Height as a Surrogate for Bodyweight for Estimating the Dosage of Praziquantel and Artesunate in theTreatment of Urinary Schistosomiasis in School-Age Children

World Health Organization recommends mass treatment of all school children in areas where the prevalence of schistosomiasis is greater than 50. Praziquantel and artesunate are reported to display broad-spectrum antischistosomal activities. Since the susceptibilities of the different stages of schistosomes to the two drugs are distinctively different; it has been established that the use of these two drugs in combination will be beneficial for the treatment of urinary schistosomiasis. Dosage is determined by weight; which can be difficult to determine in field conditions. The use of calibrated height meter with height-based dosage calibration will make the work less cumbersome in field settings. Data on age; weight; and height from 264 school children who were screened and found to be infected with Schistosoma haematobium; diagnosed by the presence of the ova in their urine; were used to predict an alternative to bodyweight and thus the dosage of praziquantel and artesunate required to treat this disease. A very strong positive correlation (r = 0.8) was obtained for the height of treated children measured against weight while a moderately positive correlation coefficient (r = 0.6) was obtained for weight against age measurements; depicting that height can be used in lieu of weight for correct dose determination. A height meter calibrated with the equivalent number of tablets of praziquantel and artesunate could thus be used as a simple measurement to determine the dosage of praziquantel and artesunate needed to treat children in the field. This calibrated height will expedite treating large population of children in mass treatment campaigns in an endemic community

Efficacy of a combination of praziquantel and artesunate in the treatment of urinary schistosomiasis in Nigeria.

The combined effects of praziquantel and artesunate in the treatment of urinary schistosomiasis were assessed among 312 randomly selected schoolchildren aged 4-20 years in Adim community, Nigeria. In the preliminary screening, infection was confirmed in 327 (38.5%) of the 850 subjects screened. Infected subjects who reported for treatment were then divided into six treatment groups of 52 subjects each; 44 subjects in each group completed their treatment regimens and submitted their urine for post-treatment assessment. Praziquantel and artesunate were administered orally at 40 mg/kg and 4 mg/kg body weight, respectively. Adverse effects due to drug reactions were assessed 72 h after medication and all perceived episodes of illness were treated. Morbidity indicators were assessed 56 days after the final dose of the drug regimens. All treatment regimens were well tolerated. The cure rates were 72.7% in the praziquantel plus placebo-treated group and 70.5% in the artesunate plus placebo group, while the artesunate plus praziquantel group had the highest cure rate (88.6%). Haematuria and proteinuria were extensively reduced after treatment with the three drug regimens. This study confirmed that the treatment of urinary schistosomiasis with the combination of praziquantel and artesunate is safe and more effective than treatment with either drug alone.

Histochemical Characterization of Rain-Forest Strain of Onchocerca Volvulus Microfilariae Isolated in Akamkpa; Cross River State; Nigeria

The histochemical characterization of rain-forest strain of Onchocerca volvulus isolated in Akamkpa of Cross River State; Nigeria was studied. In a preliminary survey of 350 persons from eight villages; 75(21.4) were found to be positive for the parasite. Males (23.6) were more infected than the females but there was no statistically significant difference in the presence of infection by gender (p=0.506). Staining pattern of the parasite using Lead nitrate method for the demonstration of acid phosphatase activity revealed that of the six patterns; four corresponded to the enzyme types already described by some authors in West African rain-forest; and Sudan. One corresponded to the type found in Guinea savannas while the remaining did not correspond to any of the strains described elsewhere. The multiple enzyme staining patterns of Onchocerca volvulus microfilariae in the study area is indicative of polymorphic strain than that of West African strains. This variation in strain might contribute to the degree of pathogenicity and clinical manifestation of onchocerciasis in this endemic zone

Prevalence of Urinary Schistosomiasis among School Children in Ukwelo-Obudu and Abini communities in Cross River State; Nigeria

Background: The prevalence and intensity of Schistosoma haematobium infection were studied in Ukwelo-Obudu; and Abini communities of Cross River State; Nigeria. Aim: To screen for the presence of ova of S. haematobium in the urine of school children in the two communities. Method: Six hundred urine specimens (400 in Abini and 200 in Ukwelo-Obudu community) were collected by random sampling from school children aged 5-17 years from the two communities and screened for ova of Schistosoma haematobium by filtration of urine and counting of filtered carbol fuchsin-stained eggs of Schistosoma haematobium. Retrospective study of Schistosoma haematobium infection was also carried out in Ukwelo-Obudu community. Results: Infection with S. haematobium was not found in Ukwelo-Obudu whereas in Abini community; a prevalence of 4.5was found. The highest prevalence of infection (7.7) occurred in the age group of 11-13 years. There was a strong positive correlation between the presence of infection (ova of S. haematobium) and existence of haematuria (r = 0.81) and proteinuria (r = 0.71) in Abini community. There was a statistically significant difference in the prevalence of proteinuria between male and female subjects examined (P=0.0008). A retrospective study of Schistosoma haematobium infection in Ukwelo-Obudu community showed 2006 as the year with the highest record of infection [11(35.5)] whereas the year 2004 recorded the lowest number of infection. Conclusion: This study has revealed a low prevalence of Schistosoma haematobium infection in Abini and the absence of infection in Ukwelo-Obudu communities respectively

Efficacy of artesunate in the treatment of urinary schistosomiasis, in an endemic community in Nigeria.

The efficacy and tolerability of oral artesunate for the treatment of urinary schistosomiasis was assessed among schoolchildren aged 5-18 years in Adim community, Nigeria. Overall, 500 children, randomly selected from those attending the Presbyterian primary school, were each invited to provide two consecutive urine samples. Using standard parasitological procedures, Schistosoma haematobium ova were found in the samples from 145 (29.0%) of the subjects. Most (87) of the infected subjects were then treated orally with artesunate, using two doses, each of 6 mg/kg, given 2 weeks apart. When the treated children were re-examined 4 weeks after the second dose of artesunate, 61 (70.1%) appeared egg-negative and were therefore considered cured. Post-treatment, the geometric mean egg count (GMEC) for the treated subjects who were not cured was significantly lower than the pre-treatment GMEC for all the treated subjects, with log10[(eggs/10 ml urine) + 1] values of 0.9 v. 1.75 (t = 4.45; P < 0.05). The cure 'rate' for the subjects aged > or = 10 years was slightly higher than that among the younger subjects. It was lowest for the heavier subjects (70% for those weighing 41-50 kg) and highest (79%) for the subjects who weighed 31-40 kg. The artesunate was well tolerated. This observation of a therapeutic effect of artesunate against S. haematobium in Nigeria confirms recent observations from Senegal. In the Adim community at least, it would be more cost-effective to treat urinary schistosomiasis with artesunate than with praziquantel. The wide-spread use of artesunate against schistosomiasis has to be considered carefully, however, if it is not to compromise the efficacy of the drug as an antimalarial, by increasing the risk of resistance developing in local Plasmodium.