Schistosomiasis continues to be an important debilitating illness, in particular when associated with other potential causes of morbidity in tropical regions. Environmental changes, international travel and migratory populations increase the prevalence of schistosomiasis. The failure to develop an effective vaccine and the failure to eliminate snail populations mean that the control of schistosomiasis must rely on large-scale chemotherapy. The administration of praziquantel in a regimen of 40 mg/kg bodyweight in a single dose has been useful for controlling this disease in several countries such as Egypt, China, Brazil, the Philippines, Puerto Rico, Tunisia, Morocco, and Saudi Arabia 
. However, rapid reinfection, incomplete cure rates, and evidence of praziquantel-tolerant schistosomes in the laboratory suggest a high risk of the development of praziquantel resistance 
Artemisinin derivatives currently offer the most important alternative for schistosomiasis treatment. They are effective against the juvenile stages of S. mansoni
, S. haematobium
and S. japonicum
, but are less effective against adult worms. Our results demonstrate that artesunate in monotherapy does not offer an alternative for schistosomiasis treatment; none of the trials included in our meta-analysis seemed to significantly favor artesunate over praziquantel as monotherapy. Artesunate monotherapy may not be beneficial because its activity only affects the early stages of the parasite. In contrast, praziquantel acts against the mature forms of the parasite, curing 60 to 90 percent of patients. We measured efficacy of artemisinin derivatives at earliest after treatment in the context of continued disease transmission, in this sense some researchers have suggested that 3 weeks might be best 
. However, more studies are needed to assess the effect of the evaluation period on the treatment outcome in those patients infected with schistosomiasis and treated with artemisinin derivatives.
Despite the incomplete efficacy of artemisinin derivatives alone in terms of cure rates, their pharmacological activities provide an excellent opportunity to combine with praziquantel. Our study confirms the Liu et al.
meta-analysis that support that artemisinin derivative plus
praziquantel used in combination significantly increase the cure rates of schistosomiasis in comparison with praziquantel alone. The rationale for choosing combination treatments is to ensure rapid and reliable cures and to avoid the development of resistance to praziquantel. However, these estimated results cannot be regarded as definitive because they are based on diverse populations and the sample size of the trials included is small. Nevertheless, meta-analysis methodology may help to improve the power of small exploratory trials, including the broadest range of data (over multiple locations).
The adverse effects related with artemisinin derivatives were mild, artemether and artesunate were both well tolerated. Furthermore, studies that evaluated the antimalarial combination of artesunate plus sulfadoxine-pyrimethamine efficacy in schistosomiasis presented significant less adverse effects compared with praziquantel. Finally, no additional side-effects caused by possible interactions between praziquantel and artemisinin derivatives were detected across the studies. Taken together, these results indicate that the incorporation of artemisinin derivatives do not present any limitation related with the increase of adverse effects.
However, the incorporation of artemisinin derivatives in mass praziquantel administration has three important limitations: first, the cost-effectiveness implications; second, owing to the sub-optimal biopharmaceutical properties (very short half-life) of artemisinin derivatives repeated treatments are required 
, and third the use of artemisinin derivatives in mass administration could contribute to the emergence of artemisinin-resistant malaria 
. Our meta-analysis shows that artesunate plus
sulfadoxine-pyrimethamine does not offer a benefit over praziquantel-based therapy for S. mansoni
and S. haematobium
infections. Note that, to date no studies were carried out to evaluate changes on schistosomiasis endemicity as a function of the large-scale use of artemisinin based therapy in malaria control programmes.
Praziquantel is a poor choice for chemoprophylaxis because of its short half-life (1 to 1.5 hours) and because it cannot kill the schistosomula stage of the parasite 
. However, a better option for schistosomiaisis prophylaxis could be the use of artemisinin derivatives because they are active against schistosomula stage 
. In fact, our results have shown the prophylactic activity of artesunate and artemether. This is in accordance with some previous published reviews 
and a former meta-analysis performed by Wu et al.
in 2003 
. Despite various levels of endemicity, different ecological settings and the diverse backgrounds of the participants, the prophylactic effect of artemisinin derivatives was demonstrated in each trial. It may be concluded that the prophylactic effect of artemisinin derivatives should be considered highly relevant in S. japonicum
infection. Many clinical trials which focused on S. japonicum
have shown that artesunate and artemether administered in multiple doses reduce the incidence of the infection to a significant extent, especially in those studies in which the target population was exposed to the infection at a specific moment because of flooding. However, the quality of the reports that evaluate the role of artemisinin derivatives as prophylatic drug was not optimal. In addition, we detected the presence of publication bias for artesunate and artemether prophylaxisis meta-analysis. Thus, the quantitative RR found might be affected in some extension by publication bias. New schistosomiasis trials focused on the prophylactic effect of artemisinin derivatives should be conducted paying attention to quality issues. In this sense, a previous report described the methodological limitations linked to clinical trials focused on schistosomiasis 
. Finally, the meta-analysis of artemisinin derivatives focused on chemoprophylactic activity against schistosomiasis has also two key limitations: first, the difficult access to some trials published in Chinese language and second the lack of studies reporting efficacy of artemisinin derivatives as chemoprophylactic drug in S. mansoni
and S. haematobium
In sum, the combination of artemisinin derivatives with praziquantel seems to be the best option for the treatment of schistosomiasis, reflecting their complementary pharmacological profiles against this disease. In addition, the auxiliary benefit of artemisinin combination treatment administered to malaria patients should be evaluated in schistosome endemic areas. We also confirm the prophylactic effect of artemisinin derivatives across the different trials performed in China. Finally, we hope to provide clinicians and policy-makers with a convenient and evidence-based summary of the primary literature on which to base their decisions.