An analysis of the safety of the single dose, two drug regimens used in programmes to eliminate lymphatic filariasis.

This review of the safety of the co-administration regimens to be used in programmes to eliminate lymphatic filariasis (albendazole + ivermectin or albendazole + diethylcarbamazine [DEC]) is based on 17 studies conducted in Sri Lanka, India, Haiti, Ghana, Tanzania, Kenya, Ecuador, the Philippines, Gabon, Papua New Guinea, and Bangladesh. The total data set comprises 90,635 subject exposures and includes individuals of all ages and both genders. Results are presented for hospital-based studies, laboratory studies, active surveillance of microfilaria-positive and microfilaria-negative individuals, and passive monitoring in both community-based studies and mass treatment programmes of individuals treated with albendazole (n = 1538), ivermectin (9822), DEC (576), albendazole + ivermectin (7470), albendazole + DEC (69,020), or placebo (1144). The most rigorous monitoring, which includes haematological and biochemical laboratory parameters pre- and post-treatment, provides no evidence that consistent changes are induced by any treatment; the majority of abnormalities appear to be sporadic, and the addition of albendazole to either ivermectin or DEC does not increase the frequency of abnormalities. Both DEC and ivermectin show, as expected, an adverse event profile compatible with the destruction of microfilariae. The addition of albendazole to either single-drug treatment regimen does not appear to increase the frequency or intensity of events seen with these microfilaricidal drugs when used alone. Direct observations indicated that the level of adverse events, both frequency and intensity, was correlated with the level of microfilaraemia. In non microfilaraemic individuals, who form 80-90% of the 'at risk' populations to be treated in most national public health programmes to eliminate lymphatic filariasis (LF), the event profile with the compounds alone or in combination does not differ significantly from that of placebo. Data on the use of ivermectin + albendazole in areas either of double infection (onchocerciasis and LF), or of loiais (with or without concurrent LF) are still inadequate and further studies are needed. Additional data are also recommended for populations infected with Brugia malayi, since most data thus far derive from populations infected with Wuchereria bancrofti.

Community empowerment in the control of lymphatic filariasis in Misima, Milne Bay Province using diethylcarbamazine in combination with albendazole.

We report the successful implementation of a community-based lymphatic filariasis control program using annual single-dose treatment with diethylcarbamazine (DEC) in combination with albendazole. The target population included over 28,000 people in the Samarai Murua District, Milne Bay Province, Papua New Guinea. A community-based delivery model was as effective as the standard health services delivery model. The number of people tested in 1998 before mass drug administration (MDA) and in 1999, one year after treatment, were 1644 and 942 respectively; the number who received mass treatment was 29,883 in 1998 and 28,965 in 1999. The prevalence of antigenaemia decreased significantly from 19% to 12%. The cost of running the program also decreased by 50%. The total number of trained health staff required to conduct the MDA program declined from 62 in 1998 to 12 in 1999, a reduction of 81%, with a cost saving in salary and allowances. A salient organizational initiative that surfaced was the use of local expertise in the private sector as a catalyst for obtaining funds from external sources to manage and facilitate the program which was conducted with locally available resources.

Prevalence of filarial antigenaemia in Papua Nnew Guinea: results of surveys by the School of Public Health and Tropical Medicine, James Cook University, Townsville, Australia.

During the period from 1991 to 1997 the School of Public Health and Tropical Medicine, James Cook University carried out filariasis surveys in several parts of Papua New Guinea using the newly introduced Onchocerca gibsoni monoclonal (Og4C3) and immunochromatographic test (ICT) antibody-based assays for filarial antigen and, in some cases, a Knott's test for microfilariae. The average prevalence of filarial antigenaemia and microfilaraemia was 56% and 35% respectively confirming earlier survey results that filariasis is hyperendemic in many parts of the country. The antigen tests detected 25% more cases than the Knott's test and the simplicity of the ICT and its capacity to produce almost instant results make it an ideal tool for surveys.