Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
      More Filters
      Clear All
      More Filters
      Source
    • Language
1,325 result(s) for "Leishmaniasis, Visceral - epidemiology"
Sort by:
Insecticide–impregnated dog collars reduce infantile clinical visceral leishmaniasis under operational conditions in NW Iran: A community–wide cluster randomised trial
To assess the effectiveness of community-wide deployment of insecticide-impregnated collars for dogs- the reservoir of Leishmania infantum-to reduce infantile clinical visceral leishmaniasis (VL). A pair matched-cluster randomised controlled trial involving 40 collared and 40 uncollared control villages (161 [95% C.L.s: 136, 187] children per cluster), was designed to detect a 55% reduction in 48 month confirmed VL case incidence. The intervention study was designed by the authors, but implemented by the Leishmaniasis Control Program in NW Iran, from 2002 to 2006. The collars provided 50% (95% C.I. 17·8%-70·0%) protection against infantile VL incidence (0·95/1000/yr compared to 1·75/1000/yr). Reductions in incidence were observed across 76% (22/29) of collared villages compared to pair-matched control villages, with 31 fewer cases by the end of the trial period. In 11 paired villages, no further cases were recorded post-intervention, whereas in 7 collared villages there were 9 new clinical cases relative to controls. Over the trial period, 6,835 collars were fitted at the beginning of the 4 month sand fly season, of which 6.9% (95% C.I. 6.25%, 7.56%) were lost but rapidly replaced. Collar coverage (percent dogs collared) per village varied between 66% and 100%, with a mean annual coverage of 87% (95% C.I. 84·2, 89·0%). The variation in post-intervention clinical VL incidence was not associated with collar coverage, dog population size, implementation logistics, dog owner compliance, or other demographic variables tested. Larger reductions and greater persistence in incident case numbers (indicative of transmission) were observed in villages with higher pre-existing VL case incidence. Community-wide deployment of collars can provide a significant level of protection against infantile clinical VL, achieved in this study by the local VL Control Program, demonstrating attributes desirable of a sustainable public health program. The effectiveness is not dissimilar to the community-level protection provided against human and canine infection with L. infantum.
Sand fly synthetic sex-aggregation pheromone co-located with insecticide reduces the incidence of infection in the canine reservoir of visceral leishmaniasis: A stratified cluster randomised trial
To evaluate the efficacy of a synthetic sex-aggregation pheromone of the sand fly vector Lu. longipalpis, co-located with residual insecticide, to reduce the infection incidence of Leishmania infantum in the canine reservoir. A stratified cluster randomised trial was designed to detect a 50% reduction in canine incident infection after 24 months in 42 recruited clusters, randomly assigned to one of three intervention arms (14 cluster each): synthetic pheromone + insecticide, insecticide-impregnated dog collars, or placebo control. Infection incidence was measured by seroconversion to anti-Leishmania serum antibody, Leishmania parasite detection and canine tissue parasite loads. Changes in relative Lu. longipalpis abundance within households were measured by setting three CDC light traps per household. A total 1,454 seronegative dogs were followed-up for a median 15.2 (95% C.I.s: 14.6, 16.2) months per cluster. The pheromone + insecticide intervention provided 13% (95% C.I. 0%, 44.0%) protection against anti-Leishmania antibody seroconversion, 52% (95% C.I. 6.2%, 74·9%) against parasite infection, reduced tissue parasite loads by 53% (95% C.I. 5.4%, 76.7%), and reduced household female sand fly abundance by 49% (95% C.I. 8.2%, 71.3%). Variation in the efficacy against seroconversion varied between trial strata. Equivalent protection attributed to the impregnated-collars were 36% (95% C.I. 14.4%, 51.8%), 23% (95% C.I. 0%, 57·5%), 48% (95% C.I. 0%, 73.4%) and 43% (95% C.I. 0%, 67.9%), respectively. Comparison of the two interventions showed no statistically consistent differences in their efficacies; however, the errors were broad for all outcomes. Reductions in sand fly numbers were predominant where insecticide was located (chicken and dog sleeping sites), with no evidence of insecticide-induced repellence onto humans or dogs. The synthetic pheromone co-located with insecticide provides protection particularly against canine L. infantum parasite transmission and sand fly vector abundance. The effect estimates are not dissimilar to those of the insecticide-impregnated collars, which are documented to reduce canine infection incidence, human infection and clinical VL disease incidence, in different global regions. The trialled novel lure-and-kill approach is a low-cost potential vector control tool against ZVL in the Americas.
Long term outcomes and prognostics of visceral leishmaniasis in HIV infected patients with use of pentamidine as secondary prophylaxis based on CD4 level: a prospective cohort study in Ethiopia
The long-term treatment outcome of visceral leishmaniasis (VL) patients with HIV co-infection is complicated by a high rate of relapse, especially when the CD4 count is low. Although use of secondary prophylaxis is recommended, it is not routinely practiced and data on its effectiveness and safety are limited. A prospective cohort study was conducted in Northwest Ethiopia from August 2014 to August 2017 (NCT02011958). HIV-VL patients were followed for up to 12 months. Patients with CD4 cell counts below 200/μL at the end of VL treatment received pentamidine prophylaxis starting one month after parasitological cure, while those with CD4 count ≥200 cells/μL were followed without secondary prophylaxis. Compliance, safety and relapse-free survival, using Kaplan-Meier analysis methods to account for variable time at risk, were summarised. Risk factors for relapse or death were analysed. Fifty-four HIV patients were followed. The probability of relapse-free survival at one year was 50% (95% confidence interval [CI]: 35-63%): 53% (30-71%) in 22 patients with CD4 ≥200 cells/μL without pentamidine prophylaxis and 46% (26-63%) in 29 with CD4 <200 cells/μL who started pentamidine. Three patients with CD4 <200 cells/μL did not start pentamidine. Amongst those with CD4 ≥200 cells/μL, VL relapse was an independent risk factor for subsequent relapse or death (adjusted rate ratio: 5.42, 95% CI: 1.1-25.8). Except for one case of renal failure which was considered possibly related to pentamidine, there were no drug-related safety concerns. The relapse-free survival rate for VL patients with HIV was low. Relapse-free survival of patients with CD4 count <200cells/μL given pentamidine secondary prophylaxis appeared to be comparable to patients with a CD4 count ≥200 cells/μL not given prophylaxis. Patients with relapsed VL are at higher risk for subsequent relapse and should be considered a priority for secondary prophylaxis, irrespective of their CD4 count.
Impact of 4% Deltamethrin-Impregnated Dog Collars on the Incidence of Human Visceral Leishmaniasis: A Community Intervention Trial in Brazil
Background: In Brazil, human visceral leishmaniasis (HVL) is caused by the protozoan parasite Leishmania infantum, primarily transmitted by the sand fly Lutzomyia longipalpis, with dogs acting as the main urban reservoir. This study aims to evaluate the effectiveness of 4% deltamethrin-impregnated dog collars (DMC) on HVL incidence. Methods: This is a community intervention study carried out from 2012 to 2015 in the municipalities of Araguaína, State of Tocantins, and Montes Claros, State of Minas Gerais, Brazil. Two areas in each were randomly allocated to either (1) culling seropositive dogs + residual insecticide spraying (control area—CA) or (2) culling seropositive dogs + residual insecticide spraying + DMC fitted to dogs every six months for two years (intervention area—IA). Cases of HVL (n = 1202) occurring from 2008 to 2020 were identified from the Brazilian Reportable Diseases Information System and georeferenced to the control and intervention areas. The HVL cases from 2008 to 2012 were considered as occurring in the “pre-intervention” period. Those cases from 2013 to 2016 and from 2017 to 2020 were regarded as occurring in the “intervention” and “post-intervention” periods, respectively. We used a mixed-effects Poisson regression model to estimate the effectiveness of the intervention, comparing the changes from the pre-intervention period to the intervention and post-intervention periods in the control and intervention areas. Results: In Araguaína, there was a statistically significant reduction in the incidence of HVL in both the control and intervention areas, comparing both the intervention and post-intervention periods with the pre-intervention period. The intervention with DMC was significantly associated with a reduction in HVL when comparing the intervention and pre-intervention periods, yielding an effectiveness estimate of the DMC of 27% (IC95% 1–46%, p = 0.045). No differences were observed when comparing the pre- and post-intervention periods (p = 0.827). In Montes Claros, cases reduced in both the control and intervention areas from the pre-intervention period to the intervention period (p = 0.913). In the post-intervention period, the incidence increased in the control area, while cases continued to decrease in the DMC area (p = 0.188). Conclusions: The use of DMC was associated with a reduction of 27% in the incidence of HVL during the period of DMC delivery, indicating that DMC is effective as an additional strategy for controlling visceral leishmaniasis in Brazil. However, no significant reduction associated with DMC was detected after the intervention period, suggesting that a control program based on the large-scale deployment of DMC might have to be maintained for more extended periods without interruption.
Effectiveness of Insecticide Spraying and Culling of Dogs on the Incidence of Leishmania infantum Infection in Humans: A Cluster Randomized Trial in Teresina, Brazil
To evaluate the effect of insecticide spraying for vector control and elimination of infected dogs on the incidence of human infection with L. infantum, a randomized community intervention trial was carried out in the city of Teresina, Brazil. Within each of ten localities in the city, four blocks were selected and randomized to 4 interventions: 1) spraying houses and animal pens with insecticide; 2) eliminating infected dogs; 3) combination of spraying and eliminating dogs, and 4) nothing. The main outcome is the incidence of infection assessed by the conversion of the Montenegro skin test (MST) after 18 months of follow-up in residents aged ≥ 1 year with no previous history of visceral leishmaniasis (VL). Reactions were measured at 48-72 h, induration of ≥ 5 mm considered positive. Interventions were executed after the baseline interview and repeated 6 and 12 months later. The effects of each type of intervention scheme on the incidence of infection were assessed by calculating relative risks and 95% confidence intervals using Poisson population-averaged regression models with robust variance. Among the 1105 participants, 408 (37%) were MST positive at baseline. Of the 697 negatives, only 423 (61%) were reexamined at the end of the follow-up; 151 (36%) of them converted to a positive MST. Only dog culling had some statistically significant effect on reducing the incidence of infection, with estimates of effectiveness varying between 27% and 52%, depending on the type of analysis performed. In light of the continuous spread of VL in Brazil despite the large scale deployment of insecticide spraying and dog culling, the relatively low to moderate effectiveness of dog culling and the non-significant effect of insecticide spraying on the incidence of human infection, we conclude that there is an urgent need for revision of the Brazilian VL control program.
A Comparison of Miltefosine and Sodium Stibogluconate for Treatment of Visceral Leishmaniasis in an Ethiopian Population with High Prevalence of HIV Infection
Background. Antimonials are the mainstay of visceral leishmaniasis (VL) treatment in Africa. The increasing incidence of human immunodeficiency virus (HIV) coinfection requires alternative safe and effective drug regimens. Oral miltefosine has been proven to be safe and effective in the treatment of Indian VL but has not been studied in Africa or in persons with HIV and VL coinfection. Methods. We compared the efficacy of miltefosine and sodium stibogluconate (SSG) in the treatment of VL in persons in Ethiopia. A total of 580 men with parasitologically and/or serologically confirmed VL were randomized to receive either oral miltefosine (100 mg per day for 28 days) or intramuscular SSG (20 mg/kg per day for 30 days). Results. The initial cure rate was 88% in both treatment groups. Mortality during treatment was 2% in the miltefosine group, compared with 10% in the SSG group. Initial treatment failure was 8% in the miltefosine group, compared with 1% in the SSG group. Among the 375 patients (65%) who agreed to HIV testing, HIV seroprevalence was 29%. Among patients not infected with HIV, initial cure, mortality, and initial treatment failure rates were not significantly different (94% vs. 95%, 1% vs. 3%, and 5% vs. 1% for the miltefosine and SSG groups, respectively). Initial treatment failure with miltefosine occurred in 18% of HIV-coinfected patients, compared with treatment failure in 5% of non–HIV-infected patients. At 6 months after treatment, 174 (60%) of the 290 miltefosine recipients and 189 (65%) of the 290 SSG recipients experienced cure; 30 (10%) of 290 in the miltefosine group and 7 (2%) of 290 in the SSG group experienced relapse, and the mortality rate was 6% in the miltefosine group, compared with 12% in the SSG group. HIV-infected patients had higher rates of relapse (16 [25%] of 63 patients), compared with non–HIV-infected patients (5 [5%] of 131). Conclusions. Treatment with miltefosine is equally effective as standard SSG treatment in non–HIV-infected men with VL. Among HIV-coinfected patients, miltefosine is safer but less effective than SSG.
Leishmaniasis
Leishmaniasis is a poverty-related disease with two main clinical forms: visceral leishmaniasis and cutaneous leishmaniasis. An estimated 0·7–1 million new cases of leishmaniasis per year are reported from nearly 100 endemic countries. The number of reported visceral leishmaniasis cases has decreased substantially in the past decade as a result of better access to diagnosis and treatment and more intense vector control within an elimination initiative in Asia, although natural cycles in transmission intensity might play a role. In east Africa however, the case numbers of this fatal disease continue to be sustained. Increased conflict in endemic areas of cutaneous leishmaniasis and forced displacement has resulted in a surge in these endemic areas as well as clinics across the world. WHO lists leishmaniasis as one of the neglected tropical diseases for which the development of new treatments is a priority. Major evidence gaps remain, and new tools are needed before leishmaniasis can be definitively controlled.
Efficacy and Safety of Amphotericin B Emulsion versus Liposomal Formulation in Indian Patients with Visceral Leishmaniasis: A Randomized, Open-Label Study
India is home to 60% of the total global visceral leishmaniasis (VL) population. Use of long-term oral (e.g. miltefosine) and parenteral drugs, considered the mainstay for treatment of VL, is now faced with increased resistance, decreased efficacy, low compliance and safety issues. The authors evaluated the efficacy and safety of an alternate treatment option, i.e. single infusion of preformed amphotericin B (AmB) lipid emulsion (ABLE) in comparison with that of liposomal formulation (LAmB). In this multicentric, open-label study, 500 patients with VL were randomly assigned in a 3:1 ratio to receive 15 mg/kg single infusion of either ABLE (N = 376) or LAmB (N = 124). Initial cure (Day 30/45), clinical improvement (Day 30) and long term definitive cure (Day 180) were assessed. A total of 326 (86.7%) patients in the ABLE group and 122 (98.4%) patients in the LAmB group completed the study. Initial cure was achieved by 95.9% of patients in the ABLE group compared to 100% in the LAmB group (p = 0.028; 95% CI: -0.0663, -0.0150). Clinical improvement was comparable between treatments (ABLE: 98.9% vs. LAmB: 98.4%). Definitive cure was achieved in 85.9% with ABLE compared to 98.4% with LAmB. Infusion-related pyrexia (37.2% vs. 32.3%) and chills (18.4% vs. 18.5%) were comparable between ABLE and LAmB, respectively. Treatment-related serious adverse events were fewer in ABLE (0.3%) compared to LAmB (1.6%). Two deaths occurred in the ABLE group, of which one was probably related to the study drug. Nephrotoxicity and hepatotoxicity was not observed in either group. ABLE 15 mg/kg single infusion had favorable efficacy and was well tolerated. Considering the demographic profile of the population in this region, a single dose treatment offers advantages in terms of compliance, cost and applicability. www.clinicaltrials.gov NCT00876824.
What pre-Columbian mummies could teach us about South American leishmaniases?
A recent report on the taxonomic profile of the human gut microbiome in pre-Columbian mummies (Santiago-Rodriguez et al. 2016) gives for the first time evidence of the presence of Leishmania DNA (sequences similar to Leishmania donovani according to the authors) that can be reminiscent of visceral leishmaniasis during the pre-Columbian era. It is commonly assumed that Leishmania infantum, the etiological agent of American visceral leishmaniasis (AVL) was introduced into the New World by the Iberian conquest. This finding is really surprising and must be put into perspective with what is known from an AVL epidemiological and historical point of view. Beside L. infantum, there are other species that are occasionally reported to cause AVL in the New World. Among these, L. colombiensis is present in the region of pre-Columbian mummies studied. Other explanations for these findings include a more ancient introduction of a visceral species of Leishmania from the Old World or the existence of a yet unidentified endemic species causing visceral leishmaniasis in South America. Unfortunately, very few molecular data are known about this very long pre-Columbian period concerning the circulating species of Leishmania and their diversity in America.
Chemical and environmental vector control as a contribution to the elimination of visceral leishmaniasis on the Indian subcontinent: cluster randomized controlled trials in Bangladesh, India and Nepal
Background Bangladesh, India and Nepal are working towards the elimination of visceral leishmaniasis (VL) by 2015. In 2005 the World Health Organization/Training in Tropical Diseases launched an implementation research programme to support integrated vector management for the elimination of VL from Bangladesh, India and Nepal. The programme is conducted in different phases, from proof-of-concept to scaling up intervention. This study was designed in order to evaluate the efficacy of the three different interventions for VL vector management: indoor residual spraying (IRS); long-lasting insecticide treated nets (LLIN); and environmental modification (EVM) through plastering of walls with lime or mud. Methods Using a cluster randomized controlled trial we compared three vector control interventions with a control arm in 96 clusters (hamlets or neighbourhoods) in each of the 4 study sites: Bangladesh (one), India (one) and Nepal (two). In each site four villages with high reported VL incidences were included. In each village six clusters and in each cluster five households were randomly selected for sand fly collection on two consecutive nights. Control and intervention clusters were matched with average pre-intervention vector densities. In each site six clusters were randomly assigned to each of the following interventions: indoor residual spraying (IRS); long-lasting insecticide treated nets (LLIN); environmental management (EVM) or control. All the houses (50-100) in each intervention cluster underwent the intervention measures. A reduction of intra-domestic sand fly densities measured in the study households by overnight US Centres for Disease Prevention and Control light trap captures (that is the number of sand flies per trap per night) was the main outcome measure. Results IRS, and to a lesser extent EVM and LLINs, significantly reduced sand fly densities for at least 5 months in the study households irrespective of type of walls or whether or not people shared their house with cattle. IRS was effective in all sites but LLINs were only effective in Bangladesh and India. Mud plastering did not reduce sand fly density (Bangladesh study); lime plastering in India and one Nepali site, resulted in a significant reduction of sand fly density but not in the second Nepali site. Conclusion Sand fly control can contribute to the regional VL elimination programme; IRS should be strengthened in India and Nepal but in Bangladesh, where vector control has largely been abandoned during the last decades, the insecticide treatment of existing bed nets (coverage above 90% in VL endemic districts) could bring about an immediate reduction of vector populations; operational research to inform policy makers about the efficacious options for VL vector control and programme performance should be strengthened in the three countries.