scholarly journals Projected Number of People With Onchocerciasis–Loiasis Coinfection in Africa, 1995 to 2025

2019 ◽  
Vol 70 (11) ◽  
pp. 2281-2289 ◽  
Author(s):  
Natalie V S Vinkeles Melchers ◽  
Luc E Coffeng ◽  
Michel Boussinesq ◽  
Belén Pedrique ◽  
Sébastien D S Pion ◽  
...  
Keyword(s):  
At Risk ◽  
Adverse Events ◽  
Control Strategies ◽  
Central Africa ◽  
Ivermectin Treatment ◽  
Loa Loa ◽  
Serious Adverse Events ◽  
West And Central Africa ◽  
And Control ◽  
The Impact

Abstract Background Onchocerciasis elimination through mass drug administration (MDA) is hampered by coendemicity of Loa loa, as people with high L. loa microfilariae (mf) density can develop serious adverse events (SAEs) after ivermectin treatment. We assessed the geographical overlap of onchocerciasis and loiasis prevalence and estimated the number of coinfected individuals at risk of post-ivermectin SAEs in West and Central Africa from 1995 to 2025. Methods Focusing on regions with suspected loiasis transmission in 14 countries, we overlaid precontrol maps of loiasis and onchocerciasis prevalence to calculate precontrol prevalence of coinfection by 5 km2 × 5 km2 pixel, distinguishing different categories of L. loa mf intensity. Using statistical and mathematical models, we predicted prevalence of both infections and coinfection for 2015 and 2025, accounting for the impact of MDA with ivermectin. Results The number of people infected with onchocerciasis was predicted to decline from almost 19 million in 1995 to 4 million in 2025. Of these, 137 000 people were estimated to also have L. loa hypermicrofilaremia (≥20 000 L. loa mf/mL) in 1995, declining to 31 000 in 2025. In 2025, 92.8% of coinfected cases with loiasis hypermicrofilaremia are predicted to live in hypoendemic areas currently not targeted for MDA. Conclusions Loiasis coinfection is a major concern for onchocerciasis elimination in Africa. We predict that under current strategies, at least 31 000 coinfected people still require treatment for onchocerciasis in 2025 while being at risk of SAEs, justifying continued efforts in research and development for safer drugs and control strategies.

scholarly journals Feasibility of onchocerciasis elimination using a “test-and-not-treat” strategy in Loa loa co-endemic areas

2020 ◽  
Author(s):  
David J Blok ◽  
Joseph Kamgno ◽  
Sebastien D Pion ◽  
Hugues C Nana-Djeunga ◽  
Yannick Niamsi-Emalio ◽  
...  
Keyword(s):  
Adverse Events ◽  
Drug Administration ◽  
Mass Drug Administration ◽  
Treatment Duration ◽  
Loa Loa ◽  
Serious Adverse Events ◽  
Endemic Areas ◽  
The Individual ◽  
The Impact ◽  
Main Strategy

Abstract Background Mass drug administration (MDA) with ivermectin is the main strategy for onchocerciasis elimination. Ivermectin is generally safe but associated with serious adverse events in individuals with high Loa loa microfilarial densities (MFD). Therefore, ivermectin MDA is not recommended in areas where onchocerciasis is hypo-endemic and L. loa is co-endemic. To eliminate onchocerciasis in those areas, a test-and-not-treat (TaNT) strategy has been proposed. We investigated whether onchocerciasis elimination can be achieved using TaNT and the required duration. Methods We used the individual-based model ONCHOSIM to predict the impact of TaNT on onchocerciasis microfilarial (mf) prevalence. We simulated pre-control mf prevalence levels from 2-40%. The impact of TaNT was simulated under varying levels of participation, systematic non-participation and exclusion from ivermectin due to high L. loa MFD. For each scenario, we assessed the time to elimination, defined as bringing onchocerciasis mf prevalence below 1.4%. Results In areas with 30-40% pre-control mf prevalence, the model predicted that it would take between 14 and 16 years to bring the mf prevalence below 1.4% using conventional MDA, assuming 65% participation. TaNT would increase the time to elimination by up to 1.5 years, depending on the level of systematic non-participation and the exclusion rate. At lower exclusion rates (≤2.5%), the delay would be less than six months. Conclusions Our model predicts that onchocerciasis can be eliminated using TaNT in L. loa co-endemic areas. The required treatment duration using TaNT would be only slightly longer than in areas with conventional MDA, provided that participation is good.

Revisiting the possibility of serious adverse events from the whole cell pertussis vaccine: Were metabolically vulnerable children at risk?

2010 ◽  
Vol 74 (1) ◽  
pp. 150-154 ◽  
Author(s):  
Kumanan Wilson ◽  
Beth Potter ◽  
Douglas Manuel ◽  
Jennifer Keelan ◽  
Pranesh Chakraborty
Keyword(s):  
At Risk ◽  
Adverse Events ◽  
Pertussis Vaccine ◽  
Children At Risk ◽  
Vulnerable Children ◽  
Serious Adverse Events ◽  
Whole Cell

scholarly journals A historical note on an imported case of loiasis in Rio de Janeiro, Brazil, 1964

2011 ◽  
Vol 53 (5) ◽  
pp. 295-297
Author(s):  
Antonio Giardulli ◽  
Guilherme Dolanda Paulo Filho ◽  
Giovanni Nicola Urberto Italiano Colombini ◽  
Walter de Araújo Eyer-Silva ◽  
Carlos Alberto Basilio-de-Oliveira
Keyword(s):  
Rio De Janeiro ◽  
Clinical Manifestations ◽  
Central Africa ◽  
Surgical Removal ◽  
Historical Note ◽  
Loa Loa ◽  
Imported Case ◽  
West And Central Africa ◽  
Inflammatory Edema ◽  
The City

Loiasis is a filarial disease transmitted by the Chrysops spp. tabanid flies in West and Central Africa. It is most commonly diagnosed by the clinical manifestations of Calabar swellings (transient localized inflammatory edema) or, most dramatically, by the appearance of a migrating worm through the conjunctival tissues or the bridge of the nose. We report the case of a 35-year-old resident in the city of Rio de Janeiro who displayed a moving Loa loa in the bulbar conjunctival tissue two years after returning from a six-month trip to Uganda. Surgical removal of the worm was performed.

Assessing the Impact of Temperature Change on the Effectiveness of Insecticide-Treated Nets

2011 ◽  
Vol 3 (3) ◽  
pp. 35-48 ◽  
Author(s):  
Gregory J. Davis
Keyword(s):  
Control Strategies ◽  
Global Climate ◽  
Financial Burden ◽  
Insecticide Treated Nets ◽  
Policy Makers ◽  
Agent Based ◽  
Mosquito Abundance ◽  
Vector Borne ◽  
And Control ◽  
The Impact

Malaria is a vector-borne illness affecting millions of lives annually and imposes a heavy financial burden felt worldwide. Moreover, there is growing concern that global climate change, in particular, rising temperature, will increase this burden. As such, policy makers are in need of tools capable of informing them about the potential strengths and weaknesses of intervention and control strategies. A previously developed agent-based model of the Anopheles gambiae mosquito is extended, one of the primary vectors of malaria, to investigate how changes in temperature influence the dynamics of malaria transmission and the effectiveness of a common malaria intervention: insecticide-treated nets (ITNs). Results from the simulations suggest two important findings. Consistent with previous studies, an increase in mosquito abundance as temperature increases is observed. However, the increase in mosquito abundance reduces the effectiveness of ITNs at a given coverage level. The implications and limitations of these findings are discussed.

scholarly journals Rapid shifts in the age-specific burden of malaria following successful control interventions in four regions of Uganda

2020 ◽  
Author(s):  
Simon P. Kigozi ◽  
Ruth N. Kigozi ◽  
Adrienne Epstein ◽  
Arthur Mpimbaza ◽  
Asadu Sserwanga ◽  
...  
Keyword(s):  
Control Strategies ◽  
Age Distribution ◽  
Indoor Residual Spraying ◽  
Malaria Prevention ◽  
Older Individuals ◽  
Multinomial Regression ◽  
Transmission Reduction ◽  
Successful Control ◽  
And Control ◽  
The Impact

Abstract Background: Malaria control using long-lasting insecticidal nets (LLINs) and indoor residual spraying of insecticide (IRS) has been associated with reduced transmission throughout Africa. However, the impact of transmission reduction on the age distribution of malaria cases remains unclear. Methods: Over a 10-year period (January, 2009 to July, 2018), outpatient surveillance data from four health facilities in Uganda were used to estimate the impact of control interventions on temporal changes in the age distribution of malaria cases using multinomial regression. Interventions included mass distribution of LLINs at all sites and IRS at two sites. Results: Overall, 896,550 patient visits were included in the study; 211,632 aged <5 years, 171,166 aged 5-15 years, and 513,752 >15 years. Over time, the age distribution of patients not suspected of malaria and those malaria negative either declined or remained the same across all sites. In contrast, the age distribution of suspected and confirmed malaria cases increased across all four sites. In the two LLINs-only sites, the proportion of malaria cases in <5 years decreased from 31% to 16% and 35% to 25%, respectively. In the two sites receiving LLINs plus IRS, these proportions decreased from 58% to 30% and 64% to 47%, respectively. Similarly, in the LLINs-only sites, the proportion of malaria cases >15 years increased from 40% to 61% and 29% to 39%, respectively. In the sites receiving LLINs plus IRS, these proportions increased from 19% to 44% and 18% to 31%, respectively. Discussion: These findings demonstrate a shift in the burden of malaria from younger to older individuals following implementation of successful control interventions, which has important implications for malaria prevention, surveillance, case management and control strategies.

scholarly journals Prone Positioning of Non-intubated Patients with COVID-19 - A Systematic Review and Meta-analysis

2020 ◽  
Author(s):  
Mallikarjuna Reddy PONNAPA REDDY ◽  
Ashwin SUBRAMANIAM ◽  
Zheng Jie LIM ◽  
Alexandr ZUBAREV ◽  
Afsana AFROZ ◽  
...  
Keyword(s):  
Systematic Review ◽  
Adverse Events ◽  
Weighted Mean Difference ◽  
Meta Analysis ◽  
Prone Positioning ◽  
Serious Adverse Events ◽  
Lack Of Control ◽  
The Impact ◽  
Substantial Heterogeneity ◽  
Major Adverse Events

Abstract Purpose: Several studies have reported adopting prone positioning (PP) in non-intubated patients with COVID-19-related hypoxaemic respiratory failure. This systematic review and meta-analysis evaluated the impact of PP on oxygenation and clinical outcomes.Methods: We searched PubMed, Embase and the COVID-19 living systematic review from December 1, 2019 to July 23, 2020. We included studies that reported using PP in hypoxaemic, non-intubated adult patients with COVID-19. Primary outcome measureed was the weighted mean difference (MD) in oxygenation parameters (PaO2/FiO2, PaO2 or SpO2) pre and post-PP. Results: Fifteen single arm observational studies reporting PP in 449 patients were included. Substantial heterogeneity was noted in terms of, location within hospital where PP was instituted, respiratory supports during PP, and frequency and duration of PP. Significant improvement in oxygenation was reported post-PP: PaO2/FiO2 (MD 37.6, 95% CI 18.8-56.5); PaO2 (MD 30.4 mmHg, 95% CI 10.9 to 49.9); and SpO2 (MD 5.8%, 95% CI 3.7 to 7.9). Patients with a pre-PP PaO2/FiO2 ≤150 experienced greater oxygenation improvements compared with those with a pre-PP PaO2/FiO2 >150 (MD 40.5, 95% CI -3.5 to 84.6) vs. 37, 95% CI 17.1 to 56.9). Respiratory rate decreased post-PP (MD -2.9, 95% CI -5.4 to -0.4). Overall intubation and mortality rates were 21% (90/426) and 26% (101/390) respectively. There were no major adverse events reported. Conclusions: Despite the significant variability in frequency and duration of PP and respiratory supports applied, PP was associated with improvements in oxygenation parameters without any reported serious adverse events. The results are limited by lack of control arm and adjustment for confounders. Clinical trials are required to determine the effect of awake PP on patient-centred outcomes.Systematic review registration: Registration/protocol in PROSPERO (CRD42020194080).

scholarly journals Mathematical modelling and phylodynamics for the study of dog rabies dynamics and control: A scoping review

2021 ◽  
Vol 15 (5) ◽  
pp. e0009449
Author(s):  
Maylis Layan ◽  
Simon Dellicour ◽  
Guy Baele ◽  
Simon Cauchemez ◽  
Hervé Bourhy
Keyword(s):  
Mathematical Modelling ◽  
Mathematical Models ◽  
Scoping Review ◽  
Control Strategies ◽  
Domestic Dog ◽  
Interdisciplinary Approaches ◽  
Dynamics And Control ◽  
And Control ◽  
The Impact

Background Rabies is a fatal yet vaccine-preventable disease. In the last two decades, domestic dog populations have been shown to constitute the predominant reservoir of rabies in developing countries, causing 99% of human rabies cases. Despite substantial control efforts, dog rabies is still widely endemic and is spreading across previously rabies-free areas. Developing a detailed understanding of dog rabies dynamics and the impact of vaccination is essential to optimize existing control strategies and developing new ones. In this scoping review, we aimed at disentangling the respective contributions of mathematical models and phylodynamic approaches to advancing the understanding of rabies dynamics and control in domestic dog populations. We also addressed the methodological limitations of both approaches and the remaining issues related to studying rabies spread and how this could be applied to rabies control. Methodology/principal findings We reviewed how mathematical modelling of disease dynamics and phylodynamics have been developed and used to characterize dog rabies dynamics and control. Through a detailed search of the PubMed, Web of Science, and Scopus databases, we identified a total of n = 59 relevant studies using mathematical models (n = 30), phylodynamic inference (n = 22) and interdisciplinary approaches (n = 7). We found that despite often relying on scarce rabies epidemiological data, mathematical models investigated multiple aspects of rabies dynamics and control. These models confirmed the overwhelming efficacy of massive dog vaccination campaigns in all settings and unraveled the role of dog population structure and frequent introductions in dog rabies maintenance. Phylodynamic approaches successfully disentangled the evolutionary and environmental determinants of rabies dispersal and consistently reported support for the role of reintroduction events and human-mediated transportation over long distances in the maintenance of rabies in endemic areas. Potential biases in data collection still need to be properly accounted for in most of these analyses. Finally, interdisciplinary studies were determined to provide the most comprehensive assessments through hypothesis generation and testing. They also represent new avenues, especially concerning the reconstruction of local transmission chains or clusters through data integration. Conclusions/significance Despite advances in rabies knowledge, substantial uncertainty remains regarding the mechanisms of local spread, the role of wildlife in dog rabies maintenance, and the impact of community behavior on the efficacy of control strategies including vaccination of dogs. Future integrative approaches that use phylodynamic analyses and mechanistic models within a single framework could take full advantage of not only viral sequences but also additional epidemiological information as well as dog ecology data to refine our understanding of rabies spread and control. This would represent a significant improvement on past studies and a promising opportunity for canine rabies research in the frame of the One Health concept that aims to achieve better public health outcomes through cross-sector collaboration.

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