Wuchereria bancrofti

About: Wuchereria bancrofti is a research topic. Over the lifetime, 2224 publications have been published within this topic receiving 44186 citations.

Strategies and tools for the control/elimination of lymphatic filariasis.

Abstract: Lymphatic filariasis infects 120 million people in 73 countries worldwide and continues to be a worsening problem, especially in Africa and the Indian subcontinent. Elephantiasis, lymphoedema, and genital pathology afflict 44 million men, women and children; another 76 million have parasites in their blood and hidden internal damage to their lymphatic and renal systems. In the past, tools and strategies for the control of the condition were inadequate, but over the last 10 years dramatic research advances have led to new understanding about the severity and impact of the disease, new diagnostic and monitoring tools, and, most importantly, new treatment tools and control strategies. The new strategy aims both at transmission control through community-wide (mass) treatment programmes and at disease control through individual patient management. Annual single-dose co-administration of two drugs (ivermectin + diethylcarbamazine (DEC) or albendazole) reduces blood microfilariae by 99% for a full year; even a single dose of one drug (ivermectin or DEC) administered annually can result in 90% reductions; field studies confirm that such reduction of microfilarial loads and prevalence can interrupt transmission. New approaches to disease control, based on preventing bacterial superinfection, can now halt or even reverse the lymphoedema and elephantiasis sequelae of filarial infection. Recognizing these remarkable technical advances, the successes of recent control programmes, and the biological factors favouring elimination of this infection, the Fiftieth World Health Assembly recently called on WHO and its Member States to establish as a priority the global elimination of lymphatic filariasis as a public health problem.

Re-assessing the global prevalence and distribution of lymphatic filariasis.

Abstract: This paper estimates the global burden of lymphatic filariasis based on a review of the published literature on infection and disease surveys. A method for aggregating and projecting prevalence data from individual studies to national, regional and global levels, which also facilitates the estimation of gender and age-specific burdens, is presented. The method weights in favour of the larger, and hence presumbably more reliable, studies and relies on estimated empirical relationships between gender, age, infection and disease in order to correct studies with incomplete data. The results presented here suggest that although the overall prevalence of filariasis cases is 2.0% globally (approximately totalling 119 million cases), the disease continues to be of considerable local importance, particularly in India and Sub-Saharan Africa. Estimates by age and gender clearly show that, unlike other helminth infections, filariasis is mainly a disease of the adult and older age-classes and appears to be more prevalent in males. This work suggests that the derivation of more accurate estimates of the burden of filariasis will require a better understanding of both the epidemiology and the spatial aspects of infection and disease. It also suggests that filariasis is preventable based on a geographically targeted strategy for control.

Helminth- and Bacillus Calmette-Guérin-Induced Immunity in Children Sensitized In Utero to Filariasis and Schistosomiasis

Abstract: Infants and children are routinely vaccinated with bacillus Calmette-Guerin (BCG) in areas of the world where worm infections are common. Because maternal helminth infection during pregnancy can sensitize the developing fetus, we studied whether this prenatal immunity persists in childhood and modifies the immune response to BCG. Children and newborns living in rural Kenya, where BCG is administered at birth and filariasis and schistosomiasis are endemic, were examined. T cells from 2- to 10-year-old children of mothers without filariasis or schistosomiasis produced 10-fold more IFN-γ in response to mycobacterial purified protein derivative than children of helminth-infected mothers ( p < 0.01). This relationship was restricted to purified protein derivative because maternal infection status did not correlate with filarial Ag-driven IL-2, IFN-γ, IL-4, or IL-5 responses by children. Prospective studies initiated at birth showed that helminth-specific T cell immunity acquired in utero is maintained until at least 10–14 mo of age in the absence of infection with either Wuchereria bancrofti or Schistosoma haematobium . Purified protein derivative-driven T cell IFN-γ production evaluated 10–14 mo after BCG vaccination was 26-fold higher for infants who were not sensitized to filariae or schistosomes in utero relative to subjects who experienced prenatal sensitization ( p < 0.01). These data indicate that helminth-specific immune responses acquired during gestation persist into childhood and that this prenatal sensitization biases T cell immunity induced by BCG vaccination away from type 1 IFN-γ responses associated with protection against mycobacterial infection.