Publications by authors named "Sebastien D S Pion"

Background: Loiasis affects millions in Central Africa and, though historically considered benign, emerging data suggest possible renal involvement. This study investigated the association between Loa microfilaremia and renal function.

Methods: We conducted a cross-sectional study in the Republic of Congo in May-June 2022.

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Individuals with high Loa loa microfilarial densities (MFD) risk serious adverse events (SAEs) following ivermectin treatment. A single dose of levamisole (LEV) induces a temporary, progressive MFD decrease. This double-blind, randomized, placebo-controlled trial evaluated the safety and efficacy of 3-day and 5-day LEV regimens for the treatment of loiasis in the Republic of the Congo.

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Background: Loiasis is endemic in Central Africa. Despite evidence of clinical complications and increased mortality, it remains excluded from the list of neglected tropical diseases. The main manifestations are Calabar swellings (CS), Eyeworm (EW) and non-specific general symptoms such arthralgia and pruritus.

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Background: Data suggest excess mortality is associated with loiasis, which is endemic to Central Africa, although the underlying mechanisms remain unknown. We hypothesized that there could be an association between Loa loa microfilarial densities (MFD) and lower spleen volume (SV) due to micro-obstruction linked to circulating microfilariae (mf). This could result in functional hyposplenia and a higher burden of infections.

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We assessed the impact of loiasis and its treatment with ivermectin on hemostasis and inflammation in 38 adults in Cameroon. Participants were divided into four balanced groups based on their Loa loa microfilarial densities. At baseline, eosinophils and platelets increased with microfilarial densities (p<0.

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Background: The standard method to diagnose Loa loa infection and quantify microfilarial density (MFD) is the microscopic examination of calibrated thick blood smears (TBSs). In 1950, it was noticed that successive L. loa MFD samples from a single capillary puncture could exhibit up to 20% variation.

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Article Synopsis
  • Loiasis, caused by the Loa loa worm and affecting around 10 million people in Central Africa, presents challenges in diagnosis and treatment due to potential severe reactions to ivermectin used for other infections.
  • Diagnosis typically involves identifying adult worms or microfilariae in blood, but many infections are "occult," prompting the need for new diagnostic tools.
  • This study compared two serological rapid antibody tests for loiasis and onchocerciasis, evaluating their effectiveness in diagnosing infections among participants, revealing a high prevalence of both microfilaremia and symptoms related to loiasis.
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Background: Loa loa filariasis (loiasis) is still considered a relatively benign disease. However, recent epidemiologic data suggest increased mortality and morbidity in L. loa infected individuals.

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Background: Loiasis is endemic in the northern and western part of the Republic of Congo. Between 2004 and 2010, surveys were conducted, using the RAPLOA method, in all departments of the Republic of Congo to assess the distribution of loiasis. Prior to 2004, only two parasitological surveys on loiasis had been conducted in Congo and mainly in the Department of Lékoumou, in the southwestern of the country.

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Background: Case reports have hypothesised that proteinuria, sometimes with glomerulopathy or nephrotic syndromes, might be associated with loiasis. To our knowledge, no study has been done to assess this association. We aimed to investigate the association between Loa loa microfilariae burden and proteinuria.

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Background-rationale: The diagnosis of microfilaremia consists in the observation, using a microscope, of microfilariae in a sample of peripheral blood spread on a slide and subsequently stained (the "blood smear technique"). The accurate quantification of microfilaremia is important because the choice of the first intention treatment depends on the patient's microfilaremia: severe adverse events can occur in individuals with high microfilarial densities when treated with ivermectin or diethylcarbamazine, the latter drug being the only one which can definitively cure the infection. However, despite the widespread usage of this technique and its role in guiding clinical management of the patient, estimates of its reliability remain scarce.

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Background: Individuals with high Loa loa microfilarial densities are at risk of developing severe encephalopathy after administration of antiparasitic drugs. Apart from this finding, loiasis is considered benign with no effect on brain function. However, recent epidemiological data suggest an increased mortality and morbidity in L.

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Background: The diurnal periodicity of Loa loa microfilaraemia is well known but few studies have documented the short- and long-term stability of microfilarial density. It seems stable over time at the community level, but significant variations have been observed at the individual level.

Methods: We assessed the temporal variability of L.

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Background: Loa loa microfilariae circulate in the peripheral blood of human hosts following a diurnal periodicity, with maximal microfilaremia levels generally observed between 10:00 am and 3:00 pm. Few studies have assessed factors potentially associated with this periodicity.

Methods: Microfilaremia data were collected repeatedly between 9:00 am and 8:00 pm from 13 individuals in the Republic of the Congo.

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Background: Albendazole is an orally administered anti-parasitic medication with widespread usage in a variety of both programmatic and clinical contexts. Previous work has shown that the drug's pharmacologically active metabolite, albendazole sulfoxide, is characterised by substantial inter-individual pharmacokinetic variation. This variation might have implications for the efficacy of albendazole treatment, but current understanding of the factors associated with this variation remains incomplete.

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Between October 2012 and October 2015, we conducted a community trial to assess the impact of semi-annual (twice yearly) community treatment with albendazole on lymphatic filariasis in Seke Pembe, a village in the Republic of the Congo. Semi-annual community treatment with albendazole has been continued in the community since October 2015. We conducted an additional parasitological assessment survey in October 2019, 6 months after the 14th round of semi-annual treatment.

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Background: Individuals with high microfilarial densities (MFDs) of Loa loa are at risk of developing serious adverse events (SAEs) after ivermectin treatment. Pretreatment with drugs progressively reducing Loa MFDs below the risk threshold might help prevent these SAEs. We assessed the safety and efficacy of levamisole for this purpose.

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Unlabelled: Levamisole was initially prescribed for the treatment of intestinal worms. Because of immunomodulatory properties, levamisole has been used in inflammatory pathologies and in cancers in association with 5-fluorouracil. Levamisole is misused as a cocaine adulterant.

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Background: The impact of semiannual mass drug administration (MDA) with albendazole (ALB; 400 mg) alone on lymphatic filariasis (LF) and soil-transmitted helminth (STH) infections was assessed during two trials conducted from 2012 to 2018 in the Republic of Congo and the Democratic Republic of Congo. The collected data were analyzed to evaluate the effect of compliance with ALB treatment on STH infections.

Methods: STH infections were diagnosed with duplicate Kato-Katz thick smears and the results are reported as eggs per gram of stool.

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The standard techniques for diagnosis of human filariasis are the microscopic examination of blood smears or skin biopsies, which are relatively invasive and poorly sensitive at low levels of infection. Recently, filarial DNA has been detected in fecal samples from non-human primates in Central Africa. The aim of this study was to demonstrate proof-of-concept of a non-invasive molecular diagnosis technique for human filariasis by targeting fragments of 12S rDNA, Cox1, ITS1 and LL20-15kDa ladder antigen-gene by conventional PCR in DNA extracted from stool samples of 52 people infected with Mansonella perstans and/or Loa loa.

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Background: The diagnostic gold standard for onchocerciasis relies on identification and enumeration of (skin-dwelling) Onchocerca volvulus microfilariae (mf) using the skin snip technique (SST). In a recent study, blood-borne Loa loa mf were found by SST in individuals heavily infected with L. loa, and microscopically misidentified as O.

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We determined the complete sequence of the mitochondrial DNA (mtDNA) of a parasite discovered between the subcutaneous tissue and the peritoneum of an African nocturnal non-human primate (NHP). The parasite and host sequences were obtained by a combination of Sanger sequencing and nanopore MinION techniques. Analyses of mtDNA gene arrangements and sequences unambiguously showed that the parasite investigated was the pentastomid Armillifer armillatus, also commonly named the tongue worm.

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Background: Two community trials conducted from 2012 to 2018 in the Republic of Congo and the Democratic Republic of the Congo demonstrated the efficacy of semiannual mass drug administration (MDA) with albendazole (ALB) alone on lymphatic filariasis (LF). However, a high interindividual heterogeneity in the clearance of infection was observed.

Methods: We analyzed trial data to assess the effect of individual adherence to ALB MDA on clearance of circulating filarial antigenemia (CFA) and microfilaremia.

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Background: The World Health Organization now recommends semiannual mass drug administration (MDA) of albendazole with integrated vector management as an option for eliminating lymphatic filariasis (LF) in areas of loiasis-endemic countries where it may not be safe to use diethylcarbamazine or ivermectin in MDA programs. However, the published evidence base to support this policy is thin, and uptake by national programs has been slow.

Methodology/principal Findings: We conducted a community trial to assess the impact of semiannual MDA on lymphatic filariasis and soil-transmitted helminth infections (STH) in two villages in the Bandundu province of the Democratic Republic of the Congo with moderately high prevalences for LF and hookworm infections.

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Background: Little information is available on the effect of ivermectin on the third- and fourth-stage larvae of Onchocerca volvulus. To assess a possible prophylactic effect of ivermectin on this parasite, we compared the effects of different ivermectin regimens on the acquisition of onchocercal nodules.

Methods: We analyzed data from a controlled randomized clinical trial of ivermectin conducted in the Mbam Valley (Cameroon) between 1994 and 1998 in a cohort of onchocerciasis infected individuals.

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