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African Journal of Infectious Diseases 2010
PubMed: 23878696
DOI: 10.4314/ajid.v4i1.55085 -
Tropical Medicine & International... Aug 2022Loa loa and Mansonella perstans are two very common filarial species in Africa. Although microscopy is the traditional diagnostic method for human filariasis, several...
OBJECTIVES
Loa loa and Mansonella perstans are two very common filarial species in Africa. Although microscopy is the traditional diagnostic method for human filariasis, several polymerase chain reaction (PCR) methods have emerged as an alternative approach for identifying filarial parasites. The aim of this study is to compare three molecular methods and decide which is the most suitable for diagnosing human loiasis and mansonellosis in non-endemic regions using dried blood spot (DBS) as a medium for sample collection and storage.
METHODS
A total of 100 DBS samples, with their corresponding thin and thick blood smears, were selected for this study. Microscopy was used as the reference method to diagnose and calculate the microfilaraemia. Filarial DNA was extracted using the saponin/Chelex method and the DNA isolated was assayed by Filaria-real time-PCR, filaria-nested PCR, and cytochrome oxidase I PCR. All PCR products were subsequently purified and sequenced. The statistical values for each molecular test were calculated and compared.
RESULTS
Overall, 64 samples were identified as negative by all tests and a further 36 samples were positive by at least one of the methods used. The sensitivity and specificity were similar for the different molecular methods, all of which demonstrated good agreement with microscopy.
CONCLUSIONS
Based on this study, and from a practical point of view (single and short amplification round), the optimal technique for diagnosing filarial infection in non-endemic regions is filaria-real time-PCR, which presents high sensitivity and specificity and is also able to detect a wide range of human filariae.
Topics: Animals; Humans; Loa; Loiasis; Mansonella; Mansonelliasis; Polymerase Chain Reaction
PubMed: 35653502
DOI: 10.1111/tmi.13786 -
PLoS Neglected Tropical Diseases Aug 2021Loa loa and Mansonella perstans-the causative agents of loiasis and mansonellosis-are vector-borne filarial parasites co-endemic in sub-Saharan Africa. Diagnosis of both...
BACKGROUND
Loa loa and Mansonella perstans-the causative agents of loiasis and mansonellosis-are vector-borne filarial parasites co-endemic in sub-Saharan Africa. Diagnosis of both infections is usually established by microscopic analysis of blood samples. It was recently established that the odds for detecting Plasmodium spp. is higher in capillary (CAP) blood than in venous (VEN) blood. In analogy to this finding this analysis evaluates potential differences in microfilaraemia of L. loa and M. perstans in samples of CAP and VEN blood.
METHODS
Recruitment took place between 2015 and 2019 at the CERMEL in Lambaréné, Gabon and its surrounding villages. Persons of all ages presenting to diagnostic services of the research center around noon were invited to participate in the study. A thick smear of each 10 microliters of CAP and VEN blood was prepared and analysed by a minimum of two independent microscopists. Differences of log2-transformed CAP and VEN microfilaraemia were computed and expressed as percentages. Furthermore, odds ratios for paired data were computed to quantify the odds to detect microfilariae in CAP blood versus in VEN blood.
RESULTS
A total of 713 participants were recruited among whom 52% were below 30 years of age, 27% between 30-59 years of age and 21% above 60 years of age. Male-female ratio was 0.84. Among 152 participants with microscopically-confirmed L. loa infection median (IQR) microfilaraemia was 3,650 (275-11,100) per milliliter blood in CAP blood and 2,775 (200-8,875) in VEN blood (p<0.0001), while among 102 participants with M. perstans this was 100 (0-200) and 100 (0-200), respectively (p = 0.44). Differences in linear models amount up to an average of +34.5% (95% CI: +11.0 to +63.0) higher L. loa microfilaria quantity in CAP blood versus VEN blood and for M. perstans it was on average higher by +24.8% (95% CI: +0.0 to +60.5). Concordantly, the odds for detection of microfilaraemia in CAP samples versus VEN samples was 1.24 (95% CI: 0.65-2.34) and 1.65 (95% CI: 1.0-2.68) for infections with L. loa and M. perstans, respectively.
CONCLUSION
This analysis indicates that average levels of microfilaraemia of L. loa are higher in CAP blood samples than in VEN blood samples. This might have implications for treatment algorithms of onchocerciasis and loiasis, in which exact quantification of L. loa microfilaraemia is of importance. Furthermore, the odds for detection of M. perstans microfilariae was higher in CAP than in VEN blood which may pre-dispose CAP blood for detection of M. perstans infection in large epidemiological studies when sampling of large blood quantities is not feasible. No solid evidence for a higher odds of L. loa microfilariae detection in CAP blood was revealed, which might be explained by generally high levels of L. loa microfilaraemia in CAP and VEN blood above the limit of detection of 100 microfilariae/ml. Yet, it cannot be excluded that the study was underpowered to detect a moderate difference.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Animals; Child; Coinfection; Female; Gabon; Humans; Loa; Loiasis; Male; Mansonella; Mansonelliasis; Microscopy; Middle Aged; Parasite Load; Parasitemia; Prevalence; Serologic Tests; Young Adult
PubMed: 34398886
DOI: 10.1371/journal.pntd.0009623 -
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 -
Microbes and Infection Jan 2006This study examined the impact of concurrent parasite infections (amoebiasis, filariasis, necatoriasis) and the effect of anti-parasite treatment on cytokine and...
Cytokine and chemokine responses in patients co-infected with Entamoeba histolytica/dispar, Necator americanus and Mansonella perstans and changes after anti-parasite treatment.
This study examined the impact of concurrent parasite infections (amoebiasis, filariasis, necatoriasis) and the effect of anti-parasite treatment on cytokine and chemokine responses in singly and poly-parasitized patients. Cellular reactivity and parasite-specific Th1- and Th2-type cytokine and chemokine profiles were investigated before and six weeks after treatment. In those patients infected with three parasite species, cellular secretion of interleukin 5 (IL-5) and IL-12p40 by PBMC was strongly diminished (p<0.005) but IL-10 was elevated in parasite-infected patients (p<0.0001) in response to protozoa- and helminth-specific as well as bacteria-specific antigens. Macrophage inflammatory chemokines (MIP-1alpha/CCL3 and MIP-1beta/CCL4), macrophage-derived chemokine (MDC/CCL22) and neutrophil activating chemokine (IL-8/CXCL8) were produced by PBMC in similar amounts in endemic controls and singly and poly-parasitized patients, but thymus and activation-regulated chemokine (TARC/CCL17) was produced the highest by PBMC from patients with triple parasite infections (p<0.0001). Following anti-parasite therapy, secretion of IL-12p40 and IL-5 augmented significantly in treated patients while IL-10, MDC, MIP-1alpha, TARC and IL-8 substantially diminished (all p<10(-5)) when their PBMC were activated with parasite- and bacteria-specific antigens. In summary, PBMC from poly-parasitized patients responded to protozoa- and helminth-specific antigens with a compromised IL-5 and IL-12p40 but high IL-10 and a substantial chemokine release. Chemokines may attract and activate effector cells in peri-parasitic tissues to limit parasite proliferation and dissemination, while depressed IL-5 and IL-12p40 but prominent IL-10 may prevent eosinophil and cytotoxic cell-mediated inflammatory processes and pathogenesis to the host. The changes in this profile following anti-parasite therapy disclosed the dynamics of an immune adaptation associated with parasite accumulation and also with clearance of parasite infections.
Topics: Adult; Animals; Anthelmintics; Antibodies, Helminth; Antigens, Helminth; Chemokines; Cytokines; Entamoebiasis; Female; Humans; Male; Mansonelliasis; Middle Aged; Necator americanus; Necatoriasis
PubMed: 16239120
DOI: 10.1016/j.micinf.2005.06.019 -
The American Journal of Tropical... Sep 2016Mansonellosis is endemic in several regions of Africa, the Caribbean, and Latin America. Mansonella ozzardi and Mansonella perstans have been reported in Latin America,...
Mansonellosis is endemic in several regions of Africa, the Caribbean, and Latin America. Mansonella ozzardi and Mansonella perstans have been reported in Latin America, including the Amazon region. A morphological and molecular microfilariae study was performed in Pauini (Brazil). Blood samples were collected from 40 individuals, and were analyzed by Giemsa-stained blood film and by two different nested polymerase chain reactions which detect internal transcribed spacer-1 and the major sperm protein gene. By microscopy, 14 of 40 were positive: 11 as M. ozzardi and three as M. perstans-like infections. Both molecular methods detected 19 positive cases as M. ozzardi, including those 14 individuals detected by microscopy, without detectable genetic differences among any of the 19 positive samples. Molecular techniques showed an improvement of mansonellosis diagnosis and may become an effective tool to evaluate the present status of M. ozzardi and M. perstans in Latin America.
Topics: Animals; Brazil; Humans; Mansonella; Mansonelliasis; Microfilariae; Microscopy; Phylogeny; Polymerase Chain Reaction
PubMed: 27402517
DOI: 10.4269/ajtmh.15-0654 -
Frontiers in Microbiology 2016Malaria and Cutaneous Leishmaniasis (CL) are co-endemic throughout large regions in tropical countries and co-infection may impact the evolution of host-parasite...
Malaria and Cutaneous Leishmaniasis (CL) are co-endemic throughout large regions in tropical countries and co-infection may impact the evolution of host-parasite interactions. In the present study, we evaluate Malaria/Leishmaniasis disease outcome, Th1/Th2 cytokine levels and the CD4 and CD8 T-cell profiles in a co-infection murine model (BALB/c) of Plasmodium yoelii 17XNL (Py) and Leishmania amazonensis (La) or L. braziliensis (Lb). Malaria parasitaemia was assessed through blood strains stained with Giemsa. Leishmania lesions were monitored with a digital caliper and parasite loads determined by limiting-dilution assay. Serum levels of IFN-γ, TNF, IL-2, IL-4, IL-6, IL-10, and IL-17 were determined using multiplexed bead assay and expression of CD3, CD4, and CD8 T-cells markers were determined by Flow Cytometry in the thymus, spleens and lymph nodes. Parasitaemia in Lb+Py co-infected group was lower than in Py single-infected group, suggesting a protective effect of Lb co-infection in Malaria progression. In contrast, La+Py co-infection increased parasitaemia, patent infection and induced mortality in non-lethal Malaria infection. Regarding Leishmaniasis, Lb+Py co-infected group presented smaller lesions and less ulceration than Lb single-infected animals. In contrast, La+Py co-infected group presented only a transitory delay on the development of lesions when compared to La single-infected mice. Decreased levels of IFN-γ, TNF, IL-6, and IL-10 were observed in the serum of co-infected groups, demonstrating a modulation of Malaria immune response by Leishmania co-infections. We observed an intense thymic atrophy in Py single-infected and co-infected groups, which recovered earlier in co-infected animals. The CD4 and CD8 T cell profiles in thymus, spleens and lymph nodes did not differ between Py single and co-infected groups, except for a decrease in CD4(+)CD8(+) T cells which also increased faster in co-infected mice. Our results suggest that Py and Leishmania co-infection may change disease outcome. Interestingly Malaria outcome can be altered according to the Leishmania specie involved. Alternatively Malaria infection reduced the severity or delayed the onset of leishmanial lesions. These alterations in Malaria and CL development seem to be closely related with changes in the immune response as demonstrated by alteration in serum cytokine levels and thymus/spleens T cell phenotypes dynamics during infection.
PubMed: 27446022
DOI: 10.3389/fmicb.2016.00982 -
Parasites & Vectors Jun 2020The Onchocercidae is a family of filarial nematodes with several species of medical or veterinary importance. Microfilariae are found in the blood and/or the dermis and...
BACKGROUND
The Onchocercidae is a family of filarial nematodes with several species of medical or veterinary importance. Microfilariae are found in the blood and/or the dermis and are usually diagnosed in humans by microscopy examination of a blood sample or skin biopsy. The main objectives of this study were to evaluate whether filariae DNA can be detected in faecal samples of wild non-human primates (NHPs), whether the detected parasites were closely related to those infecting humans and whether filarial DNA detection in faeces is associated with co-infections with nematodes (Oesophagostumum sp. and Necator sp.) known to cause blood loss while feeding on the host intestinal mucosa.
METHODS
A total of 315 faecal samples from 6 species of NHPs from Cameroon and Gabon were analysed. PCRs targeted DNA fragments of cox1 and 12S rDNA genes, to detect the presence of filariae, and the internal transcribed spacer 2 (ITS2), to detect the presence of Oesophagostomum sp. and Necator sp. infections.
RESULTS
Among the 315 samples analysed, 121 produced sequences with > 90% homology with Onchocercidae reference sequences. However, 63% of the 12S rDNA and 78% of the cox1 gene sequences were exploitable for phylogenetic analyses and the amplification of the 12S rDNA gene showed less discriminating power than the amplification of the cox1 fragment. Phylogenetic analyses showed that the cox1 sequences obtained from five chimpanzee DNA faecal samples from Gabon and two from Cameroon cluster together with Mansonella perstans with high bootstrap support. Most of the remaining sequences clustered together within the genus Mansonella, but the species could not be resolved. Among the NHP species investigated, a significant association between filarial DNA detection and Oesophagostomum sp. and Necator sp. infection was observed only in gorillas.
CONCLUSIONS
To our knowledge, this is the first study reporting DNA from Mansonella spp. in faecal samples. Our results raise questions about the diversity and abundance of these parasites in wildlife, their role as sylvatic reservoirs and their potential for zoonotic transmission. Future studies should focus on detecting variants circulating in both human and NHPs, and improve the molecular information to resolve or support taxonomy classification based on morphological descriptions.
Topics: Animals; Cameroon; Cyclooxygenase 1; DNA, Helminth; Dried Blood Spot Testing; Feces; Gabon; Genotype; Mansonella; Mansonelliasis; Necator; Oesophagostomum; Phylogeny; Primates
PubMed: 32546281
DOI: 10.1186/s13071-020-04184-1 -
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 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