An epidemiological model for the spread of lymphatic filariasis, a mosquito-borne infection, is developed and analysed. The epidemic thresholds known as the reproduction number and equilibria for the model are determined and stabilities analysed. Results from the analysis of the reproduction number suggest that treatment will somehow contribute to a reduction in lymphatic filariasis cases, but what it does not show is the magnitude of the reduction, a part answered by the numerical simulations. Numerical simulations show that even when all lymphatic filariasis cases displaying elephantiasis symptoms are put on treatment it will not be able to eradicate the disease. This result suggests that effective control of lymphatic filariasis may lie in treatment for those displaying symptoms as well as chemoprophylaxis for the exposed. 1. Introduction Lymphatic filariasis, a debilitating disease, is one of the most prevalent and yet one of the most neglected tropical diseases with serious economic and social consequences [1, 2]. Lymphatic filariasis affects women, men and children of all ages. It is a mosquito-borne disease caused by tissue-dwelling nematodes of Brugia malayi, Brugia timori, and Wuchereria bancrofti species [1, 3] and is estimated to affect about 120 million people worldwide [4–6]. Wuchereria bancrofti is responsible for 90% of the cases and is found throughout the tropical and subtropical areas of the world; Brugia malayi is confined to southeast and eastern Asia; Brugia timori is found only in Timor and its adjacent islands [7]. Infection leads to lymphedema, a buildup of fluid due to impaired function of the lymph vessels, in only a small proportion people, even in areas of intense transmission [8], as most people with long-term infections are clinically asymptomatic. Recurrent bacterial infections in some lymphedema patients lead to elephantiasis [9]. Filarial parasites are a major cause of morbidity and therefore hinder socioeconomic growth in parts of Asia, Africa, and the Western Pacific [1, 10]. Despite improved knowledge of pathology of lymphatic filariasis and existence of the drugs diethylcarbamazine and albendazole necessary to treat lymphatic filariasis, it continues to be a major public health problem in tropical and subtropical countries. Lymphatic filariasis is more common in regions that have a higher incidence of poverty [11] making it a disease of the poor and serves as an indicator of underdevelopment [1]. Surveys in Ghana have indicated that bancroftian filariasis is present in most parts of the country with considerable
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