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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.

Mansonella ozzardi is a tissue-dwelling parasitic nematode, the causative agent of mansonelliasis in almost all Latin American countries. It has been described along the Argentine Yungas region. The microscopic diagnosis can yield false-negative test results at low microfilaremia levels. The aim of this study was to optimize the molecular diagnostic technique and compare it with the Knott's method and standard blood smear procedures (thin blood films and thick smears) in 92 blood samples of individuals from an endemic area. The PCR technique followed by the sequencing of the amplified product yielded 100 % sensitivity compared to the Knott's test, which is considered a reference method. Seven more cases of this parasitosis could only be identified with the molecular technique.

Introduction: The last few years has seen an increase in the number of immigrants and travellers from endemic areas where filariasis are mainly caused by Loa loa (L. loa), Mansonella perstans (M. perstans) and Wuchereria bancrofti (W. bancrofti) species. These demographic changes has led to the need for better filariae species-specific molecular diagnostic tests to solve problems, as alternatives to the more time consuming classic parasitology methods. Thus, the objective of the present work was the implementation of optimised molecular protocols (nested-PCR and ITS1-RFLP) developed in our laboratory, for the differential diagnosis of filarial parasites. The results obtained were compared with those obtained using the conventional parasitological methods., Material and Methods: A total of 523 samples (517 peripheral blood, 5 adult worms and one vitreous body) were sent to Parasitology Department of the National Microbiology Centre, Carlos II Research Institute (ISCIII), from 47 Health Centres in the Autonomous Regions of Spain, from 2006 to 2009. The samples were studied by the Knott technique, nested-PCR and ITS1-RFLP., Results: The molecular techniques applied on blood samples showed to be more sensitive that Knott's concentration technique in the diagnosis of both L. loa (n=12 versus n=4) and M. perstans (n=57 versus n=25) infections., Conclusions: The nested-PCR and ITS1-RFLP are potential diagnostic tools for daily routine laboratory species-specific and sensitive detection of L. loa and M. perstans filarial species in immigrant population and travellers from endemic areas where these filarial species are co-endemic. Knott's concentration technique was less sensitive than molecular methods and should be carried out as a complementary diagnostic assay., (Copyright © 2010 Elsevier España, S.L. All rights reserved.)

Background & Objectives: The study was aimed at elucidating the prevalence and intensity of Mansonella perstans microfilaraemia in the Emohua Local Government Area, Nigeria, and ascertaining the abundance, circadian, and the annual biting patterns of the Culicoides vector., Methods: Thick smear of 50 µl finger-prick blood stained with Giemsa was examined microscopically in a cross-sectional study. Vector landing collection on human bait was employed in a longitudinal study of the vector biting patterns, carried out between July 2005 and August 2006., Results: Of 1486 individuals examined, 11.2% of both males and females were positive for M. perstans microfilaraemia. Microfilaraemia appeared early in life. The overall geometric mean intensity among those with positive microfilaraemia was 117 mf/ml (121 mf/ml for males and 113 mf/ml for females). The differences in geometric mean intensity between different age groups were statistically significant (one-way analysis of variance; p <0.05), being highest in the oldest age group (266 mf/ml). A total of 1183 female Culicoides sp were caught from September 2005 to August 2006. The abundance of Culicoides sp was seasonal. The circadian biting activity had a broad peak between 0700 and 1200 hrs. The monthly biting rates ranged from zero bite per person per month in January 2006 to 1151 bites per person per month in June 2006. The annual biting rate was 7382 bites per person per year., Conclusion: Majority of those with positive microfilaraemia were poor socioeconomically, underscoring the need for health education and application of effective control measures against Culicoides biting midges in Emohua.

We report the occurrence of serious reactions after treatment with oral ivermectin in two patients with Mansonella ozzardi infections. Both had systemic and respiratory symptoms and recovered without sequelae. Follow-up revealed clearance of microfilaremia in both cases, with relapse in one of them. These reactions are well described in the treatment of other filarial infections, but have not yet been reported in the treatment of M. ozzardi. We are now reporting the first such known reactions with this helminthiasis.

Mansonella perstans filariasis is widely distributed across the center of Africa and equatorial America. We describe a case of post-transfusional M. perstans microfilariasis in a young child, affected with severe Plasmodium falciparum malaria, admitted in Goundi Hospital in South of Chad. A decrease of M. perstans microfilariasis in the patient's blood was observed, with no subsequent development of either clinical symptoms or eosinophilia. We suggest that, in endemic areas, transfused M. perstans microfilariae may be cleared from the blood over relatively short periods of time. It is likely that only adult worms are responsible for symptoms and eosinophilia, whereas microfilariae in the bloodstream are unable to give clinical manifestations.

The prevalence of filariae in wild raccoons trapped in southeast Georgia was determined. Examination of blood samples revealed that 74 of 113 raccoons (66%) trapped in 6 southeastern Georgia counties were infected. Seventy-three of these raccoons (65%) were infected with Mansonella llewellyni and this parasite was observed in raccoons from every location examined. Dirofilaria tenuis was found in 22 raccoons (20%) and was observed in only 3 of the 6 counties surveyed. An adult specimen of Acanthocheilonema procyonis was found in the subcutaneous tissues of 1 of 5 necropsied raccoons. This is the first record of filariae in raccoons from Georgia. In addition, Dirofilaria-like larvae were found in Aedes taeniorhyncus mosquitoes collected in Liberty County.