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Li X, Huang M, Bi K, Zou Y, Wang F, Zheng X, Wang L. Clinical and epidemiological features of imported loiasis in Beijing: a report from patients returned from Africa. BMC Infect Dis 2024; 24:714. [PMID: 39033158 PMCID: PMC11265026 DOI: 10.1186/s12879-024-09620-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 07/15/2024] [Indexed: 07/23/2024] Open
Abstract
BACKGROUND Loiasis is one of the significant filarial diseases for people living in West and Central Africa with wide endemic area but is not seen in China. As economy booms and international traveling increase, China faces more and more imported parasitic diseases that are not endemic locally. Loiasis is one of the parasitic diseases that enter China by travelers infected in Africa. The better understanding of the clinical and laboratory features of loa loa infection will facilitate the diagnosis and treatment of loiasis in China. METHODS The study targeted travelers who were infected with L. loa in endemic Africa regions and returned to Beijing between 2014 and 2023. Epidemiological, clinical, and biological data as well as treatment of these patients were collected. RESULTS Total 21 cases were identified as L. loa infection based on their typical clinical manifestations and parasite finding. All cases had a history of travel to Africa for more than 6 months, most of them are the construction workers dispatched to West Africa with outdoor activities. Calabar swelling (n = 19; 90.5%) and pruritus (n = 11; 52.4%) were among the most common clinical symptoms followed by muscle pain (n = 7; 33.3%) and skin rash (n = 2; 9.5%). The adult worms were observed in the eyelid or subconjunctiva (n = 2; 9.5%) and subcutaneous tissues (n = 2; 9.5%). Although all patients presented with a high eosinophil count (> 0.52 × 109/L), only two cases displayed microfilariae in fresh venous blood and positive for filarial antigen. A cut section of adult worm was observed through biopsy on a skin nodule surrounded by lymphocytes, plasma cells and eosinophils. All subjects were positive in PCR targeting L. loa ITS-1. The constructed phylogenetic tree based on the amplified ITS-1 sequences identified their genetical relation to the L. Loa from Africa. All patients treated with albendazole and diethylcarbamazine were recovered without relapse. CONCLUSION This study provides useful information and guideline for physicians and researchers in non-endemic countries to diagnose and treat loiasis and L. loa infections acquired from endemic regions.
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Affiliation(s)
- Xiaoli Li
- Beijing Institute of Tropical Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China
- Beijing Key Laboratory for Research on Prevention and Treatment of Tropical Diseases, Beijing, 100050, China
| | - Minjun Huang
- Beijing Institute of Tropical Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China
- Beijing Key Laboratory for Research on Prevention and Treatment of Tropical Diseases, Beijing, 100050, China
| | - Kuo Bi
- Department of Pathology, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China
| | - Yang Zou
- Beijing Institute of Tropical Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China
- Beijing Key Laboratory for Research on Prevention and Treatment of Tropical Diseases, Beijing, 100050, China
| | - Fei Wang
- Beijing Institute of Tropical Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China
- Beijing Key Laboratory for Research on Prevention and Treatment of Tropical Diseases, Beijing, 100050, China
| | - Xiaoyan Zheng
- Beijing Institute of Tropical Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China
- Beijing Key Laboratory for Research on Prevention and Treatment of Tropical Diseases, Beijing, 100050, China
| | - Lei Wang
- Beijing Institute of Tropical Medicine, Beijing Friendship Hospital, Capital Medical University, Beijing, 100050, China.
- Beijing Key Laboratory for Research on Prevention and Treatment of Tropical Diseases, Beijing, 100050, China.
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Hildebrandt TR, Davi SD, Kabwende AL, Endamne LR, Mehmel E, Rakotonirinalalao M, Alabi A, Manego RZ, Kremsner PG, Lell B, Adegnika AA, Mombo-Ngoma G, Mischlinger J, Agnandji ST, Ramharter M. Evaluation of knowledge, attitude and practices towards loiasis in the rural community of Sindara, in central African Gabon. PLoS Negl Trop Dis 2024; 18:e0012109. [PMID: 38781277 PMCID: PMC11265652 DOI: 10.1371/journal.pntd.0012109] [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: 09/21/2023] [Revised: 07/23/2024] [Accepted: 03/27/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND More than 20 million people are infected with L. loa, and around 40 million live in high or intermediate-risk areas in West- and Central Africa. Although loiasis is associated with significant morbidity and excess mortality, little is known about the perception of loiasis by affected communities. This study assessed the knowledge, attitudes, and practices in the rural population of Sindara, Gabon, a region characterized by high loiasis prevalence. METHODS A community-based cross-sectional survey was conducted in Gabon between January and June 2022. During systematic door-to-door visits, randomly selected inhabitants were invited to participate in this questionnaire based survey. Venous blood was collected at midday from all participants for microscopic detection of filarial infection and clinical signs of loiasis were assessed. RESULTS A total of 150 participants were recruited, of which 66% were infected by L. loa. While almost everyone had some knowledge about L. loa, 72% of the participants understood that L. loa is a parasitic worm. The transmission of L. loa via the deer fly was known to only 21% of participants. The most frequently mentioned clinical symptoms attributed to loiasis were itching (84%), eye worm migration (59%), and conjunctivitis-like symptoms (53%). Participants who experienced migratory loiasis had better knowledge of loiasis and considered it as more serious. Traditional and herbal medicine was reported most often as an available treatment option (72%). While the formal healthcare sector was mentioned as the preferred treatment provider, 60% of the reported infections were treated by traditional medical practitioners. CONCLUSION Loiasis is in general well known by this community residing in a region of high L. loa transmission. Important gaps in knowledge were discovered foremost regarding the mode of transmission. The available healthcare system does not seem to provide adequate management for loiasis.
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Affiliation(s)
- Teite Rebecca Hildebrandt
- Center for Tropical Medicine, Bernhard-Nocht Institute for Tropical Medicine and I. Department of Medicine University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- German Center for Infection Research, Partner Sites Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
| | - Saskia Dede Davi
- Center for Tropical Medicine, Bernhard-Nocht Institute for Tropical Medicine and I. Department of Medicine University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- German Center for Infection Research, Partner Sites Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
| | | | - Lilian Rene Endamne
- Center for Tropical Medicine, Bernhard-Nocht Institute for Tropical Medicine and I. Department of Medicine University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | - Esther Mehmel
- Center for Tropical Medicine, Bernhard-Nocht Institute for Tropical Medicine and I. Department of Medicine University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- German Center for Infection Research, Partner Sites Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
| | - Maximilian Rakotonirinalalao
- Center for Tropical Medicine, Bernhard-Nocht Institute for Tropical Medicine and I. Department of Medicine University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
- German Center for Infection Research, Partner Sites Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
| | - Ayodele Alabi
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institut für Tropenmedizin, Eberhard-Karls-Universität Tübingen, Tübingen, Germany
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Rella Zoleko Manego
- Center for Tropical Medicine, Bernhard-Nocht Institute for Tropical Medicine and I. Department of Medicine University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- German Center for Infection Research, Partner Sites Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
| | - Peter G. Kremsner
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institut für Tropenmedizin, Eberhard-Karls-Universität Tübingen, Tübingen, Germany
| | - Bertrand Lell
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Medical University of Vienna, Vienna, Austria
| | - Ayôla Akim Adegnika
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institut für Tropenmedizin, Eberhard-Karls-Universität Tübingen, Tübingen, Germany
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
- German Center for Infection Research, Partner Site Tübingen, Germany
| | - Ghyslain Mombo-Ngoma
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- German Center for Infection Research, Partner Sites Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
- Department of Implementation Research, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Johannes Mischlinger
- Center for Tropical Medicine, Bernhard-Nocht Institute for Tropical Medicine and I. Department of Medicine University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
- German Center for Infection Research, Partner Sites Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
| | - Selidji Todagbe Agnandji
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institut für Tropenmedizin, Eberhard-Karls-Universität Tübingen, Tübingen, Germany
| | - Michael Ramharter
- Center for Tropical Medicine, Bernhard-Nocht Institute for Tropical Medicine and I. Department of Medicine University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- German Center for Infection Research, Partner Sites Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
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M'Bondoukwé NP, Owono-Medang M, Moussavou-Boussougou MN, Akoue Y, Migueba V, Bulaev D, Neven A, James LAJ, Ntsame Ella SA, Mawili-Mboumba DP, Atsame J, Vaillant M, Bouyou Akotet MK. Low diagnostic performance of thick blood smears of 50 µl in comparison with direct examination of 10 µl blood and the leukoconcentration technique of 5ml blood among loiasis-suspected patients with low microfilaremia in Gabon, Central Africa, using the STARD-BLCM guidelines. Parasit Vectors 2024; 17:138. [PMID: 38491557 PMCID: PMC10943916 DOI: 10.1186/s13071-023-06089-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 12/08/2023] [Indexed: 03/18/2024] Open
Abstract
BACKGROUND The aim of this study was to determine performance indicators of thick blood smears of 50 µl (TBS-50), following the Standards for the Reporting of Diagnostic Accuracy Studies-Bayesian Latent Class Model (STARD-BLCM) guidelines. TBS-50 was compared with two common parasitological techniques-direct examination of 10 µl blood and a leukoconcentration of 5 ml-for the diagnosis of microfilaremic loiasis. METHODS The study population was recruited among patients of the Department of Parasitology-Mycology-Tropical Medicine over a period of 1 year. Age, sex, symptoms, and eosinophilia variables were recorded from laboratory registers and medical files. Direct examination of 10 µl of blood, TBS-50, and the leukoconcentration technique with 5 ml of blood were performed for each patient. The classical formula and BLCM were used to determine the diagnostic accuracy of the three techniques as well as the prevalence of microfilaremic loiasis. Three models were built within the framework of BLCM-the BLCM model I and alternative models II and III-for sensitivity analysis. RESULTS In total, 191 patients consented to be included. The direct blood examination and TBS-50 yielded comparable qualitative and quantitative results. Hence, they are reported together. The prevalence of Loa loa microfilaremia was 9.4% (95% CI 5.7-14.5; n = 18/191) with direct blood examination/TBS-50 and 12.6% [8.2-18.1] (n = 24/191) for leukoconcentration. Comparing TBS-50 with the leukoconcentration method using the classical formula, the sensitivity was 75.0% [53.3-90.2], specificity was 100.0% [97.8-100.0], the positive predictive value was 100.0% [81.5-100.0], and the negative predictive value was 96.5% [92.6-98.7]. The prevalence of microfilaremic loiasis was estimated at 9.7% [6.2-13.7] using BLCM model I. The outputs of BLCM model I showed sensitivity of 78.9% [65.3-90.3], specificity of 100.0% [99.3-100.0], a positive predictive value of 99.1% [87.2-100.0], and a negative predictive value of 93.0% [87.3-97.7] for direct blood examination/TBS-50. CONCLUSIONS TBS-50 demonstrates low sensitivity relative to two other techniques. In one in five cases, the result will be falsely declared negative using these methods. However, this method can be deployed with limited funds.
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Affiliation(s)
- Noé Patrick M'Bondoukwé
- Department of Parasitology-Mycology-Tropical Medicine, Faculty of Medicine, Université des Sciences de la Santé, 4009, Libreville, Gabon.
| | - Matthieu Owono-Medang
- Department of Parasitology-Mycology-Tropical Medicine, Faculty of Medicine, Université des Sciences de la Santé, 4009, Libreville, Gabon
| | - Marie Noëlle Moussavou-Boussougou
- Department of Parasitology-Mycology-Tropical Medicine, Faculty of Medicine, Université des Sciences de la Santé, 4009, Libreville, Gabon
| | - Yvan Akoue
- Department of Parasitology-Mycology-Tropical Medicine, Faculty of Medicine, Université des Sciences de la Santé, 4009, Libreville, Gabon
| | - Valentin Migueba
- Department of Parasitology-Mycology-Tropical Medicine, Faculty of Medicine, Université des Sciences de la Santé, 4009, Libreville, Gabon
| | - Dmitry Bulaev
- Competence Centre for Methodology and Statistics, Luxembourg Institute of Health, 1A-B Rue Thomas Edison, 1445, Strassen, Luxembourg
| | - Anouk Neven
- Competence Centre for Methodology and Statistics, Luxembourg Institute of Health, 1A-B Rue Thomas Edison, 1445, Strassen, Luxembourg
| | - Luice Aurtin Joel James
- Department of Parasitology-Mycology-Tropical Medicine, Faculty of Medicine, Université des Sciences de la Santé, 4009, Libreville, Gabon
| | | | - Denise Patricia Mawili-Mboumba
- Department of Parasitology-Mycology-Tropical Medicine, Faculty of Medicine, Université des Sciences de la Santé, 4009, Libreville, Gabon
| | - Julienne Atsame
- Programme de Lutte Contre les Maladies Parasitaires, Ministère de la Santé du Gabon, Libreville, Gabon
| | - Michel Vaillant
- Competence Centre for Methodology and Statistics, Luxembourg Institute of Health, 1A-B Rue Thomas Edison, 1445, Strassen, Luxembourg
| | - Marielle Karine Bouyou Akotet
- Department of Parasitology-Mycology-Tropical Medicine, Faculty of Medicine, Université des Sciences de la Santé, 4009, Libreville, Gabon
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Ramharter M, Butler J, Mombo-Ngoma G, Nordmann T, Davi SD, Zoleko Manego R. The African eye worm: current understanding of the epidemiology, clinical disease, and treatment of loiasis. THE LANCET. INFECTIOUS DISEASES 2024; 24:e165-e178. [PMID: 37858326 DOI: 10.1016/s1473-3099(23)00438-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 07/07/2023] [Accepted: 07/10/2023] [Indexed: 10/21/2023]
Abstract
Loa loa, the African eye worm, is a filarial pathogen transmitted by blood-sucking flies of the genus Chrysops. Loiasis primarily affects rural populations residing in the forest and adjacent savannah regions of central and west Africa, where more than 20 million patients are chronically infected in medium and high transmission regions. For a long time, loiasis has been regarded as a relatively benign condition. However, morbidity as measured by disability-adjusted life-years lost might be as high as 400 per 100 000 residents, and the population attributable fraction of death is estimated at 14·5% in highly endemic regions, providing unequivocal evidence for the substantial disease burden that loiasis exerts on affected communities. The clinical penetrance of loiasis is variable and might present with the classic signs of eye worm migration or transient Calabar swellings, but might include common, unspecific symptoms or rare but potentially life-threatening complications. Although adult worm migration seems most closely linked to symptomatic disease, high levels of microfilaraemia are associated with clinically important complications and death. Loiasis remains difficult to diagnose, treat, and control due to an absence of reliable point-of-care diagnostic assays, safe and efficacious drugs, and cost-effective prevention strategies. This Review summarises the major advances in our understanding of loiasis made over the past decade and highlights the many gaps that await to be addressed urgently.
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Affiliation(s)
- Michael Ramharter
- Department of Clinical Research, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany; Division of Tropical Medicine, I Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Centre de Recherche Médicale de Lambaréné, Lambaréné, Gabon; German Center for Infection Research, Partner Site Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany.
| | | | - Ghyslain Mombo-Ngoma
- Department of Implementation Research, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany; Division of Tropical Medicine, I Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Centre de Recherche Médicale de Lambaréné, Lambaréné, Gabon; German Center for Infection Research, Partner Site Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
| | - Tamara Nordmann
- Department of Clinical Research, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany; Division of Tropical Medicine, I Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; German Center for Infection Research, Partner Site Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
| | - Saskia Dede Davi
- Department of Clinical Research, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany; Division of Tropical Medicine, I Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; German Center for Infection Research, Partner Site Hamburg-Lübeck-Borstel-Riems, Hamburg, Germany
| | - Rella Zoleko Manego
- Department of Clinical Research, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany; Division of Tropical Medicine, I Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Centre de Recherche Médicale de Lambaréné, Lambaréné, Gabon
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Campillo JT, Dupasquier V, Lebredonchel E, Rancé LG, Hemilembolo MC, Pion SDS, Boussinesq M, Missamou F, Perez Martin A, Chesnais CB. Association between arterial stiffness and Loa loa microfilaremia in a rural area of the Republic of Congo: A population-based cross-sectional study (the MorLo project). PLoS Negl Trop Dis 2024; 18:e0011915. [PMID: 38241411 PMCID: PMC10830006 DOI: 10.1371/journal.pntd.0011915] [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: 09/26/2023] [Revised: 01/31/2024] [Accepted: 01/12/2024] [Indexed: 01/21/2024] Open
Abstract
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. We aimed to examine whether the density of L. loa microfilariae (mfs) in the blood is associated with cardiovascular disease. METHODOLOGY Using a point-of-care device (pOpmètre), we conducted a cross-sectional study to assess arterial stiffness and peripheral arterial disease (PAD) in 991 individuals living in a loiasis-endemic rural area in the Republic of the Congo. Microfilaremic individuals were matched for age, sex and village of residence with 2 amicrofilaremic subjects. We analyzed markers of arterial stiffness (Pulse-Wave Velocity, PWV), PAD (Ankle-Brachial Index, ABI) and cardiovascular health (Pulse Pressure, PP). The analysis considered parasitological results (L. loa microfilarial density [MFD], soil-transmitted helminths infection, asymptomatic malaria and onchocerciasis), sociodemographic characteristics and known cardiovascular risk factors (body mass index, smoking status, creatininemia, blood pressure). PRINCIPAL FINDINGS Among the individuals included in the analysis, 192/982 (19.5%) and 137/976 (14.0%) had a PWV or an ABI considered out of range, respectively. Out of range PWV was associated with younger age, high mean arterial pressure and high L. loa MFD. Compared to amicrofilaremic subjects, those with more than 10,000 mfs/mL were 2.17 times more likely to have an out of range PWV (p = 0.00). Factors significantly associated with PAD were older age, low pulse rate, low body mass index, smoking, and L. loa microfilaremia. Factors significantly associated with an elevation of PP were older age, female sex, high average blood pressure, low pulse rate and L. loa microfilaremia. CONCLUSION A potential link between high L. loa microfilaremia and cardiovascular health deterioration is suggested. Further studies are required to confirm and explore this association.
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Affiliation(s)
- Jérémy T. Campillo
- TransVIHMI, Université de Montpellier, INSERM Unité 1175, Institut de Recherche pour le Développement (IRD), Montpellier, France
| | - Valentin Dupasquier
- Department of Cardiology, Montpellier University Hospital, Montpellier, France
| | - Elodie Lebredonchel
- Département de Biochimie, Hôpitaux Universitaires Paris Nord Val de Seine–site Bichat, Assistance Publique des Hôpitaux de Paris, Paris, France
| | - Ludovic G. Rancé
- Department of Anesthesiology and Critical Care Medicine, Montpellier University Hospital, Montpellier, France
| | - Marlhand C. Hemilembolo
- TransVIHMI, Université de Montpellier, INSERM Unité 1175, Institut de Recherche pour le Développement (IRD), Montpellier, France
- 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 Congo
| | - Sébastien D. S. Pion
- TransVIHMI, Université de Montpellier, INSERM Unité 1175, Institut de Recherche pour le Développement (IRD), Montpellier, France
| | - Michel Boussinesq
- TransVIHMI, Université de Montpellier, INSERM Unité 1175, Institut de Recherche pour le Développement (IRD), Montpellier, 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 Congo
| | - Antonia Perez Martin
- Vascular Medicine Laboratory, Nîmes University Hospital, Nîmes, France
- IDESP, Université de Montpellier, INSERM, Montpellier, France
| | - Cédric B. Chesnais
- TransVIHMI, Université de Montpellier, INSERM Unité 1175, Institut de Recherche pour le Développement (IRD), Montpellier, France
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Moutongo Mouandza R, Mourou JR, Moutombi Ditombi B, Roger Sibi Matotou H, Ekomi B, Bouyou-Akotet MK, Mawili-Mboumba DP. Sociodemographics, Clinical Factors, and Biological Factors Associated with Loiasis in Endemic Onchocerciasis Areas in Southern Gabon. Am J Trop Med Hyg 2023; 109:850-857. [PMID: 37339766 PMCID: PMC10551092 DOI: 10.4269/ajtmh.22-0558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 04/22/2023] [Indexed: 06/22/2023] Open
Abstract
To implement the appropriate strategies for scale-up interventions to eliminate onchocerciasis without severe adverse events, clinical and biological factors associated with loiasis were analyzed in onchocerciasis-endemic areas. Blood was collected from volunteers after examination by a physician. Detection of microfilariae and measurement of Ov16 IgG4 were performed using direct microscopic examination of blood and onchocerciasis rapid test detection, respectively. Areas with sporadic, hypoendemic, and hyperendemic onchocerciasis endemicity were found. Participants with microfilaremia were considered microfilaremic, and those without microfilaremia were seen as amicrofilaremic. Of the 471 study participants, 40.5% (n = 191) had microfilariae. Among them, Mansonella spp. was the most common (78.2%, n = 147), followed by Loa loa (41.4%, n = 79). The association between the two species represented 18.3% (n = 35). The specific immunoglobulins of Onchocerca volvulus were detected in 24.2% of participants (n = 87/359). Overall prevalence of L. loa was 16.8%. Hypermicrofilaremia was found in 3% (N = 14), and one participant had more than 30,000 microfilaremiae per milliliter. The frequency of L. loa did not vary according to the level of onchocerciasis transmission. Pruritus was the most common clinical sign (60.5%, n = 285) reported, mainly in microfilaremic participants (72.2%, n = 138/191). The prevalence of L. loa microfilaria in the study population was below the threshold at risk for the occurrence of serious side effects due to ivermectin. Clinical manifestations frequently observed could be exacerbated by microfilaremia in areas where onchocerciasis transmission is high.
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Affiliation(s)
- Reinne Moutongo Mouandza
- Department of Parasitology-Mycology and Tropical Medicine, Faculty of Medicine, Université des Sciences de la Santé, Libreville, Gabon
| | - Jean Romain Mourou
- Department of Parasitology-Mycology and Tropical Medicine, Faculty of Medicine, Université des Sciences de la Santé, Libreville, Gabon
| | - Bridy Moutombi Ditombi
- Department of Parasitology-Mycology and Tropical Medicine, Faculty of Medicine, Université des Sciences de la Santé, Libreville, Gabon
| | - Hadry Roger Sibi Matotou
- Department of Parasitology-Mycology and Tropical Medicine, Faculty of Medicine, Université des Sciences de la Santé, Libreville, Gabon
| | - Bernadette Ekomi
- Department of Parasitology-Mycology and Tropical Medicine, Faculty of Medicine, Université des Sciences de la Santé, Libreville, Gabon
| | - Marielle Karine Bouyou-Akotet
- Department of Parasitology-Mycology and Tropical Medicine, Faculty of Medicine, Université des Sciences de la Santé, Libreville, Gabon
| | - Denise Patricia Mawili-Mboumba
- Department of Parasitology-Mycology and Tropical Medicine, Faculty of Medicine, Université des Sciences de la Santé, Libreville, Gabon
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7
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Campillo JT, Hemilembolo MC, Pion SDS, Lebredonchel E, Dupasquier V, Boullé C, Rancé LG, Boussinesq M, Missamou F, Chesnais CB. Association between blood Loa loa microfilarial density and proteinuria levels in a rural area of the Republic of Congo (the MorLo project): a population-based cross-sectional study. THE LANCET. MICROBE 2023; 4:e704-e710. [PMID: 37480932 PMCID: PMC10469262 DOI: 10.1016/s2666-5247(23)00142-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 04/26/2023] [Accepted: 04/28/2023] [Indexed: 07/24/2023]
Abstract
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. METHODS We did a cross-sectional study between May 16, 2022, and June 11, 2022, to assess the relationship between Loa loa microfilaraemia densities and proteinuria in a rural area of the Republic of Congo. We included all consenting adults living in the target area at study commencement who had L loa microfilarial densities greater than 500 microfilariae per mL during previous screening for a clinical trial in 2019. This study is part of the MorLo project, and used the project's study population of individuals aged 18 years or older who were living near Sibiti. For each microfilaraemic individual, two individuals without L loa microfilarial densities matched on age, sex, and place of residence were included. The association between proteinuria (assessed by dipstick) and L loa microfilarial densities, age, and sex was assessed using an unconstrained ordinal regression model since the parallel-lines assumption was violated for microfilarial densities. FINDINGS 991 participants were included, of whom 342 (35%) were L loa microfilaraemic. The prevalence of microfilaraemia was 38% (122 of 325) among individuals with trace proteinuria (<300 mg/24 h), 51% (45 of 89) among individuals with light proteinuria (300 mg to 1 g/24 h), and 71% (15 of 21) among individuals with high proteinuria (>1 g/24 h). Individuals with high proteinuria had significantly higher L loa microfilarial densities (p<0·0001): mean microfilariae per mL were 1595 (SD 4960) among individuals with no proteinuria, 2691 (7982) for those with trace proteinuria, 3833 (9878) for those with light proteinuria, and 13 541 (20 118) for those with high proteinuria. Individuals with 5000-14 999 microfilariae per mL and individuals with 15 000 microfilariae per mL or greater were, respectively, 5·39 and 20·49 times more likely to have a high proteinuria than individuals with no microfilaraemia. INTERPRETATION The risk of proteinuria increases with L loa microfilaraemia. Further studies are needed to identify renal disorders (eg, tubulopathies, glomerulopathies, or nephrotic syndromes) responsible for loiasis-related proteinuria. FUNDING European Research Council, MorLo project. TRANSLATION For the French translation of the abstract see Supplementary Materials section.
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Affiliation(s)
- Jérémy T Campillo
- TransVIHMI, Université de Montpellier, INSERM Unité 1175, Institut de Recherche pour le Développement, Montpellier, France.
| | - Marlhand C Hemilembolo
- TransVIHMI, Université de Montpellier, INSERM Unité 1175, Institut de Recherche pour le Développement, Montpellier, France; 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
| | - Sébastien D S Pion
- TransVIHMI, Université de Montpellier, INSERM Unité 1175, Institut de Recherche pour le Développement, Montpellier, France
| | - Elodie Lebredonchel
- Département de Biochimie, Hôpitaux Universitaires Paris Nord Val de Seine, Assistance Publique des Hôpitaux de Paris, Paris, France
| | - Valentin Dupasquier
- Department of Cardiology, Montpellier University Hospital, Montpellier, France
| | - Charlotte Boullé
- TransVIHMI, Université de Montpellier, INSERM Unité 1175, Institut de Recherche pour le Développement, Montpellier, France; Department of Infectious and Tropical Diseases, Montpellier University Hospital, Montpellier, France
| | - Ludovic G Rancé
- Department of Anesthesiology and Critical Care Medicine, Montpellier University Hospital, Montpellier, France
| | - Michel Boussinesq
- TransVIHMI, Université de Montpellier, INSERM Unité 1175, Institut de Recherche pour le Développement, Montpellier, 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
| | - Cédric B Chesnais
- TransVIHMI, Université de Montpellier, INSERM Unité 1175, Institut de Recherche pour le Développement, Montpellier, France
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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.
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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
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9
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Jimenez-Vila G, Campillo-Grau A, Espiau M, Soriano-Arandes A, Soler-Palacin P, Sulleiro E, Zarzuela F. Loiasis: An Unusual Cause of Eosinophilia in a Pediatric Patient. Pediatr Infect Dis J 2023; 42:e132. [PMID: 36728668 DOI: 10.1097/inf.0000000000003820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Guillem Jimenez-Vila
- Pediatric Infectious Diseases and Immunodeficiencies Unit, Hospital UniversitariVall d'Hebron, Barcelona, Spain
| | - Anna Campillo-Grau
- Pediatric Infectious Diseases and Immunodeficiencies Unit, Hospital UniversitariVall d'Hebron, Barcelona, Spain
| | - María Espiau
- Pediatric Infectious Diseases and Immunodeficiencies Unit, Hospital UniversitariVall d'Hebron, Barcelona, Spain
| | - Antoni Soriano-Arandes
- Pediatric Infectious Diseases and Immunodeficiencies Unit, Hospital UniversitariVall d'Hebron, Barcelona, Spain
| | - Pere Soler-Palacin
- Pediatric Infectious Diseases and Immunodeficiencies Unit, Hospital UniversitariVall d'Hebron, Barcelona, Spain
| | - Elena Sulleiro
- Microbiology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Francesc Zarzuela
- Microbiology Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain
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Ayiseh RB, Mbah GE, Monya E, Ndi EM, Sakanari J, Lustigman S, Cho-Ngwa F. Development and validation of small animal models for onchocerciasis and loiasis microfilaricide discovery. PLoS Negl Trop Dis 2023; 17:e0011135. [PMID: 36827447 PMCID: PMC9994675 DOI: 10.1371/journal.pntd.0011135] [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: 05/11/2022] [Revised: 03/08/2023] [Accepted: 02/01/2023] [Indexed: 02/26/2023] Open
Abstract
BACKGROUND Onchocerciasis (river blindness) caused by the filarial worm Onchocerca volvulus is a neglected tropical disease that affects the skin and eyes of humans. Mass drug administration with ivermectin (IVM) to control the disease often suffers from severe adverse events in individuals co-injected with high loads of Loa loa microfilariae (mf). Thus loiasis animal models for counter-screening of compounds effective against onchocerciasis are needed, as are the corresponding onchocerciasis screening models. The repertoire of such models is highly limiting. Therefore, this study was aimed at developing and validating mf immunocompetent small animal models to increase tools for onchocerciasis drug discovery. METHODOLOGY/PRINCIPAL FINDINGS O. ochengi mf from cattle skin and L. loa mf from human blood were used to infect BALB/c mice and Mongolian gerbils, and IVM was used for model validation. O. ochengi mf were given subcutaneously to both rodents while L. loa mf were administered intravenously to mice and intraperitoneally to gerbils. IVM was given orally. In an 8-day model of O. ochengi mf in BALB/c mice, treatment with IVM depleted all mf in the mice, unlike the controls. Also, in a 2.5-day model of L. loa mf in BALB/c, IVM significantly reduced mf in treated mice compared to the untreated. Furthermore, the gerbils were very susceptible to O. ochengi mf and IVM eradicated all mf in the treated animals. In the peritoneal L. loa mf gerbil model, IVM reduced mf motility in treated animals compared to the controls. In a 30-day gerbil co-injection model, IVM treatment cleared all O. ochengi mf and reduced motility of L. loa mf. Both mf survived for up to 50 days in a gerbil co-injection model. CONCLUSIONS/SIGNIFICANCE We have developed two immunocompetent small animal models for onchocerciasis and loiasis that can be used for microfilaricide discovery and to counter-screen onchocerciasis macrofilarides.
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Affiliation(s)
- Rene Bilingwe Ayiseh
- ANDI Centre of Excellence for Onchocerciasis Drug Research, Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon
| | - Glory Enjong Mbah
- ANDI Centre of Excellence for Onchocerciasis Drug Research, Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon
| | - Elvis Monya
- ANDI Centre of Excellence for Onchocerciasis Drug Research, Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon
| | - Emmanuel Menang Ndi
- ANDI Centre of Excellence for Onchocerciasis Drug Research, Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon
| | - Judy Sakanari
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California, United States of America
| | - Sara Lustigman
- Lindsley F. Kimball Research Institute, New York Blood Center, New York City, New York, United States of America
| | - Fidelis Cho-Ngwa
- ANDI Centre of Excellence for Onchocerciasis Drug Research, Biotechnology Unit, Faculty of Science, University of Buea, Buea, Cameroon
- * E-mail:
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11
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Jacobsen KH, Andress BC, Bhagwat EA, Bryant CA, Chandrapu VR, Desmonts CG, Matthews TM, Ogunkoya A, Wheeler TJ, Williams AS. A call for loiasis to be added to the WHO list of neglected tropical diseases. THE LANCET. INFECTIOUS DISEASES 2022; 22:e299-e302. [PMID: 35500592 DOI: 10.1016/s1473-3099(22)00064-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 01/20/2022] [Accepted: 01/21/2022] [Indexed: 06/14/2023]
Abstract
Loiasis, also called African eye worm, is not currently on WHO's list of priority neglected tropical diseases, even though the risk that individuals with high Loa loa microfilarial densities will develop potentially fatal encephalopathy when they take ivermectin has complicated efforts to use mass drug administration for onchocerciasis (river blindness) and lymphatic filariasis control in co-endemic areas. At least 10 million residents of central and west Africa are thought to have loiasis, which causes painful and itchy subcutaneous oedema, arthralgia, and discomfort when adult helminths that are 3-7 cm in length are present under the conjunctiva of the eye. High levels of microfilaraemia are associated with renal, cardiac, neurological, and other sequelae, and an increased risk of death. The public health burden of loiasis could be greatly reduced with expanded use of diagnostic tests, anthelmintic treatment, and control of the Chrysops spp (tabanid flies) vectors that transmit the parasite. Loiasis should be added to the next revision of the WHO neglected tropical disease priority list, not merely because its inclusion will support the elimination of other skin and subcutaneous neglected tropical diseases, but also because of the complications caused by loiasis itself.
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Affiliation(s)
- Kathryn H Jacobsen
- Department of Health Studies, University of Richmond, Richmond, VA, USA.
| | - Bailey C Andress
- Department of Health Studies, University of Richmond, Richmond, VA, USA
| | - Elina A Bhagwat
- Department of Health Studies, University of Richmond, Richmond, VA, USA
| | - Ciera A Bryant
- Department of Health Studies, University of Richmond, Richmond, VA, USA
| | | | | | - Tania M Matthews
- Department of Health Studies, University of Richmond, Richmond, VA, USA
| | - Akeem Ogunkoya
- Department of Health Studies, University of Richmond, Richmond, VA, USA
| | - Tristan J Wheeler
- Department of Health Studies, University of Richmond, Richmond, VA, USA
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12
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Wu Y, Duffey M, Alex SE, Suarez-Reyes C, Clark EH, Weatherhead JE. The role of helminths in the development of non-communicable diseases. Front Immunol 2022; 13:941977. [PMID: 36119098 PMCID: PMC9473640 DOI: 10.3389/fimmu.2022.941977] [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] [Received: 05/12/2022] [Accepted: 08/01/2022] [Indexed: 12/15/2022] Open
Abstract
Non-communicable diseases (NCDs) like cardiovascular disease, chronic respiratory diseases, cancers, diabetes, and neuropsychiatric diseases cause significant global morbidity and mortality which disproportionately affect those living in low resource regions including low- and middle-income countries (LMICs). In order to reduce NCD morbidity and mortality in LMIC it is imperative to understand risk factors associated with the development of NCDs. Certain infections are known risk factors for many NCDs. Several parasitic helminth infections, which occur most commonly in LMICs, have been identified as potential drivers of NCDs in parasite-endemic regions. Though understudied, the impact of helminth infections on the development of NCDs is likely related to helminth-specific factors, including species, developmental stage and disease burden. Mechanical and chemical damage induced by the helminth in combination with pathologic host immune responses contribute to the long-term inflammation that increases risk for NCD development. Robust studies from animal models and human clinical trials are needed to understand the immunologic mechanisms of helminth-induced NCDs. Understanding the complex connection between helminths and NCDs will aid in targeted public health programs to reduce helminth-induced NCDs and reduce the high rates of morbidity that affects millions of people living in parasite-endemic, LMICs globally.
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Affiliation(s)
- Yifan Wu
- Department of Pediatrics, Division of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States
| | - Megan Duffey
- Department of Pediatrics, Division of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States,Department of Medicine, Section of Infectious Diseases, Baylor College of Medicine, Houston, TX, United States
| | - Saira Elizabeth Alex
- National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States
| | - Charlie Suarez-Reyes
- Department of Pediatrics, Division of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States
| | - Eva H. Clark
- Department of Pediatrics, Division of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States,Department of Medicine, Section of Infectious Diseases, Baylor College of Medicine, Houston, TX, United States,National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States
| | - Jill E. Weatherhead
- Department of Pediatrics, Division of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States,Department of Medicine, Section of Infectious Diseases, Baylor College of Medicine, Houston, TX, United States,National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States,*Correspondence: Jill E. Weatherhead,
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13
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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.
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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
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Tamarozzi F, Buonfrate D, Ricaboni D, Ursini T, Foti G, Gobbi F. Spleen nodules in Loa loa infection: re-emerging knowledge and future perspectives. THE LANCET. INFECTIOUS DISEASES 2022; 22:e197-e206. [PMID: 35219405 DOI: 10.1016/s1473-3099(21)00632-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 09/24/2021] [Accepted: 09/28/2021] [Indexed: 06/14/2023]
Abstract
Loiasis, the infection with the vector-borne filarial nematode Loa loa, is widely distributed in central and west Africa. Long considered a rather benign infection, recently loiasis with high microfilarial burden was associated with increased mortality risk. Eyeworm and Calabar swelling are pathognomonic signs of the infection, but other atypical, non-specific manifestations can also occur. For instance, splenic nodules have been seldom reported. In this Grand Round, we report two cases of loiasis in migrants who presented with spleen nodules, which could be followed up over time (up to 27 months) with multiple imaging techniques until their resolution. We comment on the clinical implications of these observations, including differential diagnosis with similar imaging findings, and critically review the evidence of spleen involvement in loiasis and other filarial infections.
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Affiliation(s)
- Francesca Tamarozzi
- Department of Infectious-Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Negrar, Italy.
| | - Dora Buonfrate
- Department of Infectious-Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Negrar, Italy
| | | | - Tamara Ursini
- Department of Infectious-Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Negrar, Italy
| | - Giovanni Foti
- Department of Radiology, IRCCS Sacro Cuore Don Calabria Hospital, Negrar, Italy
| | - Federico Gobbi
- Department of Infectious-Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Negrar, Italy
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Ramesh H, Somashekar S. Toponyms in dermatology. Indian J Dermatol 2022; 67:279-282. [DOI: 10.4103/ijd.ijd_71_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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16
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Manock SR, Nsue VU, Olotu A, Mpina M, Nyakarungu E, Raso J, Mtoro A, Ondo Mangue ME, Ntutumu Pasialo BE, Nguema R, Riyahi P, Schindler T, Daubenberger C, Church LWP, Billingsley PF, Richie TL, Abdulla S, Hoffman SL. OUP accepted manuscript. Trans R Soc Trop Med Hyg 2022; 116:745-749. [PMID: 35394038 PMCID: PMC9355999 DOI: 10.1093/trstmh/trac019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 12/16/2021] [Accepted: 03/12/2022] [Indexed: 11/16/2022] Open
Abstract
Loa loa microfilariae were found on thick blood smears (TBSs) from 8 of 300 (2.7%) residents of Bioko Island, Equatorial Guinea, during a Plasmodium falciparum sporozoite malaria vaccine clinical trial. Only one subject was found to have microfilaraemia on his first exam; parasites were not discovered in the other seven until subsequent TBSs were performed, at times many weeks into the study. All infected individuals were asymptomatic, and were offered treatment with diethylcarbamazine, per national guidelines. L. loa microfilaraemia complicated the enrolment or continued participation of these eight trial subjects, and only one was able to complete all study procedures. If ruling out loiasis is deemed to be important during clinical trials, tests that are more sensitive than TBSs should be performed.
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Affiliation(s)
| | - Vicente Urbano Nsue
- National Malaria Control Program, Ministry of Health and Social Welfare, Malabo, Equatorial Guinea
| | - Ally Olotu
- Department of Interventions & Clinical Trials, Ifakara Health Institute, Box 74, Bagamoyo, Tanzania
- KEMRI Wellcome Trust Research Programme, P.O. Box 230-80108 Kilifi, Kenya
| | - Maximillian Mpina
- Department of Interventions & Clinical Trials, Ifakara Health Institute, Box 74, Bagamoyo, Tanzania
- Department of Medical Parasitology and Infection Biology, Clinical Immunology, Swiss Tropical and Public Health Institute, 4002 Basel, Switzerland
- University of Basel, Petersplatz 1, 4001 Basel, Switzerland
| | - Elizabeth Nyakarungu
- Department of Interventions & Clinical Trials, Ifakara Health Institute, Box 74, Bagamoyo, Tanzania
| | - José Raso
- National Malaria Control Program, Ministry of Health and Social Welfare, Malabo, Equatorial Guinea
| | - Ali Mtoro
- Department of Interventions & Clinical Trials, Ifakara Health Institute, Box 74, Bagamoyo, Tanzania
| | - Martín Eka Ondo Mangue
- National Malaria Control Program, Ministry of Health and Social Welfare, Malabo, Equatorial Guinea
| | | | - Rufino Nguema
- National Program for Onchocerciasis and Other Filariasis Control, Ministry of Health and Social Welfare, Malabo, Equatorial Guinea
| | | | - Tobias Schindler
- Department of Medical Parasitology and Infection Biology, Clinical Immunology, Swiss Tropical and Public Health Institute, 4002 Basel, Switzerland
- University of Basel, Petersplatz 1, 4001 Basel, Switzerland
| | - Claudia Daubenberger
- Department of Medical Parasitology and Infection Biology, Clinical Immunology, Swiss Tropical and Public Health Institute, 4002 Basel, Switzerland
- University of Basel, Petersplatz 1, 4001 Basel, Switzerland
| | | | | | | | - Salim Abdulla
- Department of Interventions & Clinical Trials, Ifakara Health Institute, Box 74, Bagamoyo, Tanzania
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An Adult Loa loa Worm in the Upper Eyelid: An Atypical Presentation of Loiasis in the United States. Case Rep Ophthalmol Med 2021; 2021:6630875. [PMID: 33959400 PMCID: PMC8075677 DOI: 10.1155/2021/6630875] [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: 12/20/2020] [Revised: 03/16/2021] [Accepted: 03/23/2021] [Indexed: 11/17/2022] Open
Abstract
Purpose. To report a case of ocular involvement of Loa loa parasite. Observations. We present a rare case report of a Loiasis diagnosed in the United States from a patient presenting with subcutaneous migration of an adult worm within an eyelid who was found to have systemic disease with microfilaria in his blood. This is the second report in the United States and the eighth case in published literature worldwide. Conclusions and Importance. Due to the relatively mild disease course, Loiasis is relatively ignored in public health in low resource health districts. Understandably, the focus of public health in endemic areas must focus on basic health needs like malnutrition and diseases that entail a greater disease burden. As globalization has increased the amount of trade of physical goods, the effect of immigration also has implications for the spread of infectious disease. Medical practitioners in the United States should be aware of endemic diseases from foreign lands.
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Cheke RA, Little KE, Young S, Walker M, Basáñez MG. Taking the strain out of onchocerciasis? A reanalysis of blindness and transmission data does not support the existence of a savannah blinding strain of onchocerciasis in West Africa. ADVANCES IN PARASITOLOGY 2021; 112:1-50. [PMID: 34024357 DOI: 10.1016/bs.apar.2021.01.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Onchocerciasis (also known as 'river blindness'), is a neglected tropical disease (NTD) caused by the (Simulium-transmitted) filarial nematode Onchocerca volvulus. The occurrence of 'blinding' (savannah) and non-blinding (forest) parasite strains and the existence of corresponding, locally adapted Onchocerca-Simulium complexes were postulated to explain greater blindness prevalence in savannah than in forest foci. As a result, the World Health Organization (WHO) Onchocerciasis Control Programme in West Africa (OCP) focused anti-vectorial and anti-parasitic interventions in savannah endemic areas. In this paper, village-level data on blindness prevalence, microfilarial prevalence, and transmission intensity (measured by the annual transmission potential, the number of infective, L3, larvae per person per year) were extracted from 16 West-Central Africa-based publications, and analysed according to habitat (forest, forest-savannah mosaic, savannah) to test the dichotomous strain hypothesis in relation to blindness. When adjusting for sample size, there were no statistically significant differences in blindness prevalence between the habitats (one-way ANOVA, P=0.68, mean prevalence for forest=1.76±0.37 (SE); mosaic=1.49±0.38; savannah=1.89±0.26). The well-known relationship between blindness prevalence and annual transmission potential for savannah habitats was confirmed and shown to hold for (but not to be statistically different from) forest foci (excluding data from southern Côte d'Ivoire, in which blindness prevalence was significantly lower than in other West African forest communities, but which had been the focus of studies leading to the strain-blindness hypothesis that was accepted by OCP planners). We conclude that the evidence for a savannah blinding onchocerciasis strain in simple contrast with a non-blinding forest strain is equivocal. A re-appraisal of the strain hypothesis to explain patterns of ocular disease is needed to improve understanding of onchocerciasis epidemiology and disease burden estimates in the light of the WHO 2030 goals for onchocerciasis.
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Affiliation(s)
- Robert A Cheke
- Natural Resources Institute, Department of Agriculture, Health & Environment, University of Greenwich at Medway, Kent, United Kingdom; London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, Faculty of Medicine, School of Public Health, Imperial College London, London, United Kingdom
| | | | - Stephen Young
- Natural Resources Institute, Department of Agriculture, Health & Environment, University of Greenwich at Medway, Kent, United Kingdom
| | - Martin Walker
- London Centre for Neglected Tropical Disease Research, Department of Pathobiology and Populations Sciences, Royal Veterinary College, Hatfield, United Kingdom
| | - Maria-Gloria Basáñez
- London Centre for Neglected Tropical Disease Research (LCNTDR), Department of Infectious Disease Epidemiology, Faculty of Medicine, School of Public Health, Imperial College London, London, United Kingdom; MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Faculty of Medicine, School of Public Health, Imperial College London, London, United Kingdom.
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Pion SD, Chesnais CB. Uncovering the burden of loiasis: first estimates from Gabon. THE LANCET. INFECTIOUS DISEASES 2020; 20:1226-1227. [PMID: 32585134 DOI: 10.1016/s1473-3099(20)30324-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 04/15/2020] [Indexed: 11/27/2022]
Affiliation(s)
- Sébastien D Pion
- Research Institute for Development, University of Montpellier, Montpellier 34394, France.
| | - Cédric B Chesnais
- Research Institute for Development, University of Montpellier, Montpellier 34394, France
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Veletzky L, Hergeth J, Stelzl DR, Mischlinger J, Manego RZ, Mombo-Ngoma G, McCall MBB, Adegnika AA, Agnandji ST, Metzger WG, Matsiegui PB, Lagler H, Mordmüller B, Budke C, Ramharter M. Burden of disease in Gabon caused by loiasis: a cross-sectional survey. THE LANCET. INFECTIOUS DISEASES 2020; 20:1339-1346. [PMID: 32585133 DOI: 10.1016/s1473-3099(20)30256-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Revised: 03/12/2020] [Accepted: 03/23/2020] [Indexed: 11/13/2022]
Abstract
BACKGROUND Loiasis is a highly prevalent helminth infection found in distinct regions of sub-Saharan Africa. The disease has been considered to be of minor clinical significance, but this belief is being increasingly challenged by recent evidence. We aimed to prospectively quantify the overall burden of disease caused by loiasis in an endemic region of Gabon, using disability-adjusted life years (DALYs). METHODS We did a cross-sectional survey during 2017 and 2018 in rural Gabon. Volunteers underwent diagnostic tests for loiasis and were given a standardised questionnaire on symptoms. Participants reporting eye worm migration or harbouring Loa loa microfilariae were defined as loiasis positive. Morbidity-based DALYs associated with loiasis were estimated for the rural population of Gabon. FINDINGS Between Sept 1, 2017 and May 31, 2018, 1235 participants residing in 38 villages in the Gabonese departments of Tsamba-Magotsi and Ogooué et des Lacs were screened. 626 (50·8%) of 1232 eligible participants had loiasis. 520 (42·2%) of 1232 participants reported eye worm migration. 478 (93·9%) of 509 individuals with eye worm migration also reported associated pain, and 397 (78·6%) of 505 reported vision disturbances. After correcting for age and sex, loiasis was significantly associated with a variety of symptoms, including transient painful oedema (adjusted odds ratio 1·76 [95% CI 1·37-2·26]) and arthralgia (1·30 [1·01-1·69]). Application of attributable fractions of correlating symptoms resulted in 412·9 (95% CI 273·9-567·7) morbidity-based DALYs per 100 000 people in rural Gabon. INTERPRETATION Loiasis, with the pathognomonic sign of eye worm migration, appears to not be benign, but severely impeding to affected individuals. Furthermore, loiasis is associated with substantial morbidity, comparable to that of other neglected tropical parasitic diseases. These findings call for reconsideration of L loa as a relevant pathogen in affected populations, with a need for more concerted research and control of these infections. FUNDING Federal Ministry of Science, Research and Economy of Austria, and the European Union.
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Affiliation(s)
- Luzia Veletzky
- Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I Department of Medicine, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany; Lambaréné Medical Research Centre, Lambaréné, Gabon; Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria; Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany; German Centre for Infection Research, Tübingen, Germany
| | | | | | - Johannes Mischlinger
- Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I Department of Medicine, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Rella Zoleko Manego
- Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I Department of Medicine, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany; Lambaréné Medical Research Centre, Lambaréné, Gabon; Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany; German Centre for Infection Research, Tübingen, Germany
| | - Ghyslain Mombo-Ngoma
- Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I Department of Medicine, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany; Lambaréné Medical Research Centre, Lambaréné, Gabon; Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany; German Centre for Infection Research, Tübingen, Germany
| | - Matthew B B McCall
- Lambaréné Medical Research Centre, Lambaréné, Gabon; Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany; German Centre for Infection Research, Tübingen, Germany; Radboud University Medical Centre, Department of Medical Microbiology, Nijmegen, Netherlands
| | - Ayôla A Adegnika
- Lambaréné Medical Research Centre, Lambaréné, Gabon; Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany; German Centre for Infection Research, Tübingen, Germany
| | - Selidji T Agnandji
- Lambaréné Medical Research Centre, Lambaréné, Gabon; Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany; German Centre for Infection Research, Tübingen, Germany
| | - Wolfram G Metzger
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany; German Centre for Infection Research, Tübingen, Germany
| | | | - Heimo Lagler
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Benjamin Mordmüller
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany; German Centre for Infection Research, Tübingen, Germany
| | - Christine Budke
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Michael Ramharter
- Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I Department of Medicine, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany; Lambaréné Medical Research Centre, Lambaréné, Gabon.
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