Dear Sir,
I write you at the encouragement of Dr. Nyi Nyi, former special advisor to the Executive Director of UNICEF. I am seeking funding for an innovative project aimed at the control of schistosomiasis.
I was formerly a Peace Corps volunteer in the village of Breun, Mauritania, which lies fifteen kilometers west of Rosso, alongside the Senegal River. As a volunteer, I was present in the village at a time when schistosomiasis was unknown to the villagers, yet was becoming a serious problem. From epidemiological surveys taken just across the river near Richard Toll, Senegal, up to 100% of villagers have been found to be exposed to the disease.
The explosion of schistosomiasis in Mauritania and Senegal is a result of several factors: the damming of the Senegal River near St. Louis, the irrigated rice and sugar farming it has enabled, and the lack of adequate water and sanitation facilities.
Schistosomiasis is seen by many as a hopeless disease: when I questioned a Mauritanian health official about it in 1996, he raised his hands in the air in a gesture of defeat. Unknown to him, there have been developments that show great promise in the control of the disease.
For hundreds and perhaps thousands of years the villagers in Ethiopia have used berries from the endod bush as a soap. In 1964, Dr. Aklilu Lemma of Ethiopia discovered dead snails downstream from these areas where the berries were used. Curious, he searched upstream of the village and found live snails. After years of clinical and field research, it has been conclusively proven that the detergent properties of endod are molluscicidal; LC90=25 ppm.
Previous field studies have focused on the use of massive amounts of endod extract to treat entire bodies of water. This method was instrumental in the reduction of schistosomiasis among a group of Ethiopian children by eighty percent. However, the large amount of endod needed is expensive, difficult to acquire and dispense, and is also toxic to fish and harmless snails. For these reasons, endod has not been aggressively pursued by the development community interested in schistosomiasis control.
In more recent research, it has been found that endod at one ppm is effective at preventing the infection of carrier snails by infective schistosome miracidia. The authors of this report hypothesize that small amounts of endod could be used at focal points of transmission, drastically reducing the cost of intervention and making it possible for individual villages to take control of their own health needs with little if any outside support (beyond education and original endod supply.) These researchers performed their experiments in simulated outdoor conditions. While their conclusions certainly provide much hope for schistosomiasis control, future studies in the field must be performed to prove the viability of this approach.
The endod tree is currently being grown in many parts of Africa and South America in the hopes of using locally produced resources to control the disease. I wish to prove the feasibility of growing endod in a village situation, and establish a method of application that is applicable to many other villages at risk.
The subject of this proposal is to implement the use of endod in a village endemic for schistosomiasis. I am fluent in Wolof and French, so this project would be expedited in either Senegal or Mauritania where these languages are spoken. Cuttings of endod plants will be acquired from a plant laboratory, either in Europe or Africa, that holds a reservoir of strain 44, the most potent form of the plant. Upon receiving clearance from customs officials, these cuttings will be imported into the country. Cooperating with the Ministry of Agriculture, I will attempt to propagate the cuttings at a government agricultural research station, if available, and in a village where the chief is agreeable.
Endod does not pose a danger to the existing ecosystem, as it will have to be grown in an enclosed area for protection from grazing animals. The seeds are heavy and not easily dispersed, and the growing conditions in many places are too difficult to allow natural propagation. Chemical trials have proven its low mammalian toxicity, and the low concentrations used in this method will have a negligible effect on aquatic life.
If the plants are grown successfully in the village, upon the bearing of first fruit a trial will begin in which the unripe berries are harvested and ground up in a standard village mortar and pestle. A calibrated amount, (i.e. one kilo,) will be placed in a mesh cloth sack, which will be immersed into the river at a site where villagers collect their water.
Just before placement of the endod, snails will be collected from the river and examined for evidence of schistosomiasis infection. After the appropriate concentration of endod in the river is obtained using hemolytic analysis, a second sampling of snail infection will be taken. The reduction in snail infection will be evaluated, and if significant, assessment of villager infection and simultaneous treatment will commence. In cooperation with country health authorities, the drugs Oxamniquine and Praziquantel will be administered to those found with schistosomiasis infections.
Monitoring will serve to assure a constant, effective dosage of endod in the river, and proper administration of antihelminthic drugs to affected villagers. In addition, the effectiveness of the campaign will be assessed after the first year of the project. At that time, if the project is deemed successful, negotiations will be made with the government to take the project to scale for the entire region or country.
Project funding will provide endod cuttings, airfare for the project director and a technical advisor, salaries for project personnel including performance-based pay for Mauritanian workers, a vehicle, housing, computer equipment and supplies, and solar-electrical generation equipment. A computer and video camera will be used to fully document the success of the project and educational materials will be produced for project dissemination. I estimate that this project can be achieved for approximately $150,000.
Though the costs of this project are minimal, the rewards are potentially great. If successful, the project will:
- Decrease the incidence of schistosomiasis, especially among children. As an added benefit, incidence of morbidity and mortality will also be reduced.
- Increase villager awareness of schistosomiasis.
- Provide a sustainable, village-based method of schistosomiasis control.
- Decrease dependence on outside sources for assistance.
- Provide a free village source of soap.
- Increase village morale by their successful production and use of a beneficial plant.
I am uniquely qualified to successfully implement this program. Having worked in rural Mauritania for two years, I understand the environmental, political, and cultural factors in Arabic and Black Africa that must be recognized and applied to ensure fruition. I am scientifically qualified by a Masters of Science Degree in Public Health, specialization in Parasitology, from the Tulane University School of Public Health and Tropical Medicine. My desire to decrease the prevalence of schistosomiasis is personal: my adopted Mauritanian family lives on the edge of the Senegal River, and I will do anything to ensure their health and the health of villagers like them.
Thank you for your consideration of my proposal.
Abstracts
Tropenmed Parasitol 1983 Sep;34(3):177-183
Control of schistosomiasis in Adwa, Ethiopia, using the plant molluscicide endod (Phytolacca dodecandra).
Goll PH, Lemma A, Duncan J, Mazengia B
Control of Schistosoma mansoni transmission in a town in northern Ethiopia was attempted using the natural product, endod (Phytolacca dodecandra), and its use compared with niclosamide. Within a five year period prevalence was reduced from 61.5 to 36.4% in the area where endod was used. Most of this decline was accounted for by the reduction in prevalence among 1-6 year old subjects. The practical use of endod as a molluscicide was demonstrated to have a performance which compared favourably with the commercial product, and although more expensive than niclosamide still at minimal annual cost (US + 0.06 per capita).
Am J Trop Med Hyg 1993 Dec;49(6):701-706
Epidemiology of Schistosoma mansoni infection in a recently exposed community in northern Senegal.
Stelma FF, Talla I, Polman K, Niang M, Sturrock RF, Deelder AM, Gryseels B
Laboratory of Parasitology, Medical Faculty, University of Leiden, The Netherlands.
The epidemiology of Schistosoma mansoni infection was investigated in Ndombo, a village in the epicenter of a very recent outbreak of schistosomiasis in northern Senegal. Repeated fecal egg counts and antigen detection in urine and serum were carried out in a random population sample (n = 422). Eggs were found in 91% of the subjects, with 41% excreting > 1,000 eggs per gram of feces (epg) (mean egg load of 646 epg). The prevalence was almost 100% in groups greater than five years of age. In spite of the supposed absence of acquired immunity, intensities of infection decreased strongly in adults. Antigen detection confirmed the high prevalence and intensity of infection and the age-related distribution of worm loads. The emergence of this new focus is probably due to the ecologic impact of newly built dams and the extension of irrigation projects in the Senegal basin.
Trop Med Int Health 1996 Apr;1(2):221-226
Prevention of snail miracidia interactions using Phytolacca dodecandra (L'Herit) (endod) as a miracidiacide: an alternative approach to the focal control of schistosomiasis.
Madhina D, Shiff C
Blair Research Laboratory, Causeway, Zimbabwe.
The effect of endod berry extract against schistosome miracidia has been tested to determine the sensitivity of these organisms to the molluscicide and to see whether miracidia subjected to sublethal doses of the toxicant will be able to infect their specific host snails. Short contact (30 min) LC50 of endod extract with miracidia of Schistosoma mansoni was 8.2 parts per million (p.p.m.) (95% CL 5-13). However, exposure of S. haematobium to sublethal doses of 3 p.p.m. for 30 min or overnight in open air ponds reduced their infectivity 3.5-5.6-fold when compared with controls. It is suggested that the toxicant could be used in low doses at transmission foci to reduce schistosome infection in snails. This could be done by using a controlled release system to apply the toxicant material at such foci where transmission is likely to occur.
J Environ Sci Health [B] 1990 Dec;25(6):777-786
A new method for determining concentrations of Endod-S (Phytolacca dodecandra) in water during mollusciciding.
Monkiedje A, Wall JH, Englande AJ, Anderson AC
Dept. of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University Medical Center, New Orleans, LA 70112.
A hemolytic method was developed for the quantitative determination of oleanane saponin (Endod-S) in Phytolacca dodecandra (Phytolaccaceae), a plant with potent molluscicidal properties. A chemical method based on thin-layer chromatography (TLC) was used as a control for comparison with a hemolysis test. Standard curves for calibration of both tests of Endod-S gave high correlation coefficients. The hemolysis method gave a correlation coefficient of 0.98 for saponin (Endod-S) levels ranging from 1.6 to 4.2 mg/l. The TLC method gave a correlation coefficient of 0.99 for saponin levels above 1.5 micrograms. Due to the action of saponins on erythrocytes, the hemolysis method could not be used at levels below 1.6 and above 4.2 mg/l. Similarly, sample size limited TLC quantitation of these saponins at levels below 1 microgram. Both the TLC and the hemolysis methods on identical Endod-S water samples gave comparable results at saponin levels between 2 and 6 mg/l. A snail bioassay showed that the LC50 and the LC90 concentrations of Endod-S to the snail Biomphalaria glabrata (albino) were 2.57 and 2.92 mg/l respectively. These values fell in the standard curve range for the hemolysis method thus indicating that the hemolysis method is of practical value for testing Endod-S concentrations that would actually be used in field applications for snail control. The hemolysis method is less expensive than TLC and can be easily adapted to field conditions.
New for 6/99:
New PCVs
The Return
Plus other site enhancements
 |
 |
 |
 |
 |
 |