1
|
Burger G, Adamou R, Kreuzmair R, Ndoumba WN, Mbassi DE, Mouima AMN, Tabopda CM, Adegnika RM, More A, Okwu DG, Mbadinga LBD, Calle CL, Veletzky L, Metzger WG, Mordmüller B, Ramharter M, Mombo-Ngoma G, Adegnika AA, Zoleko-Manego R, McCall MBB. Eosinophils, basophils and myeloid-derived suppressor cells in chronic Loa loa infection and its treatment in an endemic setting. PLoS Negl Trop Dis 2024; 18:e0012203. [PMID: 38771861 PMCID: PMC11147522 DOI: 10.1371/journal.pntd.0012203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 06/03/2024] [Accepted: 05/08/2024] [Indexed: 05/23/2024] Open
Abstract
BACKGROUND Chronic infection by Loa loa remains an unsolved immunological paradox. Despite harboring subcutaneously migrating adult worms and often high densities of microfilariae, most patients experience only relatively mild symptoms, yet microfilaricidal treatment can trigger life-threatening inflammation. Here, we investigated innate cell populations hypothesized to play a role in these two faces of the disease, in an endemic population in Gabon. METHODOLOGY/PRINCIPAL FINDINGS We analyzed numbers and activation of eosinophils and basophils, as well as myeloid-derived suppressor cell (MDSC) subsets and associated circulating cytokine levels by flow cytometry in sex- and age-matched L. loa-uninfected (LL-), -amicrofilaraemic (MF-) and -microfilaraemic (MF+) individuals (n = 42), as well as microfilaraemic individuals treated with albendazole (n = 26). The percentage of eosinophils was lower in LL- (3.0%) than in the combined L. loa-infected population, but was similar in MF+ (13.1%) and MF- (12.3%). Upon treatment of MF+, eosinophilia increased from day 0 (17.2%) to day 14 (24.8%) and had decreased below baseline at day 168 (6.3%). Expression of the eosinophil activation marker CD123 followed the same pattern as the percentage of eosinophils, while the inverse was observed for CD193 and to some extent CD125. Circulating IL-5 levels after treatment followed the same pattern as eosinophil dynamics. Basophil numbers did not differ between infection states but increased after treatment of MF+. We did not observe differences in MDSC numbers between infection states or upon treatment. CONCLUSIONS/SIGNIFICANCE We demonstrate that both chronic infection and treatment of L. loa microfilaraemia are associated with eosinophil circulation and distinct phenotypical activation markers that might contribute to inflammatory pathways in this setting. In this first ever investigation into MDSC in L. loa infection, we found no evidence for their increased presence in chronic loiasis, suggesting that immunomodulation by L. loa is induced through other pathways.
Collapse
Affiliation(s)
- Gerrit Burger
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Rafiou Adamou
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
| | - Ruth Kreuzmair
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
| | - Wilfrid Ndzebe Ndoumba
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Department of Implementation Research, Bernhard Nocht Institute for Tropical Medicine & I Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- German Center for Infection Research, Partner sites Hamburg-Borstel-Lübeck-Riems, Germany
| | - Dorothea Ekoka Mbassi
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- German Center for Infection Research, Partner sites Hamburg-Borstel-Lübeck-Riems, Germany
- Centre for Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | | | | | - Ayong More
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
| | - Dearie Glory Okwu
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Department of Implementation Research, Bernhard Nocht Institute for Tropical Medicine & I Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- German Center for Infection Research, Partner sites Hamburg-Borstel-Lübeck-Riems, Germany
| | | | | | - Luzia Veletzky
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | | | - Benjamin Mordmüller
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Michael Ramharter
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- German Center for Infection Research, Partner sites Hamburg-Borstel-Lübeck-Riems, Germany
- Centre for Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ghyslain Mombo-Ngoma
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Department of Implementation Research, Bernhard Nocht Institute for Tropical Medicine & I Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- German Center for Infection Research, Partner sites Hamburg-Borstel-Lübeck-Riems, Germany
| | - Ayola Akim Adegnika
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
- German Center for Infection Research, Partner site Tübingen, Tübingen Germany
| | - Rella Zoleko-Manego
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- German Center for Infection Research, Partner sites Hamburg-Borstel-Lübeck-Riems, Germany
- Centre for Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Matthew B. B. McCall
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| |
Collapse
|
2
|
Ryan NM, Hess JA, Robertson EJ, Tricoche N, Turner C, Davis J, Petrovsky N, Ferguson M, Rinaldi WJ, Wong VM, Shimada A, Zhan B, Bottazzi ME, Makepeace BL, Gray SA, Carter D, Lustigman S, Abraham D. Adjuvanted Fusion Protein Vaccine Induces Durable Immunity to Onchocerca volvulus in Mice and Non-Human Primates. Vaccines (Basel) 2023; 11:1212. [PMID: 37515028 PMCID: PMC10385774 DOI: 10.3390/vaccines11071212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 06/23/2023] [Accepted: 06/27/2023] [Indexed: 07/30/2023] Open
Abstract
Onchocerciasis remains a debilitating neglected tropical disease. Due to the many challenges of current control methods, an effective vaccine against the causative agent Onchocerca volvulus is urgently needed. Mice and cynomolgus macaque non-human primates (NHPs) were immunized with a vaccine consisting of a fusion of two O. volvulus protein antigens, Ov-103 and Ov-RAL-2 (Ov-FUS-1), and three different adjuvants: Advax-CpG, alum, and AlT4. All vaccine formulations induced high antigen-specific IgG titers in both mice and NHPs. Challenging mice with O. volvulus L3 contained within subcutaneous diffusion chambers demonstrated that Ov-FUS-1/Advax-CpG-immunized animals developed protective immunity, durable for at least 11 weeks. Passive transfer of sera, collected at several time points, from both mice and NHPs immunized with Ov-FUS-1/Advax-CpG transferred protection to naïve mice. These results demonstrate that Ov-FUS-1 with the adjuvant Advax-CpG induces durable protective immunity against O. volvulus in mice and NHPs that is mediated by vaccine-induced humoral factors.
Collapse
Affiliation(s)
- Nathan M Ryan
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Jessica A Hess
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Erica J Robertson
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Nancy Tricoche
- Laboratory of Molecular Parasitology, Lindsey F. Kimball Research Institute, New York Blood Center, New York, NY 10065, USA
| | | | - Jenn Davis
- PAI Life Sciences Inc., Seattle, WA 98102, USA
| | | | | | | | | | - Ayako Shimada
- Division of Biostatistics, Department of Pharmacology and Experimental Therapeutics, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Bin Zhan
- Texas Children's Hospital Center for Vaccine Development, Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Maria Elena Bottazzi
- Texas Children's Hospital Center for Vaccine Development, Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK
| | - Sean A Gray
- PAI Life Sciences Inc., Seattle, WA 98102, USA
| | | | - Sara Lustigman
- Laboratory of Molecular Parasitology, Lindsey F. Kimball Research Institute, New York Blood Center, New York, NY 10065, USA
| | - David Abraham
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| |
Collapse
|
3
|
Checkouri T, Missamou F, Pion SDS, Bikita P, Hemilembolo MC, Boussinesq M, Chesnais CB, Campillo JT. Association between altered cognition and Loa loa microfilaremia: First evidence from a cross-sectional study in a rural area of the Republic of Congo. PLoS Negl Trop Dis 2023; 17:e0011430. [PMID: 37339123 DOI: 10.1371/journal.pntd.0011430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 06/03/2023] [Indexed: 06/22/2023] Open
Abstract
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. loa infected individuals, underscoring the importance of studies on the possible neurological morbidity associated with loiasis. METHODOLOGY Using MoCA tests and neurological ultrasounds, we conducted a cross-sectional study to assess cognitive alteration in a population living in a rural area endemic for loiasis in the Republic of Congo. Fifty individuals with high microfilarial densities (MFD) were matched on sex, age and residency with 50 individuals with low MFD and 50 amicrofilaremic subjects. Analyses focused on individuals with MoCA scores indicating an altered cognition (i.e. < 23/30) and on the total MoCA score according to Loa loa MFD, sociodemographic characteristics and neurological ultrasound results. PRINCIPAL FINDINGS MoCA scores were very low in the studied population (mean of 15.6/30). Individuals with more than 15,000 microfilariae per milliliter of blood (mean predicted score:14.0/30) are more than twenty times more likely to have an altered cognition, compared to individuals with no microfilaremia (mean predicted score: 16.3/30). Years of schooling were strongly associated with better MoCA results. Extracranial and intracranial atheroma were not associated with L. loa MFD. CONCLUSION/SIGNIFICANCE Loaisis microfilaremia is probably involved in cognitive impairment, especially when the MFD are high. These results highlight the urgent need to better understand loaisis-induced morbidity. Further studies investigating neurological morbidity of loiasis are needed.
Collapse
Affiliation(s)
- Thomas Checkouri
- AP-HP, Service des Urgences Cérébro-Vasculaires, Hôpital Pitié-Salpêtrière, Sorbonne Université, Paris, France
| | - François Missamou
- Programme National de Lutte contre l'Onchocercose, Direction de l'Épidémiologie et de la Lutte contre la Maladie, Ministère de la Santé et de la Population, Brazzaville, Republic of the Congo
| | - Sebastien D S Pion
- UMI 233 TransVIHMI, Université Montpellier, Institut de Recherche pour le Développement (IRD), INSERM Unité, Montpellier, France
| | - Paul Bikita
- Programme National de Lutte contre l'Onchocercose, Direction de l'Épidémiologie et de la Lutte contre la Maladie, Ministère de la Santé et de la Population, Brazzaville, Republic of the Congo
| | - Marlhand C Hemilembolo
- Programme National de Lutte contre l'Onchocercose, Direction de l'Épidémiologie et de la Lutte contre la Maladie, Ministère de la Santé et de la Population, Brazzaville, Republic of the Congo
- UMI 233 TransVIHMI, Université Montpellier, Institut de Recherche pour le Développement (IRD), INSERM Unité, Montpellier, France
| | - Michel Boussinesq
- UMI 233 TransVIHMI, Université Montpellier, Institut de Recherche pour le Développement (IRD), INSERM Unité, Montpellier, France
| | - Cédric B Chesnais
- UMI 233 TransVIHMI, Université Montpellier, Institut de Recherche pour le Développement (IRD), INSERM Unité, Montpellier, France
| | - Jérémy T Campillo
- UMI 233 TransVIHMI, Université Montpellier, Institut de Recherche pour le Développement (IRD), INSERM Unité, Montpellier, France
| |
Collapse
|
4
|
Pallara E, Cotugno S, Guido G, De Vita E, Ricciardi A, Totaro V, Camporeale M, Frallonardo L, Novara R, Panico GG, Puzo P, Alessio G, Sablone S, Mariani M, De Iaco G, Milano E, Bavaro DF, Lattanzio R, Patti G, Papagni R, Pellegrino C, Saracino A, Di Gennaro F. Loa loa in the Vitreous Cavity of the Eye: A Case Report and State of Art. Am J Trop Med Hyg 2022; 107:tpmd220274. [PMID: 35914685 PMCID: PMC9490677 DOI: 10.4269/ajtmh.22-0274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 05/06/2022] [Indexed: 11/20/2022] Open
Abstract
Loa loa is a filarial nematode responsible for loiasis, endemic to West-Central Africa south of the Sahara and transmitted by flies. This study reports a case of L. loa in the vitreous cavity of the eye of a young patient, along with an in-depth literature review. A 22-year-old woman from Cameroon who migrated from Cameroon to Italy was referred to the Emergency Ophthalmology Department at Policlinico di Bari in July 2021 with the presence of a moving parasite in the subconjunctiva of the left eye. A recent onset of a papular lesion on the dorsal surface of the right wrist and a nodular lesion in the scapular region were detected. L. loa filariasis was diagnosed based on anamnestic data, clinical and paraclinical signs, and a parasitological test confirming the presence of microfilariae in two blood samples collected in the morning of two different days. Because of the unavailability of diethylcarbamazine (DEC), albendazole (ALB) 200 mg twice daily was administered for 21 days. A mild exacerbation of pruritus occurred during treatment, but resolved with the use of an antihistamine. A single dose of 12 mg ivermectin was prescribed at the end of the treatment with albendazole. Unlike other endemic parasite infections, L. loa is not included in the Global Program to Eliminate Lymphatic Filariasis, because it is not mentioned in the WHO and CDC list of neglected tropical diseases. This can result in an overall risk of lack of attention and studies on loiasis, with lack of data on global burden of the disease.
Collapse
Affiliation(s)
- Elisabetta Pallara
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Sergio Cotugno
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Giacomo Guido
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Elda De Vita
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Aurelia Ricciardi
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Valentina Totaro
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Michele Camporeale
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Luisa Frallonardo
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Roberta Novara
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Gianfranco G. Panico
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Pasquale Puzo
- Section of Ophthalmology, Department of Medical Science, Neuroscience and Senso Organs, Bari Policlinico Hospital University of Bari, Bari, Italy
| | - Giovanni Alessio
- Section of Ophthalmology, Department of Medical Science, Neuroscience and Senso Organs, Bari Policlinico Hospital University of Bari, Bari, Italy
| | - Sara Sablone
- Section of Legal Medicine, Department of Interdisciplinary Medicine, University of Bari “Aldo Moro,” Bari, Italy
| | - Michele Mariani
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Giuseppina De Iaco
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Eugenio Milano
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Davide F. Bavaro
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Rossana Lattanzio
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Giulia Patti
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Roberta Papagni
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Carmen Pellegrino
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Annalisa Saracino
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| | - Francesco Di Gennaro
- Clinic of Infectious Diseases, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro,” Bari, Italy
| |
Collapse
|
5
|
Dieki R, Nsi-Emvo E, Akue JP. The Human Filaria Loa loa: Update on Diagnostics and Immune Response. Res Rep Trop Med 2022; 13:41-54. [PMID: 35936385 PMCID: PMC9355020 DOI: 10.2147/rrtm.s355104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 06/03/2022] [Indexed: 11/24/2022] Open
Abstract
Loa loa loiasis was considered an anecdotal disease 30 years ago. Its spread in Equatorial Africa and the side effects associated with mass drug administration programs against filariasis in co-endemic areas have drawn the attention of the international research community. Progress in research conducted to date has provided insight into the immunobiology of this parasite. An interesting finding reported in several studies is that 70% of individuals with loiasis do not carry microfilariae in their blood, and 30% are microfilaremic, suggesting the involvement of several immunological mechanisms, as shown by elevated specific IgG4 and IgE levels signifying a potential cross-linking mechanism between the two isotypes via L. loa antigen to prevent allergy. A mechanism of anergy in the appearance of microfilariae in the peripheral blood results in immunological unresponsiveness in individuals with microfilariae. There is an interaction between other pathogens (parasites, bacteria, viruses) in individuals co-infected with L. loa. The strong antigen cross-reactivity between L. loa and lymphatic filarial worms warrants a re-evaluation of the distribution of the latter in co-endemic regions. The mechanism of concomitant immunity observed in the elimination of microfilariae or infective larvae (third-stage larvae, L3) may be used for the conception of an immunoprophylactic strategy.
Collapse
Affiliation(s)
- Roland Dieki
- Department of Parasitology, International Centre of Medical Research of Franceville, Franceville, Gabon
- Department of Chemistry, Université des Sciences et Techniques de Masuku (USTM), Franceville, Gabon
| | - Edouard Nsi-Emvo
- Department of Chemistry, Université des Sciences et Techniques de Masuku (USTM), Franceville, Gabon
| | - Jean Paul Akue
- Department of Parasitology, International Centre of Medical Research of Franceville, Franceville, Gabon
- Correspondence: Jean Paul Akue, Department of Parasitology, International Centre of Medical Research of Franceville, Franceville, BP 769, Gabon, Email
| |
Collapse
|
6
|
Bma-LAD-2, an Intestinal Cell Adhesion Protein, as a Potential Therapeutic Target for Lymphatic Filariasis. mBio 2022; 13:e0374221. [PMID: 35475643 PMCID: PMC9239158 DOI: 10.1128/mbio.03742-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Lymphatic filariasis is a debilitating disease that afflicts over 70 million people worldwide. It is caused by the parasitic nematodes Wuchereria bancrofti, Brugia malayi, and Brugia timori. Despite substantial success, efforts to eliminate LF will likely require more time and resources than predicted. Identifying new drug and vaccine targets in adult filariae could help elimination efforts. This study’s aim was to evaluate intestinal proteins in adult Brugia malayi worms as possible therapeutic targets. Using short interfering RNA (siRNA), we successfully targeted four candidate gene transcripts: Bma-Serpin, Bma-ShTK, Bma-Reprolysin, and Bma-LAD-2. Of those, Bma-LAD-2, an immunoglobulin superfamily cell adhesion molecule (IgSF CAM), was determined to be essential for adult worm survival. We observed a 70.42% knockdown in Bma-LAD-2 transcript levels 1 day post-siRNA incubation and an 87.02% reduction in protein expression 2 days post-siRNA incubation. This inhibition of Bma-LAD-2 expression resulted in an 80% decrease in worm motility over 6 days, a 93.43% reduction in microfilaria release (Mf) by day 6 post-siRNA incubation, and a dramatic decrease in (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction. Transmission electron microscopy revealed the loss of microvilli and unraveling of mitochondrial cristae in the intestinal epithelium of Bma-LAD-2 siRNA-treated worms. Strikingly, Bma-LAD-2 siRNA-treated worms exhibited an almost complete loss of pseudocoelomic fluid. A luciferase immunoprecipitation system assay did not detect anti-Bma-LAD-2 IgE in the serum of 30 LF patients, indicating that LF exposure does not result in IgE sensitization to this antigen. These results indicate that Bma-LAD-2 is an essential protein for adult Brugia malayi and may be an effective therapeutic target.
Collapse
|
7
|
Colorimetric and Real-Time Loop-Mediated Isothermal Amplification (LAMP) for Detection of Loa loa DNA in Human Blood Samples. Diagnostics (Basel) 2022; 12:diagnostics12051079. [PMID: 35626235 PMCID: PMC9139441 DOI: 10.3390/diagnostics12051079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 04/22/2022] [Accepted: 04/23/2022] [Indexed: 02/04/2023] Open
Abstract
Loiasis, caused by the filarial nematode Loa loa, is endemic in Central and West Africa. Loa loa has been associated with severe adverse reactions in high Loa-infected individuals receiving ivermectin during mass drug administration programs for the control of onchocerciasis and lymphatic filariasis. Diagnosis of loiasis still depends on microscopy in blood samples, but this is not effective for large-scale surveys. New diagnostics methods for loiasis are urgently needed. Previously, we developed a colorimetric high-sensitive and species-specific LAMP for Loa loa DNA detection. Here, we evaluate it in a set of 100 field-collected clinical samples stored as dried blood spots. In addition, Loa loa-LAMP was also evaluated in real-time testing and compared with microscopy and a specific PCR/nested PCR. A simple saponin/Chelex-based method was used to extract DNA. Colorimetric and real-time LAMP assays detected more samples with microscopy-confirmed Loa loa and Loa loa/Mansonella perstans mixed infections than PCR/nested-PCR. Samples with the highest Loa loa microfilariae counts were amplified faster in real-time LAMP assays. Our Loa loa-LAMP could be a promising molecular tool for the easy, rapid and accurate screening of patients for loiasis in endemic areas with low-resource settings. The real-time testing (feasible in a handheld device) could be very useful to rule out high-microfilariae loads in infected patients.
Collapse
|
8
|
Wysmołek ME, Długosz E, Wiśniewski M. The Immunological Role of Vascular and Lymphatic Endothelial Cells in Filarial Infections. Animals (Basel) 2022; 12:ani12040426. [PMID: 35203133 PMCID: PMC8868237 DOI: 10.3390/ani12040426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/25/2022] [Accepted: 02/07/2022] [Indexed: 11/26/2022] Open
Abstract
Simple Summary The endothelium is a monolayer of cells forming a thin membrane that lines the inside of blood vessels. These cells release molecules that regulate vascular relaxation, contraction, and can control blood clotting and the immune response. During infections with filarial nematodes, common parasites of humans and animals, the endothelium is believed to play a key role in the communication between the host and the parasite, since the embryonic stage of filaroids is distributed in the bloodstream. Therefore, this review aims to gather research from different scientists in order to better understand the host immune response in infections with filarial nematodes. Abstract The embryonic stage of filarial nematodes, or microfilariae (Mf), shows daily and seasonal periodicity that requires their migration through blood vessels into the lungs, where they are sequestered when not circulating in the peripheral blood. Therefore, Mf and the host endothelium are likely in a permanent state of hide and seek. Interestingly, filarial nematodes co-cultured in media with a murine endothelial cell line survive eight times longer than those cultured in media alone. This suggests that the endothelium is an important element of the immune response in filarial nematodes, perversely promoting their survival in the host. In this review, we will focus on potential pathways involved in the relationship between filarial nematodes and the host endothelium, including the role of endothelial ICAM/VCAM/PECAM adhesion molecules, surface markers involved in the passage of Mf through host tissue, anti-thrombolic effects caused by the presence of filarial nematodes (including plasmins), endothelial cell proliferation (VEGF), and other aspects of the immune activation of the endothelium. The aim of this review is to merge the knowledge about the cross-talk between Mf of different filarial nematode species and endothelial cells (EC), thus allowing a better understanding of the mechanism of these parasitic infections.
Collapse
|
9
|
Wanji S, Chunda VC, Fombad FF, Jélil Njouendou A, Gandjui NVT, Ritter M, Enyong PA, Mackenzie C, Taylor MJ, Hoerauf A, Turner JD. Advances in preclinical platforms of Loa loa for filarial neglected tropical disease drug and diagnostics research. FRONTIERS IN TROPICAL DISEASES 2021; 2:778724. [PMID: 38654889 PMCID: PMC7615857 DOI: 10.3389/fitd.2021.778724] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024] Open
Abstract
The tropical disease, loiasis, caused by the filarial parasite, Loa, has gained prominence in global public health as a cause of excess mortality and a barrier to the elimination of the related prioritized neglected tropical diseases (NTDs), lymphatic filariasis and onchocerciasis, within Central Africa. There are no effective drug cures or vaccines available to treat loiasis safely. Here we review recent advances in loiasis preclinical platform technologies, including novel in vitro culturing systems, animal models and innovations in experimental infections of the L. loa vector, Chrysops, that have facilitated access to all L. loa filarial life-cycle stages. We detail applications of these new model systems in anti-filarial drug screening, diagnostic development, immunology, and pathophysiology research. Finally, we provide an overview of how loiasis preclinical platforms may be further utilized in translational medicine applications to support the development of much needed new interventions against filarial NTDs.
Collapse
Affiliation(s)
- Samuel Wanji
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Valerine Chawa Chunda
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Fanny Fri Fombad
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
- Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, Buea, Cameroon
| | - Abdel Jélil Njouendou
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Buea, Buea, Cameroon
| | - Narcisse Victor T. Gandjui
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Manuel Ritter
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), Bonn, Germany
| | - Peter A. Enyong
- Parasite and Vector Research Unit (PAVRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Charles Mackenzie
- Neglected Tropical Diseases Support Center l The Task Force for Global Health, 325 Swanton Way, Decatur, Atlanta, Georgia, United States of America
| | - Mark J Taylor
- Centre for Drugs and Diagnostics Research and Centre for Neglected Tropical Diseases, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn (UKB), Bonn, Germany
- German Center for Infection Research (DZIF), Bonn-Cologne partner site, Bonn, Germany
| | - Joseph D Turner
- Centre for Drugs and Diagnostics Research and Centre for Neglected Tropical Diseases, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| |
Collapse
|
10
|
Eosinophils and helminth infection: protective or pathogenic? Semin Immunopathol 2021; 43:363-381. [PMID: 34165616 DOI: 10.1007/s00281-021-00870-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 05/14/2021] [Indexed: 02/07/2023]
Abstract
Since the earliest descriptions of this enigmatic cell, eosinophils have been implicated in both protective and pathogenic immune responses to helminth infection. Nevertheless, despite substantial data from in vitro studies, human infections, and animal models, their precise role in helminth infection remains incompletely understood. This is due to a number of factors, including the heterogeneity of the many parasites included in the designation "helminth," the complexity and redundancy in the host immune response to helminths, and the pleiotropic functions of eosinophils themselves. This review examines the consequences of helminth-associated eosinophilia in the context of protective immunity, pathogenesis, and immunoregulation.
Collapse
|
11
|
Ryan NM, Hess JA, de Villena FPM, Leiby BE, Shimada A, Yu L, Yarmahmoodi A, Petrovsky N, Zhan B, Bottazzi ME, Makepeace BL, Lustigman S, Abraham D. Onchocerca volvulus bivalent subunit vaccine induces protective immunity in genetically diverse collaborative cross recombinant inbred intercross mice. NPJ Vaccines 2021; 6:17. [PMID: 33500417 PMCID: PMC7838260 DOI: 10.1038/s41541-020-00276-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/11/2020] [Indexed: 01/04/2023] Open
Abstract
This study tests the hypothesis that an Onchocerca volvulus vaccine, consisting of two recombinant antigens (Ov-103 and Ov-RAL-2) formulated with the combination-adjuvant Advax-2, can induce protective immunity in genetically diverse Collaborative Cross recombinant inbred intercross mice (CC-RIX). CC-RIX lines were immunized with the O. volvulus vaccine and challenged with third-stage larvae. Equal and significant reductions in parasite survival were observed in 7 of 8 CC-RIX lines. Innate protective immunity was seen in the single CC-RIX line that did not demonstrate protective adaptive immunity. Analysis of a wide array of immune factors showed that each line of mice have a unique set of immune responses to vaccination and challenge suggesting that the vaccine is polyfunctional, inducing different equally-protective sets of immune responses based on the genetic background of the immunized host. Vaccine efficacy in genetically diverse mice suggests that it will also be effective in genetically complex human populations.
Collapse
Affiliation(s)
- Nathan M Ryan
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Jessica A Hess
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Benjamin E Leiby
- Division of Biostatistics, Department of Pharmacology and Experimental Therapeutics, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Ayako Shimada
- Division of Biostatistics, Department of Pharmacology and Experimental Therapeutics, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Lei Yu
- Flow Cytometry Core Facility, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
| | - Amir Yarmahmoodi
- Flow Cytometry Core Facility, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Bin Zhan
- Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA.,Texas Children's Hospital Center for Vaccine Development, 1102 Bates St, Ste. 550, Houston, TX, USA
| | - Maria Elena Bottazzi
- Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA.,Texas Children's Hospital Center for Vaccine Development, 1102 Bates St, Ste. 550, Houston, TX, USA
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool, L3 5RF, UK
| | - Sara Lustigman
- Laboratory of Molecular Parasitology, Lindsey F. Kimball Research Institute, New York Blood Center, 310 E 67th St, New York, NY, USA
| | - David Abraham
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA.
| |
Collapse
|
12
|
Abstract
The domestic medical examination of newly arrived refugees is a comprehensive medical visit. It includes a review of the overseas medical examination and a thorough medical and immigration history. It should include laboratory testing for infectious diseases, pregnancy, and other conditions as recommended by the Centers for Disease Control and Prevention and resettlement state, as well as a comprehensive physical examination with attention paid to conditions known to specific refugee groups. It should also include vaccinations for age-appropriate vaccine-preventable diseases. The concept of preventive care should be introduced, and future visits should be scheduled for preventive care.
Collapse
Affiliation(s)
- Kelly Reese
- Family & Community Medicine Residency Program, Penn Medicine Lancaster General Health, 540 North Duke Street, Lancaster, PA 17602, USA.
| | - Brianna Moyer
- Family & Community Medicine Residency Program, Penn Medicine Lancaster General Health, 540 North Duke Street, Lancaster, PA 17602, USA
| |
Collapse
|
13
|
Muñoz C, Gonzálvez M, Rojas A, Martínez-Carrasco C, Baneth G, Berriatua E, Ortiz J. Massive microfilaremia in a dog subclinically infected with Acanthocheilonema dracunculoides. Parasitol Int 2020; 76:102070. [PMID: 32036036 DOI: 10.1016/j.parint.2020.102070] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/29/2020] [Accepted: 02/04/2020] [Indexed: 10/25/2022]
Abstract
Canine filarioids are worldwide distributed nematodes transmitted by arthropods with variable virulence depending on the species. Dirofilaria immitis is the most virulent and serological antigen tests are commonly employed to detect it. This study reports on the heaviest cavity filariasis recorded so far in a dog, which showed no apparent clinical signs of infection. The 6-year-old male was positive to a D. immitis antigen test. Blood samples collected and analyzed with the modified Knott's test for microfilariae revealed 264,367 microfilariae/ml. In a post-mortem examination 791 adult filarial nematodes were found in the dog's thoracic and peritoneal cavities. Morphological and molecular analysis identified the nematode as Acanthocheilonema dracunculoides and no other species were present. This is evidence that massive A. dracunculoides infections in dogs may not be clinically evident, they may cause serologic cross-reaction with D. immitis infection and become a life-threatening condition if dogs are treated with a microfilaricidal treatment without previously performing an adequate diagnosis.
Collapse
Affiliation(s)
- Clara Muñoz
- Department of Animal Health, Faculty of Veterinary, Regional Campus of International Excellence 'Campus Mare Nostrum', University of Murcia, 30100 Murcia, Spain
| | - Moisés Gonzálvez
- Department of Animal Health, Faculty of Veterinary, Regional Campus of International Excellence 'Campus Mare Nostrum', University of Murcia, 30100 Murcia, Spain.
| | - Alicia Rojas
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel
| | - Carlos Martínez-Carrasco
- Department of Animal Health, Faculty of Veterinary, Regional Campus of International Excellence 'Campus Mare Nostrum', University of Murcia, 30100 Murcia, Spain
| | - Gad Baneth
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel
| | - Eduardo Berriatua
- Department of Animal Health, Faculty of Veterinary, Regional Campus of International Excellence 'Campus Mare Nostrum', University of Murcia, 30100 Murcia, Spain
| | - Juana Ortiz
- Department of Animal Health, Faculty of Veterinary, Regional Campus of International Excellence 'Campus Mare Nostrum', University of Murcia, 30100 Murcia, Spain
| |
Collapse
|
14
|
Ahmed AE, Alshehri A, Al-Kahtani MA, Elbehairi SEI, Alshehri MA, Shati AA, Alfaifi MY, Al-Doais AA, Taha R, Morsy K, El-Mansi AA. Vitamin E and selenium administration synergistically mitigates ivermectin and doramectin-induced testicular dysfunction in male Wistar albino rats. Biomed Pharmacother 2020; 124:109841. [PMID: 31972360 DOI: 10.1016/j.biopha.2020.109841] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 01/09/2023] Open
Abstract
Avermectins are broad-spectrum antiparasitic drugs in veterinary and human medication. The current study aimed to examine the toxic effects of ivermectin (IVM) and doramectin (DRM), with or without co-treatment of vitamin E (Vit.E) and selenium (Se) on apoptosis, oxidative stress and male fertility in Wistar rats. Twenty five adult male animals were divided into five groups; G1; was control (CTL) received saline, G2; IVM (0.2 mg/kg b.w), G3; IVM plus Vit.E/Se (80/1.6 mg/kg b.w, respectively), G4; DRM (0.2 mg/kg b.w), and G5; DRM plus Vit.E/Se. Both IVM and DRM were given by subcutaneous (s.c) injections while Vit.E/Se was orally given. All treatments were administered once weekly for four consecutive weeks. By 24 h after the last treatment, the animals were sacrificed. Blood and tissue samples were collected for hematology, serobiochemistry, histopathology, and molecular assays for hepatic/ renal toxicities, oxidative stress, cell viability and fertility parameters. Apoptosis of the hepatic cells obtained from the treated rats was assayed by detection of annexin-V using the flow cytometric assay (FCA). The proliferating cellular nuclear antigen (PCNA) and DNA fragmentation in the treated rats' testicular tissues were also assayed. Moreover, the direct effects of IVM or DRM with or without concomitant administration of Vit.E/Se on testicular cells isolated from adult rat were also performed in vitro. Apoptosis of those cultured testicular cells in response to the different treatments was assayed by detection of the inhibition-concentration fifty (IC50) using the SRB method, and evaluating the viable versus apoptotic cells microscopically after staining with acridine orange-ethidium bromide (AO/EB). In conclusion, both avermectins induced apoptosis in the living and cultured cells, while those antioxidants; Vit.E and Se, reduced the oxidative stress and cytotoxicity both in vivo and in vitro, either. Furthermore, the reprotoxicity and reduced male fertility were seriously evoked by IVM, but not DRM with dramatic ameliorative effect of Vit.E/Se if concomitantly administered. Avermectins, especially ivermectin, should be given according to the dose recommended by the manufacturer company and repeated dosages should be given with Vit.E/Se.
Collapse
Affiliation(s)
- Ahmed Ezzat Ahmed
- Department of Biology, College of Science, King Khalid University, Abha 61413, Saudi Arabia; Department of Theriogenology, Faculty of Veterinary Medicine, South Valley University, Qena 83523, Egypt.
| | - Ali Alshehri
- Department of Biology, College of Science, King Khalid University, Abha 61413, Saudi Arabia
| | - M A Al-Kahtani
- Department of Biology, College of Science, King Khalid University, Abha 61413, Saudi Arabia
| | | | - Mohammed A Alshehri
- Department of Biology, College of Science, King Khalid University, Abha 61413, Saudi Arabia
| | - Ali A Shati
- Department of Biology, College of Science, King Khalid University, Abha 61413, Saudi Arabia
| | - Mohammad Y Alfaifi
- Department of Biology, College of Science, King Khalid University, Abha 61413, Saudi Arabia
| | - Amin A Al-Doais
- Department of Biology, College of Science, King Khalid University, Abha 61413, Saudi Arabia
| | - Ramadan Taha
- Department of Biology, College of Science, King Khalid University, Abha 61413, Saudi Arabia
| | - Kareem Morsy
- Department of Biology, College of Science, King Khalid University, Abha 61413, Saudi Arabia; Department of Zoology, Faculty of Science, Cairo University, Cairo 12613, Egypt
| | - Ahmed A El-Mansi
- Department of Biology, College of Science, King Khalid University, Abha 61413, Saudi Arabia; Zoology Dept., Faculty of Science, Mansoura University, Mansoura, Egypt
| |
Collapse
|
15
|
Volpicelli L, De Angelis M, Morano A, Biliotti E, Franchi C, Gabrielli S, Mattiucci S, Di Bonaventura C, Taliani G. Encephalopathy in a patient with loiasis treated with albendazole: A case report. Parasitol Int 2019; 75:102006. [PMID: 31676328 DOI: 10.1016/j.parint.2019.102006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 10/18/2019] [Accepted: 10/25/2019] [Indexed: 11/29/2022]
Abstract
BACKGROUND Loiasis is a vector-borne parasitic infection endemic across many areas of Central and West Africa. Its treatment is tricky due to the risk of serious neurologic adverse events occurring after the administration of microfilaricidal drugs, like diethylcarbamazine or ivermectin, in subjects with high pre-treatment microfilarial load. Albendazole is currently recommended to slowly reduce microfilaremia before curative regimen is prescribed. CASE PRESENTATION We report the case of a 25-year-old man from Guinea-Conakry who was incidentally diagnosed with highly microfilaremic Loa loa infection. A three weeks regimen of albendazole was prescribed. Minor neurologic side effects occurred after two weeks of administration, while serious encephalopathy developed one week later. Clinical and electroencephalographic features of the patient resembled those of an immune-mediated encephalitis. After exclusion of other causes of encephalopathy, treatment-related Loa loa encephalopathy induced by albendazole was suspected. Corticosteroid treatment was administered and the patient recovered. DISCUSSION Our case confirms that Loa loa treatment-related encephalopathy may occur even during albendazole treatment. The clinical and electroencephalographic similarities between Loa loa albendazole-related encephalopathy and immune-mediated encephalitis suggest the possibility of an underlying inflammation-based pathogenesis. Although corticosteroid administration is not recommended in Loa loa ivermectin-induced encephalopathy, in this case of Loa loa albendazole-induced encephalopathy it may have played a therapeutic role.
Collapse
Affiliation(s)
- Lorenzo Volpicelli
- Hepatology Unit, Department of Translational and Precision Medicine, Sapienza University of Rome, Rome, Italy.
| | - Maurizio De Angelis
- Hepatology Unit, Department of Translational and Precision Medicine, Sapienza University of Rome, Rome, Italy.
| | - Alessandra Morano
- Epilepsy Unit, Department of Human Neurosciences, Sapienza University, Rome, Italy.
| | - Elisa Biliotti
- Hepatology Unit, Department of Translational and Precision Medicine, Sapienza University of Rome, Rome, Italy.
| | - Cristiana Franchi
- Hepatology Unit, Department of Translational and Precision Medicine, Sapienza University of Rome, Rome, Italy.
| | - Simona Gabrielli
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy.
| | - Simonetta Mattiucci
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy.
| | - Carlo Di Bonaventura
- Epilepsy Unit, Department of Human Neurosciences, Sapienza University, Rome, Italy.
| | - Gloria Taliani
- Hepatology Unit, Department of Translational and Precision Medicine, Sapienza University of Rome, Rome, Italy.
| |
Collapse
|
16
|
Flynn AF, Joyce MG, Taylor RT, Bennuru S, Lindrose AR, Sterling SL, Morris CP, Nutman TB, Mitre E. Intestinal UDP-glucuronosyltransferase as a potential target for the treatment and prevention of lymphatic filariasis. PLoS Negl Trop Dis 2019; 13:e0007687. [PMID: 31513587 PMCID: PMC6742224 DOI: 10.1371/journal.pntd.0007687] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Accepted: 08/05/2019] [Indexed: 11/19/2022] Open
Abstract
Lymphatic filariasis (LF), a morbid disease caused by the tissue-invasive nematodes Wuchereria bancrofti, Brugia malayi, and Brugia timori, affects millions of people worldwide. Global eradication efforts have significantly reduced worldwide prevalence, but complete elimination has been hampered by limitations of current anti-filarial drugs and the lack of a vaccine. The goal of this study was to evaluate B. malayi intestinal UDP-glucuronosyltransferase (Bm-UGT) as a potential therapeutic target. To evaluate whether Bm-UGT is essential for adult filarial worms, we inhibited its expression using siRNA. This resulted in a 75% knockdown of Bm-ugt mRNA for 6 days and almost complete suppression of detectable Bm-UGT by immunoblot. Reduction in Bm-UGT expression resulted in decreased worm motility for 6 days, 70% reduction in microfilaria release from adult worms, and significant reduction in adult worm metabolism as detected by MTT assays. Because prior allergic-sensitization to a filarial antigen would be a contraindication for its use as a vaccine candidate, we tested plasma from infected and endemic normal populations for Bm-UGT-specific IgE using a luciferase immunoprecipitation assay. All samples (n = 35) tested negative. We then tested two commercially available medicines known to be broad inhibitors of UGTs, sulfinpyrazone and probenecid, for in vitro activity against B. malayi. There were marked macrofilaricidal effects at concentrations achievable in humans and very little effect on microfilariae. In addition, we observed that probenecid and sulfinpyrazone exhibit a synergistic macrofilaricidal effect when used in combination with albendazole. The results of this study demonstrate that Bm-UGT is an essential protein for adult worm survival. Lack of prior IgE sensitization in infected and endemic populations suggest it may be a feasible vaccine candidate. The finding that sulfinpyrazone and probenecid have in vitro effects against adult B. malayi worms suggests that these medications have promise as potential macrofilaricides in humans.
Collapse
Affiliation(s)
- Alexander F. Flynn
- Department of Microbiology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - M. Gordon Joyce
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, Maryland, United States of America
| | - Rebekah T. Taylor
- Department of Biology, Frostburg State University, Frostburg, Maryland, United States of America
| | - Sasisekhar Bennuru
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Alyssa R. Lindrose
- Department of Microbiology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Spencer L. Sterling
- Department of Microbiology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - C. Paul Morris
- Department of Pathology, Johns Hopkins Hospital, Baltimore Maryland, United States of America
| | - Thomas B. Nutman
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Edward Mitre
- Department of Microbiology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| |
Collapse
|
17
|
Makenga Bof JC, Muteba D, Mansiangi P, Ilunga-Ilunga F, Coppieters Y. Analysis of severe adverse effects following community-based ivermectin treatment in the Democratic Republic of Congo. BMC Pharmacol Toxicol 2019; 20:49. [PMID: 31420005 PMCID: PMC6697993 DOI: 10.1186/s40360-019-0327-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 07/23/2019] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND The progress of mass, community-directed, treatment with ivermectin (CDTI) for onchocerciasis control was disrupted by severe adverse effects (SAE) in the Democratic Republic of Congo (DRC). The study aimed at determining the frequency of post-CDTI SAE as well as factors associated with the occurrence of SAE. METHODS Our retrospective study relied on SAE collection cards, as archived by the DRC Ministry of Health, and compiled for people who benefited from ivermectin treatment then further developed SAE. The study included 945 post-CDTI SAE recorded in DRC between 2003 and 2017. These cases occurred in 15 projects out of 22 projects implemented in the country. All cards were reviewed and analysed. RESULTS Between the years 2003 and 2017, the total average population treated was around 15,552,588 among which 945 cases of SAE were registered in DR Congo, i.e. 6 cases of SAE for 100,000 persons treated per year. 55 deaths related to post-CDTI SAE were recorded, which represents 5.8% of all cases of SAE. Non-neurological SAE were dominated by severe headaches (74.8%), myalgia (64.0%) and arthralgia (62.7%). Neurological SAE were mainly coma (94.1%), motor deficit (75.4%) and palpebral subconjunctival haemorrhages (38.8%). Factors associated with the occurrence of SAE were: male, age over 18 years old, alcohol consumption, hemp intake and the presence of loiasis. The study also highlighted weaknesses of the National Program for Onchocerciasis Control (NPOC) in terms of awareness campaigns among the population. CONCLUSION Co-endemicity of loiasis and onchocerciasis is one of the key factors responsible for the occurrence of SAE following ivermectin treatment. Mobilization of resources necessary to the appropriate management of SAE and awareness of populations are essential to achieve onchocerciasis control in DRC.
Collapse
Affiliation(s)
- Jean-Claude Makenga Bof
- School of Public Health, Université Libre de Bruxelles (ULB), Route de Lennik numéro 808 à 1070, Brussels, Belgium
| | - Daniel Muteba
- National Program for Onchocerciasis Control (NPOC), Kinshasa, Gombe Democratic Republic of Congo
| | - Paul Mansiangi
- School of Public Health, Faculty of Medicine, Université de Kinshasa (UNIKIN), Route de Kimwenza, Lemba Kinshasa, Democratic Republic of Congo
| | - Félicien Ilunga-Ilunga
- School of Public Health, Université Libre de Bruxelles (ULB), Route de Lennik numéro 808 à 1070, Brussels, Belgium
- Institut Supérieur des Techniques Médicales (ISTM), Route de Kimwenza, Lemba Kinshasa, Democratic Republic of Congo
| | - Yves Coppieters
- School of Public Health, Université Libre de Bruxelles (ULB), Route de Lennik numéro 808 à 1070, Brussels, Belgium
| |
Collapse
|
18
|
Mouri O, Ezzine N, Haddad E, Achouri L, Parizot C, Thellier M, Piarroux R. New promising method to assess microfilarial Loa loa load on the peripheral blood. Diagn Microbiol Infect Dis 2019; 95:114887. [PMID: 31630909 DOI: 10.1016/j.diagmicrobio.2019.114887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 08/06/2019] [Accepted: 08/07/2019] [Indexed: 10/26/2022]
Abstract
Loiasis is a vector-borne parasitic disease caused by the filarial Loa loa (L. loa). Definitive diagnosis can be done by identifying and counting microfilariae in the peripheral blood by microscopy and with L.loa-specific PCR. An additional diagnostic method is the detection of L.loa-specific antibodies. Accurate methods are needed to automate quantification of microfilaria (mf) in peripheral blood. Indeed, the treatment procedure depends on the microfilarial L. loa load in blood. We report the first documented use of flow cytometry as a new method to count microfilaraemia in peripheral blood from a patient with L. loa infection. The diagnosis of loiasis was strongly suspected based on clinical presentation and rapidly confirmed by identifying typical features of L. loa in the peripheral blood. This diagnosis was achieved by flow cytometry using a specific fluorescence pattern for microfilaraemia count. The current report highlights the potential of flow cytometry to assess microfilarial L. loa load from a patient with loiasis infection.
Collapse
Affiliation(s)
- Oussama Mouri
- Department of Parasitology and Mycology, AP-HP, Pitié-Salpêtrière Hospital, Paris, France.
| | - Naouel Ezzine
- Department of Immunology, AP-HP, George Pompidou Hospital, Paris, France
| | - Elie Haddad
- Department of Infectious Diseases, AP-HP, Pitié-Salpêtrière Hospital, Paris, France
| | - Lhaouari Achouri
- Department of Parasitology and Mycology, AP-HP, Pitié-Salpêtrière Hospital, Paris, France
| | | | - Marc Thellier
- Department of Parasitology and Mycology, AP-HP, Pitié-Salpêtrière Hospital, Paris, France; Sorbonne Université, INSERM, France; Institut Pierre-Louis d'Epidémiologie et de Santé Publique, France
| | - Renaud Piarroux
- Department of Parasitology and Mycology, AP-HP, Pitié-Salpêtrière Hospital, Paris, France; Sorbonne Université, INSERM, France; Institut Pierre-Louis d'Epidémiologie et de Santé Publique, France
| |
Collapse
|
19
|
Maroto-Camino C, Hernandez-Pastor P, Awaca N, Safari L, Hemingway J, Massangaie M, Whitson D, Jeffery C, Valadez JJ. Improved assessment of mass drug administration and health district management performance to eliminate lymphatic filariasis. PLoS Negl Trop Dis 2019; 13:e0007337. [PMID: 31276494 PMCID: PMC6636779 DOI: 10.1371/journal.pntd.0007337] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 07/17/2019] [Accepted: 03/27/2019] [Indexed: 11/20/2022] Open
Abstract
Lymphatic filariasis (LF) elimination as a public health problem requires the interruption of transmission by administration of preventive mass drug administration (MDA) to the eligible population living in endemic districts. Suboptimal MDA coverage leads to persistent parasite transmission with consequential infection, disease and disability, and the need for continuing MDA rounds, requiring considerable investment. Routine coverage reports must be verified in each MDA implementation unit (IU) due to incorrect denominators and numerators used to calculate coverage estimates with administrative data. IU are usually the health districts. Coverage is verified so IU teams can evaluate their outreach and take appropriate action to improve performance. Mozambique and the Democratic Republic of Congo (DRC) have conducted MDA campaigns for LF since 2009 and 2014, respectively. To verify district reports and assess the declared achievement using administrative data of the minimum 80% coverage of eligible people (or 65% of the total population), both countries conducted rapid probability surveys using Lot Quality Assurance Sampling (LQAS)(n = 1102) in 2015 and 2016 in 58 IU in 49 districts. The surveys identified IU with suboptimal coverage, reasons residents did not take the medication, place where the medication was received, information sources, and knowledge about diseases prevented by the MDA. LQAS identified four inadequately covered IU triggering district team performance reviews with provincial and national teams and district retreatment. Provincial estimates using probability samples (weighted by populations sizes) were 10 and 17 percentage points lower than reported coverage in DRC and Mozambique. The surveys identified: absence from home during annual MDA rounds as the main reason for low performance and provided valuable information about pre-campaign and campaign activities resulting in improved strategies and continued progress towards elimination of LF and co-endemic Neglected Tropical Diseases. Global elimination of lymphatic filariasis (LF) is achieved through treatment of at-risk populations with annual or bi-annual mass drug administration campaigns. In Africa campaigns need to be completed in 32 countries with 343 million people at risk. The World Health Organisation recommends verification of the campaign’s administrative records using household cluster surveys at least once every 5-years. However, cluster surveys are expensive and usually completed in a few districts only or at sub-national levels. Together with National Programmes in Mozambique and the Democratic Republic of the Congo (DRC) we adapted Lot Quality Assurance Sampling (LQAS) methods to verify campaign coverage because it is relatively inexpensive in comparison to other survey approaches, provides information and facilitates actions at the Implementation Unit (IU) level, which is usually the district. LQAS signals IU whose performance is likely to need improvement because MDA coverage is below the coverage target. Our results show consistently that administrative records over-estimated campaign coverage and did not detect implementation and coverage problems due to errors in numerators and denominators, incorrect reporting, and/or incorrect aggregation of tally sheets. The LQAS verification approach prompted immediate action to remedy coverage shortfalls averting persistent LF transmission and disease, and the costs associated with failed campaigns. Our study demonstrates that a rapid probability sample to verify coverage provides district teams with information after each campaign which can be used for action, and that one coverage survey every 5-years is insufficient for infectious disease elimination in highly endemic settings where achievement of optimal coverage is essential. It also demonstrates that LQAS provides a decentralised assessment, sensitive for detecting and ameliorating programme bottlenecks and can be used to verify MDA in other countries.
Collapse
Affiliation(s)
- Carmen Maroto-Camino
- Department of International Health, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Pilar Hernandez-Pastor
- Department of International Health, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Naomi Awaca
- National NTD Programme, Democratic Republic of Congo, Ministère de la Sante Publique, Gombe, Kinshasa
| | - Lebon Safari
- Department of International Health, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Janet Hemingway
- Department of International Health, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Marilia Massangaie
- National NTD Programme, Direção Nacional da Saúde Publica, Ministério da Saúde, Eduardo Modliane, Maputo, Mozambique
| | - Donald Whitson
- Department of International Health, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Caroline Jeffery
- Department of International Health, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Joseph J. Valadez
- Department of International Health, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- * E-mail:
| |
Collapse
|
20
|
Pionnier NP, Sjoberg H, Chunda VC, Fombad FF, Chounna PW, Njouendou AJ, Metuge HM, Ndzeshang BL, Gandjui NV, Akumtoh DN, Tayong DB, Taylor MJ, Wanji S, Turner JD. Mouse models of Loa loa. Nat Commun 2019; 10:1429. [PMID: 30926803 PMCID: PMC6441053 DOI: 10.1038/s41467-019-09442-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 03/07/2019] [Indexed: 12/14/2022] Open
Abstract
Elimination of the helminth disease, river blindness, remains challenging due to ivermectin treatment-associated adverse reactions in loiasis co-infected patients. Here, we address a deficit in preclinical research tools for filarial translational research by developing Loa loa mouse infection models. We demonstrate that adult Loa loa worms in subcutaneous tissues, circulating microfilariae (mf) and presence of filarial biomarkers in sera occur following experimental infections of lymphopenic mice deficient in interleukin (IL)-2/7 gamma-chain signaling. A microfilaraemic infection model is also achievable, utilizing immune-competent or -deficient mice infused with purified Loa mf. Ivermectin but not benzimidazole treatments induce rapid decline (>90%) in parasitaemias in microfilaraemic mice. We identify up-regulation of inflammatory markers associated with allergic type-2 immune responses and eosinophilia post-ivermectin treatment. Thus, we provide validation of murine research models to identify loiasis biomarkers, to counter-screen candidate river blindness cures and to interrogate the inflammatory etiology of loiasis ivermectin-associated adverse reactions. Here, the authors develop a mouse model of Loa loa that reflects human infections, including eosinophilia, and determine effects of ivermectin treatment.
Collapse
Affiliation(s)
- Nicolas P Pionnier
- Centre for Drugs and Diagnostics Research, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Hanna Sjoberg
- Centre for Drugs and Diagnostics Research, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Valerine C Chunda
- Research Foundation in Tropical Diseases and the Environment, P.O. Box 474, Buea, Cameroon.,Parasite and Vector Biology Research Unit, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Fanny F Fombad
- Research Foundation in Tropical Diseases and the Environment, P.O. Box 474, Buea, Cameroon.,Parasite and Vector Biology Research Unit, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Patrick W Chounna
- Research Foundation in Tropical Diseases and the Environment, P.O. Box 474, Buea, Cameroon.,Parasite and Vector Biology Research Unit, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Abdel J Njouendou
- Research Foundation in Tropical Diseases and the Environment, P.O. Box 474, Buea, Cameroon.,Parasite and Vector Biology Research Unit, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Haelly M Metuge
- Research Foundation in Tropical Diseases and the Environment, P.O. Box 474, Buea, Cameroon.,Parasite and Vector Biology Research Unit, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Bertrand L Ndzeshang
- Research Foundation in Tropical Diseases and the Environment, P.O. Box 474, Buea, Cameroon.,Parasite and Vector Biology Research Unit, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Narcisse V Gandjui
- Research Foundation in Tropical Diseases and the Environment, P.O. Box 474, Buea, Cameroon.,Parasite and Vector Biology Research Unit, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Desmond N Akumtoh
- Research Foundation in Tropical Diseases and the Environment, P.O. Box 474, Buea, Cameroon.,Parasite and Vector Biology Research Unit, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Dizzle B Tayong
- Research Foundation in Tropical Diseases and the Environment, P.O. Box 474, Buea, Cameroon.,Parasite and Vector Biology Research Unit, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Mark J Taylor
- Centre for Drugs and Diagnostics Research, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Samuel Wanji
- Research Foundation in Tropical Diseases and the Environment, P.O. Box 474, Buea, Cameroon.,Parasite and Vector Biology Research Unit, Department of Microbiology and Parasitology, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon
| | - Joseph D Turner
- Centre for Drugs and Diagnostics Research, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
| |
Collapse
|
21
|
Pion SD, Tchatchueng-Mbougua JB, Chesnais CB, Kamgno J, Gardon J, Chippaux JP, Ranque S, Ernould JC, Garcia A, Boussinesq M. Effect of a Single Standard Dose (150-200 μg/kg) of Ivermectin on Loa loa Microfilaremia: Systematic Review and Meta-analysis. Open Forum Infect Dis 2019; 6:ofz019. [PMID: 30968052 PMCID: PMC6449757 DOI: 10.1093/ofid/ofz019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 01/11/2019] [Indexed: 12/17/2022] Open
Abstract
Background In central Africa, millions of individuals infected with Loa loa have received the anthelminthic drug ivermectin (IVM) as part of mass drug administration (MDA) campaigns targeting onchocerciasis control or elimination. Nonetheless, the parasitological surveys that are occasionally conducted to evaluate the impact of IVM treatments on Onchocerca volvulus do not include an assessment of the extra benefits of those MDA campaigns on L. loa. Methods We conducted a systematic review of trials on the effect of a single standard (150–200 μg/kg) dose of IVM on L. loa microfilarial density (MFD). The dynamics of MFD over 365 days of treatment were described using multilevel regression and latent class modeling. Results IVM brings about a rapid, dramatic, and sustained decrease, with reduction rates of 60%, 75%, 85%, and 90% on day 1 (D1), D2, D7, and D365, respectively. At D365, no participants (0/238) with an initial MFD of <20 000 microfilariae (mf)/mL were at risk of postivermectin severe adverse events, and only 1/57 individuals with an initial MFD of ≥20 000 mf/mL presented with an MFD above this value. The main predictor of post-treatment MFD was the pretreatment value, but this post-treatment value varied little between D8 and D365 regardless of the pretreatment level. Conclusions A single dose of IVM is very effective at substantially reducing L. loa MFD for at least a year, irrespective of the initial level of parasitemia. Individuals treated with IVM are probably not any more at risk of severe adverse events when retreated 1 year later.
Collapse
Affiliation(s)
- Sébastien D Pion
- IRD UMI 233-INSERM U1175- University of Montpellier, Montpellier, France
| | | | - Cédric B Chesnais
- IRD UMI 233-INSERM U1175- University of Montpellier, Montpellier, France
| | - Joseph Kamgno
- Centre for Research on Filariasis and other Tropical Diseases, Yaoundé, Cameroon.,Faculty of Medicine and Biomedical Sciences, University of Yaounde I, Yaounde, Cameroon
| | - Jacques Gardon
- IRD UMR 050, HydroSciences Montpellier, CNRS, University of Montpellier, Montpellier, France
| | | | - Stéphane Ranque
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, IHU-Méditerranée Infection, Marseille, France
| | | | - André Garcia
- IRD MERIT, Université Paris 5, Sorbonne Paris Cité, Paris, France
| | - Michel Boussinesq
- IRD UMI 233-INSERM U1175- University of Montpellier, Montpellier, France
| |
Collapse
|
22
|
Wanji S, Chounna Ndongmo WP, Fombad FF, Kengne-Ouafo JA, Njouendou AJ, Longang Tchounkeu YF, Koudou B, Bockarie M, Fobi G, Roungou JB, Enyong PA. Impact of repeated annual community directed treatment with ivermectin on loiasis parasitological indicators in Cameroon: Implications for onchocerciasis and lymphatic filariasis elimination in areas co-endemic with Loa loa in Africa. PLoS Negl Trop Dis 2018; 12:e0006750. [PMID: 30226900 PMCID: PMC6161907 DOI: 10.1371/journal.pntd.0006750] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 09/28/2018] [Accepted: 08/13/2018] [Indexed: 11/18/2022] Open
Abstract
Background Loiasis is a filarial infection endemic in the rainforest zone of west and central Africa particularly in Cameroon, Gabon, Republic of Congo, and Democratic Republic of the Congo. Repeated treatments with ivermectin have been delivered using the annual community directed treatment with ivermectin (CDTI) approach for several years to control onchocerciasis in some Loa loa-Onchocerca volvulus co-endemic areas. The impact of CDTI on loiasis parasitological indicators is not known. We, therefore, designed this cross sectional study to explore the effects of several rounds of CDTI on parasitological indicators of loiasis. Methodology/Principal findings The study was conducted in the East, Northwest and Southwest 2 CDTI projects of Cameroon. Individuals who consented to participate were interviewed for ivermectin treatment history and enrolled for parasitological screening using thick smears. Ivermectin treatment history was correlated with loiasis prevalence/intensity. A total of 3,684 individuals were recruited from 36 communities of the 3 CDTI projects and 900 individuals from 9 villages in a non-CDTI district. In the East, loiasis prevalence was 29.3% (range = 24.2%–34.6%) in the non-CDTI district but 16.0% (3.3%–26.6%) in the CDTI district with 10 ivermectin rounds (there were no baseline data for the latter). In the Northwest and Southwest 2 districts, reductions from 30.5% to 17.9% (after 9 ivermectin rounds) but from 8.1% to 7.8% (not significantly different after 14 rounds) were registered post CDTI, respectively. Similar trends in infection intensity were observed in all sites. There was a negative relationship between adherence to ivermectin treatment and prevalence/intensity of infection in all sites. None of the children (aged 10–14 years) examined in the East CDTI project harboured high (8,000–30,000 mf/ml) or very high (>30,000 mf/ml) microfilarial loads. Individuals who had taken >5 ivermectin treatments were 2.1 times more likely to present with no microfilaraemia than those with less treatments. Conclusion In areas where onchocerciasis and loiasis are co-endemic, CDTI reduces the number of, and microfilaraemia in L. loa-infected individuals, and this, in turn, will help to prevent non-neurological and neurological complications post-ivermectin treatment among CDTI adherents. Loa loa (the parasite causing loiasis), also known as African eye worm, is endemic in forest areas of west and central Africa. In several of the endemic areas, it co-exists with onchocerciasis and lymphatic filariasis (LF). Because of the benefit individuals suffering from onchocerciasis could have by taking ivermectin where the disease is severe, despite the risk of developing serious side-effects due to being co-infected with L. loa, mass drug administration (MDA) of ivermectin for the control of onchocerciasis has been ongoing in areas where the two diseases overlap. Ivermectin is also effective against loiasis. It is, therefore, hypothesized that several years of ivermectin MDA against onchocerciasis in those areas may have impacted on parasitological indicators for loiasis. In particular, we assess the impact of annual community directed treatment with ivermectin (CDTI) on loiasis with specific reference to the relationship between adherence to treatment and the risk of developing severe (nervous system) complications following ivermectin treatment. We also discuss the feasibility of eliminating onchocerciasis and/or LF in areas endemic for L. loa with ivermectin as the sole intervention tool.
Collapse
Affiliation(s)
- Samuel Wanji
- Parasites and Vector Biology research unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
- * E-mail:
| | - Winston Patrick Chounna Ndongmo
- Parasites and Vector Biology research unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Fanny Fri Fombad
- Parasites and Vector Biology research unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Jonas Arnaud Kengne-Ouafo
- Parasites and Vector Biology research unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | - Abdel Jelil Njouendou
- Parasites and Vector Biology research unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| | | | - Benjamin Koudou
- Centre for Neglected Tropical Diseases (incorporating the Lymphatic Filariasis Support Centre), Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Moses Bockarie
- Centre for Neglected Tropical Diseases (incorporating the Lymphatic Filariasis Support Centre), Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Grace Fobi
- African Program for Onchocerciasis Control (APOC), Ouagadougou, Burkina Faso
| | | | - Peter A. Enyong
- Parasites and Vector Biology research unit (PAVBRU), Department of Microbiology and Parasitology, University of Buea, Buea, Cameroon
- Research Foundation for Tropical Diseases and the Environment (REFOTDE), Buea, Cameroon
| |
Collapse
|
23
|
Kelly-Hope LA, Blundell HJ, Macfarlane CL, Molyneux DH. Innovative Surveillance Strategies to Support the Elimination of Filariasis in Africa. Trends Parasitol 2018; 34:694-711. [PMID: 29958813 DOI: 10.1016/j.pt.2018.05.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 05/18/2018] [Accepted: 05/30/2018] [Indexed: 01/18/2023]
Abstract
Lymphatic filariasis (LF) and onchocerciasis are two neglected tropical diseases (NTDs) of public health significance targeted for global elimination. The World Health Organization (WHO) African Region is a priority region, with the highest collective burden of LF and onchocerciasis globally. Coendemic loiasis further complicates elimination due to the risk of adverse events associated with ivermectin treatment. A public health framework focusing on health-related data, systematic collection of data, and analysis and interpretation of data is used to highlight the range of innovative surveillance strategies required for filariasis elimination. The most recent and significant developments include: rapid point-of-care test (POCT) diagnostics; clinical assessment tools; new WHO guidelines; open-access online data portals; mHealth platforms; large-scale prevalence maps; and the optimisation of mathematical models.
Collapse
Affiliation(s)
- Louise A Kelly-Hope
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Harriet J Blundell
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Cara L Macfarlane
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - David H Molyneux
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK
| |
Collapse
|
24
|
Zofou D, Fombad FF, Gandjui NVT, Njouendou AJ, Kengne-Ouafo AJ, Chounna Ndongmo PW, Datchoua-Poutcheu FR, Enyong PA, Bita DT, Taylor MJ, Turner JD, Wanji S. Evaluation of in vitro culture systems for the maintenance of microfilariae and infective larvae of Loa loa. Parasit Vectors 2018; 11:275. [PMID: 29716646 PMCID: PMC5930665 DOI: 10.1186/s13071-018-2852-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 04/16/2018] [Indexed: 01/28/2023] Open
Abstract
Background Suitable and scalable in vitro culture conditions for parasite maintenance are needed to foster drug research for loiasis, one of the neglected tropical diseases which has attracted only limited attention over recent years, despite having important public health impacts. The present work aims to develop adequate in vitro culture systems for drug screening against both microfilariae (mf) and infective third-stage larvae (L3) of Loa loa. Methods In vitro culture conditions were evaluated by varying three basic culture media: Roswell Park Memorial Institute (RPMI-1640), Dulbecco’s modified Eagle’s medium (DMEM) and Iscove’s modified Dulbecco’s medium (IMDM); four sera/proteins: newborn calf serum (NCS), foetal bovine serum (FBS), bovine serum albumin (BSA) and the lipid-enriched BSA (AlbuMax® II, ALB); and co-culture with the Monkey Kidney Epithelial Cell line (LLC-MK2) as a feeder layer. The various culture systems were tested on both mf and L3, using survival (% motile), motility (T90 = mean duration (days) at which at least 90% of parasites were fully active) and moulting rates of L3 as the major criteria. The general linear model regression analysis was performed to assess the contribution of each variable on the viability of Loa loa L3 and microfilarie. All statistical tests were performed at 95% confidence interval. Results Of the three different media tested, DMEM and IMDM were the most suitable sustaining the maintenance of both L. loa L3 and mf. IMDM alone could sustain L3 for more than 5 days (T90 = 6.5 ± 1.1 day). Serum supplements and LLC-MK2 co-cultures significantly improved the survival of parasites in DMEM and IMDM. In co-cultures with LLC-MK2 cells, L. loa mf were maintained in each of the three basic media (T90 of 16.4–19.5 days) without any serum supplement. The most effective culture systems promoting significant moulting rate of L3 into L4 (at least 25%) with substantial maintenance time were: DMEM + BSA, DMEM + NCS, DMEM-AlbuMax®II, DMEM + FBS all in co-culture with LLC-MK2, and IMDM + BSA (1.5%), DMEM + FBS (10%) and DMEM + NCS (5%) without feeder cells. DMEM + 1% BSA in co-culture scored the highest moulting rate of 57 of 81 (70.37%). The factors that promoted L. loa mf viability included feeder cells (β = 0.490), both IMDM (β = 0.256) and DMEM (β = 0.198) media and the protein supplements NCS (β = 0.052) and FBS (β = 0.022); while for L. loa L3, in addition to feeder cells (β = 0.259) and both IMDM (β = 0.401) and DMEM (β = 0.385) media, the protein supplements BSA (β = 0.029) were found important in maintaining the worm motility. Conclusions The findings from this work display a range of culture requirements for the maintenance of Loa loa stages, which are suitable for developing an effective platform for drug screening. Electronic supplementary material The online version of this article (10.1186/s13071-018-2852-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Denis Zofou
- Research Foundation for Tropical Diseases and Environment (REFOTDE), South West Region, Buea, Cameroon.,Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon
| | - Fanny Fri Fombad
- Research Foundation for Tropical Diseases and Environment (REFOTDE), South West Region, Buea, Cameroon.,Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, South West Region, Buea, Cameroon
| | - Narcisse V T Gandjui
- Research Foundation for Tropical Diseases and Environment (REFOTDE), South West Region, Buea, Cameroon.,Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, South West Region, Buea, Cameroon
| | - Abdel Jelil Njouendou
- Research Foundation for Tropical Diseases and Environment (REFOTDE), South West Region, Buea, Cameroon.,Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, South West Region, Buea, Cameroon
| | - Arnaud Jonas Kengne-Ouafo
- Research Foundation for Tropical Diseases and Environment (REFOTDE), South West Region, Buea, Cameroon.,Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, South West Region, Buea, Cameroon
| | - Patrick W Chounna Ndongmo
- Research Foundation for Tropical Diseases and Environment (REFOTDE), South West Region, Buea, Cameroon.,Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, South West Region, Buea, Cameroon
| | | | - Peter A Enyong
- Research Foundation for Tropical Diseases and Environment (REFOTDE), South West Region, Buea, Cameroon
| | - Dizzle Tayong Bita
- Research Foundation for Tropical Diseases and Environment (REFOTDE), South West Region, Buea, Cameroon.,Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, South West Region, Buea, Cameroon
| | - Mark J Taylor
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Joseph D Turner
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Samuel Wanji
- Research Foundation for Tropical Diseases and Environment (REFOTDE), South West Region, Buea, Cameroon. .,Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, South West Region, Buea, Cameroon.
| |
Collapse
|