keywords Schistosoma mansoni, praziquantel, resistance correspondence Y.S. Liang, Jiangsu Institute of Parasitic Diseases, Meiyuan, Wuxi, Jiangsu 214064, P. R.China.The tolerance of Schistosoma mansoni to praziquantel has been reported in some endemic regions (Fallon et al. 1995;Stelma et al. 1995;Ismail et al. 1996;Guisse et al. 1997). To establish the reasons for clinical failures of praziquantel, a simple, quick and economic assay is required to detect resistance. Ideally this will involve the use of eggs or miracidia since these are the stages of the parasite life cycle which can easily be obtained from the faecal material of infected humans. As praziquantel causes changes in the shape of miracidia (Coles 1979), this was used as the basis for designing a test for resistance.In 24-well flat bottom microplates we observed the effect of praziquantel on miracidia hatched from eggs obtained from the faeces of mice infected with six isolates of S. mansoni. Two isolates were praziquantel-susceptible (one from Puerto Rico and one a mixture of isolates from Puerto Rico, Brazil, Egypt and Kenya), and four isolates were praziquantelinsusceptible, including a laboratory-selected praziquantelresistant population (Fallon & Doenhoff 1994) and three Senegalese isolates. The cessation of swimming of miracidia was observed in different concentrations of praziquantel at various times and then the morphological changes were checked by adding a drop of Lugol's iodine.When the miracidia of both the susceptible and insusceptible isolates were exposed to 10 -3 and 10 -4 M praziquantel, they immediately contracted in the middle part of their bodies, giving the shapes of an unequal dumbbell or calabash, with the greater mass at the anterior end. In 5 ϫ 10 -6 M praziquantel 100% of miracidia from the susceptible isolates immediately changed shape, whereas only 11-15% of those from the insusceptible isolates did. Thus by addition of Lugol's iodine immediately after administering praziquantel, an objective measure of susceptibility could be obtained. After 1 minute in 10 Ϫ6 M praziquantel 52% to 100% of susceptible miracidia had changed shape, and after 5 min 100% had done so compared with 3% to 15% and 9% to 18% of the insusceptible miracidia. Susceptibility could also be detected by determining whether miracidia had stopped swimming but this was less easy to read as a test than change in shape.By exposing freshly hatched miracidia to 10 Ϫ6 M praziquantel and observing change in shape over one minute it should be possible to determine whether failed therapy is due to the presence of praziquantel-tolerant worms. It is planned to investigate this in field trials in China. The work was supported by the UNDP/World Bank/WHO Special Programmme for Research and Training in Tropical Diseases. ReferencesColes GC (1979) The effect of praziquantel on Schistoma mansoni. Journal of Helminthology 53, 31-33. Fallon PG, Sturrock RF, Niang AC, Doenhoff MJ (1995) Short report: diminished susceptibility to praziquantel in a Senegal isolate of Schistosoma ...

Background5S is a lean method for workplace organization; it is an abbreviation representing five Japanese words that can be translated as sort, set in order, shine, standardize, and sustain. The 5S management method has been recognized recently as a potential solution for improving the quality of government healthcare services in low- and middle-income countries.ObjectiveTo assess how the 5S management method creates changes in the workplace and in the process and outcomes of healthcare services, and how it can be applicable in a resource-poor setting, based on data from a pilot intervention of the 5S program implemented in a health facility in Senegal.DesignIn this qualitative study, we interviewed 21 health center staff members 1 year after the pilot intervention. We asked them about their views on the changes brought on by the 5S program in their workplace, daily routines, and services provided. We then transcribed interview records and organized the narrative information by emerging themes using thematic analysis in the coding process.ResultsStudy participants indicated that, despite resource constraints and other demotivating factors present at the health center, the 5S program created changes in the work environment, including fewer unwanted items, improved orderliness, and improved labeling and directional indicators of service units. These efforts engendered changes in the quality of services (e.g. making services more efficient, patient-centered, and safe), and in the attitude and behavior of staff and patients.ConclusionsThe pilot intervention of the 5S management method was perceived to have improved the quality of healthcare services and staff motivation in a resource-poor healthcare facility with a disorderly work environment in Senegal. Quantitative and qualitative research based on a larger-scale intervention would be needed to elaborate and validate these findings and to identify the cost-effectiveness of such intervention in low- and middle-income countries.

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BackgroundSchistosomiasis is one of the major parasitic diseases in the world in terms of people infected and those at risk. Infection occurs through contact with water contaminated with larval forms of the parasite, which are released by freshwater snails and then penetrate the skin of people. Schistosomiasis infection and human water contact are thus essentially linked, and more knowledge about their relationship will help us to develop appropriate control measures. So far, only few studies have related water contact patterns to infection levels.MethodsWe have conducted detailed direct water contact observations in a village in Northern Senegal during the first years of a massive Schistosoma mansoni outbreak to determine the role of human water contact in the extent of the epidemic.We quantified water contact activities in terms of frequency and duration, and described how these vary with age and sex. Moreover, we assessed the relationship between water contact- and infection intensity patterns to further elucidate the contribution of exposure to the transmission of schistosomiasis.ResultsThis resulted in over 120,000 recorded water contacts for 1651 subjects over 175 observation days. Bathing was the main activity, followed by household activities. Frequency and duration of water contact depended on age and sex rather than season. Water contacts peaked in adolescents, women spent almost twice as much time in the water as men, and water contacts were more intense in the afternoon than in the morning, with sex-specific intensity peaks. The average number of water contacts per person per day in this population was 0.42; the average time spent in the water per person per day was 4.3 minutes.ConclusionsThe observed patterns of water contact behavior are not unusual and have been described before in various other settings in sub-Saharan Africa. Moreover, water contact levels were not exceptionally high and thus cannot explain the extremely high S. mansoni infection intensities as observed in Northern Senegal. Comparison with fecal egg counts in the respective age and sex groups further revealed that water contact levels did not unambiguously correspond with infection levels, indicating that factors other than exposure also play a role in determining intensity of infection.

The ecological changes caused by projects for the development of water resources are known to affect the epidemiology of water-related diseases. The effects of the construction of the Diama dam (completed in 1986) in the Senegal River on the epidemiology of malaria, urinary and intestinal schistosomiasis, diarrhoea and dysentery were investigated in four districts in northern Senegal. To make allowance for any general trend in reported morbidity (caused by changes in demography or the healthcare system), the numbers of cases of these illnesses reported by the basic healthcare facilities before and after the completion of the dam were compared with those of respiratory disease. Prior to the construction of the dam, malaria was the most encountered water-related disease in the medical records of all districts, followed by diarrhoea, dysentery and urinary schistosomiasis. This order remained the same after the completion of the dam. Despite the optimism of health-assessment reports prepared prior to the construction of the Diama dam, the unexpected appearance and spread of intestinal schistosomiasis as well as an increase in the incidence of urinary schistosomiasis have aggravated public health in the Senegal River basin. It remains to be judged whether the economic benefits of the dam will counterbalance its adverse effects.