Published by Maney Publishing (c) W S Maney P0.05 for each). Both the preva- lence of S. haematobium infection (x2=29.2;P0.05) but slightly higher among those aged at least 10 years (70.9%) than among the younger subjects (68.8%).TABLE 1.The prevalences of schistosome infection and haematuria amongst the subjects participating in the preliminary survey, split by age and genderMalesFemalesAllx2P* 0.05 No. and (%) with haematuria20 (15.2)27 (20.5)47 (16.8)0.480.05 i10 No. examined112108220NANA No. and (%) infected48 (42.9)43 (39.8)91 (41.4)0.210.05 No. and (%) with haematuria38 (33.9)37 (34.3)75 (34.1)0.0020.05 No. and (%) infected69 (28.3)76 (29.7)145 (29.0)0.120.05*For difference between genders. NA, Not applicable.TABLE 2.The prevalences of haematuria post-treatment and the frequencies of parasitological cure, split by age and genderMalesFemalesAllx2P* 0.05 No. and (%) without post-treatment haematuria10 (90)18 (86)28 (88)1.660.05 No. and (%) with post-treatment haematuria1 (9)3 (14)4 (13)0.090.05 i10 No. treated312455NANA No. and (%) cured20 (65)19 (79)39 (71)1.400.05 No. and (%) without post-treatment haematuria23 (74)20 (83)43 (78)0.650.05 No. and (%) with post-treatment haematuria8 (26)4 (17)12 (22)0.660.05*For difference between genders. NA, Not applicable.Published by Maney Publishing (c) W S Maney Table 4). Following treatment, the heavier subjects (weighing 4150 kg) were most likely to have an uncured infec- tion (40%), whereas those of moderate weight (3140 kg) were least likely (21%). Overall, the geometric mean egg count (GMEC) appeared to be drastically reduced by treatment, with the log10(eggs/10 ml urine)+1 values falling from 1.75 pre- treatment to 0.9 post-treatment (Table 4; t=4.45; P70% of those treated and to reduce signifi- cantly the intensities of infection in those not cured. In Senegal, similarly, De Clercq et al. (2002) also found artesunate to be effective against S. haematobium, although the results they obtained with praziquantel were consis- tently better. The present results and those of De Clercq et al. (2002) differ remarkably from the observations of Borrmann et al. (2001), who found that only 27% of the subjects they treated with artesunate in Gabon were cured and that almost the samepercentage of those given placebo tablets (20%) also appeared cured. Borrmann et al. (2001) thought that their disappointing results might be the result of an inherent resistance to artemisinin or its derivatives in S. haematobium. There is, however, no evidence in the present results from Nigeria, or those of De Clercq et al. (2002) from Senegal, of marked resistance to artesunate in S. haematobium. In addition, NGoran et al. (2003) reported the protective efficacy of a closely related compound, artemether, against S. haematobium infection in Cte dIvoire, although the effect was lower than that previously reported for S. japonicum (Xiao et al., 2000b) and S. mansoni (Utzinger et al., 2000). In the present study, the use of a 2-week interval between the two doses as recom- mended, for artemether, by Xiao et al. (2000c) rather than 3 weeks, the generally low intensities of infection pre-treatment, and the fact that artesunate had not previ- ously been used in Adim may all have enhanced the (apparent) efficacy of the drug. About four fifths of the subjects of the present study had light infections when treated (Table 3). There are three important limitations of the present study. Firstly, the design of the study was non-randomized. Secondly,TABLE 5. The costs, in Nigeria, of the tablets needed to give children of various weights two doses of artesunate (each of 6 mg/kg) or a single dose of praziquantel (of 40 mg/kg), for the treatment of urinary schistosomiasisWeight (kg)No. of tablets required/subjectCosts of tablets/subject (U.S.$)*Praziquantel:artesunate PraziquantelArtesunatePraziquantelArtesunatecost ratio201.341.921.111.73:1 251.752.521.391.81:1 302.062.961.671.78:1 352.373.411.941.75:1 402.784.002.221.80:1 453.094.442.491.79:1 503.3104.892.771.76:1 553.7115.483.061.79:1 604.0125.933.331.78:1*In Nigeria, at the time of the study, a 600-mg tablet of praziquantel cost 200.00 Naira, a 60-mg tablet of artesunate cost 37.50 Naira, and U.S.$1 was the equivalent of 135.00 Naira.Published by Maney Publishing (c) W S Maney Fenwick et al., 2003), the difference pro- bably reflecting the difficulty of procuring foreign exchange for the importation of praziquantel into Nigeria. Human schis- tosomiasis is primarily a disease of rural, agricultural communities where poverty iscommon. In communities such as Adim, where large families are the rule, parents are likely to be constrained financially when procuring drugs for the treatment of their children. If left untreated, however, their children may have schistosomiasis for many years and, consequently, poor school atten- dance and academic performance (U