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Journal of Travel Medicine Nov 2023
Topics: Humans; Japan; Mansonelliasis; Emigrants and Immigrants; Gabon; Anti-Bacterial Agents
PubMed: 37788045
DOI: 10.1093/jtm/taad126 -
Parasites & Vectors Jan 2017Mansonellosis was first reported in Ghana by Awadzi in the 1990s. Co-infections of Mansonella perstans have also been reported in a small cohort of patients with Buruli...
BACKGROUND
Mansonellosis was first reported in Ghana by Awadzi in the 1990s. Co-infections of Mansonella perstans have also been reported in a small cohort of patients with Buruli ulcer and their contacts. However, no study has assessed the exact prevalence of the disease in a larger study population. This study therefore aimed to find out the prevalence of M. perstans infection in some districts in Ghana and to determine the diversity of Culicoides that could be potential vectors for transmission.
METHODS
From each participant screened in the Asante Akim North (Ashanti Region), Sene West and Atebubu Amantin (Brong Ahafo Region) districts, a total of 70 μl of finger prick blood was collected for assessment of M. perstans microfilariae. Centre for Disease Control (CDC) light traps as well as the Human Landing Catch (HLC) method were used to assess the species diversity of Culicoides present in the study communities.
RESULTS
From 2,247 participants, an overall prevalence of 32% was recorded although up to 75% prevalence was demonstrated in some of the communities. Culicoides inornatipennis was the only species of Culicoides caught with the HLC method. By contrast, C. imicola (47%), C. neavei (25%) and C. schultzei (15%) were caught by the CDC light trap method. A wide diversity of other Culicoides spp. was also identified but correlation was only found between the prevalence of C. inornatipennis and M. perstans during the dry season.
CONCLUSIONS
Here we demonstrate for the first time that M. perstans is highly prevalent in three districts in Ghana. We found a wide spectrum of Culicoides spp. Culicoides inornatipennis was the most anthropophilic and is therefore likely to be the species responsible for transmission of infection but formal proof has yet to be obtained.
TRIAL REGISTRATION
NCT02281643 . Registered October 26, 2014. 'Retrospectively registered'.
TRIAL REGISTRY
ClinicalTrials.gov.
Topics: Animals; Ceratopogonidae; Ghana; Humans; Insect Vectors; Mansonella; Mansonelliasis; Prevalence; Retrospective Studies
PubMed: 28061905
DOI: 10.1186/s13071-016-1960-0 -
PLoS Neglected Tropical Diseases Jan 2018The filarial nematode Mansonella perstans is endemic throughout Africa, northern South America and the Caribbean. Interestingly, M. perstans-infected individuals present...
Mansonella perstans microfilaremic individuals are characterized by enhanced type 2 helper T and regulatory T and B cell subsets and dampened systemic innate and adaptive immune responses.
The filarial nematode Mansonella perstans is endemic throughout Africa, northern South America and the Caribbean. Interestingly, M. perstans-infected individuals present no distinct clinical picture associated with certain pathology. Due to its relatively silent nature, research on this tropical disease has been neglected, especially M. perstans-driven immune responses. A hindrance in obtaining data on M. perstans-specific responses has been the inability to obtain adult worms since their habitats in serous cavities are difficult to access. Thus, in this study, for the first time, we used Mansonella perstans worm antigen extract as stimulant to obtain filarial-specific recall and immunoglobulin responses from M. perstans microfilaremic individuals (Mp MF+) from Cameroon. Moreover, systemic immune profiles in sera and immune cell composition in peripheral blood from Mp MF+ and amicrofilaremic individuals (Mp MF-) were obtained. Our data reveal that Mp MF+ individuals showed significantly reduced cytokine (IL-4, IL-6 and IL-12p70) and chemokine levels (IL-8 and RANTES), but significantly higher MIP-1β as well as increased M. perstans-specific IgG4 levels compared to Mp MF- individuals. In contrast, upon re-stimulation with worm antigen extract, IFN-γ, IL-13, IL-10 and IL-17A secretion was enhanced in cell cultures from Mp MF+ individuals when compared to those from cultures of healthy European individuals. Moreover, analysis of immune cell composition in peripheral blood from Mp MF+ individuals revealed increased type 2 helper T (Th2), natural killer (NK), regulatory B and T cell (Breg and Treg) subsets but decreased type 1 regulatory T (Tr1) cells. In summary, this study deciphers for the first time, M. perstans-specific immune responses using worm antigen extract and shows that patent M. perstans infections have distinct Th2, Breg and Treg subsets accompanied with reduced systemic innate and adaptive immune responses and dominant filarial-specific IgG4 levels.
Topics: Adaptive Immunity; Adult; Aged; Animals; Antibodies, Helminth; B-Lymphocyte Subsets; Cytokines; Female; Humans; Immunity, Innate; Male; Mansonella; Mansonelliasis; Middle Aged; T-Lymphocyte Subsets
PubMed: 29324739
DOI: 10.1371/journal.pntd.0006184 -
Primates; Journal of Primatology Nov 2023In the study undertaken by Souza et al. [Primates 64(1):153-159, 2022; https://doi.org/10.1007/s10329-022-01038-5 ], published in the most recent volume of this journal,...
In the study undertaken by Souza et al. [Primates 64(1):153-159, 2022; https://doi.org/10.1007/s10329-022-01038-5 ], published in the most recent volume of this journal, the blood samples of two Alouatta guariba clamitans (Primates, Atelidae) from two municipalities in the state of Rio Grande do Sul, southern Brazil were reported to be positive for Mansonella perstans. This is the first reported finding of M. perstans in A. guariba clamitans, as well as the first time that M. perstans has been recorded in Brazil outside the Amazon region. We would like to express our concern about this finding, specifically with respect to the geographical distribution of M. perstans in Brazil, as, up until this study, this filaria had only been found in the upper Rio Negro region in São Gabriel da Cachoeira, Amazonas, Brazil. Moreover, species identification was performed using partial sequences of three gene fragments, namely internal transcribed spacer 2, 12S, and 18S, yet neither the phylogenetic trees nor the BLAST alignments of these sequences provided supporting evidence that they belong to M. perstans.
Topics: Animals; Mansonella; Brazil; Phylogeny
PubMed: 37555862
DOI: 10.1007/s10329-023-01081-w -
The Journal of Infectious Diseases Feb 2021Mansonella perstans, a filarial nematode, infects large populations in Africa and Latin America. Recently, a potential new species, Mansonella sp "DEUX," was reported....
Mansonella perstans, a filarial nematode, infects large populations in Africa and Latin America. Recently, a potential new species, Mansonella sp "DEUX," was reported. Carriage of endosymbiotic Wolbachia opens treatment options for Mansonella infections. Within a cross-sectional study, we assessed the prevalence of filarial infections in 834 Gabonese individuals and the presence of the endosymbiont Wolbachia. Almost half of the participants (400/834 [48%]) were infected with filarial nematodes, with Mansonella sp "DEUX" being the most frequent (295/400 [74%]), followed by Loa loa (273/400 [68%]) and Mansonella perstans (82/400 [21%]). Being adult/elderly, male, and living in rural areas was associated with a higher risk of infection. Wolbachia carriage was confirmed in M. perstans and Mansonella sp "DEUX." In silico analysis revealed that Mansonella sp "DEUX" is not detected with currently published M. perstans-specific assays. Mansonella infections are highly prevalent in Gabon and might have been underreported, likely also beyond Gabon.
Topics: Animals; Carrier State; Cross-Sectional Studies; Gabon; Humans; Loa; Male; Mansonella; Mansonelliasis; Molecular Epidemiology; Polymerase Chain Reaction; Rural Population
PubMed: 33099649
DOI: 10.1093/infdis/jiaa670 -
Emerging Infectious Diseases Sep 2017We report 74 patients in Italy infected with Mansonella perstans nematodes, a poorly described filarial parasite. M. perstans nematodes should be included in the...
We report 74 patients in Italy infected with Mansonella perstans nematodes, a poorly described filarial parasite. M. perstans nematodes should be included in the differential diagnosis for patients with eosinophilia from disease-endemic countries. Serologic analysis is useful for screening, and testing for microfilaremia in peripheral blood should be performed for parasite-positive patients.
Topics: Adolescent; Adult; Africa South of the Sahara; Aged; Animals; Antibodies, Helminth; Child; Child, Preschool; Diagnosis, Differential; Emigrants and Immigrants; Eosinophilia; Female; Humans; Italy; Male; Mansonella; Mansonelliasis; Middle Aged; Retrospective Studies; Travel
PubMed: 28820369
DOI: 10.3201/eid2309.170263 -
Emerging Infectious Diseases Mar 2017We obtained ribosomal and mitochondrial DNA sequences from residents of Amazonas state, Brazil, with Mansonella parasitemias. Phylogenetic analysis of these sequences...
We obtained ribosomal and mitochondrial DNA sequences from residents of Amazonas state, Brazil, with Mansonella parasitemias. Phylogenetic analysis of these sequences confirm that M. ozzardi and M. perstans parasites occur in sympatry and reveal the close relationship between M. perstans in Africa and Brazil, providing insights into the parasite's New World origins.
Topics: Animals; DNA, Protozoan; DNA, Ribosomal Spacer; Humans; Mansonella; Mansonelliasis; Parasitemia; Phylogeny
PubMed: 28221120
DOI: 10.3201/eid2303.161159 -
Research and Reports in Tropical... 2018Mansonellosis is a filarial disease caused by three species of filarial (nematode) parasites (, , and ) that use humans as their main definitive hosts. These parasites... (Review)
Review
Mansonellosis is a filarial disease caused by three species of filarial (nematode) parasites (, , and ) that use humans as their main definitive hosts. These parasites are transmitted from person to person by bloodsucking females from two families of flies (Diptera). Biting midges (Ceratopogonidae) transmit all three species of , but blackflies (Simuliidae) are also known to play a role in the transmission of in parts of Latin America. and are endemic in western, eastern, and central Africa, and is also present in the neotropical region from equatorial Brazil to the Caribbean coast. has a patchy distribution in Latin America and the Caribbean. Mansonellosis infections are thought to have little pathogenicity and to be almost always asymptomatic, but occasionally causing itching, joint pains, enlarged lymph glands, and vague abdominal symptoms. In Brazil, infections are also associated with corneal lesions. Diagnosis is usually performed by detecting microfilariae in peripheral blood or skin without any periodicity. There is no standard treatment at present for mansonellosis. The combination therapy of diethylcarbamazine plus mebendazole for microfilaremia is presently one of the most widely used, but the use of ivermectin has also been proven to be very effective against microfilariae. Recently, doxycycline has shown excellent efficacy and safety when used as an antimicrobial against endosymbiotic bacteria harbored by some strains of and . Diethylcarbamazine and ivermectin have been used effectively to treat infection. There are at present no estimates of the disease burden caused by mansonellosis, and thus its importance to many global health professionals and policy makers is presently limited to how it can interfere with diagnostic tools used in modern filarial disease control and elimination programs aimed at other species of filariae.
PubMed: 30050351
DOI: 10.2147/RRTM.S125750 -
PloS One 2024Mansonella spp. have been reported to have a wide global distribution. Despite the distribution and co-occurrence with other filarial parasites like Wuchereria...
Mansonella spp. have been reported to have a wide global distribution. Despite the distribution and co-occurrence with other filarial parasites like Wuchereria bancrofti, Onchocerca volvulus and Loa loa, it is given little attention. There are few surveillance programmes for assessing the distribution of mansonellosis, due to the associated mild to no symptoms experienced by infected people. However, addressing this infection is critical to the onchocerciasis control program as current rapid diagnostic tools targeting O. volvulus have the tendency to cross react with Mansonella species. In this study we identified and characterised M. perstans from five sites in two districts in the Volta Region of Ghana and compared them to samples from other regions. Night blood smears and filter blood blots were obtained from individuals as part of a study on lymphatic filariasis. The Giemsa-stained smears were screened by microscopy for the presence of filarial parasites. Genomic DNA was extracted from blood blots from 39 individuals that were positive for M. perstans and Nested PCR targeting the internal spacer 1 (ITS-1) was conducted. Of these, 30 were sequenced and 24 sequences were kept for further analysis. Phylogenetic analysis of 194 nucleotide positions showed no differences in the samples collected. The similarities suggests that there could be one species in this area. However, more robust studies with larger sample sizes are required to draw such conclusions. We also observed a clustering of the samples from Ghana with reference sequences from Africa and Brazil, suggesting they could be related. This study draws further attention to a neglected infection, presents the first characterisation of M. perstans in Ghana and calls for more population-based studies across different geographical zones to ascertain species variations and disease distribution.
Topics: Ghana; Mansonella; Humans; Mansonelliasis; Animals; Phylogeny; Male; Female
PubMed: 38848396
DOI: 10.1371/journal.pone.0295089 -
Experimental Parasitology Nov 2019Mansonellosis arises from infections with threadlike filarial nematodes in millions of individuals, especially in sub-Saharan Africa. Since infections present no overt...
BACKGROUND
Mansonellosis arises from infections with threadlike filarial nematodes in millions of individuals, especially in sub-Saharan Africa. Since infections present no overt clinical symptoms but attenuate immune responses that might lead to increased susceptibility and worsened disease course of concomitant infections, it is truly a neglected tropical disease. Nevertheless, only few studies focus on identifying suitable safe drugs for its control and little is known about the requirements for in vitro maintenance of the Mansonella perstans transmission stage. This study, therefore, evaluated the survival of M. perstans microfilariae (mf) using in vitro conditions that have been shown to promote survival of Loa loa, a closely related filarial nematode. Furthermore, the in vitro microfilaricidal effect of 15 agents was assessed on this helminth.
METHODS
The ability of two basic culture media; Dulbecco's Modified Eagle's Medium (DMEM) and Roswell Park Memorial Institute (RPMI-1640) supplemented with 10% fetal bovine serum (FBS) and a monkey kidney epithelial cell line (LLC-MK) to support the survival of M. perstans microfilariae was investigated. Subsequently, 6 anti-helminthics, 5 anti-malarials, 1 anti-microbacterial, 2 trypanocidals and 1 anti-cancer agent were tested in vitro against mf. The suitability of the culture media as well as the effect of the anti-infective agents on mf survival was assessed by scoring their motility.
RESULTS
FBS supplement and additional LLC-MK cells significantly improved the survival of mf in DMEM and RPMI-1640 culture. In detail, RPMI-1640 supplemented with 10% FBS and LLC-MK cells sustained the maintenance of mf for at least 20 days (100.00 ± 0.00% survival). In co-cultures with LLC-MK cells without serum, M. perstans mf were maintained in DMEM and RPMI-1640 medium with a motility above 99% by day 5. Mefloquine displayed the highest microfilaricidal effect in vitro followed by artesunate.
CONCLUSION
Both RPMI and DMEM in the presence of LLC-MK cells are suitable for the maintenance of M. perstans mf in vitro. In absence of the feeder cells, the addition of 10% FBS to RPMI-1640 medium improved the parasite survival rate and motility. The microfilaricidal activity of mefloquine and artesunate on M. perstans mf was documented for the first time in this study and can therefore be considered as reference for further screening of agents against this parasite stage.
Topics: Amodiaquine; Animals; Antimalarials; Antinematodal Agents; Area Under Curve; Artesunate; Cattle; Cell Line; Culture Media; Filaricides; Haplorhini; Ivermectin; Mansonella; Mefloquine; Microfilariae; Movement; Rifampin
PubMed: 31580876
DOI: 10.1016/j.exppara.2019.107769