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Coulibaly YI, Sangare M, Dolo H, Soumaoro L, Coulibaly SY, Dicko I, Diabaté AF, Diarra L, Coulibaly ME, Doumbia SS, Diallo AA, Dembele M, Koudou BG, Bockarie MJ, Kelly-Hope LA, Klion AD, Nutman TB. No evidence of lymphatic filariasis transmission in Bamako urban setting after three mass drug administration rounds. Parasitol Res 2022; 121:3243-3248. [PMID: 36066741 PMCID: PMC9556341 DOI: 10.1007/s00436-022-07648-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 08/30/2022] [Indexed: 11/25/2022]
Abstract
Lymphatic filariasis (LF) elimination activities started in Mali in 2005 in the most endemic areas and reached countrywide coverage in 2009. In 2004, the district of Bamako was endemic for LF with a prevalence of 1.5%. The current study was designed to determine LF endemicity level in the urban area of Bamako after three rounds of ivermectin and albendazole mass drug administration (MDA). A cross-sectional study was conducted in 2011 in Bamako city, consisting of human prevalence and entomological surveys. Volunteers aged 14 years and above were invited to participate and tested for evidence of Wuchereria bancrofti using night time blood thick smear microfilarial count and blood spots for LF antibodies using the SD BIOLINE Oncho/LF IgG4 Biplex rapid test (Ov16/Wb123). Mosquitoes were collected using CDC light and gravid traps and tested using molecular methods. Poolscreen software v2.0 was used to estimate vector transmission potential. Of the 899 volunteers, one (0.11%) was found to be positive for LF using the Oncho/LF IgG4 Biplex rapid test, and none was found to have Wuchereria bancrofti microfilariae. No mosquitoes were found infected among 6174 Culex spp. (85.2%), 16 Anopheles gambiae s.l. (An. gambiae s.l.) (0.2%), 26 Aedes spp. (0.4%), 858 Ceratopogonidae (11.8%) and 170 other insects not identified (2.3%) tested. Our data indicate that there was no active LF transmission in the low prevalence urban district of Bamako after three MDA rounds. These data helped the National LF programme move forward towards the elimination goal.
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Affiliation(s)
- Yaya Ibrahim Coulibaly
- Mali - International Center of Excellence in Research (ICER-Mali), University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali.,Dermatology Hospital of Bamako, Bamako, Mali
| | - Moussa Sangare
- Mali - International Center of Excellence in Research (ICER-Mali), University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali. .,Interdisciplinary School of Health Sciences
- Faculty of Health Sciences, University of Ottawa, Ottawa, ON, K1N 6N5, Canada.
| | - Housseini Dolo
- Mali - International Center of Excellence in Research (ICER-Mali), University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Lamine Soumaoro
- Mali - International Center of Excellence in Research (ICER-Mali), University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Siaka Yamoussa Coulibaly
- Mali - International Center of Excellence in Research (ICER-Mali), University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Ilo Dicko
- Mali - International Center of Excellence in Research (ICER-Mali), University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Abdoul Fatao Diabaté
- Mali - International Center of Excellence in Research (ICER-Mali), University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Lamine Diarra
- Mali - International Center of Excellence in Research (ICER-Mali), University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Michel Emmanuel Coulibaly
- Mali - International Center of Excellence in Research (ICER-Mali), University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Salif Seriba Doumbia
- Mali - International Center of Excellence in Research (ICER-Mali), University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Abdallah Amadou Diallo
- Mali - International Center of Excellence in Research (ICER-Mali), University of Sciences, Techniques and Technologies of Bamako, Bamako, Mali
| | - Massitan Dembele
- National Lymphatic Filariasis Elimination Program, Ministry of Health and Public Hygiene, Bamako, Mali
| | - Benjamin G Koudou
- Centre Suisse de Recherche Scientifiques en Côte d'Ivoire, 01 BP 1303 Abidjan 01, Abidjan, Côte d'Ivoire.,UFR Science de la Nature, Université Nangui Abrogoua, 02 BP 801 Abidjan 01, Abidjan, Côte d'Ivoire
| | | | - Louise A Kelly-Hope
- Centre for Neglected Tropical Diseases, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, UK.,Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Amy D Klion
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Thomas B Nutman
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
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Risch F, Ritter M, Hoerauf A, Hübner MP. Human filariasis-contributions of the Litomosoides sigmodontis and Acanthocheilonema viteae animal model. Parasitol Res 2021; 120:4125-4143. [PMID: 33547508 PMCID: PMC8599372 DOI: 10.1007/s00436-020-07026-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 12/20/2020] [Indexed: 12/16/2022]
Abstract
Filariae are vector-borne parasitic nematodes that are endemic worldwide, in tropical and subtropical regions. Important human filariae spp. include Onchocerca volvulus, Wuchereria bancrofti and Brugia spp., and Loa loa and Mansonella spp. causing onchocerciasis (river blindness), lymphatic filariasis (lymphedema and hydrocele), loiasis (eye worm), and mansonelliasis, respectively. It is estimated that over 1 billion individuals live in endemic regions where filarial diseases are a public health concern contributing to significant disability adjusted life years (DALYs). Thus, efforts to control and eliminate filarial diseases were already launched by the WHO in the 1970s, especially against lymphatic filariasis and onchocerciasis, and are mainly based on mass drug administration (MDA) of microfilaricidal drugs (ivermectin, diethylcarbamazine, albendazole) to filarial endemic areas accompanied with vector control strategies with the goal to reduce the transmission. With the United Nations Sustainable Development Goals (SDGs), it was decided to eliminate transmission of onchocerciasis and stop lymphatic filariasis as a public health problem by 2030. It was also requested that novel drugs and treatment strategies be developed. Mouse models provide an important platform for anti-filarial drug research in a preclinical setting. This review presents an overview about the Litomosoides sigmodontis and Acanthocheilonema viteae filarial mouse models and their role in immunological research as well as preclinical studies about novel anti-filarial drugs and treatment strategies.
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Affiliation(s)
- Frederic Risch
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
| | - Manuel Ritter
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany
- German Center for Infection Research (DZIF), partner site Bonn-Cologne, Bonn, Germany
| | - Marc P Hübner
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany.
- German Center for Infection Research (DZIF), partner site Bonn-Cologne, Bonn, Germany.
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Purusothaman DK, Shackleford L, Anderson MAE, Harvey-Samuel T, Alphey L. CRISPR/Cas-9 mediated knock-in by homology dependent repair in the West Nile Virus vector Culex quinquefasciatus Say. Sci Rep 2021; 11:14964. [PMID: 34294769 PMCID: PMC8298393 DOI: 10.1038/s41598-021-94065-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 06/28/2021] [Indexed: 11/27/2022] Open
Abstract
Culex quinquefasciatus Say is a mosquito distributed in both tropical and subtropical regions of the world. It is a night-active, opportunistic blood-feeder and vectors many animal and human diseases, including West Nile Virus and avian malaria. Current vector control methods (e.g. physical/chemical) are increasingly ineffective; use of insecticides also imposes hazards to both human and ecosystem health. Advances in genome editing have allowed the development of genetic insect control methods, which are species-specific and, theoretically, highly effective. CRISPR/Cas9 is a bacteria-derived programmable gene editing tool that is functional in a range of species. We describe the first successful germline gene knock-in by homology dependent repair in C. quinquefasciatus. Using CRISPR/Cas9, we integrated an sgRNA expression cassette and marker gene encoding a fluorescent protein fluorophore (Hr5/IE1-DsRed, Cq7SK-sgRNA) into the kynurenine 3-monooxygenase (kmo) gene. We achieved a minimum transformation rate of 2.8%, similar to rates in other mosquito species. Precise knock-in at the intended locus was confirmed. Insertion homozygotes displayed a white eye phenotype in early-mid larvae and a recessive lethal phenotype by pupation. This work provides an efficient method for engineering C. quinquefasciatus, providing a new tool for developing genetic control tools for this vector.
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Affiliation(s)
| | - Lewis Shackleford
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, Surrey, UK
| | - Michelle A E Anderson
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, Surrey, UK
| | - Tim Harvey-Samuel
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, Surrey, UK
| | - Luke Alphey
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, GU24 0NF, Surrey, UK.
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Modi A, Vaishnav KG, Kothiya K, Alexander N. Lymphatic filariasis elimination endgame in an urban Indian setting: the roles of surveillance and residual microfilaremia after mass drug administration. Infect Dis Poverty 2021; 10:73. [PMID: 34006319 PMCID: PMC8130313 DOI: 10.1186/s40249-021-00856-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 05/04/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To secure the gains of lymphatic filariasis (LF) elimination programs, attention is needed to the 'residual microfilaremia phase', in which high-risk populations may be crucial. The present study documents the impact of mass drug administration (MDA) in the urban Indian setting of Surat City, with high rates of in-migration. METHODS Epidemiological assessment included National Filaria Control Program (NFCP) and World Health Organization recommended routine and pre-MDA microfilaremia surveys respectively. Routine filaria surveys were conducted around the year in approximately 2000-4000 people per month, while pre-MDA surveys were carried out annually among approximately 4000 people from four fixed and four random sites. In 2016, Transmission Assessment Survey (TAS) was done in primary school children. The outcomes were microfilaremia (Mf) and antigen prevalence; more specifically, microfilaremia according to place of birth, in pre-MDA and routine night blood smears (NBS) collected from 2008 to 2015. Prevalence ratios and confidence intervals were calculated. RESULTS A total of 25 480 pre-MDA and 306 198 routine NBS were examined during the study. In 2008, the Mf prevalence in the routine survey was 63/18 814 (0.33%), declining to 23/39 717 (0.06%) in 2016. Pre-MDA surveys showed a similar decrease from 47/4184 (1.1%) in 2008 to 12/4042 (0.3%) in 2015. In those born outside Surat, microfilaremia decreased below transmission thresholds, but remained more than treble that of the remainder of the population, in both the pre-MDA surveys [prevalence ratio: 3.17, 95% confidence interval (CI): 1.15-8.72], and the routine surveys (3.31, 95% CI: 1.47-7.48). Though the TAS results indicated that MDA endpoints had been reached, sub-group analysis identified that 90% of antigenemic children were from families of high-risk groups. CONCLUSIONS Extensive long-term epidemiological monitoring suggests that all the urban population, including high-risk groups, have benefitted from the ELF program. To prevent re-establishment of infection in large urban areas with unsanitary conditions conducive to filarial vector breeding, there is need to identify residual microfilaremia by customized surveys in addition to pre-MDA monitoring and TAS. The present findings can be used to develop strategies to prioritize screening, surveillance and plan treatment of high-risk groups after achieving MDA endpoints.
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Affiliation(s)
- Anjali Modi
- Department of Community Medicine, Government Medical College, Surat, Gujarat, India
| | - Keshav G Vaishnav
- Vector Borne Disease Control (VBDC) Department, Surat Municipal Corporation, Surat, Gujarat, India
| | - Kailash Kothiya
- Vector Borne Disease Control (VBDC) Department, Surat Municipal Corporation, Surat, Gujarat, India
| | - Neal Alexander
- MRC International Statistics and Epidemiology Group, London School of Hygiene and Tropical Medicine, London, UK.
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Lenk EJ, Moungui HC, Boussinesq M, Kamgno J, Nana-Djeunga HC, Fitzpatrick C, Peultier ACMM, Klion AD, Fletcher DA, Nutman TB, Pion SD, Niamsi-Emalio Y, Redekop WK, Severens JL, Stolk WA. A Test-and-Not-Treat Strategy for Onchocerciasis Elimination in Loa loa-coendemic Areas: Cost Analysis of a Pilot in the Soa Health District, Cameroon. Clin Infect Dis 2021; 70:1628-1635. [PMID: 31165855 PMCID: PMC7146010 DOI: 10.1093/cid/ciz461] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 06/03/2019] [Indexed: 11/24/2022] Open
Abstract
Background Severe adverse events after treatment with ivermectin in individuals with high levels of Loa loa microfilariae in the blood preclude onchocerciasis elimination through community-directed treatment with ivermectin (CDTI) in Central Africa. We measured the cost of a community-based pilot using a test-and-not-treat (TaNT) strategy in the Soa health district in Cameroon. Methods Based on actual expenditures, we empirically estimated the economic cost of the Soa TaNT campaign, including financial costs and opportunity costs that will likely be borne by control programs and stakeholders in the future. In addition to the empirical analyses, we estimated base-case, less intensive, and more intensive resource use scenarios to explore how costs might differ if TaNT were implemented programmatically. Results The total costs of US$283 938 divided by total population, people tested, and people treated with 42% coverage were US$4.0, US$9.2, and US$9.5, respectively. In programmatic implementation, these costs (base-case estimates with less and more intensive scenarios) could be US$2.2 ($1.9–$3.6), US$5.2 ($4.5–$8.3), and US$5.4 ($4.6–$8.6), respectively. Conclusions TaNT clearly provides a safe strategy for large-scale ivermectin treatment and overcomes a major obstacle to the elimination of onchocerciasis in areas coendemic for Loa loa. Although it is more expensive than standard CDTI, costs vary depending on the setting, the implementation choices made by the institutions involved, and the community participation rate. Research on the required duration of TaNT is needed to improve the affordability assessment, and more experience is needed to understand how to implement TaNT optimally.
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Affiliation(s)
- Edeltraud J Lenk
- Erasmus School of Health Policy and Management, Erasmus University Rotterdam.,Department of Public Health, Erasmus Medical Center, University Medical Center Rotterdam, The Netherlands
| | - Henri C Moungui
- Centre for Research on Filariasis and Other Tropical Diseases, Yaounde, Cameroon
| | - Michel Boussinesq
- Unité Mixte Internationale, TransVIHMI, Institut de Recherche pour le Développement, University of Montpellier, France
| | - Joseph Kamgno
- Centre for Research on Filariasis and Other Tropical Diseases, Yaounde, Cameroon
| | | | | | | | - Amy D Klion
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | | | - Thomas B Nutman
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Sébastien D Pion
- Unité Mixte Internationale, TransVIHMI, Institut de Recherche pour le Développement, University of Montpellier, France
| | | | - William K Redekop
- Erasmus School of Health Policy and Management, Erasmus University Rotterdam
| | - Johan L Severens
- Erasmus School of Health Policy and Management, Erasmus University Rotterdam
| | - Wilma A Stolk
- Department of Public Health, Erasmus Medical Center, University Medical Center Rotterdam, The Netherlands
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Antischistosomal, antionchocercal and antitrypanosomal potentials of some Ghanaian traditional medicines and their constituents. PLoS Negl Trop Dis 2020; 14:e0008919. [PMID: 33382717 PMCID: PMC7810346 DOI: 10.1371/journal.pntd.0008919] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 10/26/2020] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Ghana is endemic for some neglected tropical diseases (NTDs) including schistosomiasis, onchocerciasis and lymphatic filariasis. The major intervention for these diseases is mass drug administration of a few repeatedly recycled drugs which is a cause for major concern due to reduced efficacy of the drugs and the emergence of drug resistance. Evidently, new treatments are needed urgently. Medicinal plants, on the other hand, have a reputable history as important sources of potent therapeutic agents in the treatment of various diseases among African populations, Ghana inclusively, and provide very useful starting points for the discovery of much-needed new or alternative drugs. METHODOLOGY/PRINCIPAL FINDINGS In this study, extracts of fifteen traditional medicines used for treating various NTDs in local communities were screened in vitro for efficacy against schistosomiasis, onchocerciasis and African trypanosomiasis. Two extracts, NTD-B4-DCM and NTD-B7-DCM, prepared from traditional medicines used to treat schistosomiasis, displayed the highest activity (IC50 = 30.5 μg/mL and 30.8 μg/mL, respectively) against Schistosoma mansoni adult worms. NTD-B2-DCM, also obtained from an antischistosomal remedy, was the most active against female and male adult Onchocera ochengi worms (IC50 = 76.2 μg/mL and 76.7 μg/mL, respectively). Antitrypanosomal assay of the extracts against Trypanosoma brucei brucei gave the most promising results (IC50 = 5.63 μg/mL to 18.71 μg/mL). Incidentally, NTD-B4-DCM and NTD-B2-DCM, also exhibited the greatest antitrypanosomal activities (IC50 = 5.63 μg/mL and 7.12 μg/mL, respectively). Following the favourable outcome of the antitrypanosomal screening, this assay was selected for bioactivity-guided fractionation. NTD-B4-DCM, the most active extract, was fractionated and subsequent isolation of bioactive constituents led to an eupatoriochromene-rich oil (42.6%) which was 1.3-fold (IC50 <0.0977 μg/mL) more active than the standard antitrypanosomal drug, diminazene aceturate (IC50 = 0.13 μg/mL). CONCLUSION/SIGNIFICANCE These findings justify the use of traditional medicines and demonstrate their prospects towards NTDs drug discovery.
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Deribe K, Bakajika DK, Zoure HMG, Gyapong JO, Molyneux DH, Rebollo MP. African regional progress and status of the programme to eliminate lymphatic filariasis: 2000-2020. Int Health 2020; 13:S22-S27. [PMID: 33349875 PMCID: PMC7753167 DOI: 10.1093/inthealth/ihaa058] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/10/2020] [Accepted: 08/12/2020] [Indexed: 01/23/2023] Open
Abstract
To eliminate lymphatic filariasis (LF) by 2020, the World Health Organization (WHO) has launched a campaign against the disease. Since the launch in 2000, significant progress has been made to achieve this ambitious goal. In this article we review the progress and status of the LF programme in Africa through the WHO neglected tropical diseases preventive chemotherapy databank, the Expanded Special Project for Elimination of Neglected Tropical Diseases (ESPEN) portal and other publications. In the African Region there are 35 countries endemic for LF. The Gambia was reclassified as not requiring preventive chemotherapy in 2015, while Togo and Malawi eliminated LF as a public health problem in 2017 and 2020, respectively. Cameroon discontinued mass drug administration (MDA) and transitioned to post-MDA surveillance to validate elimination. The trajectory of coverage continues to accelerate; treatment coverage increased from 0.1% in 2000 to 62.1% in 2018. Geographical coverage has also significantly increased, from 62.7% in 2015 to 78.5% in 2018. In 2019, 23 of 31 countries requiring MDA achieved 100% geographic coverage. Although much remains to be done, morbidity management and disability prevention services have steadily increased in recent years. Vector control interventions conducted by other programmes, particularly malaria vector control, have had a profound effect in stopping transmission in some endemic countries in the region. In conclusion, significant progress has been made in the LF programme in the region while we identify the key remaining challenges in achieving an Africa free of LF.
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Affiliation(s)
- Kebede Deribe
- Expanded Special Project for Elimination of NTDs, World Health Organization Regional Office for Africa, Cité du Djoué, P.O. Box 06 Brazzaville, Republic of Congo
- Brighton and Sussex Centre for Global Health Research, Department of Global Health and Infection, Brighton and Sussex Medical School, Brighton, BN1 9PX, UK
| | - Didier K Bakajika
- Expanded Special Project for Elimination of NTDs, World Health Organization Regional Office for Africa, Cité du Djoué, P.O. Box 06 Brazzaville, Republic of Congo
| | - Honorat Marie-Gustave Zoure
- Expanded Special Project for Elimination of NTDs, World Health Organization Regional Office for Africa, Cité du Djoué, P.O. Box 06 Brazzaville, Republic of Congo
| | - John O Gyapong
- University of Health and Allied Sciences, PMB 31, Ho, Volta Region, Ghana
| | - David H Molyneux
- Liverpool School of Tropical Medicine, Pembroke Pl, Liverpool L3 5QA, UK
| | - Maria P Rebollo
- Expanded Special Project for Elimination of NTDs, World Health Organization Regional Office for Africa, Cité du Djoué, P.O. Box 06 Brazzaville, Republic of Congo
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Wodnik BK, Louis DH, Joseph M, Wilkers LT, Landskroener SD, Desir L, Lemoine JF, Lavery JV. The roles of stakeholder experience and organizational learning in declining mass drug administration coverage for lymphatic filariasis in Port-au-Prince, Haiti: A case study. PLoS Negl Trop Dis 2020; 14:e0008318. [PMID: 32469860 PMCID: PMC7259509 DOI: 10.1371/journal.pntd.0008318] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 04/23/2020] [Indexed: 11/22/2022] Open
Abstract
The World Health Organization (WHO) defines an effective round of mass drug administration (MDA) for lymphatic filariasis (LF) as one that reaches at least 65% of the target population. In its first round of MDA in 2011–2012, the National Program to Eliminate LF in Haiti achieved a 79% epidemiological coverage in urban Port-au-Prince. In 2013, coverage dropped below the WHO threshold and has declined year-over-year to a low of 41% in 2017. We conducted a retrospective qualitative case study to identify key factors behind the decline in coverage in Port-au-Prince and ways to address them. Our findings suggest that the main contributors to the decline in MDA coverage appear to be the absence of effective documentation of practices, reporting, analysis, and program quality improvement—i.e., learning mechanisms—within the program’s MDA design and implementation strategy. In addition to their contribution to the program’s failure to meet its coverage targets, these deficits have resulted in a high cost for the MDA campaign in both lost momentum and depleted morale. Through a proposed operating logic model, we explore how the pathway from program inputs to outcomes is influenced by a wide array of mediating factors, which shape potential participants’ experience of MDA and, in turn, influence their reasoning and decisions to take, or not take, the pills. Our model suggests that the decisions and behavior of individuals are a reflection of their overall experience of the program itself, mediated through a host of contextual factors, and not simply the expression of a fixed choice or preference. This holistic approach offers a novel and potentially valuable framing for the planning and evaluation of MDA strategies for LF and other diseases, and may be applicable in a variety of global health programs. In order to eliminate lymphatic filariasis from a region, the World Health Organization recommends a strategy of preventative drugs delivered annually to the population. At least 65% of the population must participate for four to six consecutive years for this approach to be effective. In urban Port-au-Prince, Haiti, the number of people taking the drugs has been declining progressively below the 65% benchmark since 2012. We used a qualitative case study to identify key factors behind the decline in coverage in Port-au-Prince and ways to address them. We found that the lymphatic filariasis elimination program lacks the necessary design and program infrastructure to ensure reliable learning about problems faced by pill distribution teams on the ground, and the improvisations they introduced to address these challenges. The inability to incorporate these lessons into program improvements and refinements resulted in under-performance and contributed to the decline in coverage. Furthermore, the way that people experience the program is strongly influenced by a host of contextual factors, which shape potential participants’ experience of the program and, in turn, influence their reasoning and decisions to take, or not take, the pills.
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Affiliation(s)
- Breanna K. Wodnik
- Hubert Department of Global Health, Rollins School of Public Health, and Center for Ethics, Emory University, Atlanta, Georgia, United States of America
- * E-mail:
| | - Didié Hérold Louis
- National Ambulance Center, Ministry of Public Health and Population, Port-au-Prince, Haiti
| | | | - Lee T. Wilkers
- Hubert Department of Global Health, Rollins School of Public Health, and Center for Ethics, Emory University, Atlanta, Georgia, United States of America
| | - Susan D. Landskroener
- Hubert Department of Global Health, Rollins School of Public Health, and Center for Ethics, Emory University, Atlanta, Georgia, United States of America
| | - Luccene Desir
- Hispaniola Health Initiative, The Carter Center, Port-au-Prince, Haiti
| | - Jean Frantz Lemoine
- National Programs for the Elimination of Malaria and Lymphatic Filariasis, Ministry of Public Health and Population, Port-au-Prince, Haiti
| | - James V. Lavery
- Hubert Department of Global Health, Rollins School of Public Health, and Center for Ethics, Emory University, Atlanta, Georgia, United States of America
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Yokoly FN, Zahouli JBZ, Méite A, Opoku M, Kouassi BL, de Souza DK, Bockarie M, Koudou BG. Low transmission of Wuchereria bancrofti in cross-border districts of Côte d'Ivoire: A great step towards lymphatic filariasis elimination in West Africa. PLoS One 2020; 15:e0231541. [PMID: 32282840 PMCID: PMC7153895 DOI: 10.1371/journal.pone.0231541] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 03/25/2020] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Lymphatic filariasis (LF) is widely endemic in Côte d'Ivoire, and elimination as public health problem (EPHP) is based on annual mass drug administration (MDA) using ivermectin and albendazole. To guide EPHP efforts, we evaluated Wuchereria bancrofti infection indices among humans, and mosquito vectors after four rounds of MDA in four cross-border health districts of Côte d'Ivoire. METHODOLOGY We monitored people and mosquitoes for W. bancrofti infections in the cross-border health districts of Aboisso, Bloléquin, Odienné and Ouangolodougou, Côte d'Ivoire. W. bancrofti circulating filarial antigen (CFA) was identified using filariasis test strips, and antigen-positive individuals were screened for microfilaremia. Moreover, filarial mosquito vectors were sampled using window exit traps and pyrethrum sprays, and identified morphologically at species level. Anopheles gambiae s.l. and Culex quinquefasciatus females were analyzed for W. bancrofti infection using polymerase chain reaction (PCR) technique. PRINCIPAL FINDINGS Overall, we found a substantial decline in W. bancrofti infection indices after four rounds of MDA compared to pre-MDA baseline data. CFA prevalence fell from 3.38-5.50% during pre-MDA to 0.00-1.53% after MDA interventions. No subjects had detectable levels of CFA in Ouangolodougou. Moreover, post-MDA CFA prevalence was very low, and below the 1% elimination threshold in Aboisso (0.19%) and Odienné (0.49%). Conversely, CFA prevalence remained above 1% in Bloléquin (1.53%). W. bancrofti microfilariae (Mf) were not found in Aboisso, Bloléquin, and Ouangolodougou, except for Odienné with low prevalence (0.16%; n = 613) and microfilaremia of 32.0 Mf/mL. No An. gambiae s.l. and Cx. quinquefasciatus pools were infected with W. bancrofti in Bloléquin and Ouangolodougou, while they exhibited low infection rates in Aboisso (1% and 0.07%), and Odienné (0.08% and 0.08%), respectively. CONCLUSIONS In cross-border areas of Côte d'Ivoire, LF infection indices in humans and mosquito vectors substantially declined after four rounds of MDA. CFA prevalence fell under the World Health Organization (WHO)-established threshold (1%) in Aboisso, Ouangolodougou and Odienné. Moreover, W. bancrofti prevalence in mosquitoes was lower than WHO-established threshold (2%) in all areas. This might suggest the interruption of W. bancrofti transmission, and possible MDA cessation. However, a formal transmission assessment survey (TAS) and molecular xenomonitoring in mosquito vectors should be implemented before eventual MDA cessation. However, MDA should pursue in Bloléquin where W. bancrofti infection prevalence remained above 1%. Our results provided important ramifications for LF control efforts towards EPHP in Côte d'Ivoire.
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Affiliation(s)
- Firmain N. Yokoly
- Unité de Formation et de Recherche Sciences de la Nature, Université Nangui Abrogoua, Abidjan, Côte d’Ivoire
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Julien B. Z. Zahouli
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
- Centre d’Entomologie Médicale et Vétérinaire, Université Alassane Ouattara, Bouaké, Côte d’Ivoire
| | - Aboulaye Méite
- Programme National de Lutte contre les Maladies Tropicales Négligées à Chimiothérapie Préventive, Ministère de la Santé, Abidjan, Côte d’Ivoire
| | - Millicent Opoku
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
- European & Developing Countries Clinical Trials Partnership, Cape Town, South Africa
| | - Bernard L. Kouassi
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Dziedzom K. de Souza
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - Moses Bockarie
- European & Developing Countries Clinical Trials Partnership, Cape Town, South Africa
- Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Benjamin G. Koudou
- Unité de Formation et de Recherche Sciences de la Nature, Université Nangui Abrogoua, Abidjan, Côte d’Ivoire
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
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10
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Li M, Li T, Liu N, Raban RR, Wang X, Akbari OS. Methods for the generation of heritable germline mutations in the disease vector Culex quinquefasciatus using clustered regularly interspaced short palindrome repeats-associated protein 9. INSECT MOLECULAR BIOLOGY 2020; 29:214-220. [PMID: 31693260 DOI: 10.1111/imb.12626] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 08/21/2019] [Accepted: 10/31/2019] [Indexed: 06/10/2023]
Abstract
Culex quinquefasciatus is a vector of many diseases that adversely impact human and animal health; however, compared to other mosquito vectors limited genome engineering technologies have been characterized for this vector. Clustered regularly interspaced short palindrome repeats-associated protein 9 (CRISPR-Cas9) based technologies are a powerful tool for genome engineering and functional genetics and consequently have transformed genetic studies in many organisms. Our objective was to improve upon the limited technologies available for genome editing in C. quinquefasciatus to create a reproducible and straightforward method for CRISPR-Cas9-targeted mutagenesis in this vector. Here we describe methods to achieve high embryo survival and mutagenesis rates and we provide details on the injection supplies and procedures, embryo handling and guide RNA (gRNA) target designs. Through these efforts, we achieved embryo survival rates and germline mutagenesis rates that greatly exceed previously reported rates in this vector. This work is also the first to characterize the white gene marker in this species, which is a valuable phenotypic marker for future transgenesis or mutagenesis of this vector. Overall, these tools provide the framework for future functional genetic studies in this important disease vector and may support the development of future gene drive and genetic technologies that can be used to control this vector.
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Affiliation(s)
- M Li
- Section of Cell and Developmental Biology, University of California, San Diego, CA, USA
| | - T Li
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - N Liu
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - R R Raban
- Section of Cell and Developmental Biology, University of California, San Diego, CA, USA
| | - X Wang
- College of Agriculture, Sichuan Agricultural University, Chengdu, China
| | - O S Akbari
- Section of Cell and Developmental Biology, University of California, San Diego, CA, USA
- Tata Institute for Genetics and Society, University of California, CA, USA
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11
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Nditanchou R, Dixon R, Pam D, Isiyaku S, Nwosu C, Sanda S, Schmidt E, Koudou B, Molyneux D. Testing a method of sampling for entomological determination of transmission of Wuchereria bancrofti to inform lymphatic filariasis treatment strategy in urban settings. Parasit Vectors 2020; 13:37. [PMID: 31973747 PMCID: PMC6979341 DOI: 10.1186/s13071-020-3905-x] [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: 06/03/2019] [Accepted: 01/11/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND There is on-going debate about scale-up of lymphatic filariasis treatment to include urban areas. Determining Wuchereria bancrofti transmission is more complex in these settings and entomological methodologies suggested as a solution as yet have no clear guidance. METHODS The study was conducted in six communities in Minna and Kaduna cities in Nigeria selected based on pre-disposing risk factors for mosquitoes and Transmission Assessment Survey (TAS) results in 2016 indicating need for treatment (> 1% prevalence). In each community, 4 gravid traps (GT), 15 exit traps (ET) and 21 pyrethrum spray catches (PSC) were used for 5 months targeting a sample size of 10,000 mosquitoes inclusive of at least 1500 Anopheles. Community researchers were selected and trained to facilitate community acceptability and carry out collection. We have evaluated the mosquito sampling and trapping methodology in terms of success at reaching targeted sample size, cost effectiveness, and applicability. RESULTS Community researchers were influential in enabling high acceptability of the methods of collection and were able to conduct collections independently. Overall, 12.1% of trapping events (one trapping event corresponds to one visit to one trap to collect mosquitoes) were affected by householder actions, weather conditions or trap malfunction leading to lower than optimal catches. Exit traps were the most cost-effective way to catch Anopheles (6.4 USD per trapping event and 12.8 USD per Anopheles caught). Sample size of 10,000 mosquitoes overall in each city was met though Anopheles catch was insufficient in one city. However, sample size was met only in one implementation unit out of the four. CONCLUSIONS Methods need adapting to maximise Anopheles catch: we propose planning 250 gravid trap and 3724 exit trap trapping events in similar settings in West African urban areas where Culex is dominant, not using pyrethrum spray catches, and weighting trapping events later in the rainy season. Planning should increase involvement of community researchers, incorporate null catches and participants' actions to predict catches. Importantly, evaluation units should be analogous with implementation units, the units at which treatment decisions will be made in the urban context.
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Affiliation(s)
- Rogers Nditanchou
- Policy & Programme Strategy, Sightsavers, Cameroon Country Office, BP 4484, Bastos, Yaoundé, Cameroon.
| | - Ruth Dixon
- Policy & Programme Strategy, Sightsavers, 35 Perrymount Road, Haywards Heath, West Sussex, RH16 3BW, UK
| | - Dung Pam
- Department of Zoology, University of Jos, Bauchi Road, 2084, Jos, Plateau State, Nigeria
| | - Sunday Isiyaku
- Sightsavers, Nigeria Country Office, 1 Golf Course Road, Kaduna, Kaduna State, Nigeria
| | - Christian Nwosu
- Sightsavers, Nigeria Country Office, 1 Golf Course Road, Kaduna, Kaduna State, Nigeria
| | - Safiya Sanda
- Sightsavers, Nigeria Country Office, 1 Golf Course Road, Kaduna, Kaduna State, Nigeria
| | - Elena Schmidt
- Policy & Programme Strategy, Sightsavers, 35 Perrymount Road, Haywards Heath, West Sussex, RH16 3BW, UK
| | - Benjamin Koudou
- Liverpool School of Tropical Medicine, Pembroke Pl, Liverpool, L3 5QA, UK
| | - David Molyneux
- Liverpool School of Tropical Medicine, Pembroke Pl, Liverpool, L3 5QA, UK
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12
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Suresh M, Jeevanandam J, Chan YS, Danquah MK, Kalaiarasi JMV. Opportunities for Metal Oxide Nanoparticles as a Potential Mosquitocide. BIONANOSCIENCE 2019. [DOI: 10.1007/s12668-019-00703-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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13
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Srividya A, Subramanian S, Jambulingam P, Vijayakumar B, Dinesh Raja J. Mapping and monitoring for a lymphatic filariasis elimination program: a systematic review. Res Rep Trop Med 2019; 10:43-90. [PMID: 31239804 PMCID: PMC6554002 DOI: 10.2147/rrtm.s134186] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 04/02/2019] [Indexed: 11/23/2022] Open
Abstract
Lymphatic filariasis (LF) is targeted for elimination by the year 2020. The Global Programme for Elimination of LF (GPELF) aims to achieve elimination by interrupting transmission through annual mass drug administration (MDA) of albendazole with ivermectin or diethylcarbamazine. The program has successfully eliminated the disease in 11 of the 72 endemic countries, putting in enormous efforts on systematic planning and implementation of the strategy. Mapping areas endemic for LF is a pre-requisite for implementing MDA, monitoring and evaluation are the components of programme implementation. This review was undertaken to assess how the mapping and impact monitoring activities have evolved to become more robust over the years and steered the LF elimination programme towards its goal. The findings showed that the WHO recommended mapping strategy aided 17 countries to delimit, plan and implement MDA in only those areas endemic for LF thereby saving resources. Availability of serological tools for detecting infection in humans (antigen/antibody assays) and molecular xenomonitoring (MX) in vectors greatly facilitated programme monitoring and evaluation in endemic countries. Results of this review are discussed on how these existing mapping and monitoring procedures can be used for re-mapping of unsurveyed and uncertain areas to ensure there is no resurgence during post-MDA surveillance. Further the appropriateness of the tests (Microfilaria (Mf)/antigenemia (Ag)/antibody(Ab) surveys in humans or MX of vectors for infection) used currently for post-MDA surveillance and their role in the development of a monitoring and evaluation strategy for the recently WHO recommended triple drug regimen in MDA for accelerated LF elimination are discussed.
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Affiliation(s)
- Adinarayanan Srividya
- Division of Epidemiology, Biostatistics and Operations Research, ICMR - Vector Control Research Centre, Puducherry, India
| | - Swaminathan Subramanian
- Division of Epidemiology, Biostatistics and Operations Research, ICMR - Vector Control Research Centre, Puducherry, India
| | - Purushothaman Jambulingam
- Division of Epidemiology, Biostatistics and Operations Research, ICMR - Vector Control Research Centre, Puducherry, India
| | - Balakrishnan Vijayakumar
- Division of Epidemiology, Biostatistics and Operations Research, ICMR - Vector Control Research Centre, Puducherry, India
| | - Jeyapal Dinesh Raja
- Division of Epidemiology, Biostatistics and Operations Research, ICMR - Vector Control Research Centre, Puducherry, India
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14
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Gonzales M, Baker MC, Celestino A, Santa Morillo D, Chambliss A, Adams S, Gyapong M, Kyelem D. How lymphatic filariasis was eliminated from an urban poor setting in Santo Domingo, Dominican Republic. Int Health 2019; 11:108-118. [PMID: 30285112 PMCID: PMC6398592 DOI: 10.1093/inthealth/ihy059] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 07/11/2018] [Accepted: 09/18/2018] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND While progress has been made in the elimination of lymphatic filariasis, challenges that call for innovative approaches remain. Program challenges are increasingly observed in 'hard-to-reach' populations: urban dwellers, migrant populations, those living in insecurity, children who are out of school and areas where infrastructure is weak and education levels are low. 'Business-as-usual' approaches are unlikely to work. Tailored solutions are needed if elimination goals are to be reached. This article focuses on mass drug administrations (MDAs) in urban settings. METHODS We selected the urban poor area of Santo Domingo, Dominican Republic. With three rounds of MDA and with good coverage, elimination was achieved. We wanted to understand contributing factors to achieving good coverage. A qualitative study analyzed context, barriers and facilitators using a predefined framework based on review of the literature. RESULTS Results show that barriers commonly reported in urban settings were present (population density, lack of organization in household layout, population mobility, violence, shortage of human resources and challenges in monitoring treatment coverage). Tactics used included strong visibility in the community leading to high levels of awareness, the use of laminated photo sheets during house-to-house visits and a 1:4 supervision strategy. The importance of working through community leadership structures and building relationships with the community was evident. DISCUSSION The approach developed here has applications for large-scale treatment programs for lymphatic filariasis and other diseases in urban settings.
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Affiliation(s)
| | - Margaret C Baker
- RTI International, 701 13th Street NW, Suite 750, Washington, DC, USA
| | - Ana Celestino
- Universidad Autónoma de Santo Domingo, Ciudad Universitaria, SD, Dominican Republic
| | | | - Amy Chambliss
- Georgetown University, Department of Global Health, 3700 O St, NW, Washington, DC, USA
| | - Sarah Adams
- George Mason University, 4400 University Drive, Fairfax, VA, USA
| | | | - Dominique Kyelem
- The Taskforce for Global Health, 330 West Ponce de Leon Ave, Decatur, Georgia, USA
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15
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Pi-Bansa S, Osei JHN, Frempong KK, Elhassan E, Akuoko OK, Agyemang D, Ahorlu C, Appawu MA, Koudou BG, Wilson MD, de Souza DK, Dadzie SK, Utzinger J, Boakye DA. Potential factors influencing lymphatic filariasis transmission in "hotspot" and "control" areas in Ghana: the importance of vectors. Infect Dis Poverty 2019; 8:9. [PMID: 30717788 PMCID: PMC6362603 DOI: 10.1186/s40249-019-0520-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 01/17/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mass drug administration (MDA) programmes for the control of lymphatic filariasis in Ghana, have been ongoing in some endemic districts for 16 years. The current study aimed to assess factors that govern the success of MDA programmes for breaking transmission of lymphatic filariasis in Ghana. METHODS The study was undertaken in two "hotspot" districts (Ahanta West and Kassena Nankana West) and two control districts (Mpohor and Bongo) in Ghana. Mosquitoes were collected and identified using morphological and molecular tools. A proportion of the cibarial armatures of each species was examined. Dissections were performed on Anopheles gambiae for filarial worm detection. A questionnaire was administered to obtain information on MDA compliance and vector control activities. Data were compared between districts to determine factors that might explain persistent transmission of lymphatic filariasis. RESULTS High numbers of mosquitoes were sampled in Ahanta West district compared to Mpohor district (F = 16.09, P = 0.002). There was no significant difference between the numbers of mosquitoes collected in Kassena Nankana West and Bongo districts (F = 2.16, P = 0.185). Mansonia species were predominant in Ahanta West district. An. coluzzii mosquitoes were prevalent in all districts. An. melas with infected and infective filarial worms was found only in Ahanta West district. No differences were found in cibarial teeth numbers and shape for mosquito species in the surveyed districts. Reported MDA coverage was high in all districts. The average use of bednet and indoor residual spraying was 82.4 and 66.2%, respectively. There was high compliance in the five preceding MDA rounds in Ahanta West and Kassena Nankana West districts, both considered hotspots of lymphatic filariasis transmission. CONCLUSIONS The study on persistent transmission of lymphatic filariasis in the two areas in Ghana present information that shows the importance of local understanding of factors affecting control and elimination of lymphatic filariasis. Unlike Kassena Nankana West district where transmission dynamics could be explained by initial infection prevalence and low vector densities, ongoing lymphatic filariasis transmission in Ahanta West district might be explained by high biting rates of An. gambiae and initial infection prevalence, coupled with high densities of An. melas and Mansonia vector species that have low or no teeth and exhibiting limitation.
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Affiliation(s)
- Sellase Pi-Bansa
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland. .,Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana.
| | - Joseph Harold Nyarko Osei
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana.,Department of Animal Biology and Conservation Science, University of Ghana, Legon, Ghana
| | - Kwadwo Kyeremeh Frempong
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana.,Department of Animal Biology and Conservation Science, University of Ghana, Legon, Ghana
| | | | - Osei Kweku Akuoko
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana.,African Regional Postgraduate Programme in Insect Science, University of Ghana, Legon, Ghana
| | | | - Collins Ahorlu
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Maxwell Alexander Appawu
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Benjamin Guibehi Koudou
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK.,Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire
| | - Michael David Wilson
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Dziedzom Komi de Souza
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Samuel Kweku Dadzie
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Daniel Adjei Boakye
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
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16
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Hotez PJ, Biritwum NK, Fenwick A, Molyneux DH, Sachs JD. Ghana: Accelerating neglected tropical disease control in a setting of economic development. PLoS Negl Trop Dis 2019; 13:e0007005. [PMID: 30653493 PMCID: PMC6336233 DOI: 10.1371/journal.pntd.0007005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Peter J. Hotez
- Texas Children’s Hospital Center for Vaccine Development, Departments of Pediatrics and Molecular Virology and Microbiology, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America
- Center for Medical Ethics and Health Policy, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Biology, Baylor University, Waco, Texas, United States of America
- James A Baker III Institute of Public Policy, Rice University, Houston, Texas, United States of America
- Scowcroft Institute of International Affairs, Bush School of Government and Public Policy, Texas A&M University, College Station, Texas, United States of America
- * E-mail: (PJH); (N-KB); (AF); (DHM); (JDS)
| | - Nana-Kwadwo Biritwum
- Bill & Melinda Gates Foundation, Seattle, Washington, United States of America
- Ghana Health Service, Accra, Ghana
- * E-mail: (PJH); (N-KB); (AF); (DHM); (JDS)
| | - Alan Fenwick
- Department of Infectious Disease Epidemiology, Imperial College London, United Kingdom
- * E-mail: (PJH); (N-KB); (AF); (DHM); (JDS)
| | - David H. Molyneux
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- * E-mail: (PJH); (N-KB); (AF); (DHM); (JDS)
| | - Jeffrey D. Sachs
- Center for Sustainable Development, Earth Institute, Columbia University, New York, New York, United States of America
- * E-mail: (PJH); (N-KB); (AF); (DHM); (JDS)
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17
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Wu Z, Wang L, Li J, Wang L, Wu Z, Sun X. Extracellular Vesicle-Mediated Communication Within Host-Parasite Interactions. Front Immunol 2019; 9:3066. [PMID: 30697211 PMCID: PMC6340962 DOI: 10.3389/fimmu.2018.03066] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 12/11/2018] [Indexed: 12/21/2022] Open
Abstract
Extracellular vesicles (EVs) are small membrane-surrounded structures released by different kinds of cells (normal, diseased, and transformed cells) in vivo and in vitro that contain large amounts of important substances (such as lipids, proteins, metabolites, DNA, RNA, and non-coding RNA (ncRNA), including miRNA, lncRNA, tRNA, rRNA, snoRNA, and scaRNA) in an evolutionarily conserved manner. EVs, including exosomes, play a role in the transmission of information, and substances between cells that is increasingly being recognized as important. In some infectious diseases such as parasitic diseases, EVs have emerged as a ubiquitous mechanism for mediating communication during host-parasite interactions. EVs can enable multiple modes to transfer virulence factors and effector molecules from parasites to hosts, thereby regulating host gene expression, and immune responses and, consequently, mediating the pathogenic process, which has made us rethink our understanding of the host-parasite interface. Thus, here, we review the present findings regarding EVs (especially exosomes) and recognize the role of EVs in host-parasite interactions. We hope that a better understanding of the mechanisms of parasite-derived EVs may provide new insights for further diagnostic biomarker, vaccine, and therapeutic development.
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Affiliation(s)
- Zhenyu Wu
- Department of Parasitology of Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Disease Control (SYSU), Ministry of Education, Guangzhou, China.,Provincial Engineering Technology Research Center for Biological Vector Control, Guangzhou, China
| | - Lingling Wang
- Department of Parasitology of Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Disease Control (SYSU), Ministry of Education, Guangzhou, China.,Provincial Engineering Technology Research Center for Biological Vector Control, Guangzhou, China
| | - Jiaying Li
- Department of Parasitology of Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Disease Control (SYSU), Ministry of Education, Guangzhou, China.,Provincial Engineering Technology Research Center for Biological Vector Control, Guangzhou, China
| | - Lifu Wang
- Department of Parasitology of Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Disease Control (SYSU), Ministry of Education, Guangzhou, China.,Provincial Engineering Technology Research Center for Biological Vector Control, Guangzhou, China
| | - Zhongdao Wu
- Department of Parasitology of Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Disease Control (SYSU), Ministry of Education, Guangzhou, China.,Provincial Engineering Technology Research Center for Biological Vector Control, Guangzhou, China
| | - Xi Sun
- Department of Parasitology of Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,Key Laboratory of Tropical Disease Control (SYSU), Ministry of Education, Guangzhou, China.,Provincial Engineering Technology Research Center for Biological Vector Control, Guangzhou, China
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18
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Pi-Bansa S, Osei JHN, Joannides J, Woode ME, Agyemang D, Elhassan E, Dadzie SK, Appawu MA, Wilson MD, Koudou BG, de Souza DK, Utzinger J, Boakye DA. Implementing a community vector collection strategy using xenomonitoring for the endgame of lymphatic filariasis elimination. Parasit Vectors 2018; 11:672. [PMID: 30587226 PMCID: PMC6307201 DOI: 10.1186/s13071-018-3260-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 12/05/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The global strategy for elimination of lymphatic filariasis is by annual mass drug administration (MDA). Effective implementation of this strategy in endemic areas reduces Wuchereria bancrofti in the blood of infected individuals to very low levels. This minimises the rate at which vectors successfully pick microfilariae from infected blood, hence requiring large mosquito numbers to detect infections. The aim of this study was to assess the feasibility of using trained community vector collectors (CVCs) to sample large mosquito numbers with minimal supervision at low cost for potential scale-up of this strategy. METHODS CVCs and supervisors were trained in mosquito sampling methods, i.e. human landing collections, pyrethrum spray collections and window exit traps. Mosquito sampling was done over a 13-month period. Validation was conducted by a research team as quality control for mosquitoes sampled by CVCs. Data were analyzed for number of mosquitoes collected and cost incurred by the research team and CVCs during the validation phase of the study. RESULTS A total of 31,064 and 8720 mosquitoes were sampled by CVCs and the research team, respectively. We found a significant difference (F(1,13) = 27.1606, P = 0.0001) in the total number of mosquitoes collected from southern and northern communities. Validation revealed similar numbers of mosquitoes sampled by CVCs and the research team, both in the wet (F(1,4) = 1.875, P = 0.309) and dry (F(1,4) = 2.276, P = 0.258) seasons in the southern communities, but was significantly different for both wet (F(1,4) = 0.022, P = 0.005) and dry (F(1,4 ) = 0.079, P = 0.033) seasons in the north. The cost of sampling mosquitoes per season was considerably lower by CVCs compared to the research team (15.170 vs 53.739 USD). CONCLUSIONS This study revealed the feasibility of using CVCs to sample large numbers of mosquitoes with minimal supervision from a research team at considerably lower cost than a research team for lymphatic filariasis xenomonitoring. However, evaluation of the selection and motivation of CVCs, acceptability of CVCs strategy and its epidemiological relevance for lymphatic filariasis xenomonitoring programmes need to be assessed in greater detail.
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Affiliation(s)
- Sellase Pi-Bansa
- Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland. .,Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana.
| | - Joseph Harold Nyarko Osei
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana.,Department of Animal Biology and Conservation Science, University of Ghana, Legon, Ghana
| | - Joannitta Joannides
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | | | | | | | - Samuel Kweku Dadzie
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Maxwell Alexander Appawu
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Michael David Wilson
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Benjamin Guibehi Koudou
- Liverpool School of Tropical Medicine, Liverpool, UK.,Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire
| | - Dziedzom Komi de Souza
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Daniel Adjei Boakye
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
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Eliminating Neglected Tropical Diseases in Urban Areas: A Review of Challenges, Strategies and Research Directions for Successful Mass Drug Administration. Trop Med Infect Dis 2018; 3:tropicalmed3040122. [PMID: 30469342 PMCID: PMC6306919 DOI: 10.3390/tropicalmed3040122] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 11/06/2018] [Accepted: 11/17/2018] [Indexed: 12/02/2022] Open
Abstract
Since 1950, the global urban population grew from 746 million to almost 4 billion and is expected to reach 6.4 billion by mid-century. Almost 90% of this increase will take place in Asia and Africa and disproportionately in urban slums. In this context, concerns about the amplification of several neglected tropical diseases (NTDs) are warranted and efforts towards achieving effective mass drug administration (MDA) coverage become even more important. This narrative review considers the published literature on MDA implementation for specific NTDs and in-country experiences under the ENVISION and END in Africa projects to surface features of urban settings that challenge delivery strategies known to work in rural areas. Discussed under the thematics of governance, population heterogeneity, mobility and community trust in MDA, these features include weak public health infrastructure and programs, challenges related to engaging diverse and dynamic populations and the limited accessibility of certain urban settings such as slums. Although the core components of MDA programs for NTDs in urban settings are similar to those in rural areas, their delivery may need adjustment. Effective coverage of MDA in diverse urban populations can be supported by tailored approaches informed by mapping studies, research that identifies context-specific methods to increase MDA coverage and rigorous monitoring and evaluation.
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