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Acta Tropica Sep 2011Mansonella perstans is a vector-borne human filarial nematode, transmitted by tiny blood-sucking flies (biting midges). It is widespread in many parts of Sub-Saharan... (Review)
Review
Mansonella perstans is a vector-borne human filarial nematode, transmitted by tiny blood-sucking flies (biting midges). It is widespread in many parts of Sub-Saharan Africa and also occurs in parts of Central and South America. Despite the commonness of this parasite very few studies have been carried out on its epidemiology and on the morbidity resulting from it, and only few thorough drug trials have been conducted to look for effective and suitable drugs and drug regimens for treatment and control. Here, we review currently available knowledge on M. perstans infections in Africa, including documented aspects of biology, vectors, transmission, diagnosis, epidemiology, morbidity and treatment. It is concluded that there is an urgent need for more research on this widespread but greatly neglected infection in order to properly assess its public health significance and as a background for identifying and recommending optimal means and strategies for treatment and control.
Topics: Africa; Animals; Ceratopogonidae; Clinical Trials as Topic; Filariasis; Filaricides; Humans; Insect Vectors; Mansonella; Mansonelliasis; Microfilariae
PubMed: 20152790
DOI: 10.1016/j.actatropica.2010.01.014 -
Infectious Diseases of Poverty Jul 2020Mansonella perstans infection can be considered one of the most neglected tropical infectious diseases. Very few studies have reported on the clinical picture caused by... (Comparative Study)
Comparative Study
BACKGROUND
Mansonella perstans infection can be considered one of the most neglected tropical infectious diseases. Very few studies have reported on the clinical picture caused by infection with this nematode. Therefore, our study was aimed to describe the clinical patterns and treatment of imported M. perstans infection by migrants from Africa.
METHODS
The present study evaluated a large cohort of migrants who have been diagnosed, examined and treated for imported M. perstans infection at a Spanish reference center (Hospital Carlos III Tropical Medicine Unit, Madrid, Spain) over a 19-year period. Most patients voluntarily attend the emergency unit or are referred from primary care or general hospitals in Madrid. Chi-square test was used to compare the association between categorical variables. The continuous variables were compared by Student's t-test or the Mann-Whitney test. The corresponding regression models were used for multivariate analysis.
RESULTS
Five hundred three cases of migrants from tropical and subtropical areas with M. perstans infection were identified. Two hundred sixty-four patients were female (52.5%). The mean age (± SD) was 44.6 ± 18.2 years (range: 16-93 years). The mean time (± SD) between the arrival in Spain and the first consultation was 8.6 ± 18.0 months. The major origin of the patients was Equatorial Guinea (97.6%). Regarding the clinical picture, 257 patients were asymptomatic (54.7%) and 228 were symptomatic (45.3%); 190 patients had pruritus (37.8%), 50 (9.9%) had arthralgia, 18 patients had Calabar-like swelling (3.6%), and 15 (3%) had abdominal pain. Four hundred forty-two (87.9%) migrants had hyper-IgE, and 340 (67.6%) had eosinophilia. One hundred ninety-five patients had coinfections with other filarial nematodes (38.8%), and 308 migrants had only M. perstans infection (61.2%). Four hundred thirty-seven cases (86.9%) had been treated with anti-filarial drugs; 292 cases were treated with one anti-filarial drug, and 145 cases were treated with combined anti-filarial therapy. Additionally, 20 (4%) cases received steroids and 38 (7.6%) cases received antihistamines.
CONCLUSIONS
A long series of M. perstans infections is presented in sub-Saharan immigrants whose data indicate that it should be included in the differential diagnosis in patients with pruritus or analytical alterations such as eosinophilia or hyper-IgE presentation, and they also have a high number of coinfections with other microorganisms whose treatment needs to be protocolized.
Topics: Adolescent; Adult; Africa; Aged; Aged, 80 and over; Animals; Antiparasitic Agents; Communicable Diseases, Imported; Female; Humans; Male; Mansonella; Mansonelliasis; Middle Aged; Spain; Transients and Migrants; Treatment Outcome; Young Adult
PubMed: 32703283
DOI: 10.1186/s40249-020-00729-9 -
Frontiers in Cellular and Infection... 2023species are filarial parasites that infect humans worldwide. Although these infections are common, knowledge of the pathology and diversity of the causative species is...
INTRODUCTION
species are filarial parasites that infect humans worldwide. Although these infections are common, knowledge of the pathology and diversity of the causative species is limited. Furthermore, the lack of sequencing data for species, shows that their research is neglected. Apart from Mansonella perstans, a potential new species called sp "DEUX" has been identified in Gabon, which is prevalent at high frequencies. We aimed to further determine if sp "DEUX" is a genotype of M. , or if these are two sympatric species.
METHODS
We screened individuals in the area of Fougamou, Gabon for Mansonella mono-infections and generated de novo assemblies from the respective samples. For evolutionary analysis, a phylogenetic tree was reconstructed, and the differences and divergence times are presented. In addition, mitogenomes were generated and phylogenies based on 12S rDNA and cox1 were created.
RESULTS
We successfully generated whole genomes for M. perstans and sp "DEUX". Phylogenetic analysis based on annotated protein sequences, support the hypothesis of two distinct species. The inferred evolutionary analysis suggested, that M. perstans and sp "DEUX" separated around 778,000 years ago. Analysis based on mitochondrial marker genes support our hypothesis of two sympatric human Mansonella species.
DISCUSSION
The results presented indicate that sp "DEUX" is a new species. These findings reflect the neglect of this research topic. And the availability of whole genome data will allow further investigations of these species.
Topics: Animals; Humans; Mansonella; Phylogeny; Sympatry; DNA, Ribosomal; Amino Acid Sequence
PubMed: 37124042
DOI: 10.3389/fcimb.2023.1159814 -
Parassitologia Jun 2007Mansonella perstans filariasis is widely present in Africa and equatorial America and its pathogenicity has been recently reconsidered. Although M. perstans infection... (Review)
Review
Mansonella perstans filariasis is widely present in Africa and equatorial America and its pathogenicity has been recently reconsidered. Although M. perstans infection has been considered a minor filariasis, remaining asymptomatic in most of infected subjects, more recent studies have shown that M. perstans is capable of inducing a variety of clinical features, including angioedemas, swellings like the "Calabar swellings" of loiasis, pruritus, fever, headache, pain in bursae and/or joint synovia, or in serous cavities. It is likely that some of the pathological changes observed are induced by the immune response to the infection. Eosinophilia is present in many cases of infection. Moreover M. perstans filariasis is difficult to be treated. Effective treatment is lacking and there is no consensus on optimal therapeutic approach. The most commonly used drug is diethylcarbamazine (DEC) that is however often ineffective. Although other drugs have been tried (e.g. praziquantel, ivermectin), none has proven to be reliably and rapidly effective. Mebendazole seemed more active than DEC in eliminating the infection, with a comparable rate of overall responses. Thiabendazole evidenced a small, but significant activity against the infection. Combination treatments (DEC plus mebendazole) resulted in a significantly higher activity compared with the single drugs.
Topics: Animals; Ceratopogonidae; Female; Filaricides; Humans; Insect Bites and Stings; Insect Vectors; Male; Mansonella; Mansonelliasis; Parasitemia; Transfusion Reaction
PubMed: 18416002
DOI: No ID Found -
The New England Journal of Medicine Oct 2009
Topics: Animals; Anti-Bacterial Agents; Doxycycline; Drug Therapy, Combination; Elephantiasis, Filarial; Filaricides; Humans; Mansonella; Mansonelliasis; Rickettsiaceae Infections; Symbiosis; Wolbachia; Wuchereria bancrofti
PubMed: 19812409
DOI: 10.1056/NEJMe0905193 -
Trends in Parasitology Jan 2021
Topics: Americas; Animals; Antiparasitic Agents; Host-Parasite Interactions; Humans; Mansonella; Mansonelliasis; Simuliidae
PubMed: 33168424
DOI: 10.1016/j.pt.2020.03.005 -
Microbiology Resource Announcements Jul 2020The 13,647-bp complete mitochondrial genome of was sequenced and is syntenic to the mitochondrial genome of Phylogenetic analysis of the mitochondrial genome is...
The 13,647-bp complete mitochondrial genome of was sequenced and is syntenic to the mitochondrial genome of Phylogenetic analysis of the mitochondrial genome is consistent with the known phylogeny of ONC5 group filarial nematodes.
PubMed: 32703831
DOI: 10.1128/MRA.00490-20 -
European Journal of Microbiology &... Sep 2023Mansonellosis is a widely neglected helminth disease which is predominantly observed in tropical regions. This study was conducted to assess potential associations of...
BACKGROUND
Mansonellosis is a widely neglected helminth disease which is predominantly observed in tropical regions. This study was conducted to assess potential associations of the prevalence of circulating Mansonella perstans-specific cell-free DNA in human serum and HIV infection in Ghanaian individuals.
METHODS
For this purpose, serum samples obtained from Ghanaian HIV-patients (n = 989) and non-HIV-infected Ghanaian control individuals (n = 91) were subjected to real-time PCR targeting the ITS-(internal transcribed spacer-)2 sequence of M. perstans and Mansonella sp. Deux.
RESULTS
Mansonella-specific cell-free DNA was detected in serum samples of only 2 HIV-positive and 0 HIV-negative individuals, making any reliable conclusions on potential associations between HIV and mansonellosis in tropical Ghana unfeasible.
CONCLUSIONS
Future epidemiological studies on hypothetical associations between mansonellosis and HIV infections should focus more specifically on high-endemicity settings for both Mansonella spp.-infections and HIV-infections, include higher case numbers and be based on real-time PCR from whole blood rather than from serum, in which only circulating parasite DNA but no more cell-bound parasite DNA can be detected. However, the study did not show associations of HIV infections in Ghanaian individuals with Mansonella worm loads high enough to detect cell-free Mansonella DNA in serum by PCR.
PubMed: 37751320
DOI: 10.1556/1886.2023.00028 -
Parasites & Vectors Dec 2023Loiasis is endemic in the northern and western part of the Republic of Congo. Between 2004 and 2010, surveys were conducted, using the RAPLOA method, in all departments...
BACKGROUND
Loiasis is endemic in the northern and western part of the Republic of Congo. Between 2004 and 2010, surveys were conducted, using the RAPLOA method, in all departments of the Republic of Congo to assess the distribution of loiasis. Prior to 2004, only two parasitological surveys on loiasis had been conducted in Congo and mainly in the Department of Lékoumou, in the southwestern of the country. In 2019, we conducted a parasitological survey in this same department, more than 30 years after the first surveys.
METHODS
The study was conducted in 21 villages. Loa loa and Mansonella perstans microfilaremia levels were quantified using 50 µl calibrated blood smears.
RESULTS
A total of 2444 individuals were examined. The median age of the screened individuals was 43 (interquartile range: 30-57, range: 18-91) years old. The overall prevalences of L. loa and M. perstans microfilaremia were 20.0% [95% confidence intervals (CI) 18.0-21.6%] and 1.0% (95% CI 0.6-1.4%) respectively. The proportion of individuals with a microfilarial density of L. loa > 8000 mf/ml and > 30,000 mf/ml were 5.1% (95% CI 4.3-6.1%) and 1.1% (95% CI 0.8-1.7%), respectively. The overall community microfilarial load was 3.4 mf/ml.
CONCLUSIONS
Prevalences and intensities of L. loa infection remained generally stable between the late 1980s and 2019 in the Lékoumou Department. In contrast, parasitological indicators for M. perstans have declined sharply in the intervening years for an unknown reason.
Topics: Animals; Humans; Adult; Middle Aged; Mansonella; Loiasis; Mansonelliasis; Loa; Congo; Prevalence; Microfilariae
PubMed: 38071391
DOI: 10.1186/s13071-023-06056-w -
Clinical Infectious Diseases : An... Feb 2023Doxycycline is used for treatment of Mansonella perstans infection. Immune modulatory effects of both M. perstans and doxycycline have been described but long-term... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Doxycycline is used for treatment of Mansonella perstans infection. Immune modulatory effects of both M. perstans and doxycycline have been described but long-term implications on host immune response are not defined. Here we determined multiple immune parameters of M. perstans-infected individuals before and after doxycycline treatment to characterize doxycycline effects on host T-cell immunity.
METHODS
Immune characterization of doxycycline-treated M. perstans-infected individuals was performed as part of an open-label randomized clinical trial. Immune cell population phenotyping by flow cytometry and functional in vitro T-cell assays were performed at baseline, 6 months, and "long term" (18-24 months) after treatment start. Treatment efficacy, based on peripheral blood microfilaria (mf) burden, was correlated with immune parameters and effects on immune response against concomitant Mycobacterium tuberculosis infection were determined.
RESULTS
Immune population phenotyping indicated changes in functional T-cell responses after doxycycline treatment. Constitutive and superantigen-induced T-cell activation and polarization towards T-helper type (TH) 1 phenotype at baseline declined after doxycycline treatment, whereas low proportions of TH17 and TH1* cells at baseline increased significantly at follow-up. In accordance, long-term decline in antigen-specific TH1 responses against concomitant M. tuberculosis infection was seen. Notably, only TH17 and TH1* changes after 6 months and TH17 at baseline were negatively correlated with M. perstans microfilaria burden or reduction, whereas long-term changes were not associated with treatment efficacy.
CONCLUSIONS
We found long-term immune modulatory effects of doxycycline treatment leading to decreased constitutive T-cell activation, polarization towards TH17/TH1*, and impaired immune response against concomitant M. tuberculosis infection.
Topics: Animals; Doxycycline; Mansonella; Mansonelliasis; Treatment Outcome; T-Lymphocytes
PubMed: 35657028
DOI: 10.1093/cid/ciac428