scholarly journals Mapping lymphatic filariasis in Loa loa endemic health districts naïve for ivermectin mass administration and situated in the forested zone of Cameroon.

2020 ◽  
Author(s):  
Andrew A Beng ◽  
Mathias E Esum ◽  
Kebede Deribe ◽  
Abdel J Njouendou ◽  
Patrick WC Ndongmo ◽  
...  
Keyword(s):  
Lymphatic Filariasis ◽  
Positive Association ◽  
Wuchereria Bancrofti ◽  
Cross Reactivity ◽  
Molecular Techniques ◽  
Blood Collection ◽  
Loa Loa ◽  
African Region ◽  
Strong Positive Association ◽  
Health Districts

Abstract Background The control of lymphatic filariasis (LF) caused by Wuchereria bancrofti in the Central African Region has been hampered by the presence of Loa loa due to severe adverse events that arise in the treatment with ivermectin. The immunochromatographic test (ICT) cards used for mapping LF demonstrated cross-reactivity with L. loa and posed the problem of delineating the LF map. To verify LF endemicity in forest areas of Cameroon where mass drug administration (MDA) has not been ongoing, we used the recently developed strategy that combined serology, microscopy and molecular techniques. Methods This study was carried out in 124 communities in 31 health districts (HDs) where L. loa is present. At least 125 persons per site were screened. Diurnal blood samples were investigated for circulating filarial antigen (CFA) by FTS and for L. loa microfilariae (mf) using TBF. FTS positive individuals were further subjected to night blood collection for detecting W . bancrofti . qPCR was used to detect DNA of the parasites. Results Overall, 14,446 individuals took part in this study, 233 participants tested positive with FTS in 29 HDs, with positivity rates ranging from 0.0% to 8.2%. No W . bancrofti mf was found in the night blood of any individuals but L. loa mf were found in both day and night blood of participants who were FTS positive. Also, qPCR revealed that no W. bancrofti but L.loa DNA was found with dry bloodspot. Positive FTS results were strongly associated with high L. loa mf load. Similarly, a strong positive association was observed between FTS positivity and L loa prevalence. Conclusions Using a combination of parasitological and molecular tools, we were unable to find evidence of W. bancrofti presence in the 31 HDs, but L. loa instead. Therefore, LF is not endemic and LF MDA is not required in these districts.

scholarly journals Mapping lymphatic filariasis in Loa loa endemic health districts naïve for ivermectin mass administration and situated in the forested zone of Cameroon.

2020 ◽  
Author(s):  
Andrew A Beng ◽  
Mathias E Esum ◽  
Kebede Deribe ◽  
Abdel J Njouendou ◽  
Patrick WC Ndongmo ◽  
...  
Keyword(s):  
Lymphatic Filariasis ◽  
Positive Association ◽  
Wuchereria Bancrofti ◽  
Cross Reactivity ◽  
Molecular Techniques ◽  
Blood Collection ◽  
Loa Loa ◽  
African Region ◽  
Strong Positive Association ◽  
Health Districts

Abstract Background The control of lymphatic filariasis (LF) caused by Wuchereria bancrofti in the Central African Region has been hampered by the presence of Loa loa due to severe adverse events that arise in the treatment with ivermectin. The immunochromatographic test (ICT) cards used for mapping LF demonstrated cross-reactivity with L. loa and posed the problem of delineating the LF map. To verify LF endemicity in forest areas of Cameroon where mass drug administration (MDA) has not been ongoing, we used the recently developed strategy that combined serology, microscopy and molecular techniques. Methods This study was carried out in 124 communities in 31 health districts (HDs) where L. loa is present. At least 125 persons per site were screened. Diurnal blood samples were investigated for circulating filarial antigen (CFA) by FTS and for L. loa microfilariae (mf) using TBF. FTS positive individuals were further subjected to night blood collection for detecting W . bancrofti . qPCR was used to detect DNA of the parasites. Results Overall, 14,446 individuals took part in this study, 233 participants tested positive with FTS in 29 HDs, with positivity rates ranging from 0.0% to 8.2%. No W . bancrofti mf was found in the night blood of any individuals but L. loa mf were found in both day and night blood of participants who were FTS positive. Also, qPCR revealed that no W. bancrofti but L.loa DNA was found with dry bloodspot. Positive FTS results were strongly associated with high L. loa mf load. Similarly, a strong positive association was observed between FTS positivity and L loa prevalence. Conclusions Using a combination of parasitological and molecular tools, we were unable to find evidence of W. bancrofti presence in the 31 HDs, but L. loa instead. Therefore, LF is not endemic and LF MDA is not required in these districts.

Semiannual Treatment of Albendazole Alone is Efficacious for Treatment of Lymphatic Filariasis: A Randomized Open-label Trial in Cote d'Ivoire

2021 ◽  
Author(s):  
Allassane F Ouattara ◽  
Catherine M Bjerum ◽  
Méité Aboulaye ◽  
Olivier Kouadio ◽  
Vanga K Marius ◽  
...  
Keyword(s):  
Lymphatic Filariasis ◽  
Primary Outcome ◽  
Central Africa ◽  
Wuchereria Bancrofti ◽  
Bancroftian Filariasis ◽  
Loa Loa ◽  
Open Label ◽  
Treatment Groups ◽  
Open Label Trial ◽  
To Receive

Abstract Background Ivermectin (IVM) plus albendazole (ALB), or IA, is widely used in mass drug administration (MDA) programs that aim to eliminate lymphatic filariasis (LF) in Africa. However, IVM can cause severe adverse events in persons with heavy Loa loa infections that are common in Central Africa. ALB is safe in loiasis, but more information is needed on its efficacy for LF. This study compared the efficacy and safety of three years of semiannual treatment with ALB to annual IA in persons with bancroftian filariasis. Methods Adults with Wuchereria bancrofti microfilaremia (Mf) were randomized to receive either three annual doses of IA (N=52), six semiannual doses of ALB 400mg (N=45), or six semiannual doses of ALB 800mg (N=47). The primary outcome amicrofilaremia at 36 months. Findings IA was more effective for completely clearing Mf than ALB 400mg or ALB 800mg (79%, CI 67-91; vs. 48%, CI 32-66 and 57%, CI 41-73, respectively). Mean % reductions in Mf counts at 36 months relative to baseline tended to be greater after IA (98%, CI 88-100) than after ALB 400mg (88%, CI 78-98) and ALB 800mg (89%, CI 79-99) (P=0.07 and P=0.06, respectively). Adult worm nest numbers (assessed by ultrasound) were reduced in all treatment groups. Treatments were well tolerated. Interpretation Repeated semiannual treatment with ALB is macrofilaricidal for W. bancrofti and leads to sustained reductions in Mf counts. This is a safe and effective regimen that could be used as MDA to eliminate LF in areas ivermectin cannot be used.

scholarly journals Further evidence of the cross-reactivity of the Binax NOW® Filariasis ICT cards to non-Wuchereria bancrofti filariae: experimental studies with Loa loa and Onchocerca ochengi

2016 ◽  
Vol 9 (1) ◽  
Author(s):  
Samuel Wanji ◽  
Nathalie Amvongo-Adjia ◽  
Abdel Jelil Njouendou ◽  
Jonas Arnaud Kengne-Ouafo ◽  
Winston Patrick Chounna Ndongmo ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Wuchereria Bancrofti ◽  
Cross Reactivity ◽  
Loa Loa ◽  
Onchocerca Ochengi ◽  
The Cross

Development and characterization of monoclonal antibodies against WbSXP-1 for the detection of circulating filarial antigens

2010 ◽  
Vol 85 (1) ◽  
pp. 1-6 ◽  
Author(s):  
S. Janardhan ◽  
P. Pandiaraja ◽  
V. Pandey ◽  
A. Karande ◽  
P. Kaliraj
Keyword(s):  
Monoclonal Antibodies ◽  
Lymphatic Filariasis ◽  
Wuchereria Bancrofti ◽  
Cross Reactivity ◽  
World Health ◽  
Serum Samples ◽  
Parasite Protein ◽  
Circulating Filarial Antigens ◽  
Flow Through ◽  
Health Organization

AbstractThe importance of developing effective assays to diagnose, monitor and evaluate human lymphatic filariasis has been emphasized by the World Health Organization. Presently, few immunodiagnostics are available for filarial monitoring programmes. The Wuchereria bancrofti (Wb) SXP-1 parasite protein, with 84% homology to Brugia malayi (Bm) SXP-1, was found to be highly immunogenic. WbSXP-1 is one among the diagnostic candidate molecules that were used for developing a rapid-antibody-flow-through diagnostic kit for filariasis. Studies were initiated with the aim of developing monoclonal antibodies against recombinant WbSXP-1 and prospective applications for the detection of both circulating Wb and Bm antigens in serum samples from infected individuals. The monoclones 1A6C2 of subclass IgG1k, and 2A12F8 of class IgM, specifically detected Wb and Bm microfilaria isolated from patients and did not show cross-reactivity with other filarial recombinant antigens. We anticipate that this work will address the problems faced in the rapid diagnosis of human lymphatic filariasis in endemic areas in developing countries.

scholarly journals Mapping lymphatic filariasis in Loa loa endemic health districts naïve for ivermectin mass administration and situated in the forested zone of Cameroon

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Andrew A. Beng ◽  
Mathias E. Esum ◽  
Kebede Deribe ◽  
Abdel J. Njouendou ◽  
Patrick W. C. Ndongmo ◽  
...  
Keyword(s):  
Lymphatic Filariasis ◽  
Loa Loa ◽  
Health Districts

scholarly journals Positivity of Antigen Tests Used for Diagnosis of Lymphatic Filariasis in Individuals Without Wuchereria bancrofti Infection But with High Loa loa Microfilaremia

2016 ◽  
Vol 95 (6) ◽  
pp. 1417-1423 ◽  
Author(s):  
Sébastien D. Pion ◽  
Céline Montavon ◽  
Cédric B. Chesnais ◽  
Joseph Kamgno ◽  
Samuel Wanji ◽  
...  
Keyword(s):  
Lymphatic Filariasis ◽  
Wuchereria Bancrofti ◽  
Loa Loa ◽  
Antigen Tests

scholarly journals Identification and characterization of Loa loa antigens responsible for cross-reactivity with rapid diagnostic tests for lymphatic filariasis

2018 ◽  
Vol 12 (11) ◽  
pp. e0006963 ◽  
Author(s):  
Marla I. Hertz ◽  
Hugues Nana-Djeunga ◽  
Joseph Kamgno ◽  
Abdel Jelil Njouendou ◽  
Valerine Chawa Chunda ◽  
...  
Keyword(s):  
Lymphatic Filariasis ◽  
Diagnostic Tests ◽  
Cross Reactivity ◽  
Rapid Diagnostic Tests ◽  
Loa Loa ◽  
Identification And Characterization

scholarly journals Identification and Validation of Loa loa Microfilaria-Specific Biomarkers: a Rational Design Approach Using Proteomics and Novel Immunoassays

mBio ◽  
2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Papa M. Drame ◽  
Zhaojing Meng ◽  
Sasisekhar Bennuru ◽  
Jesica A. Herrick ◽  
Timothy D. Veenstra ◽  
...  
Keyword(s):  
Lymphatic Filariasis ◽  
Rational Design ◽  
Point Of Care ◽  
Geometric Mean ◽  
Specific Antigen ◽  
Wuchereria Bancrofti ◽  
Loa Loa ◽  
Discriminative Ability ◽  
Care Assessment

ABSTRACT Immunoassays are currently needed to quantify Loa loa microfilariae (mf) . To address this need, we have conducted proteomic and bioinformatic analyses of proteins present in the urine of a Loa mf-infected patient and used this information to identify putative biomarkers produced by L. loa mf. In total, 70 of the 15,444 described putative L. loa proteins were identified. Of these 70, 18 were L. loa mf specific, and 2 of these 18 (LOAG_16297 and LOAG_17808) were biologically immunogenic. We developed novel reverse luciferase immunoprecipitation system (LIPS) immunoassays to quantify these 2 proteins in individual plasma samples. Levels of these 2 proteins in microfilaremic L. loa -infected patients were positively correlated to mf densities in the corresponding blood samples ( r = 0.71 and P < 0.0001 for LOAG_16297 and r = 0.61 and P = 0.0002 for LOAG_17808). For LOAG_16297, the levels in plasma were significantly higher in Loa -infected (geometric mean [GM], 0.045 µg/ml) than in uninfected ( P < 0.0001), Wuchereria bancrofti -infected ( P = 0.0005), and Onchocerca volvulus -infected ( P < 0.0001) individuals, whereas for LOAG_17808 protein, they were not significantly different between Loa -infected (GM, 0.123 µg/ml) and uninfected ( P = 0.06) and W. bancrofti -infected ( P = 0.32) individuals. Moreover, only LOAG_16297 showed clear discriminative ability between L. loa and the other potentially coendemic filariae. Indeed, the specificity of the LOAG_16297 reverse LIPS assay was 96% (with a sensitivity of 77%). Thus, LOAG_16297 is a very promising biomarker that will be exploited in a quantitative point-of-care immunoassay for determination of L. loa mf densities. IMPORTANCE Loa loa , the causative agent of loiasis, is a parasitic nematode transmitted to humans by the tabanid Chrysops fly. Some individuals infected with L. loa microfilariae (mf) in high densities are known to experience post-ivermectin severe adverse events (SAEs [encephalopathy, coma, or death]). Thus, ivermectin-based mass drug administration (MDA) programs for onchocerciasis and for lymphatic filariasis control have been interrupted in parts of Africa where these filarial infections coexist with L. loa . To allow for implementation of MDA for onchocerciasis and lymphatic filariasis, tools that can accurately identify people at risk of developing post-ivermectin SAEs are needed. Our study, using host-based proteomics in combination with novel immunoassays, identified a single Loa -specific antigen (LOAG_16297) that can be used as a biomarker for the prediction of L. loa mf levels in the blood of infected patients. Therefore, the use of such biomarker could be important in the point-of-care assessment of L. loa mf densities.

scholarly journals Factors Affecting the Rate of Fuel Consumption in Aircrafts

2021 ◽  
Vol 13 (14) ◽  
pp. 8066
Author(s):  
Thowayeb H. Hassan ◽  
Abu Elnasr E. Sobaih ◽  
Amany E. Salem
Keyword(s):  
Fuel Consumption ◽  
Positive Association ◽  
Pollutant Emissions ◽  
Aviation Industry ◽  
Factors Affecting ◽  
Fuel Flow ◽  
Homogeneity Of Variance ◽  
Strong Positive Association ◽  
Ground Distance ◽  
The Cost

The cost of fuel and its availability are among the most major concerns for aircrafts and the aviation industry overall. Environmental difficulties with chemical pollutant emissions emitted by aviation machines are also connected to fuel consumption. As a result, it is crucial to examine factors that affect the overall fuel usage and consumption in the airport-based aviation industry. Several variables were investigated related to the total fuel consumed, such as dry operating weight (DOW) (KG), zero-fuel weight (ZFW), take-off weight (TOW), air distance (AIR DIST) (KM), and ground distance (GDN DIST). Analysis of the correlation between total fuel consumed as well as the extra fuel and selected variables was conducted. The results showed that the most positively associated factors with the total used fuel were the air distance (r2 = 0.86, p < 0.01), ground distance (r2 = 0.78, p < 0.01), TOW (r2 = 0.68, p < 0.01), and flight time (r2 = 0.68, p < 0.01). There was also a strong positive association between the average fuel flow (FF) and actual TOW (r2 = 0.74, p < 0.01) as well as ZFW (r2 = 0.61, p < 0.01). The generalized linear model (GLM) was utilized to assess the predictions of total energy usage after evaluating important outliers, stability of the homogeneity of variance, and the normalization of the parameter estimation. The results of multiple linear regression revealed that the most significant predictors of the total consumed fuel were the actual ZFW (p < 0.01), actual TOW (p < 0.01), and actual average FF (p < 0.05). The results interestingly confirmed that wind speed has some consequences and effects on arrival fuel usage. The result reflects that thermal and hydrodynamic economies impact on the flying fuel economy. The research has various implications for both scholars and practitioners of aviation industry.

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