An Overview of the Management of Mansonellosis

Abstract

Mansonellosis is caused by three filarial parasite species from the genus Mansonella that commonly produce chronic human microfilaraemias: M. ozzardi, M. perstans and M. streptocerca. The disease is widespread in Africa, the Caribbean and South and Central America, and although it is typically asymptomatic it has been associated with mild pathologies including leg-chills, joint-pains, headaches, fevers, and corneal lesions. No robust mansonellosis disease burden estimates have yet been made and the impact the disease has on blood bank stocks and the monitoring of other filarial diseases is not thought to be of sufficient public health importance to justify dedicated disease management interventions. Mansonellosis´s Ceratopogonidae and Simuliidae vectors are not targeted by other control programmes and because of their small size and out-door biting habits are unlikely to be affected by interventions targeting other disease vectors like mosquitoes. The ivermectin and mebendazole-based mass drug administration (iMDA and mMDA) treatment regimens deployed by the WHO´s Elimination of Neglected Tropical Diseases (ESPEN) programme and its forerunners have, however, likely impacted significantly on the mansonellosis disease burden, principally by reducing the transmission of M. streptocerca in Africa. The increasingly popular plan of using iMDA to control malaria could also affect M. ozzardi parasite prevalence and transmission in Latin America in the future. However, a potentially far greater mansonellosis disease burden impact is likely to come from shortcourse curative anti-Wolbachia therapeutics, which are presently being developed for onchocerciasis and lymphatic filariasis treatment. Even if the WHO´s ESPEN programme does not choose to deploy these drugs in MDA interventions, they have the potential to dramatically increase the financial and logistical feasibility of effective mansonellosis management. There is, thus, now a fresh and urgent need to better characterise the disease burden and ecoepidemiology of mansonellosis so that effective management programmes can be designed, advocated for and implemented.

Molecular Detection and Characterization of Intestinal and Blood Parasites in Wild Chimpanzees (Pan troglodytes verus) in Senegal

“…Unfortunately, in our study, we have not been able to compare the phylogeny of both groups of sequences as they correspond to different gene fragments. Some species of filariae, such as Onchocerca volvulus or Wuchereria bancrofti , have medical importance, although mansonellosis (the disease produced by M. perstans ) is not considered a public health hazard [ 94 ]. The larvae of filariae (microfilariae) are found in the blood or the skin, while adults are found inside the host near the internal organs forming nodules or semi-protected remain confined in other areas.…”

Nodding Syndrome, a Case-control Study in Mahenge, Tanzania: <em>Onchocerca volvulus </em>and not <em>Mansonella </em><em>perstans</em> as Risk Factor

“…The midges that transmit M. perstans are most active at night [39]. Midges are very small and hence are considered to pass through bed nets [40]. However, insecticide-treated nets have been shown to offer protection to horses from Culicoides, the M. perstans vector, in the event of an African horse sickness virus epidemic [41].…”

Neutrophils: Friend or foe in Filariasis?

“…Even less is known about the epidemiology of Mansonella infections, although these potentially account for the majority of filarial nematode‐infected people, particularly in Africa (see Table 1). 38–40 Infection with Mansonella species is typically reported as asymptomatic but pathology including headaches, fever, dermatitis and rashes do occur 40 . Our lack of epidemiologic knowledge may mean adverse consequences are under reported.…”