyse acute Chagas disease (CD) outbreaks through a qualitative systematic review and discuss the determinants for its prevention and control.
OBJECTIVE
To analyse acute Chagas disease (CD) outbreaks through a qualitative systematic review and discuss the determinants for its prevention and control.
METHODS
Review of studies in which clinical cases of oral transmission were confirmed by parasitological and/or serological tests that included an epidemiological investigation of sources of infection, vectors and reservoirs.
RESULTS
Thirty-two outbreaks (1965-2022) were analysed. The main foods involved in oral transmission outbreaks are homemade fruit juices. Different species of vectors were identified. Reservoirs were mainly dogs, rodents and large American opossums (didelphids).
CONCLUSION
Under a One Health approach, environmental changes are one of the factors responsible of the rise of oral transmission of CD. Entomological surveillance of vectors and control of the changes in wild and domestic reservoirs and reinforcement of hygiene measures around food in domestic and commercial sites are needed.
Topics: Animals; Dogs; Chagas Disease; Disease Reservoirs; Genotype; One Health; Opossums; Trypanosoma cruzi
PubMed: 37488635
DOI: 10.1111/tmi.13915 -
Pathogens (Basel, Switzerland) Nov 2021Clinical trials evaluating the safety and antibody response of strategies to manipulate prophylactic and therapeutic immunity have been launched. We aim to evaluate... (Review)
Review
Clinical trials evaluating the safety and antibody response of strategies to manipulate prophylactic and therapeutic immunity have been launched. We aim to evaluate strategies for augmentation of host immunity against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. We searched clinical trials registered at the National Institutes of Health by 25 May 2021 and conducted analyses on inoculated populations, involved immunological processes, source of injected components, and trial phases. We then searched PubMed, Embase, Scopus, and the Cochrane Central Register of Controlled Trials for their corresponding reports published by 25 May 2021. A bivariate, random-effects meta-analysis was used to derive the pooled estimate of seroconversion and adverse events (AEs). A total of 929,359 participants were enrolled in 389 identified trials. The working mechanisms included heterologous immunity, active immunity, passive immunity, and immunotherapy, with 62.4% of the trials on vaccines. A total of 9072 healthy adults from 27 publications for 22 clinical trials on active immunity implementing vaccination were included for meta-analyses. The pooled odds ratios (ORs) of seroconversion were 13.94, 84.86, 106.03, and 451.04 (all < 0.01) for vaccines based on protein, RNA, viral vector, and inactivated virus, compared with that of respective placebo/control treatment or pre-vaccination sera. The pooled ORs for safety, as defined by the inverse of systemic adverse events (AEs) were 0.53 (95% CI = 0.27-1.05; = 0.07), 0.35 (95% CI = 0.16-0.75; = 0.007), 0.32 (95% CI = 0.19-0.55; < 0.0001), and 1.00 (95% CI = 0.73-1.36; = 0.98) for vaccines based on protein, RNA, viral vector, and inactivated virus, compared with that of placebo/control treatment. A paradigm shift from all four immune-augmentative interventions to active immunity implementing vaccination was observed through clinical trials. The efficacy of immune responses to neutralize SARS-CoV-2 for these vaccines was promising, although systemic AEs were still evident for RNA-based and viral vector-based vaccines.
PubMed: 34959492
DOI: 10.3390/pathogens10121537 -
PLoS Neglected Tropical Diseases Dec 2022Dengue is the fastest-spreading vector-borne viral disease worldwide. In Thailand, dengue is endemic and is associated with a high socioeconomic burden. A systematic...
BACKGROUND
Dengue is the fastest-spreading vector-borne viral disease worldwide. In Thailand, dengue is endemic and is associated with a high socioeconomic burden. A systematic literature review was conducted to assess and describe the epidemiological and economic burden of dengue in Thailand.
METHODS
Epidemiological and economic studies published in English and Thai between 2011-2019 and 2009-2019, respectively, were searched in MEDLINE, Embase, and Evidence-Based Medicines reviews databases. Reports published by the National Ministry of Public Health (MoPH) and other grey literature sources were also reviewed. Identified studies were screened according to predefined inclusion and exclusion criteria. Extracted data were descriptively summarised and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.
RESULTS
A total of 155 publications were included in the review (39 journal articles and 116 grey literature). Overall, dengue incidence varied yearly, with the highest rates per 100,000 population in 2013 (dengue fever (DF) 136.6, dengue haemorrhagic fever (DHF) 100.9, dengue shock syndrome (DSS) 3.58) and 2015 (DF 133.1, DHF 87.4, DSS 2.14). Peak incidence coincided with the monsoon season, and annual mortality was highest for DSS, particularly in the age group 15-24-year-olds. The highest dengue incidence rates were reported in children (10-14-year-olds) and young adults (15-24-year-olds), irrespective of dengue case definition. Economic and societal burdens are extensive, with the average cost per case ranging from USD 41 to USD 261, total cost per year estimated at USD 440.3 million, and an average of 7.6 workdays lost for DHF and 6.6 days for DF.
CONCLUSIONS
The epidemiological, economic, and societal burden of dengue in Thailand is high and underreported due to gaps in national surveillance data. The use of expansion factors (EFs) is recommended to understand the true incidence of dengue and cost-benefit of control measures. Furthermore, as dengue is often self-managed and underreported, lost school and workdays result in substantial underestimation of the true economic and societal burden of dengue. The implementation of integrated strategies, including vaccination, is critical to reduce the disease burden and may help alleviate health disparities and equity challenges posed by dengue.
Topics: Child; Young Adult; Humans; Dengue; Thailand; Cost-Benefit Analysis; Cost of Illness; Public Health
PubMed: 36534668
DOI: 10.1371/journal.pntd.0010966 -
Preventive Veterinary Medicine Aug 2018The growing frequency of bluetongue virus (BTV) incursions in Europe in recent years led to the largest BTV outbreak ever recorded in 2006/09, with a dramatic impact on... (Review)
Review
The growing frequency of bluetongue virus (BTV) incursions in Europe in recent years led to the largest BTV outbreak ever recorded in 2006/09, with a dramatic impact on the cattle and sheep industries. The complex epidemiology of this vector-borne disease of ruminants and its recent emergence need to be better understood to identify and implement efficient control strategies. Mathematical models provide useful tools for that purpose; many of them have been developed in the light of the 2006/09 outbreak. We aimed to provide a systematic review of compartmental mathematical models dedicated to BTV occurrence or transmission in European countries, to assess robustness of findings to different modelling approaches and assumptions. We identified relevant papers from PubMed and Scopus databases, 21 of which were included in the review following the selection process laid out in the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. We systematically extracted data from these papers to address the diversity and evolution of modelling approaches, and to identify important characteristics for future model development. Then, we summarized the main insights provided into bluetongue epidemiology, and discussed the relevance of these models as tools for risk mapping and for the design of surveillance and control systems. On the whole, the mechanistic models reviewed provided flexible frameworks, yielding mostly epidemiological insights specific to geographical areas and study periods. Despite the limitations of these models that sometimes relied on strong assumptions, we advocate their use to facilitate and inform evidence-based decision-making in animal health.
Topics: Animals; Bluetongue; Bluetongue virus; Cattle; Europe; Models, Theoretical; Ruminants; Sheep
PubMed: 29891140
DOI: 10.1016/j.prevetmed.2018.05.012 -
Risk Management and Healthcare Policy 2022Early warning system (EWS) for vector-borne diseases is incredibly complex due to numerous factors originating from human, environmental, vector and the disease itself.... (Review)
Review
Early warning system (EWS) for vector-borne diseases is incredibly complex due to numerous factors originating from human, environmental, vector and the disease itself. Dengue EWS aims to collect data that leads to prompt decision-making processes that trigger disease intervention strategies to minimize the impact on a specific population. Dengue EWS may have a similar structural design, functions, and analytical approaches but different performance and ability to predict outbreaks. Hence, this review aims to summarise and discuss the evidence of different EWSs, their performance, and their ability to predict dengue outbreaks. A systematic literature search was performed of four primary databases: Scopus, Web of Science, Ovid MEDLINE, and EBSCOhost. Eligible articles were evaluated using a checklist for assessing the quality of the studies. A total of 17 studies were included in this systematic review. All EWS models demonstrated reasonably good predictive abilities to predict dengue outbreaks. However, the accuracy of their predictions varied greatly depending on the model used and the data quality. The reported sensitivity ranged from 50 to 100%, while specificity was 74 to 94.7%. A range between 70 to 96.3% was reported for prediction model accuracy and 43 to 86% for PPV. Overall, meteorological alarm indicators (temperatures and rainfall) were the most frequently used and displayed the best performing indicator. Other potential alarm indicators are entomology (female mosquito infection rate), epidemiology, population and socioeconomic factors. EWS is an essential tool to support district health managers and national health planners to mitigate or prevent disease outbreaks. This systematic review highlights the benefits of integrating several epidemiological tools focusing on incorporating climatic, environmental, epidemiological and socioeconomic factors to create an early warning system. The early warning system relies heavily on the country surveillance system. The lack of timely and high-quality data is critical for developing an effective EWS.
PubMed: 35535237
DOI: 10.2147/RMHP.S361106