Specific schistosomiasis treatment as a strategy for disease control

The first efficient treatments for schistosomiasis were carried out using trivalent antimonials. The use of tartar emetic was initiated as a treatment for this disease by McDonagh, in 1915. Christopherson then consolidated it in 1918 and gave the first description and published the details of the positive results obtained in relation to schistosomiasis cure with this drug when administered intravenously. In 1912, Gaspar Vianna was the first to use tartar emetic in Brazil, which was administered for the treatment of mucocutaneous leishmaniasis. From 1920 onwards, it started to be used for schistosomiasis treatment, initially by Jesuíno Maciel (1920), and professionally on a large scale by Heraldo Maciel (1924, 1925) in the Health Service of the Brazilian Navy. New antimonial compounds other than tartar emetic (i.e., the double salt, potassium antimony tartrate) started to appear in later years. Among these were homologues of tartar emetic including: sodium antimony tartrate (double salt), neoantimosan, Fuadin®, Reprodal® or Stibophen® (sodium antimony disulfate), Anthiomaline® (sodium antimony thiomalate), Tiostan® (sodium antimony gluconate) and Astiban® (sodium antimony dimercaptan). In addition to intravenous administration, the last five compounds on this list could also be applied intramuscularly. However, all of these compounds were extremely toxic for the cardiac muscle and painful when applied intramuscularly. Many deaths due to muscle fibre fragmentation ( fragmentatio cordis) were observed (Dias 1949). In an electrocardiographic study on 120 patients treated with Astiban® and 30 treated with Fuadin®, Coura et al. (1963) observed significant “ischemic” abnormalities, which they correlated with the dose and frequency of application (1, 2 or 3 times a week, or daily), showing the cumulative effect of the drug. In addition, they also demonstrated both clinically and experimentally that the “ischemia” was due to arteriolar paralysis of the musculature with dilatation and delay in circulation (examination of the eye fundus in patients and histopathology of the hearts of guinea pigs treated with the drugs). Despite the limitations resulting from the toxic effects of trivalent antimonials, large-scale pioneering studies were carried out in Brazil with selective treatment. Among these are the studies by Heraldo Maciel (1924, 1925, 1929), Get Jansen (1946), Hoel Sette (1953) and Rodrigues da Silva (1958), which made important contributions towards knowledge of the results and difficulties of chemotherapy as a potential control method for schistosomiasis. Since then, specific treatment for Manson’s schistosomiasis has been one of the critical measures for controlling the morbidity of this disease in distant areas. There are difficulties in using such a treatment as a mass treatment for the entire population, because of side effects, temporary absences and refusals among individuals. Another key factor in the limitation of treatment is the importance that re-infection plays. Nonetheless, it has clearly been demonstrated that use of specific treatment may reduce the progression of the disease to severe forms and these results were confirmed by Kloetzel (1963). Specific treatment for schistosomiasis has emerged over the last 30 years, in part due to the launch of oxam+ Corresponding author: [email protected] Received 28 January 2009 Accepted 5 August 2009 Specific schistosomiasis treatment as a strategy for disease control