International Strategies for Tropical Disease Treatments - Experiences with Praziquantel - EDM Research Series No. 026
(1998; 113 pages) View the PDF document
Table of Contents
View the documentAbstract
View the documentAcknowledgments
View the documentInformation on authors
View the documentExchange rates used in the report
Open this folder and view contentsChapter 1: Policies for praziquantel*
Open this folder and view contentsChapter 2: Bayer & E. Merck: Discovery and development of praziquantel*
Open this folder and view contentsChapter 3: Shin Poong Pharmaceutical Co.: Process development in the Republic of Korea*
Open this folder and view contentsChapter 4: The Egyptian International Pharmaceutical Industries Co.: Praziquantel formulation*
Open this folder and view contentsChapter 5: The international supply of praziquantel*
Close this folderChapter 6: Demand for praziquantel and national distribution*
View the documentThe demand for praziquantel
View the documentNational distribution of praziquantel
View the documentReferences
Open this folder and view contentsChapter 7: Prices and production costs of praziquantel*
View the documentOther documents in the DAP Research Series
View the documentDAP Research Series No. 26

National distribution of praziquantel

WHO support

According to WHO, starting in 1983, a total of 24 countries have established schistosomiasis control programmes (WHO, 1993). These countries are: Algeria, Brazil, Botswana, Burundi, China, Dominican Republic, Egypt, Ghana, Indonesia, Laos, Madagascar, Malawi, Mali, Mauritius, Morocco, Nigeria, Philippines, Saudi Arabia, Sudan, Suriname, Tunisia, United Republic of Tanzania: Zanzibar, Venezuela, and Zimbabwe (WHO, 1993). WHO provides technical assistance to these programmes, but does not become involved in the funding of control programmes or in the procurement of drugs for the programmes. As part of a global monitoring effort, a computerized global database has been established in the Schistosomiasis Control Unit of WHO, with information on the epidemiology of schistosomiasis, control activities, and people responsible for control, water resources, and chemotherapy for each endemic country (WHO, 1993).

UNICEF support

UNICEF has provided some assistance to distribute praziquantel in certain countries, mainly in Asia and Africa, as a part of UNICEF-assisted schistosomiasis control programmes. UNICEF, however, does not directly become involved in the distribution of praziquantel within a country, except through an essential drugs programme. In general, UNICEF relies on each country to arrange for the effective distribution of drugs procured through its supply service. In some cases, UNICEF might provide technical support, if requested by the government.

World Bank support

The World Bank has provided significant financial support to schistosomiasis control efforts in Egypt, China, and Brazil. These activities are briefly described below.

Brazil: The schistosomiasis control project in Brazil is part of a WB-funded Endemic Diseases Control Project (Interview No. 7). Oxamniquine remains the most important chemotherapeutic agent used in schistosomiasis control in Brazil. According to the World Bank, in 1989, the price of oxamniquine was about three times the price of praziquantel in Brazil (World Bank, 1989). Even at the estimated price of US$ 2.84 for a course of praziquantel, it was calculated that Brazil could save several million US dollars by switching to praziquantel. However, the Brazilian programme has not procured praziquantel, despite strong pressure from the WB. Sales of praziquantel in the Brazilian private market are relatively small.

According to WB sources, physicians in Brazil are reluctant to prescribe praziquantel, despite evidence that praziquantel is superior to and cheaper than oxamniquine, and despite successful clinical trials in Sao Paulo. One reason for resistance is complaints about the large size of praziquantel tablets, which makes it difficult for children to swallow them. In addition, there is a general feeling that oxamniquine is a satisfactory drug for the treatment of schistosomiasis and it has been used for a long time. Further, oxamniquine is packaged locally in Brazil by a subsidiary of Pfizer, which may provide an incentive to continue the drug’s use in the national programme.

According to the Brazilian Ministry of Health, about 300,000 people are treated annually in the national schistosomiasis control programme. Each year the programme uses approximately 40,000 vials of 12 ml. oxamniquine syrup and 960,000 capsules of 250 mg. oxamniquine.

China: The WB-supported schistosomiasis project in China involves 8 provinces, which together represent almost 90% of WHO’s estimated total need for praziquantel in China (Interview No. 7). According to WB sources, almost all the consumption of praziquantel in China occurs through the government’s schistosomiasis control programme, with no significant sales in the private sector or through non-MOH sources.

The project in China is being implemented in three phases: in high intensity areas, control of schistosomiasis is through chemotherapy (praziquantel) and health education; in medium intensity areas, control is through chemotherapy, health education, and mollusciciding (using primarily niclosamide); in low intensity areas, control involves limited chemotherapy, a lot of mollusciciding, and a limited number of environmental interventions. The project also involves operations research, particularly in relation to drug efficacy and economic analysis of different interventions. According to the WB, a significant share of the project’s expenses (about 42%) are for the procurement of praziquantel, for a total of US$ 3.8 million over the course of the project, but we could not obtain estimates of the procurement volume.

When the project started in 1991, praziquantel was procured from Bayer. In 1992, Shin Poong won an international tender bid to supply all praziquantel for the project, including praziquantel tablets for human consumption and praziquantel powder for cattle. According to WB sources, the Chinese initially tried to disqualify Shin Poong and substitute it with a local supplier, but did not succeed because of WB objections on the grounds that such substitution would be an infringement of the WB’s procurement procedures (see Chapter 5) (Interview No. 7). The niclosamide used for the project was initially supplied by Bayer, but a Chinese company subsequently submitted a bid at 80% below the Bayer price. The quality of the Chinese product was found to be good, and Chinese niclosamide is now used in the project (Interview No. 7).

According to the WB, the project has been very successful. An initial survey was undertaken in 1989 by the WB, with a follow-up survey in 1992. The second survey showed that the schistosomiasis control measures had achieved a major impact-the focus was therefore shifted from chemotherapy to molluscicides and environmental measures. Further, the recent price declines for praziquantel have resulted in significant savings, which have been used to purchase niclosamide for expanded mollusciciding.

Egypt: The World Bank (WB) programme in Egypt was initiated in 1992, in order to extend the ongoing Egyptian schistosomiasis control programme to the Nile Delta region (Interview No. 7). The WB project has been funded for a period of six years (1992 to 1997), and the total project costs are estimated at about US$ 43 million, with the WB providing a loan of US$ 26.84 million. This independent project is attached to a larger Water Drainage and Irrigation project, also funded by the WB. The WB loan funds the entire procurement of praziquantel by the Egyptian government (the estimated cost of the procurement being about US$ 12.87 million), in addition to funding provided for the other components of the control programme.

The prevalence of schistosomiasis in the delta area at the start of the programme, in 1992, was estimated at over 35%. The goal of the programme is to reduce the prevalence of schistosomiasis by 75% (from >35% of the population to <10%) at the end of the six years. In 1991, the Egyptian government budgeted about L.E. 14 million (US$ 4.65 million) for the purchase of praziquantel tablets and pesticides. Since 1990, all government procurement has been from a local source (EIPICO) (see Chapter 4).

Other countries: In addition to the three countries discussed above, the World Bank has played a major role in the schistosomiasis control programme in the Philippines (providing US$ 7.3 million from 1983-1992 for the purchase of praziquantel). The World Bank has made limited contributions to national programmes in Cameroon, Côte d’Ivoire, Kenya, Nigeria and Senegal. We do not have estimates of praziquantel procurements in these countries through WB loans, due to the lack of a central database in the WB on praziquantel procurements.

Bilateral aid agencies and national schistosomiasis control programmes

Bilateral aid agencies have also assisted national schistosomiasis control programmes in improving access to praziquantel. Unfortunately, we could find no database or studies on the role of bilateral aid agencies in schistosomiasis control-including technical and financial assistance. Here we discuss only the activities of the German bilateral aid agency, since it seems to have been most active with regard to praziquantel. USAID has supported schistosomiasis control efforts in Egypt, but has devoted little attention to praziquantel procurement. The Bilharzia Fund, a German government-sponsored agency (although not technically a bilateral aid agency), has also supported national schistosomiasis control programmes.

The Health, Population, and Nutrition Division of the German Agency for Technical Cooperation (GTZ) has participated in several schistosomiasis projects in Africa. While each project was a “separate entity with its specific national background, structure and strategies,” most of GTZ’s efforts were directed at testing and implementing population-based chemotherapy with praziquantel, using specialized mobile teams (Gryseels, forthcoming). For example, in the early 1980s GTZ-assisted schistosomiasis control projects were initiated in Mali, Congo, and Madagascar, and were evaluated by external experts in 1987, 1988, and 1989, respectively (Gryseels, forthcoming). These projects were among the first large-scale applications of praziquantel for population-based chemotherapy, and showed that schistosomiasis prevalences could be quickly and safely reduced by mass or selective treatment. The evaluations also demonstrated, however, that reinfection occurred and that repeated treatment was necessary, making the vertical structures and strategies of the projects difficult to sustain in the long term (Gryseels, forthcoming). GTZ is not currently purchasing or supporting procurement of praziquantel (Korte, 1994).

Role of the private sector in praziquantel distribution

Private industry associations have also supported some schistosomiasis control programmes. The German Pharma Fund, for example, is an organization used by the German pharmaceutical industry to donate products and services to developing countries and to specific development projects. One successful project of the Fund was carried out in collaboration with WHO in Pemba, Madagascar, to supply praziquantel for the schistosomiasis control programme there.

Little information is available on the private market for praziquantel in developing countries, except that there is considerable variation in the size of the private sector by country. In Mali, for example, about 30 percent of praziquantel consumption is private, according to WHO sources (Interview No. 8). In Egypt, the private praziquantel market is between 10-15% of total consumption by volume (see Chapter 4). Certain countries, such as China, have practically no private sales of praziquantel. On the other hand, in a few countries, such as the Republic of Korea, most praziquantel consumption is through the private sector (see Chapter 3). Three points can be made regarding the size and role of the private market for praziquantel in developing countries:

• First, private market sales of praziquantel are generally quite small in most developing countries, compared to public sector procurement, in part because the public sector often provides praziquantel to patients free of charge or at nominal prices, which reduces demand in the private market.

• Second, in general, the price in the private sector tends to be much higher than in the public sector. Those consumers who are concerned about the quality of praziquantel in the public sector, or who do not want to wait in long lines at public sector clinics to receive the drug, may choose to purchase the drug on the private market.

• Third, the large gap between the private market price and the public sector price can be an incentive for pilferage of public sector supplies. Similar problems of leakage for subsidized goods occur for other pharmaceutical products as well as other commodities.

National schistosomiasis programmes

As mentioned above, by 1993, national schistosomiasis control programmes had been established in 24 countries (WHO, 1993). The experience of Mali’s schistosomiasis control programme is briefly discussed below, because that country’s programme has been extensively studied. The case of Mali suggests lessons that may apply to other countries in Sub-Saharan Africa.

The case of Mali

The national schistosomiasis control programme in Mali began with a small programme initiated in 1978 with the assistance of WHO and GTZ, to treat commercial farm workers residing around the small dams and irrigation schemes of Bandiagara (Brinkmann et al., 1991). By 1982, a national programme, under the administrative umbrella of the National Institute for Public Health Research, was developed as part of the Ministry of Health’s ten-year plan. Four regions, which were significant to Mali’s economy and where prevalence of one or more of three varieties of schistosomiasis exceeded 20%, were chosen as priority intervention areas (Brinkmann et al., 1991).

Until 1990, the schistosomiasis control programme in Mali was a vertical programme and used mobile teams to test individuals for schistosomiasis and to administer praziquantel-as part of selective or mass chemotherapy. The goal was to lower the incidence of debilitating disease (to control morbidity), rather than to reduce general prevalence (Brinkmann, et al., 1991). The programme’s praziquantel was ordered on an as-needed basis by the local GTZ office through its headquarters in Germany. GTZ’s office in Germany then ordered the tablets from WHO, which in turn acquired them from Bayer. The pills were delivered to GTZ in tins of 1000 tablets each.

The control programme in Mali had no formal logistics system. Doctors travelling to parts of the country where the drug was to be distributed simply took as many tins as they thought might be needed, put them in their trucks, and drove to the site. Yet no shortages were reported. From 1980 to 1987, approximately 75,000 antiparasitic treatments were administered, representing an average of three tablets per person, after allowing for losses (Brinkmann, 1988). This effort delivered roughly 255,000 tablets or about 255 tins.

All procurement in Mali was through the schistosomiasis control programme, and only individuals enrolled in the programme could obtain the drug. There was no organized private market for the drug, but a demand emerged for praziquantel (supported by the control programme’s widespread advertising of the programme, and the drug’s beneficial effects on morbidity), which created a flourishing black market. Physicians working in clinics were believed to contribute to this market through illegal sales of praziquantel to their patients.

The control programme in Mali achieved a major impact in reducing morbidity associated with schistosomiasis, and significantly lowered prevalence in the programme areas (Brinkmann et al., 1988). By 1992, however, GTZ had withdrawn completely from the control programme, and the programme was integrated into the primary health care system. The responsibility for mass chemotherapy and health education was handed over to district health teams, while the central team retained control over evaluation and future programming (Brinkmann et al., 1991).

This transition from a vertical programme dedicated to schistosomiasis control to a horizontal primary health care-based system had both advantages and disadvantages. As a horizontal programme, the delivery costs of the programme were drastically reduced, and a much greater population coverage was achieved (Gryseels, forthcoming). However, the move to a horizontal approach also created problems:

• First, the regional health offices, which were expected to pay for the programme’s recurrent costs, excluding drugs, were often unable to fund this portion (Brinkmann et al., 1991).

• Second, the district teams, given their multiple responsibilities, could not sustain the level of motivation displayed by the vertical programme workers (Gryseels, forthcoming).

• Third, the delimited areas of high infection did not necessarily correspond to recognized administrative demarcations, thereby hampering effective implementation.

• Finally, the supply of drugs became irregular and problematic (Brinkmann et al., 1991).

The experience in Mali suggests that more work needs to be done on the cost-effectiveness and trade-offs between horizontal and vertical approaches to schistosomiasis control. The study by Guyatt et al. (1994) in Tanzania represents a useful and important contribution in analyzing and understanding these issues. The challenge is to design an effective distribution and monitoring system that can function after the aid donor has withdrawn its human resources and material aid. Sustainability requires not only continued provision of praziquantel (because of reinfection) but also an organizational structure that will continue to administer the treatment in high-infection areas. The experience in Mali, after GTZ’s withdrawal, indicates serious problems with a decentralized approach that depends mainly on national resources for schistosomiasis control.

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